Eaton Power Circuit Breaker MDS-H08

Ensure all primary and secondary power is removed for fixed mounted circuit breakers

Remove the drawout circuit breakers from the cassette

Verify breaker operation by charging, closing, recharging, and opening the breaker

Mechanical Interlock Verification

Verify breaker does not close with Undervoltage Release not energized

Use the mating line of the housing halves as a reference guide for visual inspection

Remove the arc chutes and inspect each primary contact structure for signs of wear and/or damage

Use the contact wear indicator to inspect each contact

Is the back end of any contact below the ledge?

Replace the contact assembly if any contact is below the ledge

Charge the breaker mechanism springs

Close the breaker by applying rated voltage to the spring release accessory and verify closing by noting the state of the indicating flag

Charge the breaker mechanism springs again

If using the motor operator, disconnect power to it to prevent automatic recharging

Check the state of the pop-out trip indicator (if so equipped)

If the trip indicator is 'out', reset it

Charge the breaker mechanism springs

Press the ON pushbutton to close the breaker manually

Verify closing by noting the state of the indicating flag (Figure 93)

Charge the breaker mechanism springs again

Disconnect power to the motor operator to prevent automatic recharging

Press the OFF pushbutton to manually open the breaker

Press the ON pushbutton to manually close the breaker

Charge the breaker mechanism springs using the charging handle or motor operator.

Close the breaker by applying rated voltage to the spring release accessory and verify closing by noting the state of the indicating flag.

Charge the breaker mechanism springs using the charging handle or motor operator.

Disconnect power to the motor operator to prevent automatic recharging.

Check if the pop-out trip indicator is 'out' and reset it if necessary.