Been having the 120V 6amp control fuse blow on a Trane CGAFC304 Cold Generator with the twin scroll compressors. With the neutral grounded on the 480-120 transformer as per the print it runs for a while then trips. Take the neutral ground off and runs non stop.
After some run time, the neutral becomes 120-165V to ground and the hot becomes 7-49V to ground.
After replacing most of the corroded stakons, and rulling out the transformer, LP & HP controls, most of the wiring, even the LLSV coil, the compressor and condenser fan contactors, the only thing left in the circuit is the compressor temperature sensors and the board/relays.
Cannot find any useful information on the temp sensors. Are the sensors a Klixon type, RTD or embedded in the windings? Senors do not ohm out grounded nor do the compressors. Engineered bypass on both temperature sensors allows compressors to run non stop. Available Trane literature gives no information on the compressor temperature sensors. Replace the compressors for this reason only? Is there a remedy?