Hi, folks!

I have a question. I am developing an inverter board to run a little 5000 BTU air conditioning compressor. (out of a window A/C unit) My only problem is since it is all encapsulated, I don't know what type of motor it is. It has a cap, and that's about all I know. Would it be safe to expect that it would be a split type? I don't think it would be a variable reluctance or any switched type because I don't hear any switches or anything like that. Plus the torque req is too high. Any tests I can do to verify?

In addition, I am trying to develop an ac drive for this motor, and was thinking of doing a multiple level modified sine. That would be better than pwm, right? Anyway I seem to know enough to get into trouble. Any advice would be appreciated.

 

What is wrong with your electricity for you to use an inverter?
A battery must be huge to power an air conditioner for long.
Why not fix the intermittent electricity instead?

 

The compressor motor is an AC capacitor run type. You can't use PWM with AC motors.

 

What is wrong with your electricity for you to use an inverter?
A battery must be huge to power an air conditioner for long.
Why not fix the intermittent electricity instead?

It is a mobile application, and batteries are involved. It's one of those situations where to save money and time, I dived into something that is taking MORE money and time. But it is an approx 4.5 A @ 117 vac air conditioner, but I am only using the compressor and coils, not the fan or other stuff.

Thanks for your response.

 

The compressor motor is an AC capacitor run type. You can't use PWM with AC motors.

So you think it's a PSC type? Is there a way I can ohm it out and verify it?

Thanks for your help.

 

If there is an ID plate on the compressor, then you should be able to search on the manufacturer and get good information.

 

If there is an ID plate on the compressor, then you should be able to search on the manufacturer and get good information.

I just found it. It was hidden before, and of course you're correct.

Thanks.