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Signs your transformer needs maintenance


Depending on the type of electrical transformer that’s running on your site and its operational intensity, the electrical unit may have a lifespan of up to 30 years. During that time, the transformer will need to be regularly inspected for faults and inefficiencies that can be corrected through maintenance.

Transformer Inspection Service

Keeping a site’s transformer in top working condition can help to prevent running costs from steadily increasing over time and getting the most out of the unit before having to reinvest. In this blog we will discuss why transformer maintenance is necessary, how frequently transformers should be serviced and what signs to look out for that would indicate that urgent repairs are needed.

Why is transformer maintenance important

Like other pieces of electrical equipment, transformers need routine maintenance to ensure that you’re keeping it running smoothly and operating safely.

Carrying out scheduled routine inspections that run through a thorough list of checks can help you troubleshoot, identify and solve major and minor faults before they arise. Monitoring the health of your transformer lets you keep track of the condition of its parts over its lifespan and replace them as needed. Carrying out maintenance on a transformer’s parts also lets you ensure that the unit continues to meet health and safety standards.

How often should transformers be inspected and serviced?

The frequency of maintenance work on a transformer will depend on the usage and conditions of the environment that the transformer is kept in. A dry and clean environment is the ideal condition to keep a transformer in, and will likely only require annual inspections and maintenance according to the unit’s needs.

Environments, where the air contains contaminants like chemical fumes or dust, can have a greater effect on the transformer, meaning that more regular 3-6 month inspections may be required.

Transformer Maintenenace

When should you inspect your transformer for maintenance

Besides whenever you schedule to carry out your more routine transformer inspections, you should also remain vigilant to your transformer’s condition at all times. If the transformer trips from your energy network, or if any of the built-in safety equipment, you should immediately investigate to determine the cause.

Below is a list of symptoms to look out for when inspecting and troubleshooting either a dry-type transformer or liquid-filled transformer that indicate that the transformer is in need of repair or maintenance.

Signs your Dry-type transformer needs maintenance

These are some of the most common signs your dry-type transformer needs maintenance

  • Low insulation resistance
  • Abnormal operating temperatures
  • Automatic protection devices trip when the transformer is first energized
  • Unexpected secondary voltage
  • Non-symmetrical voltages on the secondary side
  • Spurious triggering during operation
  • Blown high voltage fuses during operation
  • Unusually amounts of noise coming from the unit
  • High earth voltage
  • Smoke

Signs your Liquid Filled transformer needs maintenance

These are some of the most common signs your Liquid Filled Transformer needs maintenance

  • Low insulation resistance
  • Non-symmetrical voltages on the secondary side
  • Triggering of the over-current relay
  • Triggering of the differential relay during operation
  • Spurious triggering during operation
  • Abnormal operating temperature measured by thermography
  • Winding and/or Top-oil thermometer alarm and/or trip
  • Oil flow trip
  • Buchholz-gas relay alarm
  • Leakage detector alarm

At Powerstar, our expert technicians are well equipped with the tools and knowledge to keep your transformers running at maximum operational capacity. We provide thorough transformer inspection services to identify any potential problems and offer high-quality maintenance and transformer rewinding services for both high voltage and low voltage transformers that maximise their lifespan.

If your Transformer hasn’t been inspected or undergone maintenance recently contact us and speak to our expert team

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