What is the general information for RM6 switchboard tests?

The principal general information for RM6 switchboard tests is set out below:

Internal fault test:

• This test involves artificially creating a short-circuit fault and measuring the response.
• Internal faults are actually very rare and may come from the line supply.
• The objective is to avoid projections which might place an operator at risk. In this case the maximum stress occurs when the volume is reduced. That is why units consisting of 3 non-extensible functions have been tested.

Leak test:

• In this case the highest stress occurs in a unit which has the greatest number of interfaces between the tank and the outside. That is why the test is carried out on an RM6 consisting of four right-extensible functions (RE-BIBI).

Thermal withstand:

• The purpose of this test is to confirm that the RM6 can withstand a short-circuit current of 25 kA for 1 second (for 25 kA / 1 second performance), entering via the first function, the busbar, and exiting via the last function: I function.
• When this test is carried out in the laboratory it takes place without voltage, as this electrical characteristic is independent of the voltage.

Continuity test:

• According to the IEC standard, this test ensures that the RM6 can make and break a circuit 100 times under rated voltage (12kV) and rated current (630A).
• This test is completely independent of the short-circuit current.

Circuit breaker continuity test:

• This test involves carrying out interruptions under rated voltage with a fault current. The standard specifies several interruption cycles with different current values. This test is not dependent on the volume. It is therefore carried out on stand-alone modules.

Earthing switch making capacity test:

• According to standard IEC 60129, a device rated at 25 kA must be able to withstand 62.5 kA (2.5 x 25). The test involves a sequence of 5 closures in response to a fault current with a first peak equal to 2.5 times Icc and under the rated voltage.
• The severity is entirely dependent on the line voltage, because the pre-ignition distance depends on the voltage (corresponding to the electric arc created when the moving part of the earthing switch moves towards the fixed part).
• The entire RM6 is compliant up to 62.5 kA under 12 kV.

Released for:Schneider Electric UK