Originally Posted by DryFly
So I think really all I need to do is protect my 12v
You have a battery, right? Maybe two? They provide excellent surge protection, better than most surge protectors.
I will copy my reply to a similar question from a year ago. The Tripp Lite device you mention is of the MOV type:
This comes up from time to time here and on other RV-related forums.
I have a background in physics and electrical engineering though these days I write software for a living.
There are two types of surge protectors for RVs that are on the market. The cheap ones are nothing more than a set of MOVs (metal oxide varistors) connected between power and ground. Those will provide some protection against lightning strikes.
The thing is that shore power connections run underground and are generally supplied by pad-mounted transformers which provide enough inherent protection against lightning that any lightning-related surge will, by the time it gets to your trailer, be weak enough that any electronics you might have present can deal with it. Good quality power supplies have their own MOVs or are otherwise designed to deal with voltage spikes.
At one of my last jobs we had a lab where there was a big red power outlet with warning signs on it and a button you could push to apply surges of varying voltages and durations to it. We tested new products on it just to be sure. We also had, on a similar piece of equipment. an insulated wand designed to provide a carefully calibrated 10,000 volt pulse to whatever it touched, and we'd apply it to all exposed connectors and surfaces.
So I would say that the cheap MOV-only surge protectors don't solve any problem RVers actually have, unless you stay in one of the few remaining campgrounds where the shore power comes to the pedestal via overhead wires.
The autotransformer-type surge protectors additionally provide some compensation for slightly low and high voltage. Hughes Autoformer is the best known brand. These will also disconnect power if the voltage is out of specification. They are heavy and expensive.
In general the input voltage range of the autotransformer devices isn't any wider than what the converter and 120v appliances can accept by themselves. In practice the converter, fridge, microwave, and air conditioner will all run fine on any input voltage between around 100 and 135 volts. I know, I've done it.
The autoformer devices will detect and correct certain overvoltage conditions that result from wiring problems in the campground or in the utility equipment serving the campground. These problems are rare.
I don't recommend surge protectors of any type as I think that the weight, hassle, and dollar cost exceeds the value of the protection they provide.
If you're concerned about your electronics, the best thing to do is run all the electronics from the 12 volt
system. The converter and 12v batteries provide much better surge protection, for equipment connected to the 12v system, than even the fancy surge protectors provide for the 120v system.
If you're concerned about damaging your converter, consider replacing it with a Xantrex Truecharge, which is designed to run on any voltage from 90-265 and will shut off by itself if the voltage is too low.
RV technicians like to blame air conditioner failures on "power surges" or low voltage. They find it much more convenient than blaming such failures on shoddy design and workmanship on the part of the manufacturer of the air conditioner. Air conditioners have thermal protectors in them which should prevent damage from undervoltage. Again in practice they'll work fine up to 135 volts or so, maybe more.
I don't have a surge protector on my trailer and doubt if I will ever get one.