Low guage readings

[drriet]

Hi all, A friend of mine asked me to look at his A/C unit before he called a tech out. He said the last time he ran it the suction line was freezing outside at the condensor and the unit was not cooling. Previous to that he said it was operating fine. I fully expected to find dirty filters or some other reason for no air flow, but all that was fine. So I put on a set of guages just to check for low charge. What i found has me a little puzzled. The outdoor temp was only about 60-65 but 90's are forcast for later this week and this was the only chance I had to look at it. Head pressure, 75psi (yes WAY low), suction pressure 70psi and after a short while the suction line started frosting from the condensor at the service ports. I have had some HVAC classes but am an electrician by trade and as I said before thought I would find an airflow problem. In short, I told him he needs to call someone out but I am beginning to wonder about whether the compressor or compressor valves are bad. Anybody have any thoughts?

Thanks, Dave

[The Freon Cowboy]

leave the hvac to us , and we'll leave electrical to you ;-)

[e-mail] wrote:

[tony]

Yes it is puzzling do your ac have service valve on suction line that comes from evaporator if so on which side of the valve did you take readings, because if you took readings on the evaporators side of the service valve your valve could be partially close or some kind obstruction with in that would explain freezing between valve and compressor high pressure on evaporator and low head at same time. Tony

[drriet]

No, No service valves on the condensor. Thanks

[Stormin Mormon]

With pressures equal like that, I'd be thinking that the compressor isn't pumping at all. Not running, or mechanical damage. But, since it started to frost at a service valve, the compressor must be pumping. If the unit was massively low on freon, you'd see a much lower suction pressure.

I'm starting to wonder if the metering device is missing, or locked open?

[tony]

[Stormin Mormon]

Really? What brand of condensing unit is it? There should be a valve on the discharge side of the condensor. Typically, after an internal filter drier, where the line comes out of the cabinet. And one service valve on the suction line where it comes into the condensing unit.

[drriet]

No TEX and the unit is a 3 ton Magic Chef about 10-12 years old..If memory serves me right I think Magic Chef was made by Lennox

[Noon-Air]

Hmmmm....no service valves, no expantion valve, 3 ton, 10 - 12 years old.... sounds like a trailer to me. This wouldn't be a heat pump by any stretch of imagination???

Maybe you should be calling a *competent* tech??

[The Freon Cowboy]

id be thinking that he doesnt know what he doing, maybe his guages are f***ed up maybe hes using the wrong kind of guages , if hes on 22 and reading 70 on suction with ice forming theres no way he'd have 75 on discharge , i think hes got a bad high side guage who knows ?

but one thing is for sure , you dont , and shouldnt be giving out advice

"Storm>With pressures equal like that, I'd be thinking that the compressor

isn't.pumping at all. Not running, or mechanical damage. But, since it started to frost at a service valve, the compressor must be pumping. If the unit wasgmassively low on freon, you'd see a much lower suction pressure.

[OLDHVACDUDE]

You just continue to prove how absolutely clueless you are about hvac. What a f****ng moron.

[tony]

[<kjpro]

Stormy&#39;s clueless about EVERYTHING. Otherwise, he wouldn&#39;t be busting door jams. :-)

[Bubba]

This is a rather simple fix. Call up Stormy and have him come over. When he gets there, bash his head in with a rock. While he is still conscious, have him beat your head in with those fuquering gauges you have no clue how to use. Then, while you are both still semi-conscious, call up tony, have him come over and both of you can bash his head in with a tire iron. Bubba

[Stormin Mormon]

He said no service ports on the condensor. I&#39;m guessing he means the cold condensor in the furnace.

[<kjpro]

Really?

Quote: "after a short while the suction line started frosting from the condensor at the service ports."

Keep guessing, "cold condensor in furnace"... LOL You need a clue Stormy.

CLUE