When reviewing emergency power system designs, I am sometimes asked about 4-pole transfer switches. The typical question is “when should I use them?“, followed quickly by “why should I use them?“. Since each project is likely to have special circumstances that make a generic answer impossible, this article focuses instead on providing the basic sources of information that should allow you … Read more
How and when to apply “3-cycle rated” vs. “30-cycle rated” transfer switches should be a rather important consideration for a design engineer. A coordination study is a critical element that must go hand-in-hand with the design and specification of a safe and reliable emergency power system. Some basic definitions Interrupting ratings – the highest current at rated voltage that a device is intended … Read more
Generator load banks offer a safe and reliable method for the periodic testing of emergency generators. This article discusses a specific load bank design known as a radiator-mounted load bank. As the name implies, these load banks are installed in front of the engine radiator, and they utilize the cooling air provided by the engine radiator’s … Read more
For as long as I can remember, engine exhaust silencer manufacturers have used attenuation “grades” to describe the expected performance of their products. “Critical”, “hospital”, and “residential” are some of the common grades used today. As an attempt to differentiate themselves from one another, silencer manufacturers have come up with new grades such as “super critical”, “super hospital” and even “extreme”! … Read more