In addition to a surge protector, it's also possible to use a voltage regulator. A voltage regulator is relatively optional, primarily protecting your heat pump / air conditioner from low voltage situations that might otherwise cause your surge guard to shut off power to the trailer.
Before our dog Skipper left us earlier this month for the Rainbow Bridge, it was super important to know that the AC would keep running if he stayed in the trailer on a warm day while we went out and about. The voltage regulator helps ensure safe power to the trailer with longer periods of enough voltage to keep the AC running without damage, even if there's a sag in the incoming voltage due to other users at the campground. (If you don't have pets in your trailer, this may be less of a concern.)
So, we have a TRC voltage regulator and have used it any time we're likely to be running our heat pump / air conditioning. Here's a link so you can see what one looks like:
http://amzn.to/1TzsMVz
Here's how we include it in our circuit:
Post => 30 amp cord => TRC Voltage Regulator => TRC Surge Guard => 30 amp cord => Trailer
We wire it this way so the regulator can protect the surge guard from low voltages, which would otherwise cause the surge guard to shut off power to the trailer. Then the surge guard protects the trailer from any other problems that may come up.
You can of course also do this if your trailer uses 50 amp power.
Regardless, we heartily recommend a surge protector such as the TRC any time you're connected to shore power - either hard-wired into your trailer or as an external unit. Perhaps I should also mention that we always test the circuit at the post with a basic checker before connecting anything to it.
Happy camping!
Voltage Regulator
Linear Mode
