Circuit Breakers: Don't Neglect the Little Things
In discussing the importance of Emergency Power Supply Systems and the proper application of maintenance in these systems, it would be a huge oversight if I didn’t touch on circuit breakers. Though they may not seem like the most exciting part of your EPSS, breakers are critical to the successful and optimal operation of your system. And if you thought I was going dive right into this subject without giving you a car analogy, then buckle up.
Let’s focus on your car’s tires this time. Your car is controlled by your steering wheel, driven by the motor, and has access to the road via its wheels. Tires wear out over time and should be rotated regularly to ensure that the wear is more uniform and not too drastic in one area or another. Neglecting tire rotations can cause problems for your vehicle that have nothing to do with the performance of its other systems. And typically, a service professional will inform you of the life of your tires after the rotation and advise you on options for replacements.
So, let’s imagine that the road our vehicle is traveling on represents current. A spike in current could cause damage to our equipment if a circuit breaker fails to trip. Think of the treads of your tire and how they are designed to expel water from beneath the tire through the grooves to help prevent hydroplaning. Assuming you still have tread on your tires because you followed a proper maintenance schedule, you can drive in many weather conditions with improved peace of mind that your tires will perform as designed. Now, we don’t get rain too often in Southern California, and I notice balding tires all too often as I walk through parking lots. So if you were to hit a nice wide pool of water on a freeway with bald tires, do you think that puddle would consider how well you maintained your controls or motor before throwing you into another lane of traffic?
The testing and maintenance of circuit breakers is probably one of the most neglected aspects of electrical maintenance when it comes to an ATS or generator. I understand that many people will assume that breakers will work as designed, being as they only have the one purpose. And perhaps that is the flaw in the thought pattern of a maintenance professional: if nothing has happened, it’s still good. From our perspective though, breakers fall under the category of fine details that should never be overlooked. And the truth is, 50% of the breakers we test don’t trip on the first try.
Circuit breakers can often sit for extended periods of time without activation, which is why NFPA 110 mandates that they be visually checked, cleaned, and exercised monthly. If proper maintenance is being performed for the breaker at your generator and every emergency breaker between it and your ATS, then they will likely function as intended. The standard also requires testing of the breakers every two years. We do this through primary injection testing, which sends current into the system and allows us to measure if the breaker will trip or fail, as well as how long it takes for the circuit to be broken. During this testing, we often have to exercise the breakers several times and go through multiple tests before the breaker will trip successfully. In the event that your breaker fails to operate as designed, then it must be replaced with one that is more reliable.
Remember, over-current protection devices are part of your system for an important reason. Do not neglect the little things. Failure to properly maintain your system will most often result in inefficient operation and undesirable failures. If you have had problems with your circuit breakers in the past or think you may be overdue for maintenance and testing, feel free to give us a call so we can help get your system back on the road.
