Adjusting PowerPacT M- and P-Frame Circuit Breakers in Motor Control Center Motor Starter Units

The following describes procedures for adjusting the trip units in PowerPacT M- and P-frame circuit breakers that have flange-mounted operator mechanisms. Circuit breaker instantaneous trip setting is factory-set to the minimum setting. It may need to be adjusted to permit motor starting in some cases. Circuit breaker trip setting dials are located behind the bail arm of the circuit breaker operator mechanism.

1. Turn off all power supplying this equipment before working on or inside the equipment, and follow lockout/tagout procedures. Always use a properly rated voltage sensing device to confirm the power is off.

2. Place the unit handle in the OFF position and open the door.

3. Insert a small, flat-head screwdriver through the opening in the mechanism bail arm and into the slot of the adjustment dial being changed (Detailed View of Mechanism Bail Arm and Typical Adjustment Dials). Turn the adjustment dial to the desired position. If one or more dials cannot be accessed through the bail arm opening, go to Step 4. Otherwise, skip to Step 9.

   NOTE: For adjustable amperage M- or P-Frame circuit breakers, the amperage dial (or Ir long time) is factory-set to the required value associated with the horsepower/voltage application. Do not change this setting. If for some reason the dial setting appears to be incorrect, consult the order drawings to verify the correct required setting and, if necessary, adjust the setting to match the drawing value.

   Detailed View of Mechanism Bail Arm and Typical Adjustment Dials

   

   DANGER
   HAZARD OF ELECTRIC SHOCK, EXPLOSION, OR ARC FLASH To avoid the possibility of a short circuit, do not drop screws into components below the bail arm assembly. Failure to follow these instructions will result in death or serious injury.

4. Disassemble the bail arm by removing the four 1/4-20 x 3/8 in. mounting screws (Bail Arm Disassembly). Retain the screws for re-assembly. Do not attempt to remove or loosen the four 1/4-20 x 1/2 in. toggle plates adjustment screws.

   Bail Arm Disassembly

   

   A	Bail arm mounting screws
   B	Toggle plates adjustment screws

   Refer to Circuit Breaker Trip Unit Adjustment for the following steps.

5. If the circuit breaker trip unit is provided with a door, use the screwdriver to open it (A).

6. Insert the screwdriver into the slot of the adjustment dial being changed. Turn the adjustment dial to the desired position. Repeat as necessary for other dials (B).

7. Close the trip unit door. Use a MicroLogic Trip Unit Tamper Evident Seal, (MICROTUSEAL, not provided), if necessary, to provide tamper evidence (C).

   Circuit Breaker Trip Unit Adjustment

8. After making the necessary adjustments, re-assemble the bail arm using the four screws removed in Step 4. Torque each screw to 70 lb-in.

9. Close and latch the unit door.

10. Test the operation of the circuit breaker mechanism by closing and opening the circuit breaker using the operator handle.

11. If the circuit breaker mechanism does not operate properly, contact your local Schneider Electric representative.