High liquid line pressure

[hvacpros1]

I have a system I just installed 3 to 14 seer 410a
ac with a 5 ton evap. coil , txv, on a furnace with a 4 to drive.
pulled a good vacuum, and let 410a into the system.
suction side is at 150 psi, and the liquid lie pressure is bouncing between 375-550psi.
what the heck is going on???
any suggestions will be appreciated.
Thanks,
Chris

[Joe Harper]

Non condensibles

[TheChillerMan]

Why is this post in the job discussion forum?

[Dustykyle]

Did you charge the system with more freon, generally a new condenser only comes factory charged with enough freon for a15 foot line set. And if you did what was your super heat and sub cooling. Under charged system with a txv valve will give you some weird pressures.

[jim147]

Is that a 3 ton condenser with a 5 ton coil and a four ton furnace?

It must be my confused night.

jim

[beenthere]

Threads merged, please don't make duplicate threads, thank you.

[T&C_Mechanical]

So in cooling is the reversing valve energized did you wire correctly. If so is txv receiving liquid or is it being bombarded with gas pockets (undercharge). Was it a new line set or was old set used and what sizes are the line sets? 410 is very very temperamental air flow must be correct and system must be correctly sized for application. You may be low on freon or gas pockets in the system that is slamming against the needle of the txv and that may be your violent swings in pressure

[martyinlincoln]

What's a good vacuum? Used a micron gauge or just let the pump run for a long time? If you pulled to under 500 microns and it held there with the pump off we should be able to eliminate noncondensables as the problem. If you didn't use a micron gauge then Joe is probably right.

[figaro12]

What's a good vacuum? Used a micron gauge or just let the pump run for a long time? If you pulled to under 500 microns and it held there with the pump off we should be able to eliminate noncondensables as the problem. If you didn't use a micron gauge then Joe is probably right.

Yup, seen that a few times. Might have to recover, evac and recharge to rule it out for sure. Whats your comp discharge temp?