Maintaining the PowerPact B Circuit Breaker during Operation

  • 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.

Like most equipment, electrical switchboards age whether they are being used or not. Aging is mostly caused by environmental influences and operating conditions.

To help circuit breakers keep the operating and safety characteristics specified in the catalog for the whole of their service life:

  • Install circuit breakers in optimum environmental and operating conditions (described in the following table).

  • Make sure that maintenance operations are carried out by qualified electrical personnel.

Environmental and Operating Conditions

The following table describes optimum environmental and operating conditions.

Environmental and Operating Factors

Optimum Conditions


Average annual temperature outside the switchboard is < 25 °C (77 °F).


Loading is < 80% of In for 24 hours a day.


Harmonic current per phase is < 30% of In.


Relative humidity is < 70%.

Corrosive atmosphere (SO2, NH3, H2S, Cl2, NO2)

The circuit breaker is installed in environmental category 3C1 or 3C2 (IEC60721-3-3).

Saline environment

The circuit breaker is installed in an environment free of salt mist.


The dust level is low. If necessary, the circuit breaker is in a switchboard that is fitted with filters or is IP54 ventilated.


Continuous vibration is < 0.2 g.

Maintenance programs apply to optimum environmental and operating conditions. Outside these limits, circuit breakers are subject to accelerated aging, which can quickly lead to problems.

In harsh environmental and operating conditions, refer to the derating tables and reduce the maintenance intervals (see Enviromental Conditions).

Regular Preventive Maintenance

Maintenance recommendations are intended to maintain the equipment or subassemblies in a satisfactory operational state for their useful service life.

The following table summarizes maintenance operations and intervals for the three preventive maintenance levels:

Maintenance Interval

Maintenance Operations

Performed by

1 year

Basic level tasks: visual inspection and functional testing, replacement of inoperative accessories.

  • Qualified customer employee with basic training

  • Schneider Electric certified partner

  • Schneider Electric field services

2 years

Advanced level tasks: Basic level tasks, plus operational servicing and subassembly tests.

  • Qualified technician with advanced training

  • Schneider Electric certified partner

  • Schneider Electric field services

3 years

Exclusive level tasks: Advanced level tasks, plus manufacturer diagnostics and part replacements by Schneider Electric Services.

  • Schneider Electric field services

The maintenance intervals in the previous table are for normal environmental and operating conditions. If all environmental conditions are more favorable, maintenance intervals can be longer. For example,

Advanced level tasks could be carried out every three years.

If any one of the conditions is more severe, perform maintenance more frequently. For advice, contact Schneider Electric Services.

Functions linked specifically to safety require particular maintenance intervals.

NOTE: Regularly test that the remote safety commands work. For example, test at least every six months.

Maintenance Operations Required

Maintenance operations mainly consist of checks and inspections A, E, F, and G, as defined for commissioning (see List of Checks and Inspections).

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.

Maintenance operation

Year 1

Year 2

Year 3

Year 4

Year 5

Insulation and dielectric strength tests (A)

Inspect mechanical equipment (E)

Measurement of insulation resistance

Check mechanical operation (F)

Check the closing time, opening time, and voltage release characteristics

Clean equipment (G)

For a detailed definition of the maintenance operations, contact Schneider Electric Services.

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