An Emerald 60,000 BTU duct type air conditioner was operating well since it was installed from about 3 years.
Actually, the compressor isn't starting up when powered through the backup diesel electric generator.. It's like the contactor is going on and off at a period of 0.5 sec.
Please note that the air conditioner is still operating well when powered through the 250 KVA transformer.
The Phase to Phase voltage of the generator is 380 V, while it's about 415 V on the transformer. (Which are both included in the rated operating range of the air conditioner).
I noticed a voltage drop to 312 V on start up when powered through the generator; this problem is actually not present when working on the transformer, nor previously even when the generator is in operation.
Can anyone help me resolve this problem please?