Sanyo Air Conditioners 36,000 BTU - Not Restarting

Contact the vendor for advice.

I vote for the delay timer. Most self-contained A/C units now employ a hermetically sealed cooling circuit and use a capillary tube instead of a metering valve. After the unit has shut down it should not be restarted until pressure on the high side (the condenser side) of the circuit drops enough to allow the compressor motor to start without stalling. This can take several minutes.

A motor stall in a hermetic unit can cause severe (and expensive) damage to the compressor. That start-delay timer may have saved you a big-ticket service call.

I also agree with power-on delay timer.

I have experienced this after a power loss.

Delay on mine is approximately 7-8 minutes if the unit was running when the power went off.

One would anticipate such units being on their own breakers that is also detached from the servers?

The Air-conditioning Unit working and power goes, it will not start immediately and there will be a delay time set to restart due to the following reasons:

1. Once Electrical Power Utility power goes. Sometimes, Utility power comes and goes immediately till it stabilizes. It takes some time. That may affect the compressor winding. So to stabilize Electrical Power & to re-start AC unit compressor motor, the manufacturer keeps the delay Time around 5minutes.

2. Once power is witched on and compressor motor develops the full torque high enough to push the piston in compressor to develop high pressure at high pressure section of Air-condition Refrigeration cycle. If power goes or failure, motor will stop. After a few seconds power comes back, Motor will not start due to low starting torque of the compressor motor against high pressure of high pressure section of the Air-condition Refrigeration cycle or as if compressor motor rotor were locked. Then motor would be in the state of Locked rotor condition and motor would draw 6 times the full load current till motor would develop its full torque. Prolong locked rotor current may burn or affect the motor winding.

Owing to this, manufacturer keeps the delay time to re-start once power goes. During this delay time (5minutes) High Pressure in the High pressure section of the refrigeration cycle become very low pressure at that time, motor re-stars with its starting torque that will be sufficient to rotate the compressor motor shaft and pushes the pistons without going into Locked Rotor Current State that makes the motor winding not being subjected to high current and winding life will be long.

Time delay to restart will be provided for Air-conditioning Unit having BTU/hr around 36,000(3Ton) or above. But delay time will not be provided to window AC Unit of 18,000Btu/hr (1.5Ton) or less.