[b]Discharge Superheat[/b]

[joeywpittman]

Discharge Superheat is a subject i would like to know alot more about.

I know it is the Discharge temperature minus the condensing saturated temperature.

Example: Discharge temp. = 142*
Condensing Sat. temp. = 91*
so the discharge superheat would be = 51*.

i was told that you should only check it, when the machine is running at 80% LOAD or higher.

On a YORK YSDC the discharge superheat should be about 40*.
As you add more refrigerant to the unit the discharge superheat starts to drop.

That is about all i know on the subject. Someone please expand my knowledge? Thanks

 

[imok2]

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.