Liebert ?

[shavedbygrace]

Hello all,
I have inherited a Liebert system ( challenger 3000 ) w/ side discharge remote condenser. The problem we have is that any time there is a power disruption the system will not cool until we add enough charge to get it out of bypass. the only thing is that I do not see the optional bypass controls in the cond. unit. Any suggestions as to what the issue could be? It boggels me that the unit operates with no issues until the aforementioned outages.

[blewbyu2]

Not much info to go on, model serial number. I'm assuming your talking about the hot gas bypass won't shut down after a power interuption. You could shut off the line voltage, unhook the hot gas solinoid, put your volt meter on those control wires and see at what pressure the control is energized. Defective solinoid or valve or circuit board, could be a number of causes. If you do have any more info I think I may have some manuals in my van.

[blewbyu2]

Forgot to say that the HG bypass solinoid should energize on startup and only deenergize during pumpdown.

[Airmechanical]

sounds like you inherited someones problem, which means you cant eliminate any problem, you may have a freon leak,

get the charge correct first, then simulate a power interuption, if it goes right back into fault condition,

then you know its not a low charge issue, you need to understand the sequence of operation,

get the leibert manual for that specific sytem, all of the good leibert techs out there have all the manuals,

they are full of quality information about wiring, control, and sequence of operation!

remember a leibert is just a glorified hvac system (with all the bells and whistles)



.

[madhat]

Liebert had some issues with that very unit/set-up with head pressure on Scroll compressors. The cure was to put an expansion chamber in the discharge line. Also check for a R2 relay, shouldn't be one on an air cooled Condenser. There were units shipped out of the factory, with the relay on the wrong units. The units wiring diagram should tell you whether it is needed or not. If you are supposed to have the R2 relay there is a little slot in it. Push it in with a thin insulated screw driver, if the compressor starts, replace relay.