Very high pressure....
 

Hello,
New to this forum, looks like a good place to find info....
I;m a maintenance supervisor for a couple of apartment properties in AZ.
Our team tackles as many challenges as possible-to save money, but mostly to gain knowledge in as many areas as possible.
Our weakest area has to be within the hvac field....
One of our rooftop a/c units is showing very high pressure on the high side-350-400psi....Low side at 70...
I don't have the unit model no. at hand...
WeatherKing(Man. by RUUD)
1.5 ton,12 seer
All units(99 of them) are now out of warranty....
Compressors starting to go. Daily temps now regularly 95-110 F.
This particular unit is running cold initially, reaching 49 deg.F at the closest vent to the evap/handler.
But within 10-15 minutes of continuos running the temp starts to raise until eventually room temp. air is just circulating.
The capacitor was replaced and a hard start kit was installed and it seemed to be cycling/cooling fine up until I left for the day 2-3 hrs later.
But what could cause such high pressure on the high side, and the low side seems to be within range??

Dirty condensor coils or overcharged cause the high head pressure. Get them hosed out good then clean the evap coils. After that come back with superheat,subcool,outdoor ambient temp,indoor wet bulb temp and metering device and we can be of more help.

Overcharge is definately a concern. When I got up on the roof, the disconnect box door was open, and when we opened the panel on the unit the screws to both the start relay and the capacitor were both loosened and the parts not secure.....
So, whoever serviced it last(was not an employee of the property,would have been a service tech..) left it in that state...Who knows what else they did to the system.
The condenser coils are clean, but I'll clean the evap. coils monday for sure when I go back to check on things....
Thanks for the info.

Get in the habit of checking superheat and subcool instead of just reading pressures. They'll tell you what's going on in the refrigerant circuit.

It's very hard to get qualified people with all these requirements for the salary these Condo want to to pay......

- HVAC certified.
- Electrical experience
- Plumbing experience
- Painting experience
- Grounds keeping experience
Time has been changing.......Pay for it.

I’m dog gone tired to see these APT/CONDO asking for Apartment Maintenance Tech paying slave salary. Just saying….

Plus you got to pay for a helper like jjboy here.

I'm not qualified. They want five years of experience. LOL

This is a family site, with a G rating, lets watch our language.

If those coils are clean and it's 105 degrees out I don't see what more you can do but take out some gas. you will loose some of your efficiency but the unit should at least stay online and not trip on high pressure.

Thanks for all of the input from everyone....
hvacbenny- you nailed it.....the property mgt. companies want employees with multiple trade skills and experience but want to pay peanuts-especially in Arizona....(right to work state).
Hubcap, we did relieve some pressure-thanks

MartyS,
Thanks, but honestly, I'm in the dark checking superheat/subcooling.....
I'm taking BABYSTEPS..........That's why I'm here.....!!!
Thanks

Bad Compressor, Evap and Condenser. New system $7000 cheap. :thumbsup: