Power Quality Issues
Most automatic transfer switches (“ATS”) are known as “open transition,” which means your load is disconnected from the grid for about 100 milliseconds before it is connected to the generator. This time delay is enough to cause lights to flicker, but seldom causes operational issues. An alternative ATS is a “closed transition” switch. In this case, the generator and grid are first synchronized, then the load is simultaneously connected to both the grid and the generator, and about 100 milliseconds later the grid is disconnected.
“Micro-outages” are caused by power quality problems. Usually, this results when large induction motors are turned on or off, causing a significant drop in power factor. Another cause is switching power supplies deployed by variable frequency drives (“VFD”). These VFDs can cause a significant amount of harmonics (noise) causing circuit breakers to trip. Lastly, and most insidiously, are problems originating from your incoming power. It could be a function of poor power factors or noise from a neighboring facility, or issues caused by intermittent renewable energy connected to the grid nearby.
No; these outages are much faster than an generator can start and pickup the load. Most micro-outages are shorter than 3 seconds. A fast start (NFPA 110-compliant) generator will take 10 seconds to accept load.
No; power quality problems are typically the result of your load or poor-quality incoming grid power.