Issue:
Arc Flash mitigation
Product Line:
Circuit Breakers
Resolution:
Arc Flash mitigation
Product Line:
Circuit Breakers
Resolution:
- Prior to October 2015, the AMS system was used. AMS employed a RIM module to enable and disable a restraint signal to the breaker's short-time delay function. When in maintenance mode, restraint was disabled which resulted in the ability to trip on a fault with no intentional delay. Refer to FAQ FA176050 for more information on this option.
- AMS has been replaced with MMS, which also enables and disables restraint to the breakers short-time delay to enable tripping without intentional delay if a fault occurs. The difference between AMS and MMS is that AMS uses a switch and a RIM module, whereas MMS uses only a switch.
- Since October 2015, the energy reduction maintenance setting (ERMS) system has been the preferred method of reducing arc flash incident energy. When ERMS is activated, the instantaneous trip pickup point is reduced (2x is the default but it can be set to another value if desired). Basic components of the ERMS system are:
- A Masterpact or Powerpact circuit breaker with a Micrologic P or H trip unit with a blue label on the upper right corner with the letters ERMS
- An I/O Module (Input/Output Programmable Module), LV434063
- A switch, ULP cable, and power supply