What causes compressor to trip on high pressure?

[OldSchoolMech]

They are coming out tomorrow, between 8am and noon. I had them put a gauge on it when they did the fan and they said it was fine, but it had only been running about one minute at the time.

He wasn't one of those super cool Techs that hook up the Blue gauge and see 40 and everything is allright was he? Cause he should have hooked up 2 gauges one red to read highside one Blue to Read lowside. Sounds like High head if she is still charged to me.

[kirbinster]

You nailed it, he only hooked up one gauge which I thought was odd - but I did not take note of which one it was.

[vstech]

did he have a bottle of gas hooked up to the gauges? if so, it was just the blue gauge he connected... and it's useless for determining issues with pressure in the condenser...

[garyed]

Its very possible that the fan has got nothing at all to do with the problem & there is another problem now. There are quite a few things that can cause a pressure switch to trip but given the info you've posted & of all the possibilities my guess is that the fan is running backwards. I'd say that's about a 25% probability so i wouldn't bet any money on it.<g>

[DLZ Dan]

Its very possible that the fan has got nothing at all to do with the problem & there is another problem now. There are quite a few things that can cause a pressure switch to trip but given the info you've posted & of all the possibilities my guess is that the fan is running backwards. I'd say that's about a 25% probability so i wouldn't bet any money on it.<g>

There's an idea..Kirbinster, can you put a pice of paper on top of the fan? Does it blow it away or pull it in?

[kirbinster]

No refrigerant hooked up, he just connected one gauge.

The fan is running the correct way, as I had a long discussion with him about which way it should run. It is sucking are through the coils and venting it up the top of the unit.

[vstech]

try the paper test anyway. if its blowing out the top of the coil, and sucking in from the grille it could still be fan placement causing an issue.
get a small piece of paper. start at the bottom of the coil, and lift slowly towards the top. if it sucks in at the bottom, but towards the top it blows out, you have at least found a problem. if it sucks in on the grille towards the outside or the inside, it points to other problems as well.

[Shophound]

You said the coils are clean. Does that mean someone actually CLEANED them, or are they merely getting the eyeball pass of "clean"?

[kirbinster]

You said the coils are clean. Does that mean someone actually CLEANED them, or are they merely getting the eyeball pass of "clean"?

Purely an eyeball examination. I can see through the fins and there are no globs of stuff on them. Again, everything was fine till a week ago when the shaft on the fan broke.

[Six]

One gauge ? What a lazy.......well you know what

It's unfortunate that you had to deal with someone that had a terrible work ethic.

I would ask for another tech. How could he leave with the unit tripping or did he not test it ?

So one gauge and then doesn't actually test or wash the coils ?

Useless.

[kirbinster]

Well I think the only reason he put one gauge on the unit was because I asked him to test the refrigerant level, he was not even planning on doing that. He did sort of test the unit, he turned it on and it ran for a few minutes. The problem is that it does run for a few minutes, it takes 15 to 20 minutes for it to trip. In all fairness to him, I don't think too many people would have waited around for 20 minutes - but maybe I am wrong.

[Shophound]

Could be wrong motor and blade combo. Could be capacitor was not changed when new motor was installed. Visual check of coils not good enough...clean them and then there is no doubt. Only a low side gauge? Don't even bother calling that moron back out. Hire a comptetent technician.

[ar_hvac_man]

Condenser is ALWAYS dirty, even if its shiny. Lazy bas!@#$ dont want to drag their water hose out. Still, the problem occurred after the motor and blade change so thats where I would focus and yes, Id wait 20 minutes or an hour if I had to.