Automatic Transfer Switchgear (ATS)

Automatic Transfer Switchgear (ATS)

2.4kV, 4.16kV, 7.2kV, 12.47kV, 13.2kV, 13.8kV, 14.4kV, 15kV Medium Voltage Applications


APTView SCADA Control Panel HMI

Medium Voltage Automatic Transfer Switchgear APT-Power

The APT Automatic Transfer Switchgear (ATS) is a medium voltage product used to switch power from a normal source to an emergency source.

PDF IconAPT 5kV-15kV Medium Voltage Automatic Transfer Switchgear (MV ATS) Brochure

DOCX Icon APT 5kV-15kV Medium Voltage Automatic Transfer Switchgear (MV ATS) Specification Word Document

Open Transition


Automatic standby with (Open Transition) return operation:
o Time delayed control sensor detects if a utility outage has occurred.
o When timer expires, the generator set is automatically started and brought up to speed and voltage.
o Utility circuit breaker opens and generator circuit breaker closes (after adjustable time delay) so that generator supplies power to the site load.
o When a healthy utility is connected for a set time delay, the generator breaker opens and the utility breaker closes and Normal power is restored.

Closed Transition


Automatic standby with (Closed Transition) return operation:
o Time delayed control sensor detects if a utility outage has occurred.
o When timer expires, the generator set is automatically started and brought up to speed and voltage.
o Utility circuit breaker opens and generator circuit breaker closes (after adjustable time delay) so that generator supplies power to the site load.
o When a healthy utility is connected for a set time delay and the generator is synchronized with the utility,
the generator circuit breaker shall open within 100ms and Normal power is restored.

Soft Loading/Unloading


Automatic standby with (Soft loading/Unloading) operation:
o Time delayed control sensor detects if a utility outage has occurred.
o When timer expires, the generator set is automatically started and brought up to speed and voltage.
o At that time utility circuit breaker as well as 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.
o When a healthy utility is connected for a set time delay, the soft close transition of the load to the utility shall begin.
o The generator bus synchronizes with the utility source and when in synchronism, close the utility circuit breaker. At this time soft unloading of the generator set shall begin.
o When the genset loads are gradually reduced to the level of the unload trip setpoint the generator synchronizing breakers trip open and the gensets are put in the cooldown mode of operation.

Import/Export Control


This mode seeks to maintain constant utility contribution to a site load. This is accomplished by monitoring utility contribution and trimming generator set load levels up and down as site loads change. Import control means the generator set is contributing less than the total site load requirements and the utility supplies the difference. Export control means the generator set is contributing more than the total site load requirements and the utility is absorbing the difference.