50A surge protectors

Yep, I bought my Hughes autoformer 15 years ago when a state park had power at 105v and dropping. After listening to the A/C complain, I turned it off and spent a hot, sweaty night pledging, "never again!"

My autoformer allowed me to keep that pledge.

ScottG wrote:
I guess I've been lucky. We stay at State CG's and a few private places and I have never seen low voltage. I have to admit though, we rarely get out of our home state and I imagine those traveling around the country and staying at the occasional CG that has older infrastructure could have peoblems.

There's nothing special about where you camp, look for low voltage and you will see it as "older infrastructure" isn't the only culprit. Here in S Ontario we have one of the most modern up to date power grid systems in the world and the Ontario provincial park system (2nd largest in N America only to the US national park system) is constantly improving and upgrading it's campground electrical service yet each summer I can absolutely be assured that low incoming source voltage to the trailer will be an issue, sooner or later. It's a matter of load on the system - take a park with 1000+ campsites, 30% to 40% which are 30 amp electrical, pack the park completely full during the busy summer months, and once all those with A/C start drawing from the system voltage does drop, alarmingly. I wouldn't ever plug in these days without the protection of an EMS.

ScottG wrote:


I guess I've been lucky. We stay at State CG's and a few private places and I have never seen low voltage. I have to admit though, we rarely get out of our home state and I imagine those traveling around the country and staying at the occasional CG that has older infrastructure could have peoblems.

Come to the northeast sometime, bring your voltmeter with you. My experience is that most that "never had a problem" give me a blank stare when low voltage is mentioned.

pianotuna wrote:
Hi Scott,

My comfort zone is 108 volts and above.

ScottG wrote:
Personally, I bought the EMS because our new rig is 50A and I didn't want to worry about open neutrals and the like. If it was 30A I wouldn't have bothered and would have just installed individual surge protectors on TV's and appliances like I did on our last RV.
I have never in nearly 30 years of RVing had a problem with low voltage at any park so I haven't given any thought to getting an autoformer.

I guess I've been lucky. We stay at State CG's and a few private places and I have never seen low voltage. I have to admit though, we rarely get out of our home state and I imagine those traveling around the country and staying at the occasional CG that has older infrastructure could have peoblems.

Hi Scott,

My comfort zone is 108 volts and above.

ScottG wrote:
Personally, I bought the EMS because our new rig is 50A and I didn't want to worry about open neutrals and the like. If it was 30A I wouldn't have bothered and would have just installed individual surge protectors on TV's and appliances like I did on our last RV.
I have never in nearly 30 years of RVing had a problem with low voltage at any park so I haven't given any thought to getting an autoformer.

Only time i had a voltage problem was a couple years ago in EX KOA on the West side of Sacramento CA. The voltage was 108, I wound up running my AC on my generator

Personally, I bought the EMS because our new rig is 50A and I didn't want to worry about open neutrals and the like. If it was 30A I wouldn't have bothered and would have just installed individual surge protectors on TV's and appliances like I did on our last RV.
I have never in nearly 30 years of RVing had a problem with low voltage at any park so I haven't given any thought to getting an autoformer.

I was full time up to one month ago. I never needed a surge device--but used the autoformer 9 times out of ten.

Autoformers are especially useful in winter time so that the full wattage on electric heating becomes available.

Here is an example:

power 750 watts at 120 volts (120 x 120)

power at 100 volts (100 x 100)

750 X .6944 ~= 520.8 watts

That makes a huge difference of slightly over 30% more power at the correct voltage. Since I generally heated 100% electrically this was important. My peak load was 7000 watts and the average about 5200 in the dead of winter.

hotpepperkid wrote:
So in other words if you have an extra $800 buy both

That's about it. ;) For those who full time in parks where power is problematic an autoformer is probably worth the cost but since we're just occasional RV campers I chose to buy an EMS and just live with those times it might decide power to the trailer needed to be disconnected.

hotpepperkid wrote:
So in other words if you have an extra $800 buy both

IMHO get the EMS (I prefer the EMS-HW50C) and if you have extra money get the Autoformer.