weird Refrigeration

[Koopy]

hi all,

i have an o6e recip running full load.

77 amps fla
running 52 amps

suction 270 kpa
Discharge 1800 kpa
sst 8.5 C
sct 49 C
liquid pipe temp - 39 C
Suction Pipe Temp - 21 C

Running on 3 x TXV

Air on evap - 26 C
Air off Evsap 23 C
condenser 18 k split

Need to be seeing 10 k split over evap.
Used to get it but another tech attended site, gas leak and now i cannot trim the charge correctly very frustrating any ideas?

[marc5180]

Hi,
I've no idea what an "o6e" is but i'll try and help.

Firstly what refrigerant is it running on?

With 10K subcooling and 12.5k superheat i would start looking at the TEVs for underfeeding.

Are the filters clean and is the airflow correct in the evap?
(This is assuming it isn't a chiller, If it start looking at your flow rates on your chilled water.)

[NoNickName]

sst 8.5°C and suction temp 21°C for me mean clogged filter or coil, or air flow restriction.

[Grizzly]

Hi,
I've no idea what an "o6e" is but i'll try and help.

Firstly what refrigerant is it running on?

With 10K subcooling and 12.5k superheat i would start looking at the TEVs for underfeeding.

Are the filters clean and is the airflow correct in the evap?
(This is assuming it isn't a chiller, If it start looking at your flow rates on your chilled water.)

Hi Mark.
An 06E is a carrier recip!
The attached is a 07e but is very similar.
Grizzly

[marc5180]

Hi Mark.
An 06E is a carrier recip!
The attached is a 07e but is very similar.
Grizzly
Oh in that case i haven't a clue:D

[Brian_UK]

If you want a pretty picture of an 06E then...

http://www.commercial.carrier.com/commercial/hvac/product_description/0,,CLI1_DIV12_ETI434_PRD211,00.html

[Gary]

I would be looking for a plugged drier, liquid line kink or plugged TXV inlet strainer.

[Gary]

Also check for a dirty condenser.

[marc5180]

Also check for a dirty condenser.
Can i aks why check for a dirty condensor? If condensor become fouled suction superheat decreases doesn't it?

[monkey spanners]

Did the other tech put the correct refrigerant in it?

[Gary]

Can i aks why check for a dirty condensor? If condensor become fouled suction superheat decreases doesn't it?

Separate problem. The condenser split seems high... especially with the evap severely underloaded. The primary problem would be liquid restriction.

Over the years, I have found that multiple problems are the norm.

[Koopy]

Could a restriction in the suction line cause this issue. There ia no restriction in the liquid line at all. Ahu filters are brand new Evap coil clean carried out a month ago. I like the blocked tx valve strainer idea. Will look into it.

[Koopy]

And r22 gents

[Magoo]

High discharge, low suction, if not drier look at failed TX valve. Liquid stacked in high side.

[Tesla]

Hi Koopy
This one sounds tricky with high discharge temp and high superheat with acceptable subcooling. A couple of things to check here - first touchy feely check for temp differences in the liquid and suction lines, like Gary (Mr Wisdom) said there could be more than one fault and monkey spanners is there a contaminant in the system (check history with previous tech). It would be prudent to search this forum to find link and download the O6E manual. From what you wrote it is a DX air cooled a/c system, what is the ambient and serial number?

[paul_h]

High discharge temp means not much cold vapour coming down the suction line.
High superheat means not much liquid passing through the TX valves into the evap.
Subcooling good because that's where all the liquid is, in the condenser and liquid lines.

Like gary said, liquid line problem, drier, strainers or TX valves themselves.

edit:

Could a restriction in the suction line cause this issue. There ia no restriction in the liquid line at all. Ahu filters are brand new Evap coil clean carried out a month ago. I like the blocked tx valve strainer idea. Will look into it. Could, but you are going to have some serious frosting at the restriction if it's in the suction line. Also where are you measuring your suction pressure? If at the compressor, then suction line problem a possiblity, but if you measure low pressure at the evap itself, then that shows the problem before the evap in the liquid line as said.

[bunda]

Carried out further repairs on same unit, changed driers (partially blocked), pressure and leak tested properly, evacuated system to below 500 microns, then charged system and is now running fine.

I came to the conclusion that the system was full of non-condensable's due to low or no vacuum done on original job.

Amazing what you can achieve when you take the time to do the job properly.