View Full Version : Surge protector question: Using 50 amp unit on 30 amp service.

Chuck Richard
07-15-2008, 07:49 PM
Hello All,

Looking for some help from the more experienced group. I was just reading about the NoCal fall rally and the park recommends a surge protector. Unfortunately I can't make the rally but it reminded me of a question. I would like to buy a surge protector but which one. I have the 50 amp power cord but most sites I go to here in Oregon have 30 amp service. If I go for the 50 amp will it work with an 30 amp adaptor? I hate to buy two as the better ones are quite expensive but I also do not want to buy a 50 amp and have it not work at the 30 amp sites. Hope someone with good electrical knowledge or just experience can help.


07-15-2008, 08:21 PM

There are a few popular brands of surge protectors and autoformers. I believe most of these will function fine on 30 amp service. I have a 50 amp Hughes Autoformer (http://www.autoformers.com/?id=rv450&loc=inc). Recently, I used it with a 50 amp to 30 amp adapter cable for a week and it worked fine.


07-15-2008, 08:52 PM
Go ahead and cough up the bucks, Chuck! What's another couple hundred dollars? :D :D

A 50A Surge Guard like this one: 50A Surge Guard (//heartlandowners.org/50A Surge Guard), is designed to trip when discovering a "miswired pedestal". Since a 50A surge guard is looking for (2) separate 120V circuits, I believe a 50A rig with a 30A adapter would fall into this category. :)

07-15-2008, 09:25 PM
I chose to instal a Progressive EMS. It is 50 amp, stays permanently mounted so it works using 20 or 30 amp, most importantly it protects against over and under current. It also has a few other features I like.
Read all about it here.

07-15-2008, 10:10 PM
Blows my theory...I stand corrected! :)

07-16-2008, 01:14 AM
We use the portable 50A surge protector from Camping World with locking hasp.


DH says it will work fine with your 50A to 30A converter plug.

Have fun and be safe whatever you choose.


07-16-2008, 07:45 AM
I've used my 50amp SurgeGuard with 30amp service using an adapter... you just have to watch that you don't overload the 30amp service that is now going to your unit.

In one park, we kept blowing the park's breaker but that was because they had crappy electrical service.


07-16-2008, 08:56 AM
I use a Progressive EMS PT50C. I bought it several years ago. I recently used it at a campground in Mystic Lake Casino Minnesota and it tripped. It would not reset but it saved my rig from damage (probably a over-voltage spike). When I got to the Escapade one of the owners of Progressive EMS had a booth. I took it to him, he checked the device and found it to be defective. He replaced it with a brand new device without question. I have used it on both 30 and 50 amp and believe the one time it tripped the spike was so severe it destroyed the device not my RV and in that instance paid for itself. I would recommend the Progressive EMS. For more info check out http://www.progressiveindustries.net/ems_pt50c.htm

Chuck Richard
07-16-2008, 09:39 AM
Thanks everyone, looks like a 50 amp protector is in my future now I just need to review all of your links and pick one.

07-16-2008, 11:35 AM
I also use the portable 50 amp surge protector from Camping World with the locking hasp. It has done its job well in the brief time I have used it. I would only add one caveat. The pigtail which comes out of the surge protector and plugs into the park's outlet is exceptionally short. It's difficult to explain but because of the short pigtail and the bulky nature of the surge protector, it hangs at an odd angle from the outlet. The surge protector does not hang straight down from the box and tends to try to pull out of the receptacle. This has been the only drawback that I have experienced. I have looked with no success for a very short extension cord with a 50 amp male at one end and a 50 amp female at the other.

07-16-2008, 11:46 AM
Not that it's better but the Hughes Autoformer sits on the ground and has about a 2 foot pigtail. Used in only 6 CGs this far and 1/2 at 30 amp recepticles. So far so good :)

07-16-2008, 03:37 PM
I had a smiliar problem. I wanted to protect my Bighorn 3400RE from power problems. So I purchased the 50a portable Surge Guard. Here is where I purchased mine. There are some other options also..

I use the http://www.tweetys.com/index.asp?PageAction=VIEWPROD&ProdID=6758

I also found that the upper pigtail is to short to use in some Shore Power also. I looked at a lot of places to find a 50amp short extension. I happen to find this 18" extension.

I also found another product but I don't remember the URL. It was a web type strip of material that you put between the male and female plug that lets you grab the connectors and pull them apart...

Hope this helps..

07-16-2008, 04:03 PM
Thanks Bob,

If I am reading it correctly, this should be exactly what I am looking for. Just to be 100% sure, the 50amp one is 50 amp male on one end and 50 amp female on the other???? I ask this because it looks exactly like a 50 amp to 30 amp connector that I already own. Thanks again. Pete

Chuck Richard
07-16-2008, 07:59 PM
Thanks Pete, more good info. I sure like the transformer Jim has but mighty expensive for a part timer. I have seen replacement cord ends but not sure where you could buy the cable to make up a short lead.

07-16-2008, 08:28 PM
Yes... That is a 18" Extension for a 50amp service. It is not a 50 to 30 adapter.
I looked a long time before I found that one..
Hope it helps you.. If you would like to see a picture of it let me know..

07-16-2008, 09:28 PM

You should be able to find the cable you need by the foot at most of the building centers. I think it is 10 gauge 4 conductors.


07-16-2008, 10:09 PM
Jim, I believe it's 6/3 w/ground.

07-17-2008, 08:11 AM
Thanks for that update Dave. I was going by what I recall marked on the jacket of the 50 to 30 amp adapters that I have. I can see how the 50 amp cable would need to be heavier to carry the 50 amp load.


07-17-2008, 08:50 AM
we have a 50 amp and it works just fine on 30 amp sevice.
Be sure to secure your serge protector to the post or it could go missing.
Keep Smilin All

07-17-2008, 08:53 AM
Thanks again, Bob. I went ahead and ordered that 18' extension last night. I think it's exactly what I need. I'm still not sure why they would design the surge suppressor with such a short connector. Even 4 more inches or so would have made it perfect. Oh well. Take care.

07-17-2008, 08:56 AM
And I did mean 18" - not 18'. 18' might be overkill.

07-17-2008, 12:42 PM
Pete and Sharon,

My guess is they did not want the unit to by lying on the ground. But to have it hang from the receptacle puts a lot of strain on the receptacle. In fact, I have seen many broken ones.

When you add your 18" extension, you may want to adapt one of those ground mounted RV water filter stands or some such to hold the unit.



07-17-2008, 08:23 PM
Thanks Jim. I actually used to have exactly the water filter stand you have pictured although I never used it and subsequently lost it. I think you're right about not wanting it to lay on the ground. They specifically tell you to position it with "this end up" or they warn that it may take in water. I guess I would have lengthened the top pigtail and maybe shortened the bottom one if that was the case though. I have found that if the top pigtail were even 4" longer, that would do the trick in most cases. I think I will try to rig something up to hold it up. That sounds like a good idea. With the 18" pigtail it may come pretty close to laying on the ground.

07-18-2008, 06:51 PM
Well the Camco 18" extension came today and it is exactly what I need. I think it solves the problem perfectly. Thanks again for the help guys.

07-19-2008, 12:54 PM
Hay guys
we are in Niagara Falls area. Pulled into a good campground and when I connected the Surge Guard it only showed only line one working. Talked to the campground owner and he had an electrician out in two hrs. and had it fixed. Neighbor said two MH's were in the site and had problems with it coming on. If it had not been for my Surge Guard I might not have known that there was a problem..

I think I will keep mine.

As mentioned above, I wish Surge Guard had made the top pigtail about 4" longer. Mine does lay on the ground. Not much of a choice. Shore power posts are normally fairly short to the ground. Some are to close to connect the Surge Guard without the 18" extension.

07-19-2008, 02:33 PM
I had a similar experience at a campgound in Winona, MN. Typically the surge suppressor has a two minute period before you hear a pop and it is live. For whatever reason, I would hear the pop but the red light would still be flashing. Since this was just an overnight stay I simply connected to the 30 amp outlet and it was fine. Not sure what the issue was with the 50 amp outlet but I also wouldn't have known without the surge suppressor.

08-17-2008, 07:51 PM
We purchased a 50 amp surge protector from CW. We used it at one camp site for several weeks with no problems. (30 amp/adaptor) Then we used it at another camp site (30 amp) in a different park and all of our lights kept getting real dim and then real bright. We then used it at yet another park (this time 50 amp) and the lights kept doing the same thing so we just quit using it. When we got home we used the protector again with our 30 amp connection and have not had a problem since. Has anyone else had this problem? Could it be the wiring at the camp sites or a faulty surge protector?


Forrest Fetherolf
08-17-2008, 09:18 PM

Surge protector.........gotta be the camp sites if it works ok at home.


08-18-2008, 11:14 AM
Forest, thanks for your reply. I guess you're right but we thought it was strange that it happened at two different camp sites in two different cities. I guess I am more concerned about the lights getting real bright (more so than usual) than them getting real dim. Will see what next trip offers.

Thanks again