Operating 60 cycle scroll compressor with 50 cycle 3 phase current

[megavac]

Need info whether is it safe to connect 50 cycle power supply and run a 60 cycle scroll compressor? The compressor has no indication whether it can be operated with 50 cycle current.

Appreciate for response. Thank you.

[ernestlin]

Hi, megavac. If I remember correctly, there is no problem that 60 cycle compressor run with 50 cycle current, and it'll reduce original capacity to 5/6.

[Caesar]

On the Mechanica perspective, this will affect the rpm of any rotating machines that is connected to an electrical motor. However, on the reversed condition, eventually, this will burn down the drive motor with 50 Hz rating and connected to 60 Hz.

caesar

[coolments]

Just replaced a Maneurop SZ300A4ABA performance schroll Compressor on R407c. this was rated at 60hz (cylcles) but works fine on UK 3ph 415v 50Hz.

I asked if i could fit an inverter to this and have been informed unaficially it will run as low as 35hz.

[Samarjit Sen]

There is no problem if 60 Hz is run on 50 Hz. Only difference will be that due to reduced rpm, the capacity of the compressor would be lowered slightly.

[Electrocoolman]

Hi Megavac,
The important point to check is the VOLTAGE rating of the compressor windings.

The frequency affects the speed of rotation which will as previously stated affect the refrigeration capacity. To obtain refrigeration capacity at 60Hz multiply 50Hz value by 1.2 . To go from 60 to 50 multiply by 0.83333

Following info from Unite Hermetic (Techumseh) relating to their dual frequency rated reciprocating compressors:

.....Rated............Approved
A) 100-1-50.........90/110-1-50
....115-1-60........103/127-1-60

C) 208-1-50....... 187/230-1-50
....230-1-60....... 207/253-1-60

J) 380-3-50........ 340/440-3-50
...440-3-60......... 396/484-3-60

K) 220-3-50 ........180/253-3-50
....220-3-60........ 187/264-3-60

As you can see, when you run on 50Hz as opposed to 60Hz, the voltage range that you can use is reduced.
This is because the reduced motor speed results in a reduced 'back emf' from the motor, and so inorder to keep motor current within limits, you need to reduce the line supply voltage.

Have you contacted the compressor manufacturer to see what they advise?

ECM.