bayberien help!

[nixcool]

Iam a HVAC contractor owner operator.The unit is a 134a little bayberien TXV valve system box sticker is scratched off so i dont know factory charge the condenser was changed 2 months ago by another company #m2fl-ao25-iaa-020.The call complaint was not cooling and when i got there the evap coil was iced up.so the first thing i check evap fan motor was working and is.than check for defrost heater and is none or defrost timer but has a tstate so is it a air defrost??So than i defrosted the coil and put my gauges on it my lowside was like 20 degrees evap temp and highside was 90 degrees so i tried to add a little because it should be alest 50 psi acording to my pt chart 134a and evap temp stayed the same but my compressor temp climbed.so i check compressor amps.
The RLA on comp is 4.9 and it was at 6.4 amps and would not change as i charged so i think its the txv valve? but not sure please help

[2sac]

Iam a HVAC contractor owner operator.The unit is a 134a little bayberien TXV valve system box sticker is scratched off so i dont know factory charge the condenser was changed 2 months ago by another company #m2fl-ao25-iaa-020.The call complaint was not cooling and when i got there the evap coil was iced up.so the first thing i check evap fan motor was working and is.than check for defrost heater and is none or defrost timer but has a tstate so is it a air defrost??So than i defrosted the coil and put my gauges on it my lowside was like 20 degrees evap temp and highside was 90 degrees so i tried to add a little because it should be alest 50 psi acording to my pt chart 134a and evap temp stayed the same but my compressor temp climbed.so i check compressor amps.
The RLA on comp is 4.9 and it was at 6.4 amps and would not change as i charged so i think its the txv valve? but not sure please help

Sure about that?

[nixcool]

Iam new to this site soo how much?

[jim147]

I have no idea what the charge would be, but if your not going to diagnose and repair your problem you might as well fill it till it's full.

And I think your PT chart is broke.

jim

[danbb]

I'd probably fire the unit up, and charge as much liquid into the suction port as possible, it should bring those compressor amps right down...

[nixcool]

I tried filling the system but the evap temp stays the same 20 to 25 degrees ang comp pressure just keeps going up and it does have a sight glass and when i first got there it was clear like it was full with no bubbles and when i shut it off i saw the oil pass threw.so what should be evap temp fully charged with the box temp say at 65 degrees?or it could be t-state causing icing?

[nixcool]

really i never heard of sending liquid through the suction line, wont that hurt the compressor??

[danbb]

If the sight glass was full and you knew it was a TXV system, why would you add charge to try to change your superheat? Makes about as much sense as giving the compressor a good drink of liquid

[VTP99]

Hold on now..... these guys are just toying with you. That's just there nature don't take it personal. They know that you have little experience from what you have said. Slow down a little and give them some info they can work with. Have you ever done refrigeration before ?

[nixcool]

Yes i have but not an expert with small refridgeration mostly central a/c systems

[danbb]

Alright, assuming you're a contractor, it sounds like there was a defrost problem, but now there is also an overcharge problem. You should probably charge based on subcooling, which will mean reading a P/T chart, as well as the proper use of manifold gauges. You're probably going to need to recover refrigerant, and I would aim for 5 degrees of subcooling on that unit. If there still are problems, then you should start investigating TXV issues causing a low evaporator temp

[jim147]

Hold on now..... these guys are just toying with you. That's just there nature don't take it personal. They know that you have little experience from what you have said. Slow down a little and give them some info they can work with. Have you ever done refrigeration before ?

Read the start of this thread http://hvac-talk.com/vbb/showthread.php?t=158850 and then load us up with the info.

jim

[nixcool]

Ok now when iam checking line temp for subcooling i should be taking that temp as closest to my compressor?and iam a license contractor trying to expand for more work.