Danfoss softstarter MCD500

[Keith1976]

Hi All;

Does anyone have experience using the above softstarter?

The marketing article said that it has learning capability to have smooth stop.

Keith

 

[Marke]

The important issue is the torque being produced by the motor. If the flow is high but the torque is low, then the result will be very different from the case where the flow is the same, but the torque is high. This can happen due to external hydraulic effects.
The soft starter only controls the voltage applied to the motor and by so doing, it causes the motor to stall. Open loop voltage controllers are very dependent on the motor curves. Closed loop soft stop systems are commonly torque based rather than voltage based and provide more consistant speed curves on stop.
If the starter is performing correctly, and the conditions are exactly the same, the soft stop performance should be the same.

Best regards,
Mark.

Mark Empson
L M Photonics Ltd

 

[Keith1976]

Marke;

Can I replace "similar external hydraulic effects" with "similar suction & discharge pressure"?

Keith

 

[Shozza]

Keith,

Just as a side note and something for you to consider in the design of the retrofit, to use the AAC learning functionality you will need to ensure you install the soft starters in the in-line (3-wire) configuration as the AAC function is disabled in the inside delta (6-wire) configuration.

 

[Keith1976]

Thanks SHozza