All Your Branch Box Questions Answered (Mini Split 3 Port Branch Box Install)

This video will answer questions that you may have had concerning installing a 3 Port Branch Box on a 48 K BTU Condenser with 3 Wall Units. Setting the Dip Switches can be tricky and if it is not done correctly can be very costly just in additional time and supplies to correct a mistake at this stage of your install.
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[@ductlessplushvac]

Wow, Denver great job!

[@jorgeureno7309]

Gracias por la informacion profesores

[@ductlessplushvac]

You're welcome!

[@saveriotranquilli929]

Great job, man! And many thanks for explaining everything! What about the other switches on the main board, like SW4 or SW5? Do they need to be in the off position? Also, do you have a video showing how to recharge the additional refrigerant in the system? Thank you!

[@ductlessplushvac]

Not yet but we will make one for you.

[@taylorthuannguyen]

Hello Sir, so glad I found this Video! Please help me me here, I have a 5 zone branch box, it will be use as B, C, D, E! So on "SW1", # 2, 3, 4 & 5 will be on? How about 6 on SW1? How about the rest of SW switches on BB and outdoor unit? Leave them to OFF? Thank you Sir!

[@ductlessplushvac]

Only turn on the ones that are getting used the ones that aren’t getting used needs to be off.

[@tonyyagiello1130]

I have lg with branch box that needs to be charged, how do you charge past the branch box?

[@evanchilds1365]

Just curious, Are you using 14/4 stranded to power the branch (L-1 and L-2) from the condenser or is that another type of wire you keep on hand? Seems like 14/2 romex would work well and be cost effective for that wire.

[@ductlessplushvac]

We use 14-4 stranded wire. I feels it's a better way to go and we have additional wire in the event of a failure.

[@BenBuildsDIY]

Did you install a breaker (or disconnect) between the B1/B2 connections on the outdoor unit and the L1/L2 connections on the branch box? I have an MXZ-SM48 and the install instructions aren't clear whether this is optional or required. Thanks!

[@ductlessplushvac]

We only install a disconnect for the outdoor unit. Run the wires straight to the BB connections on the branch box from the outdoor unit.

[@BenBuildsDIY]

@@ductlessplushvac thanks! Super helpful

[@Jemsurak]

For the side that isn’t grounded, what did you do with the wire? Cut it down or do you cap it off and leave it in the branch box? Just curious. Thanks!

[@ductlessplushvac]

Wrap it with electrical tape. And land the M1-M2

[@jtburn7862]

I have been quoted a system that uses a Branch Box (4 head Hyper Heat). I am concerned that his adds more points of failure. What are the pros to having a Branch Box? Should I consider 2 separate outdoor units or another manufacturer?

[@ductlessplushvac]

The only benefit for 2 units is they should have a better efficiency VS a BB install. I would use a BB install for the cleaner look

[@guybeavers6026]

Where to you get your propress flare fittings? Are they a standard Streamline product or are they specific to Mitsubishi?

[@ductlessplushvac]

It's a Mueller product

[@KB-Mini_Splits]

I'm a ductless installer out of MA and was just curious about only grounding the M-NET wire on one end. The distributor/installer I spoke with today said that it should be grounded on both sides, but I am wondering if he somehow wasn't understanding what I was explaining even though I mentioned to him about it turning into an antenna if I ground both sides. If you don't mind me asking, was it Mitsubishi that mentioned to you to only hook the ground up on one side? Also, how long does it usually take you to vac down a 3port branch box system usually? I had the vac pump on for about 90min today and was still only at 760microns, but I know I didn't have any leaks since when I valved everything off it stayed right at 760. I use a 7cfm pump with 1/2" Navac high refrigerant flow hose and removed all the valve cores. I'm going back tomorrow to finish it all up and vac down for a little while longer but just was wondering if it usually takes you guys a while to vac down branch box systems as well or if I am missing something on these new Smart Multi condensers. Thank you for the informative videos!

[@ductlessplushvac]

Yes, Mitsubishi told us not to ground the 2 sides. Only one side; it doesn't matter what side you ground. If you have a higher-than-normal humidity level, you should break the vacuum with nitrogen. You should perform that three times (Triple evac). When you vacuum a system, and if it has any moisture in it, it will freeze. This will not allow you to perform a high-quality evacuation. We don't have a high humidity level here, but in lower elevations, you will. I like to purge the nitrogen out of the system and perform a blowout. Once I feel the nitrogen has passed all the air out, then I pressure test. Once it passed the pressure test, we then perform the evacuation process. It's safe to be within 1000-500 microns. The lower, the better, tho. Also, micron gauges can be misleading. Make sure your gauge is calibrated and working normally and that you have a high-quality fresh battery. (This is also helpful. Never entirely remove the nitrogen to zero. Leave a little in the loop and then start the evacuation. Open your gauges very slowly to not shoot the nitrogen out of the vacuum pump. This ensures no air enters the system) thanks for watching the videos and please subscribe so we can make more videos you may like HVAC on brother! Jared

[@lostincause3418]

I'm literally in the parking spot waiting for a part 2 of a mitsubishi class. My instructor said to ground only 1 side, it's also in our manual.

[@ductlessplushvac]

@@lostincause3418 thank you for watching

[@AlexHorwatt]

@@ductlessplushvac What do you pressure test these multizone branch box unit to? 300? 450? 600?

[@danmartens1282]

@@lostincause3418do they want the shirld landed on both side and add the grounding jumper on one side?

[@pauljamilkowski3672]

If 2 branch boxes off 1 condenser, do you set one to 01 and one to 02 and leave the condenser at 51?

[@ductlessplushvac]

That's a great question no. 1st BB is 01 then it depends how many indoor units you have if you had 6 indoor units it would be 06.

[@denverwilcox2237]

Handsome fella

[@ductlessplushvac]

Yep

[@diegosantos9632]

What happens if branch box is not address correctly. I ran into one were unit is set to 47 also 47 at branch box. How will the system operate? Will the indoor units work properly? 4-zone. When all zones is calling for cool, only 2 cools and the other 2 furthest from branch box not cooling.

[@ductlessplushvac]

It may still work but it won't work correctly Just do it 51 - 01

[@shawnm8772]

Why would you add a pro press nipple with a flare on it? and not just flare the end of the pipe and skip the extra pro press joint? aren't less joints preferred? or are the pro press flares superior?

[@ductlessplushvac]

Pro press 1000000% better

[@danmartens1282]

Can you pull vacuum right thru the branch box valves?

[@ductlessplushvac]

No you do it at the unit

[@danmartens1282]

@@ductlessplushvac are the branch box valves hard close?

[@bradmarshall7075]

Who make the pro press fittings with the flares? And can you use rls jaws?

[@ductlessplushvac]

Milwaukee pro press

[@edsmith8482]

Does Viega make the fittings?

[@ductlessplushvac]

@@edsmith8482 Milwaukee ARC PRESS

[@mikemiller9030]

Mitsubishi 5 branch box here. Probably best to use 12 awg vs 14 for the power into the branch? Still needs a signal wire set between the "m" terminals? Im not an electrician but am mostly calable Lol. If you have time for an answer i would be most humbled

[@ductlessplushvac]

I'm not sure what your asking. The M1,M2 terminals must be landed @ the BB

[@mikemiller9030]

@@ductlessplushvacsorry. My outdoor compressor will send line voltage to the 5-branch box. Might it be ok to use 12 awg stranded vs 14 awg solid for that, or is solid wire the usual choice? Aside from all this, will still need the m-terminals wired between the outdoor compressor and bb?

[@ductlessplushvac]

@@mikemiller9030 just do what the instructions say and you will be perfect

[@christophermoeder-oc8my]

Is that an electrically rated box cutter

[@ductlessplushvac]

Yes

[@rickross7796]

Curious why you crimped that connection instead of flaring it seems like one more point of failure

[@ductlessplushvac]

The crimp fittings are way superior

[@dsheli3]

Not using Nylog anymore?

[@ductlessplushvac]

The oil is cleaner

[@mylesm7947]

That oil refrigerant compatible

[@ductlessplushvac]

I'm not sure I understand your question. What about the oil.

[@RichCollins-rm6om]

What is the proper way to run the communication wire if there are 2 branch Boxes ? 7:09 Do I run two wires from the condenser. Or do I run one wire to branch box1. Then run a jumper from branch box 1 to branch box 2?

[@ductlessplushvac]

Daisy chain them from the outdoors then to 1st BB THEN to 2nd BB, Only land the ground wire on one end not both sides.

[@RichCollins-rm6om]

@@ductlessplushvac Great thanks. That’s the way I ran it hoping it was right. Your videos are perfect. Couldn’t have done it without them

[@ductlessplushvac]

@@RichCollins-rm6om Make sure to give us a sub! Thanks for watching. Jared