technical 230v fridge question

[GUMPY]

I have two "identical" LEC L5010W fridges, they however have different compressors, one has a start capacitor the other doesn't. Which one will have the lowest start up surge?

[bigste]

A capacitor stores the power in order to release a needed surge so that one ought to require less surge from the mains socket. That's the theory anyway.

[smileypete]

I have two "identical" LEC L5010W fridges, they however have different compressors, one has a start capacitor the other doesn't. Which one will have the lowest start up surge?

 

The one with the smaller compressor

 

Seriously though, I'd do it by measuring the compressor LRA (locked rotor amps). Wait til the fridge runs for 5 mins, switch off for a few seconds then back on for a few seconds.

 

When switched back on the compressor will likely stall and the LRA can be read with something like a clamp ammeter or plug in meter, see which fridge gives the smallest reading.

 

cheers, Pete.

~smpt~

[Batavia]

A capacitor stores the power in order to release a needed surge so that one ought to require less surge from the mains socket. That's the theory anyway.

Er no.

 

The purpose of the capacitor is to introduce a phase shift between the main and auxiliary winding currents in order to produce a rotating magnetic field in the motor. The pulsating field from a single phase winding at zero speed can be resolved into two equal contra-rotating magnetic fields, which produce equal and opposite torques on the rotor and hence no movement Once the rotor starts moving in one direction, the torque in that direction will exceed the opposing torque and the motor will want to run in that direction.

 

The purpose of the start (and run, if fitted) capacitor(s) is to increase the rotating magnetic field in the desired direction, so that the motor will self start.

 

Back to the original question ---- I think that there are too many factors involved in the design of the motors to give a proper answer to Julian's question - so the only option is to do some tests.

 

Chris G

[smileypete]

Soooo,

 

Which one is the winner?

 

cheers, Pete.

~smpt~

[GUMPY]

No tests yet away boating