Superheat

[frank]

Comments Please

The limit to any compressor discharge temperature is 225 degrees F. If the discharge temperature gets higher than 225 degrees, the system may start to fail from worn rings, acid formations, and oil breakdown. Remember, if the discharge temperature is 225 degrees, the actual discharge valve will be about 75 degrees hotter. This will bring the actual compressor’s discharge valve to 300 degrees. It is a known fact that most oil may start to break down and vaporize at 350 degrees. If this occurs, serious overheating problems will happen. And, since compressor overheating problems are today’s most serious compressor field problems, service technicians must always monitor compressor discharge temperatures and keep them under 225 degrees. You can record superheat at any time but the biggest effect is when your fully loaded, you can always put a recorder with the senseo mounted about 6" from the discharge service valve. Some of the reasons for high compressor discharge temperatures are:

High condensing pressures;
Low suction pressures;
High compression ratios; and
High compressor superheats.

[Brian_UK]

Comments Please

NO !

Oh, OK, it seems to be a valid comment and something that we should all be aware off.

One is tempted to ask whether additional safeties should be fitted to compressors to monitor discharge temperatures to protect the compressor. Yes, I am aware that they are fitted but is that ALL compressors ?

[wambat]

Botrous: When your in superheat there is no PT relationship so head pressure cutout is not the answer you need to put a tenperature control with a senser about 6" from service valve to cutout the compressor and set it for about 250*F