Go Back   iRV2 Forums > MOTORHOME FORUMS > Class C Motorhome Discussions
Join iRV2 Today

Mission Statement: Supporting thoughtful exchange of knowledge, values and experience among RV enthusiasts.
  This discussion is proudly sponsored by:
Please support our sponsors and let them know you heard about their products on iRV2
Thread Tools Search this Thread Display Modes
Old 04-30-2014, 10:28 AM   #1
Senior Member
Join Date: Apr 2014
Posts: 212
Autoformer / Surge Protection Order

Hey All,

I know there is a old thread on the Class 'A' forum, but I wanted to start one here for the visibility of us 30 AMP folks.

I have a 30 Amp Hughes Autoformer. I do *not* have a automatic transfer switch. I used the install kit that you can buy separately so that I have this:

Coach -> 5' Autoformer Cord from install kit -> Autoformer -> Original Coach power cord (with plug from the Autoformer install kit attached to the formerly naked end) -> pedestal. Just as Hughes recommends.

What I WANT to do is assure that a surge doesn't fry the Autoformer and the Coach. The Autoformer has some nice voltage regulation but its surge rating is not particularly good. Plus for the cost of it, I don't want the Autoformer performing surge duty anyway.

My thoughts were to put a SurgeGuard 34730 30 Amp in between the Pedestal and Autoformer. So essentially I'd have this:

Coach -> 5' Autoformer Cord from install kit -> Autoformer -> SurgeGuard 34730 -> Original Coach power cord (with plug from the Autoformer install kit attached to the formerly naked end) -> pedestal.

This gives me a few things:
A. Both Autoformer and Surgeguard can sit in the electrical compartment away from the elements and hopefully thieves
B. I protect everything I care about in the Coach including the Autoformer
C. The SurgeGuard cuts power between 102v and 132v. Why would I want the power cut if I have a Autoformer? The Hughes Autoformer is only going to bump my volts by 10% max. If my park volt levels are that low to begin with, at 103 volts my Hughes is only going to get me up to a little over 113 volts anyway. Super low voltage is not going to be addressed by my Autoformer, so I might as well have the system cut off until it can be managed again.

So - am I missing something here?

2015 Jayco Greyhawk 29MV
s1njin is offline   Reply With Quote
Join the #1 RV Forum Today - It's Totally Free!

iRV2.com RV Community - Are you about to start a new improvement on your RV or need some help with some maintenance? Do you need advice on what products to buy? Or maybe you can give others some advice? No matter where you fit in you'll find that iRV2 is a great community to join. Best of all it's totally FREE!

You are currently viewing our boards as a guest so you have limited access to our community. Please take the time to register and you will gain a lot of great new features including; the ability to participate in discussions, network with other RV owners, see fewer ads, upload photographs, create an RV blog, send private messages and so much, much more!

Old 05-01-2014, 11:55 AM   #2
Senior Member
Damon Owners Club
Workhorse Chassis Owner
Join Date: Mar 2009
Posts: 21,177
IF your concern is surges (SUSTAIN HIGH VOLTAGES)

Park--Surge Guard--Autoformer---RV

However the more common problem is LOW voltages.

Park---Autoformer----Surge Guard---RV...

LOGIC: First, the auto former can take some LMITED over voltage, (Though I think pulging into 240 volt welder outlet may fry it). But it will correct low voltage so your low voltage protection with the surge guard will be 100A% operative and will not shut you down when the autoformer is working properly and effetively.

On the other hand... IF you plug into a welder outlet.... Well, meter before you connect and that way you can avoid that problem.

Home is where I park it!
wa8yxm is offline   Reply With Quote
Old 05-01-2014, 12:24 PM   #3
Senior Member
Join Date: Apr 2014
Posts: 212
Is it safe to run the coach on 113 CORRECTED volts? I thought anything under 115 was generally considered bad. That's why I though the SurgeGuard first would be okay. ???
2015 Jayco Greyhawk 29MV
s1njin is offline   Reply With Quote
Old 05-02-2014, 02:26 PM   #4
Senior Member
bcbounders's Avatar
Newmar Owners Club
Join Date: Mar 2005
Location: Abbotsford, BC
Posts: 523

No... it sounds like you've thought it through pretty well. I currently have my RV setup the way wa8yxm does (Park---Autoformer---Surge Guard---RV) based on the same logic: that the Autoformer will provide some over voltage protection, while ensuring that it gets to boost the low voltage before the Surge Guard would cut me off. I'm pretty sure the Autoformer will also cut out it's operation at some low voltage level... which would then pass through the low voltage for the Surge Guard to cut it off. But I don't know the numbers where that happens off hand.

As an aside, I just saw today that there's a giveaway for a Hughes Autoformer... so anyone in the market for one may want to enter! You can check it out here:

Protect Your RV From Low Voltage with a Hughes Autoformer
2005 Newmar MADP
bcbounders is offline   Reply With Quote

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

Similar Threads
Thread Thread Starter Forum Replies Last Post
Surge protection bruc RV Systems & Appliances 8 08-03-2014 05:36 PM
Surge Protection BRS50 Excel Owner's Forum 19 06-14-2014 12:43 PM
Surge Protector Install on 4018 Dutch Star Dutch Star Don Newmar Owner's Forum 16 02-22-2014 04:34 AM
Surge guard protection?? meffrig Class A Motorhome Discussions 9 02-04-2014 06:50 AM
Trying to order on eBay wagonmaster2 Technology: Internet, TV, Satellite, Cell Phones, etc. 13 07-20-2013 04:57 PM

» Virginia Campgrounds

Reviews provided by

Our Communities

Our communities encompass many different hobbies and interests, but each one is built on friendly, intelligent membership.

» More about our Communities

Automotive Communities

Our Automotive communities encompass many different makes and models. From U.S. domestics to European Saloons.

» More about our Automotive Communities

Marine Communities

Our Marine websites focus on Cruising and Sailing Vessels, including forums and the largest cruising Wiki project on the web today.

» More about our Marine Communities

Copyright 2002-2015 Social Knowledge, LLC All Rights Reserved.

All times are GMT -6. The time now is 11:55 AM.

Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2016, vBulletin Solutions, Inc.