Ice forming on compresser?

[jbomba]

Hi there guys im working on an old bradway package unit. It was found to have a refrigerant leak so i recovered refrigerant and fixed the leak vacced then recharged with 6 kg of refrigerant. Anyway when the unit goes on cooling mode ice forms on the compresser from top to bottom. My first thourght was the tx valve flooding the compresser with liquid , when i looked at the tx valve there is no way to adjust the superheats, the tx valv has an equalising line but thats it, theres no way to make adjustments. I had a look at the phial and gave it a shake its the first phal ive encounted that sounds like a spray can when i shake it ( like somethings hard in there that rattles round) not to sure if this is normal? I recharged with the recomended ammount of refrigerant. What are some other causes for ice forming on the compresser? BTW im using R22

[Grizzly]

As you say it sounds like phial / TXV malfunction?
Have you tried warming the phial (with a hot air gun) to see if the rattle disappears.
Or s/heat control returns?
Grizzly

[nike123]

Do you have any superheat?

[Toosh]

Hi there guys im working on an old bradway package unit. It was found to have a refrigerant leak so i recovered refrigerant and fixed the leak vacced then recharged with 6 kg of refrigerant. Anyway when the unit goes on cooling mode ice forms on the compresser from top to bottom. My first thourght was the tx valve flooding the compresser with liquid , when i looked at the tx valve there is no way to adjust the superheats, the tx valv has an equalising line but thats it, theres no way to make adjustments. I had a look at the phial and gave it a shake its the first phal ive encounted that sounds like a spray can when i shake it ( like somethings hard in there that rattles round) not to sure if this is normal? I recharged with the recomended ammount of refrigerant. What are some other causes for ice forming on the compresser? BTW im using R22

Hi My first question what kind of tx valve is it that has no adjustment is it electronic

Norm

[nike123]

Hi My first question what kind of tx valve is it that has no adjustment is it electronic

Norm

There are many ordinary TXV made for OEM with fixed superheat!

Danfoss (http://www.danfoss.com/NR/rdonlyres/C72BAE74-C34C-400F-B8D3-ECD257EA9635/0/RD1A1B02TD1.pdf)

[Magoo]

Clean air fiters and wash out the evap coil.
magoo

[jbomba]

problem solved , changed the tx valve and all is well. This was a very old tx valve id never seen one before without superheat adjustments, Im gna cut the file open tonite to see what the rattle was. Thanks for the help.

[Slatts]

Clean air fiters and wash out the evap coil.
magoo
The only way you can have ice on the compressor is if the refrigerant isn't picking up heat in the evaporator, either because the evap is blocked with crap, the filters are dirty or the fan is blocked / not working.
If the problem were TX valve related, the compressor would either be cold and swetting not iced up or if the valve was starving, the compressor would be too hot.


problem solved , changed the tx valve and all is well. This was a very old tx valve id never seen one before without superheat adjustments, Im gna cut the file open tonite to see what the rattle was. Thanks for the help.
The rattle will be a ceramic block.
Sounds like you've closed the new valve and are starving the evap. Any bets that the evap will now ice up?
EDIT: for more info on the rattle, read page 5 in this .pdf file (http://www.ra.danfoss.com/TechnicalInfo/Literature/Manuals/01/PF000G102_chapter_01.pdf)

[frostedflake]

greetings

in this matter i did some forum research to find the common cause for compressor sweating, i found a couple of posts that talked about different causes, one being an overcharge that caused liquid flooding and evaporating at the compressor. The other as in this post was related to an unbalanced txv that caused low evaporator superheat therefore boiling at compressor again.

any comments on this two scenarios?

[a.jalilkhani]

is your evapotator temperature is ok?if yes i think you can buy one txv aproprate to r22 and adjust superheat.it seems your system superheat is near 0.if answer of above q is not so may be you should clean evaporator.

[Slatts]

Anyway when the unit goes on cooling mode ice forms on the compresser from top to bottom.
once more time. in order for ice to form on the compressor the refrigerant returning to the compressor must be below 0C. In order for the refrigerant to be below 0C the suction pressure has to be below 58PSI.
If the TXV was flooding the suction pressure would rise above its normal operating pressure (at least 65 PSI) and the result would be a cold and sweaty compressor.
EG: no ice.
I suppose it's possible that the pin seals in the TXV are totally shot and liquid was squirting up the external equalizer line and flooding back to the compressor but I'd expect the OP to mention that the external equalizer line was iced up and the evaporator was warm.

In order for the suction return to be below 0C, the evaporator must not be picking up heat from the air that should be flowing over it. This would indicate either blocked filters, slow or backwards evap fan or a dirty evaporator.
You could stop the system from coming back cold by replacing the TXV with an adjustable one as our intrepid OP did then throttling it to within an inch of its life. This would have the effect of starving the coil and increasing the system superheat and would be an all round bad idea.

[Gary]

As others have pointed out, the real problem is airflow. Replacing the TXV seems to have worked, most likely because the system was off long enough to defrost the coil.

[Gary]

Hi there guys im working on an old bradway package unit. It was found to have a refrigerant leak so i recovered refrigerant and fixed the leak vacced then recharged with 6 kg of refrigerant. Anyway when the unit goes on cooling mode ice forms on the compresser from top to bottom. My first thourght was the tx valve flooding the compresser with liquid , when i looked at the tx valve there is no way to adjust the superheats, the tx valv has an equalising line but thats it, theres no way to make adjustments. I had a look at the phial and gave it a shake its the first phal ive encounted that sounds like a spray can when i shake it ( like somethings hard in there that rattles round) not to sure if this is normal? I recharged with the recomended ammount of refrigerant. What are some other causes for ice forming on the compresser? BTW im using R22

TXV's, once adjusted, almost never need to be adjusted again.