Transformer

• Overloading – fluctuation density of core.
• Loose connection of bolt on clamping structure. Use of wrong sized crimp or improper tool.
• No precaution of sound isolating pad / vibration damper for mounting.

• Comply with the requirements of electrical installations as per BS 7671:2008+A3:2015, SS CP 5:1998, NFPA 70 [5]; including the location and number of power points.
• Ensure switchboards have adequate space and access for operation and maintenance.
• Specify suitable switch closets with regard to moisture exposure conditions.
• Refer to the definition of types and functionality of RCCBs and specifications for RCBOs as per SS 480:2016 (IEC 61009-1:2010+AMD1:2012+AMD2:2013 CSV BS EN 61009-2-1:1995).
• Provide sub-metering system with remote measurement capability and link to BMS/EMS to track energy consumption data trends [6].

Construction

• Conform to the guidelines for construction and compliance inspection of electrical connections and earthing thereof (BS 1363-4:2016, SS 403:2013).
• Refer to BS 8512:2008 for storage, handling and installation of power cables on wooden drums.
• Install sub-metering system with remote measurement capability and link to BMS/EMS to track energy consumption data trends [6].
• All accessible metal parts of connection units should be in electrical contact with the earthing terminal(s) (BS 1363-4:2016, SS 403:2013).

Maintenance

• Conform to the maintenance of electrical installations as per BS 6423:2014, BS 6626:2010, SS 538: 2008, [3;7].
• Check for insulation damages (e.g. cracks, blisters, warping) caused by overheating, physical impact or by spillage of cleaning chemicals.
• Check for potential short circuits or ground faults. Ensure that switchboards are not exposed to direct sunlight or alternative heat sources.
• Conduct annual shutdown to eradicate hot spots along the distribution network as witnessed by the owner and certified by a Licensed Electrical Worker (LEW).
• Provide necessary warning notices/labels at switchboards (e.g. shock hazard warnings).

• Insufficient air ventilation in the room or heat dissipation.
• Loose or wrong sized parts increase resistance.
• Over greasing, lack of training & proper tool causes loose connections
• Eddy current, excessive overloading.
• No thorough investigation to detect the problem in inner parts.
• Dirt, grime from insulation and windings prevents heat dissipation.

• Foreign make – not suitable for higher ambient temperature of tropics.
• Careless lubrication.
• Excessive corrosion overlooked for a very long time.

• Damage during transportation is not checked before installation.
• Poor cleaning – often hindered by poor access.
• High acidity of cooling liquid. Should be checked and changed.
• Breakdown of insulation from overheating.

Room used as storage for combustible materials and other equipments

Worn protective mat

• nsufficient space design or transformer room used as storage.
• Protection mat deteriorated with time or spillage of chemical.
• Inadequate lighting and ventilation.
• Slippery, dirty floor surface from oil spillage, scattered parts.
• Omission or missing warning sign or locks.
• Door mechanism of transformer room is not set to de-energize transformers upon opening the door.