keithholstead
26-11-2007, 03:45 AM
Dear Forum:
I just built and installed a small refrigeration (freezing) system for my boat. It is my first system. The evaporator is of holding plate type with 3.6 gals of eutectic glycol solution (30% Gly/H2O). I didn't have a charging scale so I went ahead and followd standard procedures and got the unit running at 184-185 PsiG Hi side pressure and average 40 PsiG low side with unit running. After the unit has been off for several hours and begins to come back on, it short cycles several time (two or three) and then smooths out and does fine. My water in to my condensor is 72 deg F and water out of it is 76 deg F. My TXV is set for 9 deg F. My box is well insulated but never seems to go below 30 degrees.
My questions are this:
What should my hi and lo side pressures be for ideal operation?
Do you think I need more refriogerant based on the short-cycling?
What would be a good differential on cut-in/cut-out pressures on the low pressure control?
Any help will be greatly appreciated.
I just built and installed a small refrigeration (freezing) system for my boat. It is my first system. The evaporator is of holding plate type with 3.6 gals of eutectic glycol solution (30% Gly/H2O). I didn't have a charging scale so I went ahead and followd standard procedures and got the unit running at 184-185 PsiG Hi side pressure and average 40 PsiG low side with unit running. After the unit has been off for several hours and begins to come back on, it short cycles several time (two or three) and then smooths out and does fine. My water in to my condensor is 72 deg F and water out of it is 76 deg F. My TXV is set for 9 deg F. My box is well insulated but never seems to go below 30 degrees.
My questions are this:
What should my hi and lo side pressures be for ideal operation?
Do you think I need more refriogerant based on the short-cycling?
What would be a good differential on cut-in/cut-out pressures on the low pressure control?
Any help will be greatly appreciated.