SL82
15-09-2009, 11:54 PM
Has anyone here done much work on Trentons Thermosaver units?
They are a two pipe hot gas defrost system that is apparently known for smashing compressors. I cant post the links because Im new to this site but if you google trenton thermosaver you will get an illistrated description of how it works in both refrig and defrost modes.
These units have massive slugging in defrost due to the fact that it uses the liquid line as a hot gas line and pushes all the liquid that is upstream of the liquid line solenoid (located in the evap) through the evap. If you have a long line set thats alot of liquid! We work on a few of these units at a number of locations and they're all going through compressors. What another mechanic at my company tried was eliminating the Liquid line solenoid at the evap and putting one in at the condensing unit upstream of the liquid line check valve. So now we pump out all the liquid in the line before sending the hot gas down.
But I found that by doing this we don't build up enough pressure in the evap to ever terminate on pressure, and the return gas at the compressor gets really warm. (90 + degrees)
With the system running the way it was designed the hot gas going to the evap is maybe superheated 2-3 degrees at most (this is due to the heat exchanger upstream desuperheating the discharge gas). So I think once we hit the cold evap we start condensing right away reducing the surface area of the evap and eventually pressures rise to termination.
With the new piping we pump all the liquid out and there is nothing in the
suction to exchange heat with the discharge gas before it is sent to the evap. Now we are sending gas that is superheated 80+ degrees down to the coil.
My question is are we just desuperheating the gas in the coil and not having a chance to condense. This would explain why the pressure wont rise. If we dont condense we dont reduce the surface area and pressures wont rise.
Does this sound right?
Any thoughts on this would be great.
Thanks
Steve
They are a two pipe hot gas defrost system that is apparently known for smashing compressors. I cant post the links because Im new to this site but if you google trenton thermosaver you will get an illistrated description of how it works in both refrig and defrost modes.
These units have massive slugging in defrost due to the fact that it uses the liquid line as a hot gas line and pushes all the liquid that is upstream of the liquid line solenoid (located in the evap) through the evap. If you have a long line set thats alot of liquid! We work on a few of these units at a number of locations and they're all going through compressors. What another mechanic at my company tried was eliminating the Liquid line solenoid at the evap and putting one in at the condensing unit upstream of the liquid line check valve. So now we pump out all the liquid in the line before sending the hot gas down.
But I found that by doing this we don't build up enough pressure in the evap to ever terminate on pressure, and the return gas at the compressor gets really warm. (90 + degrees)
With the system running the way it was designed the hot gas going to the evap is maybe superheated 2-3 degrees at most (this is due to the heat exchanger upstream desuperheating the discharge gas). So I think once we hit the cold evap we start condensing right away reducing the surface area of the evap and eventually pressures rise to termination.
With the new piping we pump all the liquid out and there is nothing in the
suction to exchange heat with the discharge gas before it is sent to the evap. Now we are sending gas that is superheated 80+ degrees down to the coil.
My question is are we just desuperheating the gas in the coil and not having a chance to condense. This would explain why the pressure wont rise. If we dont condense we dont reduce the surface area and pressures wont rise.
Does this sound right?
Any thoughts on this would be great.
Thanks
Steve