Mitsubishi outdoor and branch box installation
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- čas přidán 20. 01. 2023
- This video covers the installation of a 60K BTU/hr outdoor unit and the associated branch distribution box.
The previous video at: • Mitsubishi split AC in... covers the installation of indoor units including a one-way ceiling canister and a 24K BTU/hr wall unit with lines exiting the back on left side instead of right side.
See comments for good discussion on SW2 position 5 setting (switch to ON), and link to site with discussion on problem solved by setting SW2-5 to ON. - Jak na to + styl
8:57 What a complex system. What could possibly go wrong? < sarcasm > Call me a slow to adapt to change Neanderthal. All that efficiency is exciting while it is trouble free. 10:55 The line set routing and channels are a work of ART!
Once installed they seem to be pretty reliable. I installed a LG system in the back of the house about 5 years ago and it has been trouble free.
czcams.com/video/m6DD_dCc5GY/video.html
Nice work.
Excellent work. I will be putting one of these in for a customer, my first branch box install. How did you determine the additional refrigerant amount? I’ve been reading the spec sheet and instructions for condenser pre-charged pipe length but have only seen maximum total pipe length for system.
In the instruction manual under "installing the refrigerant piping" in my manual it is section 4 is the sub section "Additional refrigerant charge" in my manual it is section 4.7 The amount depends on pipe size and length, plus capacity of the indoor units. A sample calculation is provided
I am going to do a similar install myself, but I wasn't sure about the nitrogen/refrigerant component. I was wondering if it requires special certification for adding refrigerant. How did you learn to do nitrogen pressurization? Also, can you explain the process for adding drain lines for condensate?
Nitrogen pressurization is covered in the installation manual. You can rent nitrogen from a local welding supply shop. However, you will probably have to buy a regulator. You should check all flare connections with soapy water. If you pull a permit you will likely need a licensed person to observe the adding of refrigerant. Some people do the install and then have a licensed contractor do the pressure check and refrigerant addition. Drain lines exit the indoor units with the refrigerant and electrical lines. Key is to keep drain lines flowing down hill. In my case, the drain lines separated from the other lines where the refrigerant and electrical turned from downhill to horizontal aiming toward the branch box, and the drain lines continued straight down to close to the ground.
Nice Job!!!! Did you have to energize the branchbox for the nitrogen to distribute to the air handlers? or are all the ports open. Thanks in advance! again great, clean install.
My recollection is that i did not energize the branch box
Do these outdoor units ever need to have coils cleaned? What would be the best way to access the coils for cleaning? Can you just pull the fan and clean from the front?
I think all outdoor units have to be cleaned from time to time. Pulling off the metal top followed by metal panels exposes the coils enough for cleaning.
Sir thanks for sharing this great video … very helpful .. may I ask where did u buy the unit and will Mitsubishi provide the warranty since it was a self install
Units were purchased from ecomfort.com. Line sets were mostly purchased from SupplyHouse.com. Yes, Mitsubishi did provide warranty after submitting serial numbers for each unit.
I am trying to design a four zone Mitsubishi mini split system. I was planning on a very similar design and had a question.which condenser model do you use? I am looking for a heat pump model and am unsure if I need one with service valves for 1 circuit or 4 circuits or if it even matters with a branch box? I was planning on only running 1 lineset from the condenser to a branch box in the attic. 4 zones coming off the branch box.
The outdoor unit model number is MXZ-SM60NAM-U1 which is a 60k BTU/hr unit. My logic in choosing this unit is as follows. Based on the 4 indoor units I was planning on installing, I needed at least the 48k BTU/hr unit. The 48k BTU/hr unit still requires a branch box and by going to the 60k BTU/hr unit I left room for possibly adding a 5th indoor unit in the future since the branch box has 5 ports. Also, for cold climates the H2i models might be necessary, but my installation is in southern California where it does not get all that cold, and we already have natural gas fired forced air for heat in the winter. Both the outdoor and indoor units were purchased from ecomfort.com.
What size wire is used for connecting power from the condenser to the branch box?
Branch Box installation manual states 2.5 sq mm which is 12 AWG. I used 10 AWG. Not sure why, probably had extra laying around. Larger diameter OK.
Those branch boxes usually placed indoors like attic for cleaner install, but wall units would be problematic I guess. Perhaps small ducted units or ceiling cassettes would work best with this type of unit:)
Yes. Branch box is designed for indoor installation UNLESS protected by NEMA weather proof enclosure, which I did use.
Agree, I clicked the video because I had not seen that before. Im not a fan of wall units anyways except for shop type installs but hate the big ugly box hanging on the wall. one way cassettes look best IMO Makes no sense to me to have a branch box installed a couple feet from the outdoor unit.
One way ceiling cassette used in kitchen. Wall units used in dining room and bedrooms - open beam ceilings. Check out indoor unit video
czcams.com/video/T4PdK8yTljk/video.htmlsi=G6Hh-VZLaocvsbGe
If you’re installing a branch box, don’t you need to turn the dip switch on from the outdoor unit SW2 dip switch 5 to ON position? Having trouble w this unit
I see what you are referring to. It has been a while and I do not recall if I flipped SW2 position 5 to on or not. When I get a chance I will check and report back.
I checked and sw2 position 5 is still in the OFF position. Nonetheless, everything seems to be working properly
@@ron12april yes sir. Learned a lot from your video, amazing install!
I am pretty sure SW2-5 should be set to ON position.
Here is the address of discussion where outdoor unit with branch box problem solved by setting SW2-5 to ON.
hvac-talk.com/vbb/threads/2255627-What-s-Wrong-with-my-Mitsubishi-system
I never ran into problem because I mostly run only one of the indoor units at a time. The problem described in the discussion is when 2 units were on full load.
I set my unit’s SW2-5 to ON. Everything still works fine.
If you have snow in your area best be sure to clear the front and side of unit to breath don’t let it ice up if you have freezing / snow conditions . Typically installed 16’ minimum on clearance from bottom / fan.
I'm in Southern California. I'm hoping I never see snow or ice here :)