A few facts about WL trip units and breakers will help the tester understand how best to accomplish the
required testing quickly and easily.
Air Core Sensor Technology
WL Breakers are equipped with air-core current sensors (Rogowsky coils, also known as linear couplers)
and as such, the ETUs cannot be tested by conventional secondary injection techniques.
Ground Fault Protection
WL Breaker trip units can be equipped with ground fault protection according to the table below. Ground
fault protection cannot be disabled if it has been installed at the factory. Setting the Ground Fault Mode is
either done via switch (see below) or via menu (consult WL Circuit Breaker Operator’s Manual for details)