Users Guide
53
Circuit breaker
One of the more classical applications of a high current
injection equipment, is the trip time test of thermo-magnetic
circuit breakers (generally low voltage) directly connected to
the mains, in their different construction forms:
MCB, corresponds to Small Automatic Circuit Breakers
(generally up to 125 A nominal current)
MCCB, corresponds to Automatic Moulded Case Circuit
Breakers (they can reach up to 4000 A nominal current)
The test consists of measuring the trip time of the circuit
breaker at different current values, so that, when compared
with its nominal trip curve, the correct or incorrect behaviour of the circuit breaker can be
verified under test conditions, both in terms of its thermal element and its magnetic or
instantaneous element.
Template configuration:
The template is configured as follows:
• Generator: Pass-through turn
• Time display: As chronometer in seconds
• Chronometer start: ON output
• Chronometer stop: Due to lack of
current
Connections:
Connect the output of the pass-through turn to
each side of one pole of the circuit-breaker tested.
The circuit breaker must be closed.