For Large Motor and High Inductive Load Transfer Applications
Dual-operator automatic transfer switches allow inductive loads to be re-energized with normal inrush starting current after transfer. These inductive loads typically involve large 3-phase motors or transformers.
A time delay between the opening of the closed contacts and the closing of the open contacts allows large motor loads to demagnetize before transfer. This prevents the severe “bump” caused by switching a rotating motor (which momentarily acts as a generator) from one source to another source that is not in synchronism.
This transition time delay is approximately 400 milliseconds, but it may be increased through the switch’s controller.