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Thread: Evaporator pump down.
28-04-2012, 08:26 AM #1
Evaporator pump down.
So I'm a second year apprentice, and today I'm working on a 90 ton trane Intellapack. Someone found a leak on the condenser. Boss man told me to pump the refrigerant into the evap. So i wouldnt have to recover any 22 and make the repair. Is there a way? Because I couldn't figure it out, without it going in a vacuum or off on high head and ending up with a pumped down condenser. What I did was close the discharge of the comp and liquid line valve. And just recovered what was in the condenser. Made my repair, pressure tested, pulled a vacuum and recycled the refrigerant back into the system. Let me know if there's a better or faster way to do something like that for the future please..... Thanx.
28-04-2012, 09:20 AM #2
Re: Evaporator pump down.
I can't think of a way unless it was a reverse cycle system but even then it's not that straight forward.
Not familiar with your system but if it was a normal heat pump (to me that means like a bog standard split with EEV outdoors) you'd have to get the indoors in heating, find a suction port (not a port on the pipes to the indoors as they will now be discharge and liquid return to the outdoor unit). Close the liquid pipe first (smaller pipe), wait for the suction pressure to pump down then close the gas pipe. One in this state you would need to ensure the reversing valve stays energised to keep the system in heat pump mode.
Even then I doubt you would have the correct access ports in place and means to fiddle to 4 way valve. Could use a magnet I suppose.
Personally I'd have gone your route or recovered the whole lot and pressure tested the complete system.
My old boss told me it is possible to have a high head pressure if a system was short of charge once. Never did work that one out either!
Edit: Just to make the bit about keeping the unit in Heat Pump mode, this is because you have discharge pressure from compressor outlet, through 4WV to larger pipe at service ports. If you were to put the unit into cooling mode thne this line is then diverted to the outdoor coil. Thinking further this would need recovering as after pressure testing a vac pump might not get this bit out due to valve/reeds in compressor not letting vapour by to the suction pipe.
Double edit: Just checked your model and found it's a packaged unit, probably bearing little resemblence to what I've been rambling on about. Hey Ho!
Last edited by Tayters; 28-04-2012 at 10:57 PM. Reason: Speling, then thinking too much,Health and safety first..........unless I'm in a hurry.
28-04-2012, 10:16 PM #3
Re: Evaporator pump down.
hi mad ..
if the size of the evaporator contains the entire charge of refrigerant, the best solution and have a recovery outside and pump the refrigerant charge in the evaporator previously isolated by closing valves.