About Inverter Compressor: Starting Current

In summary: I think it's a bit of both. The compressor may need full torque at "zero" speed, or it may fail to start.
  • #1
Anand Sivaram
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If we would like to go completely off-grid with a Solar inverter:

Normal refrigerators use induction motors for compressors and these induction motors do require around 5x starting current. So, if we use a refrigerator with rated power of 200W, we would require an inverter/power supply rating of minimum 1000W. Otherwise there is chance that the inverter/power supply could trip.

What about refrigerators using modern Inverter Compressors? What type of starting current do they take? What type of motors these Variable Frequency Drive based Inverter Compressors use - Induction or Synchronous AC motors?
 
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  • #2
At a guess you'd think inverter based drive would have softstart functionality, ie lower inrush, as far as machine types go, I'd bet that its still using the very cheap to make induction machine.
 
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  • #3
I am pretty sure that the fridge compressors are piston style, that is part of the issue, the compressor may need full torque at "zero" speed, or it may fail to start. An inverter based fridge MAY help, but all of the energy in this start then needs to be in the DC link - I doubt it was built to do this due to the cost.

Best bet is to ask the manufacturer for a start profile. If you explain your situation properly, and they are a customer focused company they should, eventually, get you the answer.
 
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  • #4
Windadct said:
I am pretty sure that the fridge compressors are piston style, that is part of the issue, the compressor may need full torque at "zero" speed, or it may fail to start. An inverter based fridge MAY help, but all of the energy in this start then needs to be in the DC link

It used to be a standard AC induction motor based on/off compressors, but nowadays many of the 5-star energy efficient refrigerators and ACs are using Inverter VFD compressors.
 
  • #5
Yes - but the starting torque, may still need a large amount of current - ran into this problem in residential AC, it can be done but it is difficult AKA expensive. The starting process, I believe was patented ( in that case).
 

Related to About Inverter Compressor: Starting Current

1. What is an inverter compressor?

An inverter compressor is a type of compressor commonly used in refrigerators and air conditioners. It uses a variable speed drive to control the speed of the compressor motor, allowing it to adjust its cooling capacity according to the demand.

2. What is the purpose of the inverter compressor's starting current?

The starting current of an inverter compressor is used to power up the motor and start the compressor. This current is higher than the normal operating current and is necessary to overcome the initial resistance and inertia of the motor.

3. How does the inverter compressor's starting current affect energy efficiency?

The starting current of an inverter compressor is only used for a short period of time during startup. Once the compressor is running, it operates at a lower and more efficient speed, resulting in overall energy savings compared to traditional compressors.

4. What are the benefits of using an inverter compressor?

Inverter compressors offer several benefits, including improved energy efficiency, quieter operation, and longer lifespan due to reduced wear and tear on the motor. They also provide more precise temperature control, resulting in better food preservation and comfort in air conditioning.

5. Are there any drawbacks to using an inverter compressor?

One potential drawback of inverter compressors is their higher initial cost compared to traditional compressors. However, the energy savings and longer lifespan can offset this cost over time. Additionally, inverter compressors may require more maintenance and specialized repairs, but this can vary depending on the specific model and brand.

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