Commissioning the PowerPact B Circuit Breaker

List of Checks and Inspections

  • Apply appropriate personal protective equipment (PPE) and follow safe electrical work practices. See NFPA 70E, CSA Z462, NOM-029-STPS, or local equivalent.
  • This equipment must only be installed and serviced by qualified electrical personnel.
  • Turn off all power supplying this equipment before working on or inside equipment.
  • Turn off all power supplying the downstream equipment by manually opening the circuit breaker.
  • Before working on or inside equipment, always use a properly rated voltage sensing device to confirm that power is off.
  • Replace all devices, doors, and covers before turning on power to this equipment.
  • Beware of potential hazards, and carefully inspect the work area for tools and objects that may have been left inside the equipment.
Failure to follow these instructions will result in death or serious injury.

When equipment is commissioned or returned to service after a lengthy downtime, perform a general check on the equipment.

The following table summarizes when to carry out checks or inspections:

When to Carry Out Checks and Inspections








Before commissioning new equipment

Periodically during operation (see Maintaining the PowerPact B Circuit Breaker during Operation)

After carrying out work on the switchboard

Periodically during lengthy downtime

After a lengthy downtime

After a lengthy downtime and modification to the switchboard

A Carry out insulation tests and dielectric strength tests

B Carry out temperature rise tests

C Inspect switchboard

D Check compliance with the diagram

E Inspect mechanical equipment

F Check mechanical operation

G Clean equipment

A: Insulation Tests and Dielectric Strength Tests

Insulation and dielectric strength tests must only be carried out by qualified electrical personnel.
Failure to follow these instructions can result in injury or equipment damage.

Insulation tests and dielectric strength tests are done before the switchboard is delivered. These tests are compliant with the currently applicable standards.

B: Temperature Rise Tests

Temperature rise tests are done before the switchboard is delivered. PowerPact B-frame circuit breakers comply with product standards IEC60947-1 and 2.

For general-purpose systems, tests are carried out at an ambient temperature of 40 °C (104 °F). Above 40 °C (104 °F), thermal protection characteristics are slightly modified and the values defined in the derating tables must be taken into account. These values are valid for circuit breakers with or without terminal shields.

C: Inspect Switchboard

Check that the circuit breakers are installed:

  • In a clean environment, without waste from assembling the equipment (such as wiring, tools, shavings, metallic particles).

  • In a properly ventilated switchboard (unobstructed ventilation grills).

D: Check Compliance with the Diagram

Check that the circuit breakers comply with the installation diagram:

  • Identification of the feeds on the front of the circuit breakers

  • Rating and breaking capacity (shown on the device identification label)

  • Presence of additional functions (rotary handle, control, or indication auxiliaries, locking, sealing)

E: Inspect Mechanical Equipment

Visually inspect the general state of the circuit breakers: terminal shields and interphase barriers, protection, case, and connections.

Check the equipment integrity: a circuit breaker found with a cracked case or burn marks must be immediately taken out of service and replaced.

Check the mounting and mechanical strength of the following equipment:

  • Circuit breakers in the switchboard, power connections, and heat sinks

  • Auxiliaries and accessories on the circuit breakers:

    • Rotary handles

    • Installation accessories, such as terminal shields and interphase barriers

    • Auxiliary circuit connections

  • Locks, padlocks, and padlock support tabs

F: Check Mechanical Operation

Check the mechanical operation of the circuit breaker:

  • Opening

  • Closing

  • Tripping with the push-to-trip button

  • Resetting

G: Clean Equipment

To reduce dust deposits that can affect the mechanical operation of circuit breakers, clean the circuit breakers when performing maintenance:

  • Non-metallic parts: Always use a dry cloth. Do not use cleaning products.

  • Metallic parts: Preferably use a dry cloth. If a cleaning product is used, do not apply or splash the cleaning product on non-metallic parts.

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