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How are P and H trip units powered?

Issue:  
Trip unit will not light up.  

Product line:  
Molded case circuit breakers

Environment:  
Micrologic P and H trip units for Powerpact and Masterpact breakers

Resolution:  
For protection functions, trip units are automatically self-powered by the current flowing through the circuit breaker.  

A voltage power supply powers the trip unit with 100Vac or more between two phases or phase to neutral.  The standard configuration for the voltage probes inside the breaker is at the bottom connections. There is an option for external voltage probes that could be connected anywhere in the system.  

The optional but recommended 24 Vdc control power.  
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