Bob & Ann wrote:
Jim
Yes you can use both. I checked with both the coach manufacturer and surge protector manufacturer. Typically your built in unit will not do all that you need it to. The second surge protector just makes for smart business. If there is a power problem that burns up your portable unit nothing in you coach is harmed. Just throw it away, buy a new one and continue on with your trip.
Or if it is a lifetime warranty product such as my PI EMS PT50C, you just send it in and they replace or repair it under the lifetime warranty. This happened to me this past September. My PT50C saved me from a surge caused by a lightning strike to a nearby tree. One leg of the PT50C would not operate. I always carry a spare PT50C so I put it in service and everything worked fine. Sent the dead one back to PI and received a replacement within a week. The original unit had been in full time service since 2011.