Compressor won't switch on, have tried reset switch and circuit breaker, but though the wall unit comes on the compressor wont..anything I can do? This has three phase power Mitsubishi..Mr Slim

Hi Morris

Am suspecting your electric or power supply.
I need you to try the following steps.
1. unplug all your units or appliances
2. Reset your circuit breaker
3. try to plug your tv only and turn it On, if its turn On, then your tv is Ok
4. You mention window unit, is this aircondition window type?
Now try to plug this window unit and turn it On, if electricity went out again, then the problem is in your circuit breaker.

It could be the specs or rating of your circuit breaker does not much with the rating of your window unit.

check the condensor fan in the compressor area and make sure its running if not the compressor will overheat causing high head pressures on the compressor causing it to draw too much current to operate the compressor and kick the breaker out,also make sure the condenser coils there are clean and it has ample air movement away from the wall

hello
maybe you have over current .compressor act over loud.
you wait was cooled compressor .than start again and check current and over loud and condenser fan.

As a general rule, what you are describing happens if the power is interrupted for a short time and the machine doesn't get a chance to do a reset before the power comes back. There is a good chance if you power the unit off then actually unplug it from the wall and leave it 20 minutes it should do a reset and be OK. REcognising this is a built in, I would hope there is an isolator switch somewhere nearby you can flick, but if not you will have to switch the breaker that feeds the kitchen in your breaker box.

Hi, here is the theory on the reset button on Air Conditioners. They reset via the breaker panel box in your house. Check that first before anything else. However if your unit is popping breakers, it is because the rating for the breaker is incorrect, or there is something that needs servicing usually in the outside unit called the condenser. That piece contains the compressor. A faulty compressor and pop the breaker. Or If the condenser fan that blows over the coils of the outside unit stops (common failure) The compressor will overheat and shut down. That may not trip the breaker but the house will get hot anyway. Usual action for this is to replace the condenser fan motor and starting capacitor. Make sure the speed rating and directional rotation for the replacement motor is the same as the motor removed.
There are other reasons why the system won't come one fully. If the wall thermostat is digital and does nothing. including turning on the fan. There will be a small fuse located on the circuit board of the air handler (part of Air Conditioner mounted inside the house. It houses the circulation fan). That fuse could be blown. That one shuts down just about everything.
On air handlers mounted up into the attic crawl space there is an overflow pan. This pan is mounted directly below the air handler. This pan can fill with water when the drain pain contained inside the air handler starts to overflow because the drain system to that is clogged.
There is a "float switch" mounted in the overflow pan wired to the system in such as way as to shut down the entire AC system if that pan fills.
The handling is to clear the obstruction in the Drip Pan inside the air handler. Then remove enough water from the overflow pan and the AC will run as though nothing has happened.
If you have more questions, write to me on this site.
One thing more. The capacitor alone in the Outside condenser unit can fail and that will stop the condenser completely if it is of a "split" design and used for both the compressor and fan. When replacing this unit alone, ALWAYS find the same specification part.
I hope this helps,
Have a Happy New Year,
Mark

pull the fuse/breaker disconnect panel outside by unit and main breaker inside,remove compressor access panel,re-power unit trace your thermostat wires to the terminals by compressor and short the two term together and see if unit starts,sounds as though you broke wire in more than one place.good luck be careful doing this,its 240 volts at most compressors on a central A/C

Hello,
If the breaker had tripped, you'd detect some looseness in the trip switch, even though it may not appear to be tripped. Once you have identified the correct breaker, trip it to OFF and then back to ON. Also check at the unit; it will either have a service disconnect, a fused disconnect or a circuit breaker at the wall. Compressor units have a thermal relay that causes them to shut down on high temperature. Let the unit cool down thoroughly. If this is the issue, and you are standing close enough, you may hear it reset when it cools. Usually, cool down occurs in 30 minutes or less. Try it again, but don't leave it unattended until it has made it through several cycles and you are confident that the unit is back to nornal. If any further issues develop from this incident, shut the unit down, trip the circuit breaker for the unit to off and call a serviceperson.
I hope this gets you going again!

Best regards, W/D

Three points to ck. !) make sure disposer is plugged in under ther the sink. 2) Make sure the circuit breaker at the breaker panel has not tripped. 3) Make sure disposal is off and make sure it is not jammed, 3) Press reset breaker located on bottom of unit (red button.) Then try wall switch again.

Check your wiring between the contactor and compressor for a short to ground, or check the compressor windings for short to ground.
With the Tstat off, the contactor should be open so the only way for the compressor to be trying to do anything is if the 110 volts from the unbroken side are traveling through the compressor to ground. Since 110v is not enough to run it, the overload is kicking it out, cooling off, and repeating the cycle. When you kick on the Tstat, the contactor is supplying voltage directly to ground without going through the resistence of the compressor windings and kicking the breaker.
Post back and let me know what you find.

If the compressor turns off and won?t come back on during a very hot day, the unit may have built up a high "head" pressure and the high-pressure limit switch may have tripped. This is usually located right inside the access panel on the compressor unit. Simply push the button to return it to operation. If your central air conditioner doesn't go on automatically: 1) Be sure the thermostat is set to "cool" and set below room temperature. 2) A central air conditioner should be on a dedicated 240-volt circuit; check the main electrical panel and any secondary circuit panels for a tripped breaker or blown fuse. If you find the problem here, reset the breaker or replace the fuse. 3) Make sure the furnace power switch is turned on and that the outdoor condenser's power switch, mounted on the outdoor unit, hasn't been shut off. Also be sure the 240-volt disconnect next to the compressor (in a metal box, usually mounted on the house wall) hasn't been shut off. 4) Turn off the power to the air conditioner and check the thermostat. 5) Remove the thermostat's cover and unscrew the wire from the Y terminal. 6) Turn the power back on. 7) Holding the wire by its insulation, touch the bare end to the R terminal and hold it there for about 2 minutes. If the compressor kicks on, the thermostat is faulty; replace it or call an air conditioning technician. If the compressor doesn't go on when you hold the two wires together, turn the power back off and call a service technician.