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Preventive Maintenance Guidance for Industrial Circuit Breakers

June 2, 2020

Circuit breakers form the foundation of safety for any industrial electrical system as they protect both your equipment and your crew from harm caused by overloaded circuits, short circuits, and other electrical problems. All protective systems should have a routine maintenance system in place to make sure everything is working as it should, and preventive maintenance will help you avoid costly breakdowns and industrial circuit breaker repairs.

Inspection & Maintenance Schedules

Regular maintenance and testing of your circuit breakers are critical as planned production interruption will always be preferred over emergency industrial circuit breaker repair. The specific schedule and routine for your breakers will depend on the type of breaker (i.e., molded case, low-voltage, medium-voltage, and high-voltage) as well as the environment in which your systems are operating. For example, a clean production environment such as electronics manufacturing may require less frequent cleaning and maintenance than one that creates a substantial amount of dust and debris.

Testing is another important aspect of routine maintenance for your industrial circuit breakers, and this routine is also determined by the type of breakers you are using. Molded case circuit breakers need very little maintenance. Low-voltage breakers should be inspected every one to three years, medium-voltage annually. High-voltage circuit breakers need the most frequent tests and inspections with a maximum of six months between checks.

Failing to Maintain Breakers

One of the greatest dangers of deteriorating industrial circuit breakers is that they remain idle most of the time and are not in operation. Unlike the rest of your equipment where a breakdown will be noticeable, you may not notice a problem with your breakers until one fails completely and you’re looking at halting production to perform industrial circuit breaker repairs. If dirt and debris have accumulated inside the breakers, they may not be able to operate correctly. Lubrication can break down over time and become sticky and gummy. This may also prevent the parts from moving freely and functioning as they should.

Routine Testing Procedures

Routine testing is generally a simple procedure that can be done onsite and without halting operations in most cases. NETA-certified acceptance testing ensures your devices are working according to the most recent NETA specifications. Key components should be inspected, including arc chutes, contacts, and connections. Contact resistance testing should be done to verify proper resistance values, and more. For low voltage breakers, primary and secondary injection testing is also completed to verify fault trip and overload protection. The exact type and frequency of testing depend on your operations, but these are some standard testing procedures that may be performed to avoid disruptive industrial circuit breaker repairs:

  • Circuit Breaker Analyzer. This device tests the timing of the open and close operations of the breaker as well as the synchronism of the poles in different operations.
  • Micro-ohmmeter. Resistance testing, such as those performed with a micro-ohmmeter, is necessary to avoid hot spots within the breaker and detect the possibility of imminent problems.
  • Infrared Inspections. Infrared inspections are useful for finding hot spots that can be caused by defective connections and components. When an increase in resistance causes excessive heat, components may fail. Early heat detection can prevent failures.

Routine Maintenance Procedures

Some breaker types, such as molded case circuit breakers, need very little maintenance. Other breaker types should be part of a regular maintenance schedule that is frequent enough for your equipment and environment. Some common maintenance procedures may include:

  • Cleaning. Dirt and debris inside the breaker can cause several problems, from failure to trip to fluctuations in the power supply. Cleaning involves removing the cover from the breaker, performing a visual inspection, and cleaning using vacuum tools or swabs and isopropyl alcohol.
  • Lubrication. Lack of lubrication or the deterioration of the lubricant is one of the leading causes of breaker failure leading to industrial circuit breaker repair. Primary and auxiliary connections, pivot points, main contacts, and operating mechanisms should all be checked for proper lubrication.
  • Tightening & Retorquing.The NEC has added proper tightening torque to the list of requirements for electrical connections in 2017, and this includes circuit breakers. The manufacturer of the breaker will have a recommended value printed on the breaker or listed in their literature and these values should be verified periodically.

Avoid Costly Downtime

Routine maintenance and testing are far easier to work into your production schedule than unexpected downtime. If you’re not sure how frequently to test and inspect your electrical equipment or what type of routine maintenance is necessary, Quad Plus can help. We’ll work with your team to develop a schedule and routine that help avoid unexpected industrial circuit breaker repair and reduce the incidence of costly downtime.