CTTS enables power supply switching without power outage
Includes Asco contact technology, synchronous switching function, etc.


Schneider Electric launched its Closed Transition Transfer Switches (CTTS) using a double throw power contactor method on the 2nd.

CTTS is a device that allows users to receive electricity without experiencing a power outage when the power supplied by KEPCO is cut off for a specific reason and power is supplied from an emergency power source. It is based on the principle that KEPCO and an emergency generator supply electricity at the same time and momentarily just before a power outage occurs, filling the gap.

The 5000A CTTS from Schneider Electric subsidiary Asco can instantly switch from one switch to another when a load is applied between two power sources. It is also arc-resistant, making it suitable for facilities handling critical loads.

The 5000A CTTS is manufactured with the same frame as the existing UL certified product in accordance with the international standard (IEC), and Asco's ▲contact technology ▲synchronous transfer function ▲fault current support function ▲N-phase overlapping transfer function, etc. are applied as is. In addition, it has obtained China Compulsory Certification (CCC).

The drive unit uses a solenoid mechanism for accurate and fast switching, and uses a special alloy main contact made of silver composite to increase thermal conductivity.

The spring device is separately configured to withstand vibrations during switching, so arcing rarely occurs and cracks do not form in the contacts even after long-term use.

The synchronous switching function is a synchronous switching function (within 15 degrees of phase angle) that considers the phase angle of the load side and each power source, and is provided as standard in all Asco switches.

If there is a motor or rotating machine on the load side, it prevents accidents caused by overcurrent when switching from generation to KEPCO power, and with the fault current support function (Withstand Current Rating; WCR) that can withstand more than 30 cycles, it can ensure safety even against fault currents such as surges or short circuits.

Meanwhile, Asco is a company that has acquired all four certification marks including IEC, US safety standard certification (UL), European integrated certification (CE), and Dutch electrical safety certification (KEMA), and was merged into Schneider Electric in November 2017.