Too much inductive load for Victron Phoenix and Multiplus?

[@shanonedser1]

Hi Andy, I love your videos! I’m a mature age Electrical Engineering student (my father is an Electrical Engineer too which comes in very handy) and I’m a budding Electrical Safety Device Inventor. I also have a Multiplus 2 48/5000, (10KWh of Pylontech batteries) that is AC coupled to a Fronius Primo 5kw PV inverter. My system has some problems which result in lights flickering occasionally as the Fronius ramps up and down, that I suspect is caused at least in part by harmonic distortion from inductive loads such as the two small inverter air conditioners it runs and an inverter fridge, this interference affects the ability of my MP2/Fronius to remain in phase with one another (although they can communicate) and this also diminishes power factor. It’s a common problem with Victron/Fronius AC Coupled setups like mine and Fronius apparently has a firmware upgrade to address it which I hope to have soon. I have experimented with adding a resistive load (as Victron suggest) both a rice cooker (~400W) which didn’t help consistently but did help somewhat and separately a kettle (~2KW) which solved the problem immediately. I believe this proves that harmonics is the problem and I’m planning on buying a power analyser in the near future so I know for sure (I just want one anyway as I’m such a propeller head🤓😂) One of the improvements I plan to make are some Passive Harmonic Reactors at each air conditioner which I expect will both improve Power Factor and reduce THD (Total Harmonic Distortion) For your situation maybe you could also try a Passive Harmonic Reactor at the aircon at least, and in VE Configure reduce your input current limit of your Multi and increase the boost factor which I understand will make the Multi take care of a greater share of the inrush current of the aircon. I would be very interested to see how much THD you have and what your Power Factor is doing. Regards, Shanon🤓

[@cods41]

Andy's A/C unit is not an inverter type from what I can tell. It shouldn't be introducing any significant harmonics like you'd get from an inverter type unit.

[@OffGridGarageAustralia]

Thanks a lot for sharing, Shanon. That is very interesting. I had no luck with increasing the resistive load in my mix. As soon as the AC is included, the system freaks out. I had a look at the Passive Harmonic Reactors and it looks pretty interesting, just not something which you can just buy and plugin. I have some other option with building this battery room for example and could be installing a proper split AC to keep the whole room cold. At the moment this portable AC is just a test to see if cooling makes any sense or just chews up more energy.

[@junkerzn7312]

This the difference between VA (volt-amps) and W (watts). A good rule of thumb is to take the wattage that inductive loads (mostly pumps and compressors) pull and multiply by 2, and that is the continuous output that the inverter must be able to deliver. The difference is calculated at power factor. PF = W/VA. Watts is the real power consumed by the device. VA is the apparent power... apparent power is essentially the real power delivered to the device PLUS additional power delivered to the device which the device reflects back to the inverter or generator. Power is reflected back to the generator when the voltage waveform and the current waveform have a phase difference. When they are in-phase the power factor is 1.0 and nothing is reflected. So here's the skinny on reflected power returned to an inverter. The inverter will (if it is designed properly) recycle the power. It basically feeds back onto the DC side of the inverter (shows up as ripple) and is captured by diodes and capacitors and fed back into the inverter in the forward direction. That way the battery only needs to output the real power and not the apparent power (which would waste the battery). Without this circuit the inverter must dissipate the difference between W and VA directly. For actual physical generators it is far worse. Generators often have no ability to recover power and must dissipate the reflected power directly. This means that the inverter is essentially inverting the reflected power TWICE, which is why inverters have a VA limitation... because the heat dissipated by the inverter is based on VA and not on Watts delivered. And there are two heat sources possible here. Just inverting a portion of the power delivered twice generates more heat, and then in addition, any inverter or generator which is NOT able to recover and recycle the reflected power must instead dissipate it directly which generates a massive amount of additional heat. Even with recovery circuits, a certain portion of the reflected power cannot be recovered. All generators and inverters have a VA specification. This is also why UPS's are specified in VA and not Watts. DC-to-AC inverters also typically have information on just how bad a power factor they can handle at load as well. -- Solutions: You can add a power factor correction device, but if the power factor swings all over the place (as it often does in small systems), this might not work well. Power factor correction devices basically just add capacitors and/or inductors to shift the current waveform so it is back in-line with the voltage waveform on the AC. You can put a power factor correction device JUST on the air conditioner (and maybe another on your irrigation pump) to deal with the problem. This is probably your best solution. This will create a larger surge when the device starts, but once it is running the device should be able to correct the power factor back to near 1.0. You have to mess with it though because the phase error is different for every inductive load. -Matt

[@junkerzn7312]

p.s. put a Kill-a-watt meter on your AC output... ahh, a kill-a-watt can usually only handle roughly 1500W so just connect it to the air conditioner. You can then display W, VA, PF, and other things. The vehicle charging should be almost a resistive load if it is built properly. They do have switching supplies, but they should be PFC based supplies which will pull current from the entire waveform, not diode bridges which only pull current from the tops and bottoms of the waveform. Pool pump, A/C, any other pump, hot water system ... those are probably inductive loads.

[@upnorthandpersonal]

Yep - and to add to this, the Multiplus is much better at dealing with reactive power than the Phoenix is.

[@rklauco]

@@junkerzn7312 Hot water system is a resistive heater only. The rest of your response is spot-on.

[@junkerzn7312]

@@upnorthandpersonal Almost certainly, yes. Ok, this is prompting me to read the Phoenix datasheet.... and its specified for 3kVA, not 3kW. That's the problem in a nutshell. The wattage consumed by those inductive loads must be multiplied by (roughly) 2x with regards to what the Phoenix inverter can actually handle. Also, since it is running in parallel with the multi-plus.... how the reactive load is distributed back to the two inverters is not going to be 50-50. It depends heavily on how their output stages are designed. It could very well be that the Phoenix inverter winds up trying to handle the entire reactive load.

[@junkerzn7312]

I'll add one more thing to head off any confusion about Watts and Volt-Amps. Watts is the average power delivered and not reflected from taking many samples of the voltage and current and multiplying them together. W = V * I, many data points sampled over the 50hz or 60hz cycle. SOME of these samples are going to have negative current and positive voltage, or positive current and a negative voltage, and thus be negative, which subtracts. Thus Watts does NOT include the reflected power, only the power actually consumed by the device. When there is no phase difference, all samples will either be positive-current x positive-voltage, or negative-current x negative-voltage .... both calculations wind up being positive, and watts winds up being the same as VA because there is no reflected power. VA, on the other-hand, is just Irms x Vrms. The root-mean-square average current multiplied by the root-mean-square average voltage, measured independently, and ignoring any phase difference. This calculation cannot differentiate between reflected power and forward power... the two are combined together, basically. There are some other little side notes, but those are the basics.

[@xNYCMarc]

I noticed on your VRM screen that the L1 frequency was bouncing all over the place, as low as 47hz. That indicates that there isn't enough "reactive" power. That's a "power factor" issue. You need power factor correction or a bigger inverter that is capable of supplying more "reactive" power. You should test with a Kill-A-Watt or similar plug in meter and see what the Power factor (PF) is with the air con on.

[@cods41]

I think you are onto it. I'm surprised that the VRM console doesn't show VA which would be helpful in this situation (but would probably confuse most users in normal situations)

[@OffGridGarageAustralia]

The Kill-A-Watt meter seems to go to 125VAC only. Seems an US thing only. I'll google around if I can find something similar for the 240V market. Thanks for the tip.

[@xNYCMarc]

@@OffGridGarageAustralia Big Clive uses one on his channel in the UK. I think he calls it "the Hopi". I assume that's the brand name. But it's the 240 version of the Kill-A-Watt meter. If you search KZbin for: "This energy monitor plug is actually really smart inside.", you'll see his review of it on his channel.

[@matthewwakeham2206]

Your inverters have to sync their AC waveform. If both are trying to match the other they may be failing to do so under the load of the AC. The waveforms may be distorted differently as the inverters have different power capabilities. They may lose sync and shut down to protect themselves. I think you would really need a 10KVA inverter to start high power inductive loads. You could also get a second multiplus and run them in parallel (although Victron say this should be done by a professional).

[@docugraf]

as the Phoenix acts like a "dumb" generator only the Multiplus adapts its waveform

[@batterynerd8779]

Professionals😉 we all are if we need to

[@OffGridGarageAustralia]

None of the inverters shut down actually, they both keep running. And it's not the startup of the A/C, it is when it is running as well

[@ericdelevinquiere9902]

It’s your AC compressor stressing, hard to adjust power in these circumstances. A bigger inverter or a dc air conditioner would remedy the problem.

[@jotaemebee]

I agree, keen an eye at the 50hz swinging to 52hz, multiplus is trying to compensate the inrush, this also happens at my victron system when I’m running offgrid

[@ewokjerky4508]

Test swapping out the Air Conditioner's runtime capacitor with one of a slightly higher value. Just make sure you don't use a "startup" capacitor as those will burn up in seconds.

[@OffGridGarageAustralia]

I'll have a look if this is an option.

[@shawni38]

I have seen this before on many different inverters, most likely the older compressor. You done the right thing by simply putting that load to a dedicated inverter. The same thing actually can happen in a grid environment but, is harder to detect until the utility bill arrives.

[@Shep5847]

I love my Quattros for this very reason. I put my loads on one output leg, and I use the opposite input leg to “charge” my batteries. When there’s a surge on the inverter, it doesn’t surge the “main line” as well. Because victron inverters being limited on their inputs are not always limited. If you pull more than the inverter can handle, and it can pull from the mains, it will exceed that input current limit. Also, they make inline “soft start” capacitors that you can get and plug in between the AC and the inverter. If sized right, it should work.

[@glencooke494]

Come on 53,300 people we gotta give him a heap of thumbs up give him some support Cheers everyone

[@rcinfla9017]

I think I found the manual for the A/C unit you bought. It is NOT an inverter variable speed unit. It is a conventional single phase induction motor compressor with a single run/start capacitor. Good news is it can fairly easily be run power factor corrected. Bad news is it has fairly high startup surge current, as does your pumps. So besides needing a power factor meter, you can add an AC clamp-on amp meter that has an accurate AC startup surge current measurement to measure peak startup surge current on your pumps and air conditioner. Startup surge current on single phase induction motors is highly inductive for the first 0.4 to 0.5 seconds after power applied with a power factor of between 0.3 and 0.5 for the half second spin up time of motor. Your issue IS inductive power factor loading, total of pumps and air conditioner. You are likely exceeding the total VA load on the Phoenix. Nothing especially bad about the air conditioner other than it is the straw that breaks the camel's back on poor power factor VA loads on inverters. Poor inductive power factor loading 'might' be a factor in the way the load sharing is happening between MultiPlus and Phoenix units. As the MultiPlus takes more or less of the load it may dilute or increase the poor power factor seen by the Phoenix. You might think this is a good thing but if the power factor seen by the Phoenix wobbles around it may explain the sounds the Phoenix is making and the variable load current readings. The MultiPlus has a feature called dynamic load shaving where it increases its inverter supplementing of AC input port when it sees the AC input current rise quickly. In theory it gets a jump on preventing exceeding AC input current limit setting, but it might also result in an instability between the two inverters. I doubt the engineers though about another inverter acting as an external generator when they designed the dynamic load shaving feature. You might check to see if you can turn this feature off on the MultiPlus. Just the 'dynamic' part, not the actual load shaving which is needed to prevent overloading the Phoenix. You might want to ask Victron about this condition.

[@Fisco46]

Your Phoenix generates your sine wave and then MP2 adapts the load. This behaivor is the same when you have a generator that is not optimal or small The reference sine wave its Phoenix so if Phoenix cant give a decent sinewave, then MP2 disconnects and start the UPS fuction. This usually happens with inductive loads and smalls generators

[@OffGridGarageAustralia]

Hmmm, but shouldn't the MP have the issue instead of the Phoenix? The Phoenix is limited by the settings.

[@junkerzn7312]

@@OffGridGarageAustralia I think Fisco is right. I don't know the precise algorithm the MP is using, but the phrase they are using is "assist" and that kinda implies that all it is doing is trying to boost the waveform that is already present. So it could very well be that the MP is not handling any of the reactive load at all and the Phoenix has to deal with the entirety of the reactive load. That is, the reactive load of the entire system, not just its portion of it. Which will crowbar it. This would also account for the buzzing you hear from its cabinet. That's gonna be a transformer or inductor crying out for help. It's probably working directly against the reactive load and overheating.

[@seanajacobs]

Do you have weak AC enabled? If so then the phoenix could be still charging the batteries while the MP inverts and doesn’t assist. This doesn’t really answer the question and doesn’t really help since it will be a loop then. Don’t do this! Hahah if it was a real generator or wires to different batteries. I presume your MP is setup not to charge the batteries anyway

[@Fisco46]

​@@seanajacobs phoenix is a "Inverter Only", it has not charger inside

[@seanajacobs]

@@Fisco46 I know. But the MP does. Doesn’t matter I’m sure his charger in the MP is off

[@rcinfla9017]

Since the air cond seems to be the problem child I think you need to check the power factor on it. Many cheap small inverter A/C's (if it is an inverter variable speed A/C) have a simple rectifier-filter for AC to HV DC to run the three-phase inverter for compressor. They have PF around 0.60 to 0.65. This is creating high peak currents only at the +/- voltage peaks of AC sinewave. EU regulation requires power factor correcting power supplies in mini-split units, but the cheap unit you bought likely does not. This is the same problem you have with your 60vdc 20A bench power supply. It is non-power factor corrected AC to DC rectifier-filter, so it overloads your small stand-alone inverter you use for testing. It likely has a PF of about 0.65. Inverters, transformers, and generators are rated for VA not watts, so poor power factor cuts down on their maximum load capability and increases their internal losses (lower conversion efficiency). I am surprised you don't have a Kill-A-Watt meter or similar device to measure PF. You need to get one that will take your maximum device load current you want to measure the power factor of. The car has a power factor corrected charger, guaranteed. It is likely about 0.95 PF. There is a difference between inductive motor loads and rectifier-filter poor power factor but they both create higher peak current for the watts consumed. The induction motors likely have a PF around 0.75 to 0.85 but it depends on their mechanical loading. The inductive motors can easily be power factor corrected with right uF value oil-foil filled run capacitor put in parallel with motor. Have to know the motor's typical run AC voltage, AC current, and power factor to calculate the correct compensation capacitor to put across the motor. Correcting a rectifier-filter based poor power factor is a bit more complicated. They do sell PF correction modules but they put out about 360vdc which is a little greater than just a rectified-filtered 240vac, at a DC level of about 330vdc.

[@damianhla]

The issue is with the air cond. Try using air cond specifically designed for offgrid solar. I have a few Zero Breeze 2 and they work perfectly with the offgrid solar. Have soft starts and very low power consumption. Very happy with them. 😊👌You can run multiple units to achieve to cooling required.

[@spiro6363]

This is an interesting topic to find an answer to. as I’m sure many out there have come across this problem and not really understood the cause. It’s useful too in terms of understand how these inverters are specified in WATTS & V/A and the implications Many thanks as always, great demonstration and discussion by all. Keep up the good work.

[@TrevorFraserAU]

Awesome sauce! Looking forward to seeing the reasons from the community!

[@koffibanan3099]

Very interesting issue you've stumbled upon again Andy, also reading the comments is interesting!! I think most of the comments focus on the startup current of the A/C, but you said that sometimes the issue only happens when it's running for a while? We really need to see some waveform and ampclamp goodness in the next video :) Thanks a bunch for taking us along!

[@OffGridGarageAustralia]

Yeah, as shown in the video. it happens with both situations, starting and already running. I've got a scope here and will need a clamp for it. Let's see if I can find one...

[@SkypowerwithKarl]

I’m getting so sick of that spam pretending to be Andy. KZbin, read and take action on the reports and get a handle on this 💩

[@Danny-pp8xz]

andy if u check the datasheet on the victron phoenix u see that the continous power load at around 40c it drops to 2200W. The multiplus shoud be able to 3700w so 5900w is ur total wattage usable , if u pauze at 8.06min u see the phoenix is trying to deliver 2400w so the peak power is probally reached at these tempatures. maybe change set the multipluss as the generator and the problem will be solved.

[@stanislavmlcuch2085]

And which inverter will be the main one? Phoenix has no ACin 😀

[@Danny-pp8xz]

@@stanislavmlcuch2085 didn't know that assumed that all victron have had the parallel function , woud be hard to switch them up then :) maybe limit the amperage in the phoenix to 6-7 A then this way he wont go over his max power draw continious(let the multipluss work harder?)

[@OffGridGarageAustralia]

I have more like 30° in the garage thanks to the A/C.

[@junkerzn7312]

@@Danny-pp8xz Victron's do have a parallel function but that isn't the topology that Andy is using. If he had multiple Multiplus units in parallel it would probably work fine. But he's using the Phoenix as a master (when its on) and the Multiplus as a follower, so even though the AC busses are tied together, the two inverters are not going to react to inductive loads in proportion to the power they are configured to produce.

[@JD-cx5oy]

My thoughts are that the AC is a large inductive load on startup and as the compressor cycles on/off. This can be smoothed out using a 'soft start' module inline with the AC. Amazon has multiple listings if you search for 'soft start kit for air conditioner'.

[@rw-xf4cb]

I stuck a soft starter on my motor 1.1kw to stop my MPP PIP alarming now it shows as 4KW spike but the motor is usually only started once a day and then off when the solar goes. An AC with 3rd party soft starter may not work too well as the compressor may not get the benefit unless the whole power circuit to it is shutdown and restarted. Unless the AC has soft start features built in which being a portable probably wouldn't.

[@cods41]

It's not tripping on start up

[@chrisr819]

It’s the waveform and cos pi that gets thrown off by Ac and pool pump as both most likely don‘t have a semiconductor that also flattens these distortion. What is interesting to see is that the bigger constant load is taken over by 5kw MP while the 3kw has to deliver the full shorttermed surge currents, that’s the reason it shuts off right away. Would be interesting if you reverse your config means the 5kw is the generator and the 3kw is the assistant device and test what happens then. I was always concerned how this power assist really works and your test shows it can add constant power but the short surge loads cannot be assisted and been taken over by the gen aka 3kw MP. Please test as I have an identical setup but with a cheaper HF 3,5kw inverter and a 3kw MP. Because if that is the case then the 3kw MP will be gen and cheap HF 3,5kw the assistant as it cannot Domspatzen loads but MP can.

[@andrewradford3953]

Your next tool might be a digital oscilloscope. That Aircon is introducing distortion when used on top of other loads. Will be interesting if you can find a solution, that's if you can find the exact problem.

[@chevrofreak]

This is the perfect excuse to install a 48VDC mini-split in the garage.

[@fransvankralingen725]

You should get an osiloscope - the load on the phenix is (probably) disrupting its abilty to maintain a sinus waveform - as a result the multi can no longer synchronise (it cannot see 50hz input anymore) and has no other choise to disconnect the power assist - upon disconnected the phenix can stabilize its waveform wich the assist recognizes as valid and reconnects.

[@matthewwakeham2206]

What he said.

[@cfeigel]

Agreed. Would love to see both Volts and Amps wave forms demanded by each load. Power factor may be a . . . factor. That might be fixable with simple addition of capacitance.

[@AnarlaurendilAnarion]

I approuve the osiloscope use

[@OffGridGarageAustralia]

I have a scope here but no shunt to see the current. Just voltage and frequency...

[@cfeigel]

@@OffGridGarageAustralia Perhaps you can use one of the cables leading to your AC loads as a shunt. Hook up the scope to show the voltage drop across the length of the cable. The waveform would effectively show the current. Superimpose the waveform of the AC voltage to see if the peaks line up or if one leads or lags the other significantly. It's not necessary to know the exact value of current in Amps, just to visualize the relationship of the two waveforms. (OK, the resistance of the cable could be calculated from values in a standard chart. If I recall: 4 feet of 4 AWG cable is 1 milliOhm.) Really curious to see what you figure out! Good luck!

[@boatelectricaldiy]

I would suggest that having the smaller unit in charge of creating the sine wave is the most likely problem. In general it is best practice to parallel devices of the same make and model to achieve a higher V/A system if you don't want to have problems. But if you must, then have the larger unit in control of things as it will have components that will handle inrush current and any imbalances in power factor better.

[@OffGridGarageAustralia]

The Phoenix should be limited to the set power output. It really should act as a base generation, regardless what the load is. The Multiplus should handle all variations.

[@boatelectricaldiy]

@@OffGridGarageAustraliaComputing takes time, electricity doesn't wait for that. Having parallel units of the same capacity insures that the electricity will not choose on it's own because of imbalance issues in the components while the computing takes place. There is of course the possibility of it being something other then what I have mentioned here, therefore the possibility for other solutions. I look forward to what you discover in upcoming videos my friend.

[@xsnrgvid]

@@OffGridGarageAustralia The Phoenix is limited, but it is also providing the waveform. The MP is assisting the Phoenix, so if the Phoenix cannot handle the inductive load, the MP will disconnect because of distortion of the signal.

[@Mywhtjp]

@@OffGridGarageAustralia SHOULD IS the key word there. Old AC unit is the problem. replace it with something newer or mini split (which are much more efficient. Troubleshooting 101: always replace the cheapest item first.

[@OffGridGarageAustralia]

@@Mywhtjp Mini split is out of question, I have no wall to install it on... When I build the battery room though...

[@michapapa882]

Andy you are a professor for me.. But I didn't make your mistake.. I simply feed the 5kva multiplus ii, with a 5kva phoenix inverter..

[@Fix_it_y]

Inductive currents late, from school days. I have the same problem with a freezer. Multi support and pure sine wave inverter generator (no phoenix)! the starting current from the compressor is 5-6 times the rated power. Depending on the position of the compressor, sometimes it runs and sometimes it doesn't. I thought it was my s... inverter but. Thanks Andy for not getting a Phoenix until now. Will probably put more on a multi in parallel operation. 👍😉 (Matthew Wakeham had a good comment)

[@OffGridGarageAustralia]

Thanks for sharing.

[@davedave6404]

Waveform distortion, power factor related. Consider this , system designed to have a "real" generator. This might be say a 5kVA unit with a flywheel. The inertia in the generator caused by the flywheel and the magnetic fields in the generator coils will handle the air con a lot better. I am guessing that the air con is inverter drive to the motor. When running on grid normally with the very low source impedance the grid absorbs these variations. If one runs that size air con on a small generator it randomly trips. I have a 4kVA , 3.2kW inverter generator, that kind of load occasionally trips the overload in the generator, whereas if I ran it on a conventional 6 kVA diesel (with a big flywheel of course, no problem). You are asking a lot from quite small systems actually, they are doing very well in reality Andy. Get yourself a power recording device and have a look at the parameters varying over time, that would be really interesting too. The addition of a resistive load helps the situation as shown. So a very interesting video Andy. Thank You !

[@asderven]

Hi Andy, sorry didn't read any of the comments, not feeling the best. I had a similar situation in my house. Whenever I started something in the house like an AC, the voltage would drop and the battery disconnected. I have another issue, I have a voltage stabiliser on one phase in the house rated at 12kva. That humming sound and peak sound you mentioned, usually happens for us when the grid is providing higher voltage than 225v, as the hum increases the stabilisers (step down only I think), the voltages are being reduced. After a certain time their is a click and I am guessing the capacitors start again. As for your AC problems. My solution was to tighten all the connections in all the breakers in the house and the solar setup, a few were loose. Outside my house, due to net metering, there is a manual disconnect, the neutral wire was burnt. Because of that the voltage in the inverter was going wonky like yours. I got my solar company folks to do it as they installed it. Your extension cord might have a similar issue, see if you can make/buy a larger cable extension cord that can run 3x max current of the AC at peak. Your AC might have problems. In Pakistan we get two types, the old kind which run at full blast and wreck havoc 😁, or the new DC inverter AC. The DC inverter AC take 20 seconds to 40 seconds to ramp up to their max amp withdrawal, which makes it easier on the system. For comparison, on a 5kw solar system, I can barely run 3 DC inverter AC, 2 is recommended, you know us 🤭. If I was to run a regular AC, only one would work and would only work during peak production. If you can swap out the AC with something that has like a soft start up, your issues might get resolved. Your AC is playing havoc with voltages like my washing machine during the spin cycles, but the watts are about 400-600 watts for the washing machine. I have two electrical space/element heaters, that use 300w-800w electricity, depending on settings. For the life of me I can't figure out what happens when I run one in the kitchen and one in my room, the whole house goes dark. If I run only one, nothing happens. Some appliances are wonky and don't work as advertised, no matter whom we buy from. They work with the grid, but not the solar setup. Hope something helps you out.

[@hummmingbear]

Your Frequency/Hz is jumping all over the place. Others have spoken as to why that might be. There is a setting in VE Config under Grid "Accept wide input frequency range (45-65) which would be more flexible before cutting off your phoenix "generator". You should try enabling this to see if it stops cutting off the AC Input. It does not resolve the larger issue of why the Hz are shifting so much

[@SkypowerwithKarl]

The inverters handled the inrush current on the air conditioner well. I don’t think the frequency stability of the Victon is very strong and seems to be easily, sympathetically influenced by the harmonics(back emf?) of AC motor as it slips synchronous lock. As you can see, the frequency climbs and descends. Kinda like a car with a steady throttle on a row of hills, slow on the climb and fast down.

[@galen__]

Test Phoenix only connected to AirCon? I’m thinking UPS mode on the MultiPlus maintains 230V 50Hz using a “Generator” algorithm which works well for motor generators and Grid systems, but not so well with DC inverters that try to adapt to both input and output.

[@michaelbouckley4455]

I built my Lifepo4 24v system specifically for a 1/3hp. Aircon, typically using 575W. Chose a low frequency toroidal SNADI inverter rated 3Kw. Was 8S, one cell gassed, so now 7S, which the inverter prefers, it does not cut out due to HVD. Runs aircon all night, no problem.

[@infinitygreenpower]

This happening because the inductive load is reactive power , therefore the reactive power sending from the inverter to the inductive load and this will reduce the voltage output and then the inductive power again sending back the reactive power to the inverter and this will increase the voltage output. I faced the same problem in one of my projects. If you need to solve this problem you should use one of the following solutions: 1. Add AC capacitor equal to the inductive load. 2. Or you run the air-conditioning by VFD inverter and any motor with VFD, this will solve your problem.

[@esunayg]

just put power factor correction caps to all your inductive loads. It might help.

[@OffGridGarageAustralia]

What caps? Where to buy? How to size and not over compensate when the A/C motor is not running. Great theory but...

[@esunayg]

@@OffGridGarageAustralia first connect a power meter (with power factor function) to individual devices. note them. check which one has a run capacitor connected to motor (most cheap one dont have). even if they have a run cap on them you need to check if they are still holding their specs. they tend to degrade over time. if there is no info on the motor about the run cap specs on web there are many online calculators. there should be no need to have more then 5uf on your case i guess. i would start with the ac and then irrigation (considering mobile ac is not inverter hp).

[@upnorthandpersonal]

@@esunayg Agreed, it's a cheap and quick way to test by just adding a cap and see what happens so you don't even need a power factor meter at first to begin with. I wouldn't be surprised if that A/C unit either doesn't have one or it's dead.

[@dirkvornholt2507]

Die Tesla Charger haben eine PFC. Die sollten sich also annähernd wie eine resistive Last verhalten. Beim Klimagerät sollte eigentlich auch sowas verbaut sein, aber ich kenne die Vorschriften in Australien nicht. Das lässt sich aber einfach mit einem Zwischenstecker Energie Messgerät (Kill a Watt) ermitteln. Ich hab hier in D (Hessisch Sibirien) zumindest so ein Teil, das auch den Power Factor anzeigt. Die Kombinstion Poolpumpe und Klimagerät hat möglicherweise Synchron und Asynchronmotoren. Das kann zu Schwebungen durch den Schlupf der Asynchronmaschine in der Poolpumpe führen oder beide haben Asynchronmotoren und auch dabei kann es zu Schwebungen kommen. Im Zweifel hilft da nur Messen mit Oszi. Großes Lob für Deinen Kanal. Ich versuche auch off grid zu gehen und hab schon 16kWp und 40kWh Speicher verbaut. Wärmepumpe und BHKW sind in der Mache.

[@georgeskamagas5476]

Excellent work my friend.....beautiful videos and very interesting....always... keep walking 🚶‍♂️

[@FutureSystem738]

Thanks Andy. As a comparison, my caravan aircon is a Panasonic inverter, (bedroom size) 2.5kW cooling and draws under 600w maximum when running flat out. I can start and run it flat out briefly from a 300w continuous, 600w peak Suresine inverter (for a few minutes), and if I keep the power low it will happily run indefinitely from that same inverter.

[@OffGridGarageAustralia]

Yeah, totally different animal you have there. This unit I have is terrible and not efficient at all.

[@GapRecordingsNamibia]

Hmm.... I wonder if the motor and compressor run caps in the AC are failing??? The fan and compressor motors are a shaded pole type which rely rather heavily on the run caps, maybe one or both caps could be failing?

[@OffGridGarageAustralia]

That's a good point. I'll have a look. Thanks.

[@TobyRobb]

Trouble syncing? the Hz values were differing by several hz when it was humming..

[@HouseboatRenovations]

you can also use a full wave bridge on the ac input for the air conditioner. Victron use toroidal transformers on some of there inverters and any small amout of dc component on the ac line will saturate the core of the toroid. You can sometimes use a heatgun on low setting to produce the same effect as they use a diode for lower heat setting.

[@joachim65]

Then Victron can't deal with inductors so well? Phase shift is there probably a problem with a certain load? Is there an inductive and capacitive compensation in the Victron devices? Actually, there are also indications of the load limit up to which inductances can be processed

[@trollgarten]

You might consider adding a power analyser continously recording your system "health". For example my fridge consumes around 34VA, however the power-on spike is about 1200 Watt for about 1.2 seconds. The power-on spikes from your air-conditioner devices might be much higher. I have measured this with a sample rate of 50ms.

[@uksa007]

I'm guessing the "cheap" Aircon has insufficient capacitance, is it an inverter type by chance? Put your power meter on it and have a look at the power factor, that could also be a problem. Edit: Found the manual online with the schematic, there are two blower fans and the compressor, looks to be non inverter, so could be electrically noisy causing noise on the AC upsetting the inverter. Caps on the input and some common mode chokes, would probably help, really need to look with an isolated scope on the ac input to see how bad it is.

[@dan2304]

Andy, obviously the air-con unit needs to have the load filtered so that the variance in inductance does not affect the inverter. I don't have enough knowledge to suggest the solution.

[@alexschulein7002]

Hi Andy A compressor like an airconditioner has 2 modes, the compression stroke where it can use up to 3 times the rated power and the back stroke where it takes new gas and the compressor is actually dumping power back into your net from the residual compressed gas. This feedback part of the compressor stroke is probably upsetting your inverter possibly upsetting the phoenix inverter into an over voltage mode. An other idea is the feedback from the compressor is deforming your ac so bad that the other inverter doesn't know what to do or desyncs the assist into working against the phoenix inverter. The power rating of the airconditioner is the average of the 3 times usage and the amount fed back into the net. Hope this helps understand your issues

[@OffGridGarageAustralia]

You're saying the A/C is feeding power into my off-grid? That would explain the messed-up wave form when it runs. Maybe not an issue when it runs on the real grid but with the inverters it could be a problem. Interesting thought.

[@jeffgendron1959]

I think the feedback from the compressor deforming the AC is likely something to look at. Put an oscilloscope on and see what the sign wave looks like under load.

[@alexschulein7002]

@@OffGridGarageAustralia this issue is specific to compressors not really inductive loads. Only inductive loads have a startup draw up to 3 times regular rating.

[@pieterbarneveld9518]

I have a similar issue on my boat sometimes when I run my 230v refrigeration which is a 5/8hp or 550wattt compressor … keen to see what you find out . I’m running one Victron inverter and one TBS inverter charger .. CHECK out the voltage on the neutral wire… see if you are getting a strange reading like I am… regards Pieter

[@lucdesmedt7056]

Putting some capacitors in parallel with your inductive loads should be an intresting approach for your next testing step

[@Razza2250]

capacitors in parallel with the supply lines of an alternating current source have another name: a bomb. Capacitors can't be used for AC the way they can be used for DC, in AC applications they are used for phase shifting and even voltage regulation (in series with the load). Please don't ever connect a capacitor directly across AC power

[@john_in_phoenix]

Have you measured the power factor? You may have just figured out why the air conditioner was a bargain.

[@OffGridGarageAustralia]

It runs fine on the other inverter. But yeah, could be why...

[@john_in_phoenix]

@@OffGridGarageAustralia It's likely a combination of loads causing the problem. I will try and find a video that I recently watched where he managed to accomplish PFC measurements with a simple Kill-a-Watt meter and calculate the correct capacitor values. But correcting each load one at a time will work wonders. The parts are usually under $20 on ebay (probably much more from mouser or digikey). Found it, search for "Power Factor Correction and Inverters" by R Brown, it seemed like something you might try.

[@davecollier8946]

Hi Andy. I know that you really want the house off grid. I would Highly recommend the selectronic brand made in Melbourne. They have a toroidal transformer so inductive loads are not an issue.They have units that can output 7.5k kw continuous with 14kw 20 sec peak 12.5kw for 30 minutes and so on read the specs. I would recommend 2 units if you go off grid. That way any problems with a unit and you are still with power. Also if you are grid connected and the power goes out there is no interuption to your supply. Unlike other sonnen and tesla power walls as far as I know. They are extremely heavy due to the transformer eg 42kg. I have the 5kw model in my shed under test. Not connected to the mains running off grid currently. it also is 96% efficient. Unlike my other inverters that run at around 92%. Keep up the good work. 🙂

[@OffGridGarageAustralia]

My sparky has recommended them as well. He suggested two 7.5kW units in parallel. They are far more expensive than the Victron gear but maybe worth it with such a huge power output. He has used them with other off-grid installations and was impressed about the power output. I had a look but there is no way to integrate non-Victron inverters to the system other than having them show up as general DC-Load. I also don't like the software the Seletronics are using, nothing cloud based, no app to view or change parameters on the go. I discussed with my sparky and we probably add another MP5kVA first and still can use the 3kVA Phoenix as the generator for peak loads.

[@davecollier8946]

@@OffGridGarageAustralia I got the modbus registers from selectronic all you have to do is enable the internal port in the installation tool but all good. :-) The more I play the more impressed I am with the unit. it can run as a microgrid controlling inverters that are connected to it without any control wires. 🙂

[@igornedashkivskyi1472]

It was very useful video to me, Andy! I have only one inverter/charger which behaves like this during charging batteries from the grid after absence of the electricity. We have very often absence of electricity during the day here in Ukraine, because our country electricity energy system was damaged by missiles and drones attacks from russia, that's why I'm always should charging batteries from the grid. I'm very interesting in how are you going to fix this problem?.. Thanks to you about such videos.

[@putteslaintxtbks5166]

My prayers for you and for peace to return to your country.

[@igornedashkivskyi1472]

@@putteslaintxtbks5166 Thanks, Really Appreciate!

[@Stefan_Dahn]

@@igornedashkivskyi1472 Slava Ukraini from Germany! Throw out the orcs, brave Ukrainians! 🇩🇪❤️🇺🇦

[@FutureSystem738]

Ditto from me, and Slava Ukraine. My heart absolutely bleeds for the brave Ukrainian defenders and citizens, with the ongoing invasion and attacks from the evil Russian invaders.

[@grantc8436]

Andy - new title to add to your resume - 'Inverter Wisperer'😆

[@stuart4858]

Agree with upnorth... I think you problem is related to noise on the AC power line from the airconditioner. AKA crap quality unit. The suggestion for adding some capacitance will begood for Power Factor, but I would put an oscilloscope on the main side of the Airconditioner to get a picture of any noise on the line. Suggest using a line isolation transformer if you do.

[@pinteapiki]

As the reactive power increases, the apparent power increases and thus the required capacity of the installation. Harmonic reactive power also ensures a smaller available capacity due to the derating of transformers and generators. Inductive reactive power can be reduced by applying a capacitor bank.

[@OffGridGarageAustralia]

That's all good theory.... yes, capacitors can compensate for inductive loads but this nothing you can just buy off the shelf and plug in.

[@Stefan_Dahn]

First you have to measure Ampere and Volt on an Ozzi or Cos(phi).

[@gruetoo1]

@@OffGridGarageAustralia They sorta do, with high end auto audio setups. For the Subwoofer in my truck needed 2 of the big caps....

[@lexicase8805]

@@gruetoo1 thats on the dc side though, right?

[@gruetoo1]

@@lexicase8805 yes

[@todamnbad]

What battery cut off switch brand are you using? I have 48 volt bluesea and they told me they won't work on lifepo4 because of the higher then 48 volt state of charge/charge voltage but they are working on a higher voltage model

[@NukeFPV]

Another tricky one…. I’m wondering if it could possibly be frequency related ? The AC compressor constantly kicks in and out according to the temperature/thermostat setting. Is it possible as the compressor kicks out it’s delivering some dirty ‘Back EMF’ back onto your circuit ?

[@lloydwilson9104]

Hi Andy interesting problem. after some reading this may be due to inductive kickback caused by the AC unit (or other inductive loads) cycling, when the inductive load cycles it can cause back EMF which the Victron may see as an issue, adding a flyback diode to the circuit may solve the issue by providing a pathway for the decaying load

[@Mywhtjp]

Mixed hardware and OLDER type AC. Different wavelengths not happy with each other.. replace AC with newer inverter tech and thing will probably work properly.

[@TruWrecks]

The startup surge on the AC can be x5 or more of the rated compressor load, and it can last for several seconds. That is likely the main issue.

[@mozismobile]

Can be worse, a lot of them rely on mains voltage sag when starting to limit current. My window mounted air starts better on an extension cord for that reason (the motor 'BONG' when it starts plugged into the DB is much louder)

[@OffGridGarageAustralia]

But it's not just the start moment which causes the problem...

[@mozismobile]

yeah, that definitely seems to be an interaction between the inverters. While watching I kept thinking "Victron are gunna love this video". Not sure whether it's waveform or phase difference that's the problem, but it seems likely to be down in the doodbley-doo of the software.

[@xpatrikpvp]

Its probably happneing because the two inverters arent communicating (as a two multipluses would) and the multiplus is in a "grid tie mode" with the grid being the phoenix. And the multiplus when running in that mode has a limit how much output power (watts per second) can increase. So when the loads gets higher the phoenix is running the big load and then after some time the multiplus incerases the output power. You should try enable "Dynamic current limit" (in ve configure) if that helps with the problems.

[@OffGridGarageAustralia]

They don't need to communicate. If the Phoenix would be a generator or the grid, there would be no comms either. I'll have a look at these settings, but I believe, I don't have them as I don't have a grid code set.

[@xpatrikpvp]

@@OffGridGarageAustralia By the communication i meant that a two multiplus setup would work differently (same lenght ac cables and connected ac outpus). Also i dont think you can change the power increase per second on the multi but you can enable the "Dynamic current limit" you should try enabling that and seeing if it fixes the issue or at least helps with the multiplus switching off the acinput

[@Sanwizard1]

I guess there is something to be said for low freq high KVA inverters when inductive loads are in play, and like everything else, size the system with more than enough overhead for expansion and headroom. And also keep the equipment similar.

[@OffGridGarageAustralia]

So, what is to be said about LF inverters and inductive loads?

[@CollinBaillie]

@@OffGridGarageAustralia I'd love to hear a clear discussion on this also. What I understand is that the low frequency inverters are using a honking great big transformer (toroidal in the better quality units) and thus are themselves inductive, and handle large inductive loads better. (I may edit this and add more over time, as time permits)

[@junkerzn7312]

@@OffGridGarageAustralia Basically LF inverters are more resilient when it comes to inductive loads than HF inverters. The LF inverters have a lot more momentum due to the much larger (and much heavier) transformer, which means that they can push or pull an enormous amount of current during the portions of the waveform that are massively out of whack due to the inductive load. HF inverters are much more limited in how much current they can push or pull at any given point in the waveform, even if the "average" power they can push appears to be the same. So HF inverters cannot handle reactive loads as well as LF inverters. Not to say that LF inverters can't overheat too... they most definitely can. But to be honest, I far prefer HF inverters. They are more efficient (by a lot). And I think HF inverters are safer, too. Just over-spec it and it should be fine. Though I'd also add power factor correction devices to the individual inductive loads to keep your AC clean.

[@michaelbouckley4455]

@@OffGridGarageAustralia they can handle 4x surge current, and the transformer smooths out the harmonic distortion

[@porcini-alpha]

You can try setting the "dynamic current limiter" in the general tab and carefully increasing the boost factor a little bit to reduce fluctuating, but I would recommend to get an inverter aircon as this load is just too big for an 3kVA unit (which is the main power source at this moment).

[@the_schmue2973]

As we say in Germany: Irgendwas is immer.. stay tuned Andy ✊

[@airgead5391]

Andy: using a stand alone inverter is a completely different thing that your setup. It is essential to understand this. What Victron is doing is impossible, so they are not doing it..... An inverter is from it's nature (should about be) an (AC) voltage source. What is happening in your setup is that two AC voltage are sources are "mixed together" that is that their outputs are hard wired together. Yes, you can put // (parallel) two voltage sources in a computer simulation, not so in the real world. So how does it work in the real world? The Multiplus tries to sync with the Phoenix so "listens" to the Phoenix. The Phoenix can act as a normal inverter, as a voltage source. Yes, it can (and will) have a feedback, but that is a simple voltage feedback one. The Multiplus is acting as a slave: it doesn't "know" the frequency, or the the phase or the voltage it should generate on it's output so it has "to listen" to the incoming AC from the Phoenix. There will be so called time constants build in the "listening feedback loop" of the Multiplus else things would get unstable. In an abstract way of speaking the Multiplus will have some of the characteristic of a current source... This implicates that "sudden & nasty shit" solely rests on the shoulder of the Phoenix. It is even a wonder that things work as good as they already do, and I think you are just asking too much from the system. Keep it simple! An dedicated inverter for the air conditioner comes to mind.... It is useless to fret about it. It is not a fault in your system but a characteristic. Things work how they should work. Trying to change the air conditioners electrical behavior by using capacitors or what have you, as suggested by some, is nuts.

[@peterdkay]

I think the problem is in communication between inverter and Multiplus. It sounds like the inverter was hunting. Some AC's use "direct on line" starting which places 2 to 4 times the load on the system during start. This higher load forces the inverter shift load to Multiplus. A second later, it discovers the running load of the AC is much lower so it takes load back. May pay to get a 10kw inverter and forget the load sharing Multiplus.

[@CSEV661]

The multiple inductive loads are interfering with each other and both are distorting the AC waveform in different ways, as such the 2 inverters are not able to match each other's frequency due to the distorted waveform. Simply put, the inverters don't know how to handle that situation. This can be seen by the rapidly fluctuating voltages and currents of both inverters in trying to match each other. As for a solution, as someone else mentioned, a 'soft start' module would most definitely help both for startup and running, but would require potentially rewiring the air conditioning unit. I believe the Victron units are high frequency inverters, but I could be wrong, and for inductive loads, a low frequency inverter would be better but less efficient overall. I wonder if an isolation transformer would help in this case? Either that or a beefy inductor in series with the air conditioning to smooth out any back-EMF. It would be very interesting to see the waveform on an oscilloscope to see how each inductive load effects the overall waveform.

[@koffibanan3099]

Victrons are LF. I think a beefy inductor would make things worse :)

[@76queen]

Is the airconditioner a inverter type? The inverters in airconditioners are pretty crude devices changing AC voltage to DC and outputting to 3 phase modified dc waveform to emulate 3 phase power. Pool pump is also a inverter load.

[@rbartsch]

Andy, have you measured voltage, amperage and frequency at the A/C? Maybe a runtime capacitor is broken in the A/C.

[@brankovanderveen7034]

I think the sinuswave will be desturbed. The Amps is flucuating without the airconditioning to, almost 3 Amps but the Kw ist almost constant. With the airconditioning on, the Hz is flucuating to and the Amps also. Maybe the airconditioning is faulty to. I would Masseure the input voltage amps and Hz on the airconditioning to, also to confirm it’s not faulte, The inverter has sensitiv Elektroniks. Mabye a VDE-Prüfung (weiß nicht wie es auf Englisch heißt) brings transparency. I fix fully automatic coffee machines for a living and sometimes the coffee machines do work but after the VDE-Prüfung it’s faulty and must be fix before it can be used again.

[@marlomontanaro3233]

A building I worked in a bunch of years ago had 480V, 3-phase, 1500A service. We kept tripping the main building circuit breaker. Couldn't figure out why for the longest time. We finally traced it to a faulty motor on a roof mounted air condition compressor. Between the main breaker and the faulty motor was a step down transformer along with a breaker, followed by a whole panel of breakers on the secondary of the step down transformer which finally fed the motor. NOTHING tripped except the main building breaker. The thing that led me to the motor was a similar behavior- I could hear a surge of current going through the step down transformer whenever the compressor switched on. The thing that was actually tripping the main breaker was ground current which tripped the GFCI sensor on the main breaker. The surge of current was so great that we actually melted the windings in the step down transformer which eventually caught fire. All caused by a faulty motor on the air conditioning compressor. I would seriously look at that air conditioning unit you have and make sure it is not defective. Make sure as the motor heats up you don't have a low resistance path for ground current, faulty motor windings, etc. It would be worth taking it somewhere where you have standard AC mains (not from an inverter) and observing its behavior, measuring current, etc. If you could get a scope on the input to the motor that may be helpful. Or just try another AC unit if one is available, see if the problem persists. I honestly feel you have a fault there, not just high inductive loads causing an out of whack power factor. But an oscilloscope or power factor meter would go a long way towards answering that also. Or it could be the pool pump motor? At the end of your video you switched the pool pump back on and the problem came back... Either way, I think you have a faulty motor there.

[@Buzzybee73]

What a novel setup. I always thought you had to run in parallel, and network together, but yes, running in series is a great idea! 2 Observations; At 17:13 the display briefly shows input current of 16A. Inverter 2 has a maximum output of around 11A, and this would cause an overload condition. The unstable current readings could be because of this. Have you enabled dynamic current control setting for inverter 1. This slowly ramps up the load on the "generator" to avoid surges on the input supply. Keep up the good work.

[@OffGridGarageAustralia]

I tried different settings for the current limiter with no luck. You would think, limiting the 'gen' current to 8A would not allow more than 8A to be pulled from the generator, but I could see spikes up to 13A for the 'generator'. I think I have not activated the Dynamic Current Limiter, so that could be an option. Thank you.

[@OffGridGarageAustralia]

That was it! I have turned on Dynamic Current Control and even the voltage and frequency coming from the Phoenix still varies a lot, the A/C is now running fine without the Phoenix dropping out any more. The Multiplus is smoothing out these variations now and it seems to be fixed. I'll keep testing and make a video as well. Thank you for this suggestion.

[@grzesoffg4523]

I have a question. I have been using the Phoenix 48/3000 Smart Inverter for 6 months. During this time he worked under various loads. Today, for the first time, a high temperature message popped up when operating at 2300 W. Does it require cleaning?

[@OffGridGarageAustralia]

Most likely not. 2300W is already at the limit for this inverter at higher temperatures. Have a look in the manual where is shows a table with the permanent load it can power under different temperatures. It's not a great inverter.

[@fouroakfarm]

Would it be viable to change the generator rules setup so that it assists only when the MultiPlus is absolutely maxed out. It seems right now the "generator" is turned on quite a bit before it is actually needed

[@5885ronny]

Dein Video gesehen super 🤗👍🤗👍☘️

[@tujuprojects]

I have played a lot with generator, grid and quattro. In my experience the most important factor is grid frequency.

[@mirek3542]

Hello Andy I just plugged in my new Multiplus 48V/5000VA/70-100, (battery SOC=86, Cerbo GX) and after about 3-4 hours of flawless operation, the inverter started to hum loudly and then shut down after a few minutes. It does not matter whether the inverter load is 30W or 700W or 0W. The warning is: "Inverter overload" (red LED overload remains on until reset) what could be the problem? thx

[@dusangazi4150]

Hi mirek. If you are from czech reublic, your problem might be caused by utility control signal that is used to switch billing gridmeter to different tariff. Are you running latest firmware in your mp2? Victron made fixes for this problem aprox. 4 months ago.

[@mirek3542]

@@dusangazi4150 Thanks Dusan for the answer, I'm from Slovakia, and I have an island connection, so it won't be the connection of a grid meter and another tariff. I have up-to-date firmware everywhere. I already wrote to the manufacturer and I have to contact the seller, so we'll see, thanks Mirek

[@Lulastyle]

Hi Andy, a question from your Italian fan, if I have a 3000va multiplus 2 connected to the mains, how can I increase the watt production? i read that i could connect the 2 inverts on the dc output but i don't know if they create sync issues. thanks bye

[@MarioRossi-my9kc]

ho lo stesso inverter, se ti servono informazioni scrivimi pure

[@glencooke494]

So Andy, I am sure at least one of these commenters has solved your issue. I think you only paid $80.00 for the aircon as a trial so you haven't lost much, "Ditch it" Put up a couple of polycarb clear walls Install a quality split system make sure you leave enough room in the room for a bed and the S.P.A.T fridge and you are set!!!!!!!

[@upnorthandpersonal]

Likely a very bad power factor - i.e., too much reactive power. Try putting an AC capacitor on the air-conditioner to see if it changes anything.

[@ewokjerky4508]

Make sure that it is a "runtime" capacitor as a startup capacitor isn't made for continuous use. They WILL burn up if used improperly. There are videos on it.

[@bryanspears2045]

the phase shift is affecting one inverter then that causes a surge in the other due to misalignment.. imo

[@OffGridGarageAustralia]

What capacitor, where to buy, what size, how to control when load changes? It's all easy said but in practice almost impossible to implement...

[@upnorthandpersonal]

@@OffGridGarageAustralia You don't need to control it when the load changes: the capacitor should only be switched together with the load: it usually is part of the device to do power factor correction. Your pool pump likely has one, etc. Perhaps the one on the A/C is broken, or whatever. You can easily test this by adding a cap and test, and this won't be an issue to have the cap there even when the A/C is off for testing purposes. You should be able to get one at any electronics store, online and offline. Try a 4uF to 10uF one or something and see if the humming changes. It's a cheap test, and if it doesn't do anything, it's one option eliminated.

[@wayne8113]

Thanks Andy 🤔 👍

[@awo1fman]

Air conditioners are NOT constant loads. The compressor will frequently kick on and off even though the fan stays on, and it's the compressor that is the bigger load by far. But the fan makes more noise, so it's not obvious to you when the compressor turns on and off. The timing of the compressor differs according to a number of different variables. Even if the fan doesn't stay on all the time, it will not coincide with the compressor much, and never when the compressor goes off. The fan will keep blowing for a while after the compressor goes off no matter what else is going on. The only time they will shut off together is if you shut down the system completely and/or remove power. Even if the compressor is running constantly, the load will vary based on the state of the system. The load on the compressor varies while it's running. If it's a reverse cycle unit or has more than one mode (such as dehumidification) then it will have valves and states that will vary the load even more.

[@toreediassen144]

It is a bit difficult to help when we do not know how the compressor is controlled. Is it controlled by Frequency Inverters? Or something else that gives the compressor more speeds? Or just on/off?

[@JPs_ElectricGarage]

gotta like this comment as this might be the case here, could also be some other loads with one diode rectifiers that only put load on the positive half way etc....

[@OffGridGarageAustralia]

The compressor is just on off, no frequency control as far as I could see...

[@toreediassen144]

@@OffGridGarageAustralia Maybe a soft starter can help. But it is electronics that create 230 VAC. And you have electronic and inductive loads. I know that on boats you often use large filters (many kilos of iron core). It might help in combination with softstarter. But then there must be something that can be combined with your production of 230 VAC. It's probably easier to buy something that has a soft start...

[@pete4778]

Does Victron inverter multi plus two supply the loads with solar after the battery are full.

[@jimthvac100]

Consider switching to the larger 10kVA Quatro. Quatro is quieter and less buggy too.

[@claudev.k2]

Try to disable the UPS Function. Even with my inverter based generator I have to disable this setting. I guess with this option enabled the Multiplus expects a very clean "gridlike" voltage and has additional measurements/calculatons running, that rate the quality of the incoming sine wave.

[@ahbushnell1]

I looked at the data sheet on multiplus and it says it good for 65 C. Sounds like they don't meet spec if they are overheating. Measure in the inlet temperature of the air?

[@OffGridGarageAustralia]

The A/C is blowing at the MP. It is below 30°C sometimes intake air.

[@BeastMovies]

I did this with Growatt Inverters and fried them. I'm amazed you didn't fry both of yours. Caps inside are very sensitive to being overloaded and you did this multiple times. I'll Invest in Victron Inverters after watching you actively trying to destroy them. Put too much power through a Growatt or MPPT and you get magic smoke, no second chances. You've not said what watts the aircon is? Most older ones are 4-5Kw. When you've only got 6Kws to play with, there's your problem. Upgrade the cap in the aircon to stop the ramping up or buy another 5Kw Victron and P them. In the Growatt setting the gen runs everything. Charges batteries and runs loads, so you need to be very careful when the gen is running so no one does something stupid like trying to run multiple pumps.

[@mondotv4216]

You could try an air conditioner "soft starter". They ramp up the compressor slowly to avoid the inrush current.

[@OffGridGarageAustralia]

It's not the start process what causes the problem.

[@matthewlam9416]

You need to put in a soft start circuit onto your air conditioner. When the air conditioner draws the power, it is draw higher current which the inverter can not recover from the large current draw. You can try to add a large capacitor but that is not a permanent solution. Soft start would be a more permanent solution.

[@egnegn123]

Have you tried to remove the tick at wide frequency range? To do so allows the inverter to stabilize its frequency first before the MP syncs again.

[@KevIsOffGrid]

Weird that it kills the Phoenix - which shouldn't take the extra power, and not the multiplus which should be the one making the difference. PS - my solar now on VRM, its bad this time of year normally, but been especially wet and dark - 50w max today (over 2kw of panels) and only 5.8kwh for the year to date but only 4 days solar in the VRM. Will get better! Will be enough to live on sometime in Feb! PS - pushing it this morning Andy - 4% and incoming not yet matched the load - low SOC Alert on your VRM.

[@OffGridGarageAustralia]

Exactly, the Phoenix should be running no matter what and the MP should have the problems... but it's the other way around... Had to charge the car this morning. Can easily go down to 3% with such a big load. I saw the solar on your VRM. checking it out every day 😉Nice!

[@KevIsOffGrid]

@@OffGridGarageAustralia it is great how much the Victron BMV can be trusted to be accurate too in those scenarios. You may notice I'm using cheap rate 11pm-6am electric to charge overnight and make up for lack of solar. 12p/kwh rather than 36p/kwh. that may help the VRM make sense.

[@edwardvanhazendonk]

I guess maybe there is some protection in the Victron equipment to keep the frequency around 50Hz. Maybe when the deviation is to big it tries to flatten. I also think when your phoenix is generating 52Hz, it might let the mp2 throttle down (like normally switching solar off at 51Hz when mains is 51Hz (the vde norm). Might it be that some of these settings are into effect in your system.

[@hansjrgenkristensen4034]

If it took some time before the problems came with the Air Conditioning, I guess there is filter in Air Conditioning that puts greater strain on the fan and compressor, that could be the cause. Should be checked in any case. How often shuld it be cleaned?

[@mechcraft]

My observation for this was the peak surge of the airconditioner consumes the pheonix peak surge and dies. And the multiplus can't catch those surge of current to assist the pheonix. I think it's time to upgrade the pheonix sir to a higher wattage capacity. Compressor running plus fan consumes a kilowatt so maybe 3kw or 5kw pheonix inverter would solve this issue. Thinking around 3 to 5 times surge peak just for the conditioner.

[@b.r.i.a.n.]

When the phoenix starts changing its phase relationship with the other inverter due to the lagging current the result is called Hunting as the 2 start trying to synchronise which causes the oscillation noises in the phoenix.

[@OffGridGarageAustralia]

That makes sense, thank you.

[@pmacgowan]

Andy, how are you getting 16amps from your granny charger, it only has a 10a (8a) and 15a (12a) tails, are you using a 3p plug ?

[@b.r.i.a.n.]

Thats why some things like electric blankets with electronic control connected to a phoenix hums the same as the electronic heat control chops the waveform and causes the toroid to be magnetised in a non sinusoidal pattern

[@edc1569]

I can't figure out which inverter is in charge of leading the frequency and which one is following, I suspect this might be part of the issue?

[@Full-of-Starships]

Quick thought on noise in the phoenix. Is it possible this is harmonics on the mains, IE higher frequencies? Try recording the sound and then analyse it for harmonics?

[@panospapadimitriou3498]

i m thinking of the 48/5000 but it has not a single watt extra surge mode . and i have an eco flow delta 2 .. is it possible with an OK oK non optimal suicide cable to pretend that eco flow is the extra generator ? when i instal it my delta 2 will be a bit useless thats why i m asking and in shed i might need some more than 4500wats if heavy tool starts !!!! shed is off grid of course

[@astrogerard]

When the two inverters on, which one decides the frequency to run on? It seems both inverters, frequency wise react to each other.

[@OffGridGarageAustralia]

The Phoenix dictates both, voltage and frequency. The MP adapts to whatever comes in.

[@peterking1134]

The aircon could be introducing noise if it has an inverter that does not have filtering on the inputs.

[@burnzy56469]

The same thing happened to me with the ac voltage not being constant. I was useing a extension cable to power the airconditioner. The extension cable was broken and only had a couple strands of copper. Man that cable got hot