With minimal disruption to chiller drives and other loads. Effective transfer solutions are needed to minimize large inrush current and associated torque damage created when a motor, which becomes a generator at the moment of transfer, connects with a live source that is out of phase with the disconnected source.
Two to three cycle hot to hot transfer times in conjunction with in phase transfer are needed to minimize large inrush current and associated torque damage created when the motor is reconnected at the completion of load transfer.
ASCO’s single solenoid mechanism provides the speed and consistency to assure in phase transition. Two transfer solutions—in- phase transfer and closed transition transfer— both require fast and consistent transfer times. ASCO’s uniquely designed solenoid operator delivers the required and repeatable transfer speed time after time. They transfer potentially problematic motor loads reliably, and are the least disruptive power transfer solutions. In-phase transfer monitors the phases of both the normal and emergency power sources. It transfers the motor when the two are approaching zero phase angle. No more than normal inrush current ever occurs. For the most demanding business-critical applications, closed transition transfer is the ultimate solution. It momentarily parallels the two live synchronized sources during hot-to-hot source transfers, using an overlapping transfer technique on all switching poles which eliminates momentary load interruptions.
Closed transition transfer is the only way to mitigate transformer magnetizing inrush current on transfer. It is a passive transfer method that allows transfer only when the two sources are synchronized and within specific voltage and frequency differentials.
Soft load, closed transition transfer also is available when block loading of the generator is a factor to actively control the engine generator and gradually ramp the load from one source to another. The result: no load interruption, no inrush current, thus, no risk to sensitive equipment.
ASCO introduced the first in-phase monitor on transfer switches and the first closed-transition transfer switch.