34
2.2.2
Test procedure
Set the main output controls to zero (anti-
clockwise) and the timer mode to “OFF”.
Switch on the main output, and increase the currents for each phase to the desired level.
Switch off the main output.
Switch the timer to “single contact” mode, and reset the relay.
Switch the main output on. The output will be switched off and the timer will start when the
relay trips. The timer will stop when the relay auto-recloses.
2.3
Timing Circuit Breakers
Testing CBE’s MCB’s and other devices with no auxiliary contacts is possible using the current
operated timer mode on the 200A-3PH mk2. This mode starts the timer when the output
current on the selected phase exceeds 20% of the selected current range, and stops the timer
when the current on the selected phase falls below 20% of range. The phase on which to start
and stop the timer is selected using the phase select switch.
Figure 2.3 Connections for testing circuit breakers
Device Under Test
