I have posted this over in the professional section, but I think that perhaps someone here may know of a remedy. Thanks
The oil pressure reset on a chiller is giving me some trouble, and I am trying to figure out what is going on here. This is a Trane model is CGACD121RANLL623GW.
I took the oil pressure at 115, the suction at 60 and the head at 225. If I am figuring right, this gives me 55 psi on the oil pressure. The switch appears to be made at all times, but for some reason the reset is kicking. Now, when I place a jumper on the P1 and P2 terminals after initial startup, the chiller runs fine. When I remove it, the chiller is off in about 30 seconds to a minute.
One thing that I have noticed on this particular switch is that the signal is going out and coming back at 17 volts. The common on the controller is 17 volts as well. the other switch has about 22 volts going to the common and around 19 available at the P1 and P2 terminals. I am wondering if perhaps the signal is weak and that is causing the reset to kick, but if the signal is weak it would be weak with the jumper too.
I guess perhaps the controller could be going bad, but this still doesn't tell me why the unit runs fine with the jumper on the P1 and P2 terminals.
Anyway, I hope you guys have some history with these old controllers. I think this unit is about 19 years old.
Thanks in advance.