The Electronic Trip Unit is a microprocessor controlled multifunction overcurrent protective SB Encased Systems Breakers. The adjustment flexibility provided by the trip unit allows the user to easily accommodate load changes and other protective requirements. With the adjustable functions, the trip unit is designed to use field interchangeable rating plugs. These rating plugs allow the ampere rating of the breaker to be changed to meet specific applications. The trip unit has been designed as a plug-in unit to mount directly into a SB breaker frame. Current sensors within the SB breakers provide signal currents and operating power for the trip unit. Therefore, when the breaker is closed, the trip unit requires no external connections or control power to perform its protection functions.
The Trip units are available in six basic overcurrent protection configurations. All trip units have Adjustable Continuous Current and Long Time Delay. Protection Configuration:
Long Time/Short Time (LS)
Long Time/Instantaneous (LI)
Long Time/Short Time/Instantaneous (LSI)
Long Time/Short Time/Ground Fault (LSG)
Long Time/Instantaneous/Ground Fault (LIG)
Long Time/Short Time/Instantaneous/ Ground Fault (LSIG).