Last weekend, we performed a scheduled ground fault test on the main electrical system at a school.
We have tested it according to the manufacturer’s directions for 19 years. It passes every year!
This time, it failed! The main switch did NOT turn off. Had this been an actual ground fault, the utility power would have continued to feed power to the failed system, overheating cable, switches and expensive copper bus. The excess heat would have melted components, raising the temperature to above flash point, and a fire could have begun.
Investigation of the issue proved a failed shunt trip coil. A small and inexpensive device, but extremely important; it makes the main power shut off when the protection package senses a dangerous ground fault.
Regular active testing of ground fault systems is extremely important. These systems do NOT announce failure on their own; they require scheduled maintenance. And without testing, you just won’t know if they work. When they don’t work, the entire facility remains in jeopardy.
Scheduled testing of critical protection systems is an effective way to determine the health of a facility’s ground fault protection system. It’s a simple and cost-effective method to reduce the risk of dangerous electrical ground faults.
Remember, electrical protection systems do NOT announce failure on their own. They HAVE to be tested.
A working Ground fault protection system is the #1 best defense against electrical fires. Regular scheduled testing and maintenance is the ONLY way to make certain it works!!