DRASH Unit AC issue

[Daltondbl]

Maybe this is in the right location but anyway.

I have a 2008 DRASH unit, generator works perfectly but my issue lies with AC unit itself. Specifically getting the AC compressor to start and pump. If the soft starter starts the compressor, you can hear it run but it will not pump the refrigerant (verified by gauges).

However, I can manually press the contactor in on the soft starter with a screw driver and the compressor will start and pump.

anyone had this issue? I’m leaning towards a bad soft starter but not sure if something else would be tripping the thermal overload on the compressor. The soft starter itself is not tripping or throwing a fault code. Picture is of the soft starter I’m dealing with. Timers seem to be working as they should as it does delay when the call for cooling is on before it tries to start.

 

[Guyfang]

I think there is a schematic on one of the doors. What gives the contactor the impulse to close the contactor?

 

[Daltondbl]

I think there is a schematic on one of the doors. What gives the contactor the impulse to close the contactor?

I have the schematic for it, the 24v runs through all the pressure switches and given all you those safeties are closed, the 24v goes to a relay and then into the contactor. The starter pulls in like it’s supposed to and stays pulled in but the compressor is tripping out on something. Unless I just hold the contactor in, it runs fine. I’ve even tried doing the 100% initial torque and 0sec ramp time to simulate just mashing the contactor in and it won’t start it and pump. The compressor runs but won’t pump. Never heard of that but there is a sticker on the compressor that says it will do that if tripped on thermal overload. System is not overcharged either

 

[Guyfang]

And you have tried to jump all the pressure switch? I would jump the whole pressure/safety circuit and see if it kicks in. If it kicks in, then you at least know where to start. One switch at a time.

 

[Daltondbl]

And you have tried to jump all the pressure switch? I would jump the whole pressure/safety circuit and see if it kicks in. If it kicks in, then you at least know where to start. One switch at a time.

Yes, on these, in order for the soft starter to actually engage with the 24v. The 24v has to flow through all of the safeties in order for it to pull in and I have traced where the 24v comes out of the last switch and I have 24v which then runs into a timer and a relay which then tells the soft starter to pull in and start the compressor.

However the soft starter pulls in like it should but the compressor unloads and wont pump. Only unloads when the soft starter starts the compressor. Manually started by just pushing the contactor in at the soft starter with a screwdriver, compressor starts, pump and cools like it should, condenser fan follows in correctly etc. it’s just getting the soft starter to start the compressor. I just don’t know if there’s something else I’m missing that’s causing the compressor to unload. I don’t know is somethings up with the lower half of the soft starter and somethings not closing or what’s up with it.

 

[Guyfang]

Is the contactor getting any voltage at X1/X2, (The coil on the contactor?)