Hughes Autoformer power booster and surge protector

I asked the same question on the Hughes website and they responded with this reply:
"The question is, which surge protection unit do you have? If it is the one that shuts of your RV in extreme voltage situations(102-132V), plug our unit in first so the protector will be protected from low volts and will not shut your RV off. If it's the simple surge protector with all the LEDs indicating what the various input conditions are, plug that unit in first so you get the benefit of the indicators as well as a little more surge protection".
Exactly what many of you recommended and suggested. I picked up a decent surge protector that does not shut off at low and high voltage levels, so I plan on plugging that into the pedestal, and then plug the autoformer into that. Atleast that way I will get some protection offered to the autoformer as well as the RV.
Thanks for all the replys and help from everyone

I wired mine with the autoformer first, then surge guard. The autoformer generally stays unconnected until I note park power getting too low, then I plug it in (both devices permanently mounted in compartment)

tvman44 wrote:
I would do that surge protector first then autoformer. :)

Since a surge protector probably shuts off at low voltages, your autoformer would never kick in.

I would do that surge protector first then autoformer. :)

Other than change 30 to 50 I use both.. Currently it's park-SG-Hughes-RV but I plan to change that as soon as I get ye old round tuit.

Proper sequence is park-hughes-SG-RV

That way if the voltage does down the HUGHES will bring it up and the SG will not cut you off till the voltage is beyond the HUGHES ability to compensate.

An autoformer the basic unit should be inherently tough as nails. Hard to damage. A secondary transient voltage protection device would or should be located close enough to the basic voltage correction device that it would suppress voltage transients that degrade the insulation of the voltage correction device. Got it?

Devices that use wall warts or AC/DC voltage converters really do not care a heck of a whole lot about wide voltage spans. But excessive transient voltage events degrade transistors, capacitors, IC's, etc. in the devices.

Has anyone out there taken apart a transient voltage suppressor device (referred to as a surge guard)? Is there anything more than a series of metal oxide varistors inside? To be UL approved the device must have a fuse inside. Single/overall fuse protection is a pure neanderthal grade design. Each MOV should have a backup WHEN not if the first MOV gets tired and dies. Individual fuses. Same for Transient Voltage Suppressors. Avalanche diodes. Paralleled and individually fused. I use Gas Discharge Tube (3-leg) protection against Armageddon-like events.

Simple MOV only devices do not have the reaction time of avalanche rectifiers. High frequency transients slip by the MOVs.

Avalanche rectifiers by themselves do not have the capacity that a slower reacting MOV has.

A major event such as crossed power line, shorted pole transformer, or nearby lightning strike will blast through avalanche rectifiers and MOVs and burn them out. Enter the Gas Discharge Tube device. It buys enough time to allow a lightning feeder to ionize a path to earth negative. Power pedestal, shore power cord, and suppressor device all go up in smoke. But a protected RV stands a good chance coming out unscathed. This theory is not hypothetical. It has saved the interior electronics of three homes that I am aware of in Mexico. One galvanized steel power drop pole was melted on the tip, the meter was shattered, and the 8 gauge feeder wires were carbonized. The bolt fried the suppressor to ash, and it's ground wire disappeared. But all the electronics in the home continued to function once the damage was repaired. Done right, this stuff works.

But when I run across ads for upper end suppressors that boast Gas Discharge Tube, Avalanche TVS, and MOV protection, the price is cruel. The components are not that expensive. Hell, a 44,000 joule Vishay MOV costs fifty seven dollars retail. I have several pounds of MOVs, avalanche diodes and GDT's that'll be here next weekend. The BIGGEST capacity units available.

kerry4951 wrote:
I recently purchased a 30 Amp Hughes Autoformer power booster, Mdl RV2130. Prior to this, I was using a Surge Guard Mdl 34730 unit for just surge and spike protection. I was wondering has anyone ever used both? I am thinking of plugging the Surge Guard first into the park power pedestal, and then plugging the Autoformer into the Surge Guard before any power enters the RV. I know the Autoformer does have some limited surge protection, but Im thinking by hooking up both of them I might have the best of both worlds. Does anyone use both working together?

Here's what Surge Guard recommends for the 34730 when using it with their voltage regulators . . .

The VRSG (Voltage Regulator by TRC) is not a protective device and the connected RV will not be protected from damage should an open neutral develop during the course of operation. The fault indicator panel is for indication only. Note: The VRSG is not a surge protector. To achieve the ultimate combination of line voltage and surge protection, use with Surge Guard models 44750 or 34730 which must be plugged in after (downstream) of the VRSG. In addition, to provide surge protection for the VRSG, use Surge Guard model 44260 which must be plugged in before (upstream) of the VRSG.

The Hughes Autoformer Manual says that the unit protects against "various spikes and surges" but "In certain instances, a surge or spike might actually damage your Autoformer while it’s protecting your RV."

Pretty vague.

I follow Surge Guard's (TRC) advice with my 50A setup which is . . . Power Pedestal -> 44270 fault indicator -> 50A TRC Voltage Regulator -> 50A Surge Guard Plus.

However, the 44270 is just a fault "indicator".

You plug it in first and pray that nothing bad happens after you connect it to the voltage regulator and surge guard. Because if an open neutral occurs, the voltage regulator would get fried.

jjj wrote:
Just a reminder if the surge protecter is after the booster it is not protected. I had a franks booster that served me well for years until a transformer blew at my local thousand trails and it fried both my circuit boards at a cost of 400.00 just for the boards and not labor. I now have a nice heavy paperweight cause I can not afford to get it repaired and at that cost I may well just get a new one, but at least it save my trailer.

Yea thats why I was initially thinking surge protector at pedestal first and then autoformer plugged into surge protector.

Just a reminder if the surge protecter is after the booster it is not protected. I had a franks booster that served me well for years until a transformer blew at my local thousand trails and it fried both my circuit boards at a cost of 400.00 just for the boards and not labor. I now have a nice heavy paperweight cause I can not afford to get it repaired and at that cost I may well just get a new one, but at least it save my trailer.

kerry4951 wrote:
Thanks Larry. That does make more sense. I guess I was hoping to also offer surge protection for the Autoformer. I can see where your system will work.

I have a different brand but, like mine, I believe the Autoformer has some surge protection capability. In the event of an extreme surge I think both have a sacrificial diode that will protect the unit but require a visit to the manufacturer to replace the diode.