[Kpp]

So my installer while doing LG multi splits took a break for a day and it rained.

The copper pipes are .8 mm wall thickness and 1/4th and 1/2 respectively.

The part that connects outdoor was taped and tapered down with one missing the tape touching ground. I have attached an image.

When he started back we removed about 2 metres from the end and purged with nitrogen before flaring and sealing.

Question is triple evac needed? Comissioning is going on and we are able to pull a vaccum of 250 microns, it wasnt holding it so we are planning to do this tomorrow... maybe some loose ends.

Can we still have corroded copper walls inside if humidity gets in without water?

 

[kdean1]

There may be a leak. Has a pressure test been performed before evacuating?
How can they be commissioning the unit if it isn’t running?

 

[Kpp]

It turned out that the vaccum guage was erratic. We switched and it was holding vaccum fine. Pressure test was done before and there wasnt a single psi drop. Thank you so much for your response.

 

[kdean1]

Again, how can the unit be commissioned if it isn’t running?

 

[pecmsg]

Again, how can the unit be commissioned if it isn’t running?

It wasn’t.

 

[kdean1]

It wasn’t.

The OP says it was being commissioned in post 1.

 

[TechmanTery]

"There wasn't a single psi drop"? I think a better pressure drop scale is needed. For each inch(") of vacuum there is 25,400 'microns'. KindaSorta, there is 30'' of vacuum. In 'psi' there is 14.7 psia/0 psig at Sea-level. So there is 2'' of vac for every 1 psi of negative pressure( 50,800 microns). So, pulling down to the very last 500-250 microns from the original starting point of 762,000 microns is an amazing feat. Then once you get there, the isolated system has to 'stay down there' to pass a 'decay test'