inverter refrigerators

[fynn...@yahoo.com]

l have come across quite a number of refrigerators that has inverter for its compressor motor these days. The problem is these compressors will not work when connected to 50 or 60HZ mains. Please can someone give me an explanation on how these circuits work, how to test both circuit and compressor?
Thanks

[Phil Allison]

** So called "inverter compressors" employ BLDC motors in place of induction motors. This allows for variable speed and less heat loss in the motor.

Such motors are normally 3-phase with a rotating magnet providing the output torque. The drive circuits are quite complex and use high voltage MOSFETS
or IGBTs.

Search using " inverter compressor BLDC motor" and you will get more info.


.... Phil

[fynn...@yahoo.com]

On Sunday, 19 March 2017 00:21:59 UTC, fynn...@yahoo.com wrote:
> l have come across quite a number of refrigerators that has inverter for its compressor motor these days. The problem is these compressors will not work when connected to 50 or 60HZ mains. Please can someone give me an explanation on how these circuits work, how to test both circuit and compressor?
> Thanks

Thanks so much Phil so it means they are DC motors? or they use pulsating DC. What is the typical voltage

[jurb...@gmail.com]

>"Thanks so much Phil so it means they are DC motors? or they use pulsating DC. What is the typical voltage "

He said three phase. That means that while you might feed it DC, the board generates a three phase output to drive the coils, making brushes unnecessary. It also might be a VFD (variable frequency).

There is no typical voltage, though many just use rectified mains power to save money.

Bottom line is it needs the board to run. It is not an inverter.

[Phil Allison]

fynn...@yahoo.com wrote:

> >
> Thanks so much Phil so it means they are DC motors? or they use
> pulsating DC. What is the typical voltage
>
>

** BLDC motors are nowadays *everywhere* - time for you to catch up and do some Googling. The name is misleading, cos they are really multi-phase, synchronous, AC, permanent magnet motors.

No brushes, but an electronic drive circuit that replaces the rotating commutator used in a regular DC motor and where the rotating part is a magnet.

Electric vehicles, washing machines, small fans and RC hobby motors all use the same idea.


.... Phil

[Jon Elson]

The problem is the motors have no provision for starting, that is supplied
by the motor drive circuit that gradually increases applied voltage and
frequency as the motor picks up speed.

If the windings are not shorted to the housing, the motor is most likely
good. (Can't test the compressor as a whole so simply.)
The drive circuits are VERY complex, probably using IGBTs and a logic
circuit to drive them, which likely has a microprocessor in it.
I'm not sure we can really tell you how to test the drive circuit on such a
forum as this. And, be aware there are dangerous voltages in such circuits.

Jon

[fynn...@yahoo.com]

On Sunday, 19 March 2017 00:21:59 UTC, fynn...@yahoo.com wrote:

> l have come across quite a number of refrigerators that has inverter for its compressor motor these days. The problem is these compressors will not work when connected to 50 or 60HZ mains. Please can someone give me an explanation on how these circuits work, how to test both circuit and compressor?
> Thanks

Thanks everyone for your support and concern. This is what makes me love this group and electronics in general, people are always ready to help.