Ralph Cramden wrote:
Even an EMS won't always save you. A few years back two bozos decided to rewire a 50 amp RV into a 30 amp pedestal, in the box itself, at a state park. They blew the main at the distribution panel killing power to around 30 sites for an hour and a half. That ended up costing me a microwave and fridge element and I was not the only person to lose something. I assume the PI EMS just was not fast enough to catch it.
EMS surge trip is usually < 1 nanosecond so it's unlikely a surge was the cause. Most EMS units are programmed with a low / high voltage trip delay that may vary from 6" to 10" to help avoid nuisance trips when incoming source voltage hovers just slightly above & below threshold trip voltages so perhaps these BOZOS created an abnormal situation the EMS didn't recognize. I too lost a microwave oven but
before I started using an EMS, since then I typically see at least a dozen trips each season, most often because of low voltage, but so far no damage to the trailer itself so while perhaps not a 100% guarantee an EMS is still certainly worth using. :B