Another Mini-split question

[ALinCarolina]

I have installed a single head Mini-split in the past and everything went well but I am now in the process of installing a 3 head unit and I have two questions. The outside unit has the 3 high and low fittings for each of the 3 inside units as expected but there is also another service port on the suction side above the set of 3. So I assume I need to nitrogen pressure test and deep vacuum each of the 3 circuits individually? What do I do about the bigger service port at the top? It seems to me that the one up top doesn't go anywhere much other than to the accumulator and I assume is already charged with refrigerant. The installation manual makes no mention of course.
The second question concerns the adapters sent with the unit, It is a 12/9/9 BTU unit and the suction flares on the outdoor unit are 3/8. The line set for the 12K head is 1/2" suction. They sent 3 adapters: 3/8 to 1/2 flare which would be used for the larger line set. There is a piece of flared copper tube inside the adapter. I assume that this stays in place so that there is soft copper between the brass flare surfaces. But I have never used one of these and wanted to make sure it wasn't there just for their testing. Thanks.

 

[Phuckin' Jim]

For your viewing pleasure.
Even if yours isn't a Senville, this would still apply.

 

[ALinCarolina]

Thanks. I did some more searching and still confused. Check this video from Cooper and Hunter company about 8:20

 

[ALinCarolina]

The guy in this second video took short cuts but seems he did like the C&H video. Check about 34:50. I think I will follow the C&H since it is coming from the C&H company.

 

[fitter30]

The A- B - C valves on the left have three caps right is the flare for line, middle is to open the valve, left is port also has a schrader to pressure test.

 

[Phuckin' Jim]

I watched doublewide's video, and I noticed that he didn't make reference to the copper inserts in the adapters, so he probably didn't use them.

 

[ALinCarolina]

I guess there is no harm in pressure testing each zone independently but say I hook up the nitrogen to zone A using my valve core removal tool. I would think that all 4 flare fittings (2 on the outside and 2 on the inside unit) would be tested on that zone without opening the front seated valve with the hex wrench. Then test the other 2 zones. Then should I do the vacuum decay testing with all 3 service valves open? or vacuum each separately? If everything is good to go then open the master service valves on the upper suction and liquid lines and all 3 service valves on A, B, and C

 

[Z6LG32]

deleted

 

[ALinCarolina]

To update in case anyone runs into the same question concerning multi-zone mini splits. I nitrogen pressure tested and evacuated each zone independently. After doing that I opened all six valves where the suction and liquid lines attach. Then opened the 2 master valves. Working well on the startup test.