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What does the 24V DC power supply do when provided on an Ammeter trip unit for P-frame, R-frame, and Masterpact breakers?

Issue:
What does the 24V DC power supply do when provided on an Ammeter trip unit for P-frame, R-frame, and Masterpact breakers?

Product Line: 
Powerpact Molded Case Circuit Breakers

Environment:
3.0A, 5.0A, and 6.0A Trip Units in Masterpact, Powerpact P-frame, and Powerpact R-frame Breakers

Resolution:

Without the 24V DC power supply, the Ammeter trim unit:
  • Provides fault protection for LSIG functions
  • Provides LED trip indication (powered by an onboard battery)
  • Ammeter and bar graph powers with the current flow on one phase of 25% of the sensor rating or more.
  • Ground-fault push-to-trip button works for testing ground fault with current flow on one phase of 25% of the sensor rating or more.

With the 24V DC power supply wired to F1 (- terminal) and F2 (+ terminal) on the terminal block on top the the trip unit, the Ammeter trip unit:
  • Provides all of the above
  • Ammeter and bar graph displays are functional below 20% of the sensor rating current flow on one phase
  • Ground-fault push-to-trip button works for testing ground fault with no current flowing through the breaker
  • Highest fault current reading and phase that tripped
  • Optional Modbus communications

Ground-fault push-to-trip button will also be functional if a hand-held test kit or full-function test kit is powering the trip unit.
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