Preventive Maintenance Checklist

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PREVENTIVE MAINTENANCE CHECKLIST FOR ELECTRICAL DISTRIBUTION SYSTEMS IN
COMMERCIAL & INDUSTRIAL ESTABLISHMENTS
A preventive maintenance checklist for electrical distribution systems in commercial buildings
Electrical distribution and control systems are the heart of any facility, yet it is often the most under-appreciated utility.
Without a reliable source of electrical power, operations of any facility would not be possible. In spite of the critical
nature of electrical equipment, regular scheduled maintenance is not always a primary focus in many facilities.
Neglecting the maintenance of electrical equipment over a long period of time will inevitably lead to costly emergency
repairs and equipment failures in addition to elevated safety and property risks.
Here are 4 reasons why your establishment needs preventive maintenance:
1. 77% of equipment breakdowns can be reduced by implementing a preventative maintenance program.
2. The Institute of Electrical and Electronics Engineers report that the failure of electrical components is three times
higher for systems without preventative maintenance programs.
3. Effective electrical preventative maintenance will help avoid the extra expense caused by disruptions & lost profit.
4. On average a small electrical failure could cause a minimum of six hours of interruption
With preventive maintenance, there is no ‘one size fits all’ approach; programs must be custom designed to fit the
characteristics and vulnerability of the facility. Therefore one should take the following considerations into account:
 Redundancy in production
 Business interruption costs
 Spoilage of product (consequential)
 Age of equipment
 Changes in system loads over the years (design and expansion)
 Type of loads (increasing digital loads)
 Sensitivity to power quality
 Geographical consideration (weather)
 Environmental conditions in which your facility operates (moisture, dirt, dust)
Preventative Maintenance Checklist for Electrical Distribution Systems:

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Intrusive LV Switchboards
❒ Check function of all power meters before shutdown.
❒ Check function of lamps and indicators.
❒ Inspect locking devices for signs damage or worn.
❒ Clean thoroughly, vacuum and full visual inspection of exterior and interior of all LV switchboards.
❒ Inspect control wiring, relays, power supply units, timers, etc. where applicable.
❒ Check electronic surge protection is intact where installed.
❒ Verify control circuit fuse rating and continuity.
❒ Check and torque test bolted electrical connections as necessary to specified levels.
❒ Visual inspection for signs of overheating or deterioration.
❒ Inspection of all panels for paint work damage and signs of corrosion.
Non-Intrusive LV Switchboards
Note: These maintenance procedures require no shutdowns.
❒ Check function of all power meters before shutdown.
❒ Check function of lamps and indicators.
❒ Inspect locking devices for signs damage or worn.
❒ Clean thoroughly, vacuum and full visual inspection of exterior only.
❒ Visual inspections of control wiring, relays, power supply units, timers and fuse carriers.
❒ Check electronic surge protection is intact where installed.
❒ Visual inspection for signs of overheating or deterioration.
❒ Inspection of all panels for paint work damage and signs of corrosion.
ACB Chassis
❒ Rack out ACB.
❒ Clean/ vacuum internal chassis.
❒ Check operation of safety shutters closing.
❒ Check shutter locking devices are intact.
❒ Check operation and position of contacts.
❒ Operate padlocking system.
❒ Grease clusters as necessary.
ACB’s
❒ Check general condition of the device and clean with diluents like Henkel 273471 and Vacuum.
❒ Check filters clean/vacuum arc-chutes.
❒ Visual check for contact wear.
❒ Check auxiliary wiring insulation.
❒ Check ACB locking devices.
❒ Open/close manually and Charge the device manually.
❒ Secondary injection with FFT Kit, produce trip curve report.
❒ Check earth fault protection/earth leakage protection.
❒ Grease disconnect contacts as necessary.
Busbar & Accessories
❒ Visual inspection all Power bar runs
❒ Check supports, alignment, straight runs, joint packs and directional change pieces
❒ Check panel flanges, earth continuity etc.
❒ Thermal image survey of complete runs
Meters MCCB checks
❒ Voltage connections ❒ MCCB trip test with report.

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❒ CT connections ❒ Motor operator
❒ Meters Calibration ❒ Under voltage release
❒ Power supply unit & Control relays
PDU
❒ Verify control circuit fuse rating and continuity
❒ Check function of lamps and indicators
❒ Check and torque test bolted electrical connections as necessary to specified levels
❒ Check all cable connections for tightness and torque terminals
❒ Visual inspection for signs of overheating or deterioration
❒ Inspection of all panels for paint work damage and signs of corrosion
❒ Inspection to insure all clear after work completed before fitting covers
Thermal Imaging Surveys
Thermal imaging is becoming more common within preventive maintenance programs to help detect excess heat in
electrical components. It can be carried out while the system is under a full load with no impact to operations
Thermal imaging technology can detect loose connections, corroded elements, short circuits, overloaded circuits and
busway-joint analysis. This non-invasive technique also allows to gather data from a remote location, away from
potentially dangerous situations.
With electrical distribution systems continuing to top the list with the most premature breakdown, an electrical
preventive maintenance program will effectively reduce your risk of an unscheduled outage by as much as 66%.
It is important to remember that performing electrical maintenance does require specialized training in testing
technology and safety. Energized testing is a key component, staff will be working on live equipment, therefore safety
MUST always be a primary concern.