Current transformer shorting device

This device ensures:
• The protection of persons working within the HV measuring circuits
• The protection of the HV systems
Within the measuring circuits, this device provides the short-circuiting of CT secondary circuits, thus ensuring the protection of operative personnel. This operation is required before any servicing work or opening of circuits if the primaries are live.
In protection circuits, the short-circuiting device protects HV installations by preventing potential increases in voltage from induction by fixing the common point to the earth potential.


Improved safety

The short-circuiting device is made from a 4-pole SIDER visible load break switch, mounted in an isolating housing with a transparent cover. The operator can see the device's operating status before any servicing work or during preventive checks. The positions "SHORT-CIRCUIT CURRENT" (position I, switch off) and "NO SHORT-CIRCUIT CURRENT" (position 0, switch on) are marked on the external side-operation plate. An auxiliary NO+NC contact can signal the switch's position, used for a control circuit.

Easy to install

The CT short-circuiting device is easy to install with its threaded rods, included on the plate. It can be mounted onto the plate itself, in a panel or on a chassis.

Easy wiring

The connection is carried out by integrated bolts (intended for one or multiple 6 mm² cables with lugs), and by 6.35 mm Faston connectors for the auxiliary contact. A clear,
to-scale diagram is screen-printed on the transparent cap, to make it easy to identify terminals and positions.

Turnkey solution

The short-circuiting devices are delivered assembled. They are ready to be installed on delivery.