Hey guys
Im having trouble setting the parameters on my VFD for this 3 phase compressor.
It’s a Mitsubishi compressor and I’m using a Dura pulse GS20 VFD.

Here’s a photo of the compressor name plate

 

I was able to get the compressor to come on but it sounds really rough. Maybe I need to install a reactor?

 

That appears to be a PM rotor 3ph motor, the VFD has to be specially programmed and/or Manuf customized.
VFD's are intended for induction motors.

 

IN BIG LETTERS the label states "Use ONLY with DC inverter". while the exact interpretation is unclear, it certainly means some specific type of inverter. And as it is, I Guess, a PM rotor motor, NOT an induction motor, but a synchronous motor. certainly it must be driven by the correct type of inverter. THAT MUCH IS STATED on the label!! My guess is that you are using a driver made for induction motors.

 

check 4-263 of the manual. Supplier may have a default file for a typical application. We would stack up to 3, 350 hp pm motors for top drives.

 

"Use ONLY with DC inverter" usually is intended to mean a drive aimed at modern PM rotor 3ph motors .
The attempts I have made to run this type of motor on a induction motor VFD has been very much less than stellar !

 

IN BIG LETTERS the label states "Use ONLY with DC inverter". while the exact interpretation is unclear, it certainly means some specific type of inverter. And as it is, I Guess, a PM rotor motor, NOT an induction motor, but a synchronous motor. certainly it must be driven by the correct type of inverter. THAT MUCH IS STATED on the label!! My guess is that you are using a driver made for induction motors.

I think you’re right and that’s my mistake.
so basically I need a DC inverter.
I did some research on this and from my understanding PM motors are much more complex to drive than induction motors.
That being said, if I don’t have the exact specs of the motor inside the compressor, I’m not able to derive the necessary input parameters for a DC inverter?

 

"Use ONLY with DC inverter" usually is intended to mean a drive aimed at modern PM rotor 3ph motors .
The attempts I have made to run this type of motor on a induction motor VFD has been very much less than stellar !

Thank you for the correction.
I honestly didn't know the difference between a DC inverter and VFD.
So I need a DC inverter instead.
Is it necessary to know, for example, the number of poles, resistance, and other specifications of the motor?
Based on my readings, it's not just going to be a plug and play.

 

Knowing the type of commutation is usually necessary, for a start!

 

Knowing the type of commutation is usually necessary, for a start!

Yes definitely.
Are DC inverters more specific to the motor its driving compared to a VFD and induction motor?
If so, can you explain in what ways?

I'm trying to figure out if there's a "driver" that I can use on this compressor as well as other sized compressors.

 

There are basically two types of PM rotor motor, one is just 3 phase driven, the other is BLDC (Brushless DC ) the latter requires some kind of commutation such as sensors, or an initial exercise of the motor rotor to detect its position relative to the stator .
The BLDC only energizes two of the 3 phases at a time.
So yes in most cases the driver is dependent on the motor construction.

 

There are basically two types of PM rotor motor, one is just 3 phase driven, the other is BLDC (Brushless DC ) the latter requires some kind of commutation such as sensors, or an initial exercise of the motor rotor to detect its position relative to the stator .
The BLDC only energizes two of the 3 phases at a time.
So yes in most cases the driver is dependent on the motor construction.

Very interesting.
So without the specifications of the actual BLDC motor, I would most likely not be able to drive it properly?
You do mention an "initial expertise". What type of equipment would I need to test such a thing?

 

There are basically two types of PM rotor motor, one is just 3 phase driven, the other is BLDC (Brushless DC ) the latter requires some kind of commutation such as sensors, or an initial exercise of the motor rotor to detect its position relative to the stator .
The BLDC only energizes two of the 3 phases at a time.
So yes in most cases the driver is dependent on the motor construction.

Maybe something like this would work?
https://www.power-motor.com/?BrushlessMotorControllers/UniversalMotorController.html

Based on what I'm reading online, a Hall sensor may be what we're looking for?

 

There is typically 3 hall sensors in a BLDC motor, they are spaced according to the pole count of the motor.
This would usually mean that the motor would have 6 leads, 3 for power & 3 for commutation.

 

There is typically 3 hall sensors in a BLDC motor, they are spaced according to the pole count of the motor.
This would usually mean that the motor would have 6 leads, 3 for power & 3 for commutation.

Every compressor I’ve ever worked on has had 3 leads. I have seen smaller BCLD fan motors that have 3 for power and 3-5 for commutation/data.

 

Given that this is a sealed unit refrigeration compressor, it is not likely that it has internal sensors for commutation. So that limits the possible driver connection scheme a lot. And as the voltage range and wattage are also given, finding a suitable driver will be a price driven task.

 

Even if the motor were designed for one set RPM, sensor commutation could be used, a BLDC motor requires some kind or another, in the absence of physical sensors, the armature is generally exercised briefly initially and the relationship to the rotor is sensed,
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