Six ways to avoid electrical testing problems

It is important to safely start up electrical systems and restarting them securely after routine maintenance has taken place. Six tips to avoid these problems are highlighted below.

By David Manney, L&S Electric November 8, 2016

In any large-scale industrial facility, one of the critical times where problems occur is starting up electrical systems and restarting them after routine maintenance has taken place. In either case, it is important to do so both safely and securely to reduce any problems that could occur. Those problems may be associated with a reduced equipment lifespan. Alternatively, with the safety of those who work in the area.

When it is time to start the electrical systems at your facility, use technicians who have specialized training. This includes any electrical testing and troubleshooting required for the startup to occur without problems. Any issues occurring during this time may result in a loss of productivity due to unnecessary delays. Perform several tests before startup to ensure that everything goes off without a hitch.

Consider these six kinds of electrical testing to avoid potential problems:

  • Partial discharge testing: Partial discharges occur within the insulation of high or medium voltage electrical equipment. They are tiny electrical sparks and occur as a result of an air pocket breaking down within the insulation. Over time, they could erode the insulation and eventually, may lead to the failure of the insulation. Partial discharge testing can be part of an ongoing predictive maintenance program.
  • Insulation resistance testing: This test, sometimes known as the Megger, applies DC voltage to a particular spot within the insulation to test for resistance. The measure of the resistance can determine the condition of the insulation.
  • Contact resistance: Also referred to as the Ductor Test. The contact resistance test checks the resistance of electrical connections, including the connectors, joints, and terminations. It is one way to detect specific problems, such as eroded contact surfaces, loose connections, and corroded contacts.
  • Primary injection testing: This type of testing is typically associated with high-voltage power distribution systems. It injects a test current into the primary side of the system to see how it behaves with that level of current. Secondary injection testing may also be of value. However, it applies the test current to the trip relay directly on the secondary side.
  • Power factor: This test is typically performed on large transformers. It ensures the integrity of the insulation is still intact.

Gas sampling: Sometimes referred to as dissolved gas analysis, it looks at the gases in transformer oil. Testing the oil in this manner determines the level of equipment breakdown since insulating materials liberate gases as they break down.

Along with running these tests as part of a routine preventative maintenance program, there may be some other factors to consider as well. By testing the equipment regularly and doing any repairs that are necessary before they become a major problem, it can help to save your business money and prevent costly and inconvenient downtime.

– David Manney is a marketing administrator at L&S Electric. This article originally appeared on L&S Electric Watts New Blog. L&S Electric Inc. is a CFE Media content partner.

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