3 Phase RCD testing

[sparks1234]

Are there any particular ways of testing 3-phase RCD's or anything to avoid?

 

[sparks1234]

Bump bump

 

[IQ Electrical]

The IET has this to say:

Tests are made on the load side of the
RCD between the phase conductor of
the protected circuit and the
associated cpc. Any load or appliances
should be disconnected prior to
testing. RCD test instruments require
a few milliamperes to operate; this is
normally obtained from the phase and
neutral of the circuit under test.
When testing a three-phase RCD
protecting a three-wire circuit, the
instrument’s neutral is required to be
connected to earth. This means that
the test current will be increased by
the instrument supply current and
will cause some devices to operate
during the 50% test, possibly
indicating an incorrect operating
time. Under this circumstance it is
necessary to check the operating
parameters of the RCD with the
manufacturer before failing the RCD​

 

[davelerave]

tricky one alright -the 3 wire-testing

if the operating current of tester is small -may not matter much