Change-over in gensets
The change-over switch is equipped with three stable positions (I-O-II) and is independent of external supply. In operations there is no risk of an unexpected opening of the switch due to loss of supply voltage and no supply voltage is necessary to keep the switch in the closed position. The change-over switch carries out the switching and the reliable isolation between the primary network supply and the alternate supply, thus ensuring the continuity of performance.
The modular change-over switches OT16...125 are tested for high mechanical endurance for frequent use according to IEC 60947-3 and IEC 60947-6.
Busbar coupler in distribution systems
The connection of supplies to busbar systems or the connection of the busbars to earth, ensuring safe power off, is secured in the change-over switch by the inbuilt mechanical interlocking and position change via the OFF-position. They prevent that parallel connection of two supplies could not occur, even in case of transient voltages.
Transfer switch in ATSE
In Automatic Transfer Switching Equipments the energy power is automatically transferred to one or more load circuits from one supply to another by a logic system controlling the OEM transfer switch. The switches are mechanically interlocked to prevent simultaneous connection to both normal and alternative supplies and the operator independent quick make/quick break mechanism ensures distinct opening and closing of the contacts.
The OETL/OEM 200...1600 range is endurance tested as transfer switch according to IEC 60947-6 categories AC-31 and AC-33, both for frequent and infrequent use, and is independent of which logic system is used for the automatic control.
The global solution
This range is covering manual change-over functions from primary supply to back-up supply in equipment specially designed for the UL market, but also used on the IEC market.
The OT sizes are UL 508 Listed up to 80 Amp and the OETL-NFC range is UL 1008 Recognized for resistive load up to 1200 Amp and for total load up to 630 Amp.
The corresponding IEC ratings are 125 Amp for the OT range and 1600 Amp for the OETL-NFC range.
Maintenance bypass for UPS
The OESC 250…500 range is a "make before break" or Closed Transition Transfer Switch type that guarantees a transfer from the static switch to the power line as manual bypass switch and back again without any interruption. This ensures equipment is powered, even when maintenance work is carried out.
The OESC switches have double rated neutral to withstand the thermal overload from the harmonics, normally produced by the UPS and added up in the neutral conductor.
The range is UL 508 Recognized.
Rotary change-over switches
The door mounted rotary cam switches up to 40 Amp are the most space saving changeover solutions, for the door and modular base mounting.
The standard range includes a black handle and finger protected terminals. A large variation of front plates for customized engraving enables special change-over switches.