Compressor Hard Start Education With The Supco SPR5

Compressor hard starts are somewhat polarizing within the HVAC industry. A little education may help with that. In this video we cover the Supco SPR5 and some hard start education that may help with understanding compressor hard starts a little better.
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[@HVACKnowItAll]

They can and will help

[@CheaddakerT.Snodgrass]

Thank you for your response. Do you know if compressors that use an inverter rather than a start capcitor and run relay are the same? I see a lot of videos about how to test the output of inverters but I was thinking that just using a hard start could work. I'm guessing in a non-inverter there is a sensor that closes with warm temperatures that causes power to be applied to the hard start which then starts the compressor. I fix everything myself but refrigeration systems are a weakness at this point. I used a Supco hard start the day before Thanksgiving and it worked flawlessly; I'd say thing just seem better than ever witht he fridge. I had bought the hard start about ten years ago on the advice of someone to have it on hand.

[@russellebenton]

Everytime there is a "start capacitor" video, I want to throw my phone away if they don't talk about the DIFFERENCE in "hard start" kits. I only say that because the only people seeing these videos are usually newer in the industry and its pretty important to understand the types of starting systems. And I'm not saying this won't be fully covered but it is honestly the best way to build the bones of understanding. Start with the variance everytime.. before even explaining WHY they are used/useful. A potential relay is really the best way. There are three ways to pull the start cap back out of the circuit. Potential relay Electronic relay Positive Temp-Coefficient Start Relay. Each has a different method. The Potential relay uses electro-back voltage that qualifies the motor is running to pull it out. That is good. The electronic relay has a set amount of time (like 60 or 90 seconds) and jerks it out. This is okay, but the relay fails more often than a Potential and can leave it in longer than needed. The PTSR relay uses basically a resistance circuit to get hot and pull it out. These were used a long time ago to add the third wave by themselves by delaying the power supply slightly and used by some manufacturers. If you've ever seen a strange 1.5 inch cylinder with wiring from the contactor to the herm side of the contactor on an old Carrier or Goodman, that was what it was. This type is the most inefficient because if it cuts off, and back on, the replay components won't cool enough to even bring the start cap back in the circuit. If you have a two wire hard start kit - if it is an "all in one" it is almost always a PTSR relay. If it is a two wire but has a seperated relay that looks kind of like a Potential relay, it is usually a electronic relay. If it is the 5-3-1 - its a Potential relay. You want the 5-3-1. It is the superior starting control mechanism. This is the end of my Ted Talk.

[@ore-georgecicovic6533]

I wish more comments are like this. Cheers

[@inception727]

How about supco mpr5 it has two wire ,but sold as mechanic potential any idea why? Also the 1-3 tons kit by supco Mpr5 has a capacitance of 290uf? And the 5-3-1 for 1-3 tons only has 88-105uf any idea which is better?

[@mrmotofy]

So if I just say start kit...I'm good right?

[@matt_in_maine]

Just relocated cross country and also making the jump from comfort ac to refrigeration. My new employer put one of these on my van. I look forward to the others you are talking about and if I need those on the van as well. Happy HVACing

[@HVACKnowItAll]

Thanks for watching Matt

[@CheaddakerT.Snodgrass]

You're the number one video when searching for Supco Hard Start Kit other than one from Supply House. If you happen to see this comment I'm wondering if there is something like this for inverter refrigerator compressors? I'm wondering is you could use this to confirm that the compressor does run and cool. I know there are tests with a multimeter to determine voltages from the inverter and you can ohm the compressor; but again, just wondering if my idea could or would work.

[@HVACKnowItAll]

Unfortunately there isn't for inverter compressors no.

[@robertgaitskell7212]

I think it’s great that you are talking about these starting devices. I have used similar hard start kits for 20 years and I have seen compressors run for many years, the longest is 12 years. I don’t fit original starting electrics anymore and have saved many compressors and have introduced many other techs to these as well, and they also have had success. There is a misconception that these damage compressors. You may get some compressors fail shortly after fittings these stating electrics, but the compressor was going to fail anyway. I have a few different ones in my van and never get caught without being able to get a compressor going, I enjoy your videos keep them coming.

[@HVACKnowItAll]

This is great info, thank you

[@walterdockins8475]

MY 90's Armstrong condenser unit actually shows the option for a start cap and relay. However, non are installed and here years later, the compressor is not starting... even after replacing the run cap. I think a hard start kit is the nest step to see if the life can be extended. Only makes sense!

[@coldfinger459sub0]

👍👍👍 excellent topic great video. Another extreme case if they failed one or two times before because of the contact points going out. Wire in your own heavy duty 40 amp contactor don’t use the internal switching points use them as a trigger only to engage a heavy duty contactor and it will last the life of the unit. Yes I know extra expense extra complication and wiring but a happy customer that will never have to have you come back for that problem again.

[@HVACKnowItAll]

Nice add

[@MrMultitool]

I have No problem with a hard start . I forget which one but at one time there were some new units that came with a hard start already in stalled. A good thing to keep on hand for sure.

[@mikefreedom5612]

Thank you for your feedback

[@HVACKnowItAll]

You're welcome

[@VergilArcanis]

I find this amusing for the units i work on because other contractors have put these in without a drop-out relay, so the power is way higher than the motor in an LG rotary compressor is rated for, so the usual result is the common terminal gives out and shorts to ground. Although the units already runs pretty hard, so adding more capacitance in permanent split-capacitance system is dangerous for them, if the issue wasn't already a compressor failure. However, the scope of my work usually never sees a hard start used correctly for the units, so the damage ends up costing customers close to $1500 to repair a fractional tonnage system (water sourced heat pumps are not easy to repair correctly). Under the right circumstances, i can see why these would work for startup circuits, but would need to dropout during run.

[@Ray-wr2wr]

Is it Boost spp6 would be efficient for 45+5 mdf capacitor? Thanks!

[@hvacir9176]

i use starting components Saved my But so many times, i stock them all the time

[@HVACKnowItAll]

Good stuff

[@JahonCross]

Hi there so I have this problem I need help with, it's a chest freezer and the hard start kit I bought to make it run again isn't working. Again not sure if I bought the wrong one or is something I'm doing here. Hopefully you respond to my question.

[@michaelfassino4314]

I have a new ac split system. My evap coil came with a txv installed. The condenser is a different brand Should I install a hard start kit of sorts ?

[@reza49363]

Thank for your time and video, Please bring more of these and explain the differences

[@HVACKnowItAll]

Thank you I appreciate it. I will do my best.

[@OurSecondlifeabroad]

Hi, our compressor has the letters U, V and W. How do we connect the supco to this?. Thanks

[@titoeson3944]

Is it applicable to an air compressor 5.5hp?

[@mrmotofy]

Trying to figure out if there's an easy way to add something ideally plug and play to a generator/inverter to help on high draw loads like an air compressor, power saw or air conditioner etc Or do these types of kits ONLY get installed to the compressor itself?

[@HVACKnowItAll]

These are for single phase machines that are induction start capacitor run

[@JoeSmith-um2sg]

Thanks, just what I needed!

[@HVACKnowItAll]

My pleasure

[@Darton-ok5xt]

pls help, how do i know which ac hard start kit for my residential ac lennox 5 ton

[@HVACKnowItAll]

Look up the selection that Supco has and their specs

[@jerrymontalbano3222]

Is it universal, or do I have to purchase a specific Hard Start Kit with specifications for my Carrier 3-ton unit?

[@HVACKnowItAll]

Some are universal, some are a little more equipment specific

[@henryperez5404]

Good shit

[@HVACKnowItAll]

Thanks Henry!

[@PH-md8xp]

So, first of all hard start kits should only be installed if there are symptoms of a compressor hard starting, such as locked rotor, voltage drops at startup, short cycling. These kits do not necessarily lengthen the life of a compressor that is running well. If you do install a hard start kit on a compressor, there’s a risk of serious damage to the compressor if the run capacitor fails as they sometimes do, especially as they get older. The way to safeguard against this is to replace the existing run capacitor with one that has compressor protection capability (CPT) built in. One manufacturer of these is Amrad and they are quite inexpensive and I think good insurance and protection for the compressor. Not sure if you get these in Canada or not, but it’s something to consider.

[@Mike-01234]

I always heard these should be installed on every unit. I had a 4-ton goodman packaged heat pump unit bought in 2007 I'm in Phoenix. I had installed a cheap hard start kit just two wires no relay. It was on there until about 2020 I replaced it with a 5-2-1 I probably should have replaced the caps at that point. The condenser fan failed in 2021 I replaced it and installed a new cap for the fan motor. 2022 I smelled smoke inside the house every time AC would start up I thought it was the inside fan motor. Turned out the motor is a brushless motor it soft starts it has no cap new motor was $350 put that in unit would not turn on. I called local AC tech he came out we decided to jump the contactor see if the compressor would start. It just buzzed after an OHM test found one winding shorted 2 were open it was done. I wonder if that 5-2-1 maybe caused that compressor to fail if manufactures wanted bigger caps to start them why not put bigger caps on it. These caps are 150-400 MFD just getting big joint of voltage. I had other issues evap coil was dirty, and I admit should have replaced those caps in the past.

[@james10739]

No those capacitors are not polarized