Installing a mini split

[drew27]

the wire from the outdoor unit to the indoor is a 4 wire, sjo, do not use the t-stat wire. their is an inverter that sends dc voltage through that wire to communicate.

 

[ZinksInk]

Couple of things for Mini split installers. Most units (I had a Samsung) get their power from the out door unit. The outdoor unit is hooked up by a 240 main line.

The indoor units, yes do have a hook up for com cables, and power.

I would not recomend using "sealant" for the copper tubes. If you are unsure how much to tighten down the connectors consult the manual and get a torque wrench.

My first attempt at an install i over tightened the connectors and slit the copper tube. If this happens buy a tube cutter and a flaring tool. Consult the manual to see which flare size to use.

To do a legal electrical install there needs to be an outdoor shut off for the unit.

Companies wont want to help you with the install as the HVAC community is mean and they clearly state on all forums its not a DIY community. Should you really have an issue obtaining materials you need to complete the install you can just get your self EPA certified which is enough for a sale. The EPA website offers free R410 certification and and the Basic 101 cert is like 25 bucks.... Study materials are free.

Pumping down the unit is easy if you have a vacuum pump and a pressure manifold.
Charging the unit is also fairly easy. Buying a tank of R410a... not

You also can not realiably check for leaks once your unit is charged with R410a using the soapy watter check...

Should you wish to do this type of pressure check do it prior to the chargeing the out door unit.
You can fill the system up with nitrogen and and see if it holds. You can then spray the connectors with soapy watter and they will bubble as expected should their be a leak. The other advantage to using nitrogen is you can hear it often escaping.

If you do want to check your system with nitrogen you will have to procure a nitrogen regulator as well as a tank. You cant use the R410a manifold for the nitrogen...

The other option to check for leaks prior to charge is to pull a vacuum and then just see if it holds.

When ordering parts from a supplier know what you want. They will hang up if you ask too many questions and refuse a sale.

hope this helps.