I started a thread relating to a surge/spike that hit our rig at a CG. It took out our microwave, keurig and convertor. We had a TRC Surge Guard protecting our rig. I was stumped as to how a surge/spike could have gotten by our surge protector until I found an article on the net which explained a few things. I'm pasting some useful information I found while researching our event.
- A spike is similar to a surge except that it lasts for one or two nanoseconds, whereas a surge lasts longer. A good analogy is water pressure. If your water pressure is excessively high, you'll have blown lines in your plumbing system.
-A surge protector will prevent these spikes and surges from passing through the system. It does this by utilizing metal oxide varistors, commonly knows as MOVs. A MOV does nothing at normal voltage levels, but when the voltage rises to an unsafe level, it shorts that power to ground. Energy surges are rated in units of joule.
-Most products referred to as surge protectors also contain some sort of low- and high-voltage protection. This is important because many RV electrical problems stem from low-voltage power from a campground pedestal. When the voltage drops, the amperage increases and this creates extra heat, which causes items such as motors and electronics to fail. A good surge protector will disconnect power to the RV whenever the incoming voltage falls out of the acceptable operating parameters, typically 106 volts on the low side and 132 volts on the high side.
- Later in the afternoon when other campers switch on their AC, the load on the grid can be too much, so the voltage drops to an unsafe level. Those campers without surge protectors run the risk of causing serious damage to their AC compressor motors, capacitors, and other electric components.
the majority of the Surge Guard units do not indicate if the MOVs have blown and will continue to pass current even after the surge protection capability has failed.
That is likely what happened to our surge protector. It likely protected us at some point, but without a sign that the MOV's had deteriorated to the point where the unit was not functioning/protecting as it was intended, we were literally sitting ducks till the fatal next surge/spike. I hope this is helpful and gets people thinking about their TRC surge guards. Our particular SG was 4 years old.
This chart does a good job comparing surge protectors. We have ordered a Progressive Industries EMS PT 50C through amazon which is delivering it to the campground today.