15A-AT 2.4kV-15kV Metal-Clad Automatic Transfer Switchgear (ATS)

   Soft Loading/Unloading

Automatic standby with (Soft loading/Unloading) operation:

• Time delayed control sensor detects if a utility outage has occurred.
• When the timer expires, the generator set is automatically started and brought up to speed and voltage.
• At that time, the utility circuit breaker and the designated feeder breakers shall open, and generator circuit breakers shall close (after adjustable time delay). The synchronizing circuit breaker of the first available generator closes to a dead bus. At this time, the generator is supplying power to the site load.
• When a healthy utility is connected for a set time delay, the soft close transition of the load to the utility shall begin.
• The generator bus synchronizes with the utility source. Close the utility circuit breaker once they’re in sync. At this time, soft unloading of the generator set shall begin.
• When the genset loads are gradually reduced to the level of the unload trip, setpoint the generator synchronizing breakers trip open. The gensets are then put in the cooldown mode of operation.