Soft starters on marginally rated Gensets.

[marke]

Hi

 

Gensets are frequently used to power pumps stations which may have only one or two pumps. The genset is minimised in size for obvious commercial reasons and in some cases things work very well, but in others there are major problems.

 

The action of the phase control of the SCRs to reduce the voltage during start, creates a distortion and phase modulation of the generator output waveform This can interact with the operation of the soft starter algorithms and result incurrent instabiltiy and excess current draw, often shutting the genset down.

This is very soft starter dependent and also can be dependent on the setup of the start parameters of the soft starter.

 

I am interested in developing a knowledge base to come up with better guidelines as to what is a good set up and what is bad.

Sizing of the genset is not a major issue, see http://www.LMPhotonics.com/genset.htm, but the selection and/or set up of the soft starters is also critical.

 

Any experiences to record?

 

Best regards,

[marke]

I will kick this off with some of my experiences:

 

AuCom EMS series soft starters work very well, no set up issues.

 

AuCom IMS2 series work well provided that the frequency does not drop more than a couple of Hz (engine must be sized correctly)

 

Fairford QFE soft starters work OK provided that the start voltage is set above 50%.

 

Emotron MSF soft starters work well in TVR mode. There can be some hunting in torque control mode.

 

Any additions?

Best regards,