TRANE TCD048 Rooftop Problem

[Gabrielnqn]

Hi guys..I hope someone can give me an answer:

Replaced a 4 ton (TCD048 Rooftop) Trane Compressor, which was as well replaced by a Tecumseh like 2 yrs ago.
I installed a NEW (Sealed) Copeland Hermetic 47,000 Btu/h 3PH 230V.

The old compressor's coil was grounded. Compressor burned.

I pulled all the R22 out, and cleaned the system with N2. Installed new compressor. After all solderings, I pulled high Vac for 30 min. Charged and tested, pressures were good. 65LB/240LB 88°F Outdoor.

Problem:
Inside temp only 10°F bellow Outdoor temp. I get 78°F from any supply register.
Any clue?

[Gabrielnqn]

by the way, I charged by weight and charged with 12LB R22 as says in the plate.

[dandyme]

Did you replace the driers?
Are you running 100 o/o outside air?

[Gabrielnqn]

Of course, I did replace the filter...I found some dust inside the piping so I used N2. Then I installed the filter and did the solderings connecting the new compressor.

Another question.....Shoud I have add some suniso oil?

[ucp]

Just curious, but what is the return air temp before evap?

That 88 degree outdoor, did you actually measure that near condenser on roof?

That suction pressure looks a bit low if your return is warmer than 75 degrees or so.

I wouldnt think the economizer is open with that low suction press.

Can you measure temperature drop across evaporator coil,return and supply temperatures and measure suction line temperature near compressor while taking pressure readings and outdoor ambient near condensor please and post all here?

That will help us to try and get you some answers.

[Gabrielnqn]

88°F near condensor.
Yes, suction pressure seem to be too low.
I think it shoud be like 75, correct?

I will go and take temperature/pressures readings again tomorrow if needed.

[Gabrielnqn]

Unit does not have economizer.

[ucp]

Actually I dont think anyone can give you an accurate answer on what suction pressure should be untill the return/supply temperatures are known along with other goodies I mentioned.

If I had around 80 deg return I would expect near 75/80 psig, but I suspect your return temperature was higher than that considering you had a 78 degree supply after you started up and seemed some cooling was getting done with those pressures you mentioned.


Trust me, you will get some good answers here when you get the info.

[toptech]

Was trane out of compressors?
Why the re-engineering on a tcd048?
Copeland? Techumseh?
I did not know they made replacements for trane, then again, I don't get out much!!
Bernie

[Gabrielnqn]

yes, they told me the trane compressor would take 1 week ans cost $750...very expensive, the costumer will not pay that much for all the work.
Copeland came with $350 for same btu/h and performance.

[kool it man]

Originally posted by Gabrielnqn
Hi guys..I hope someone can give me an answer:

Replaced a 4 ton (TCD048 Rooftop) Trane Compressor, which was as well replaced by a Tecumseh like 2 yrs ago.
I installed a NEW (Sealed) Copeland Hermetic 47,000 Btu/h 3PH 230V.

The old compressor's coil was grounded. Compressor burned.

I pulled all the R22 out, and cleaned the system with N2. Installed new compressor. After all solderings, I pulled high Vac for 30 min. Charged and tested, pressures were good. 65LB/240LB 88°F Outdoor.

Problem:
Inside temp only 10°F bellow Outdoor temp. I get 78°F from any supply register.
Any clue?

Did you clean the condensor coil?

[Gabrielnqn]

What did you mean? If I cleaned the condensor using a coli cleaning agent? No I did not. And it doesn't seam bad.

[deanm]

What is Delta-T @ Evap Coil? Cap Tube or TXV? Subcool & Superheat need to be checked. Previous replacement may not have been charged properly. Trane has great tech support but make sure you have all info above along with pressures b4 talking to them. Also M# & S#.