30 amp Hughs Autoformer

Hi,

It is always a good idea to monitor the usage. I use one of these for watts: Efergy Elite Watt Meter I follow the voltage on a kill-a-watt unit.

I do this because I often do not have access to the shore power breaker.

Yes, Progressive Industries PT30C or HW30C which provides provides power protection including high/low voltage but does not boost the voltage.

It's also possible that the pedestal CB was allowing more than 30A. Let's assume it allowed 37A and you had 100V at the pedestal, possible low voltage since there were 2 heavy draw 30A plugs on the pedestal. And 120V/30A autoformer output considering about a 2% loss in the autoformer. So in this scenario 37A input to the autoformer which doesn't expect more than 30A.

Autoformers are a good product but I prefer the PI power protection. BTW Surge Guard is a different and IMHO inferior product to the PI unit.

yes the plug blade which was where the white wire joins was fried, the tip was burnt off. That is the plug blade or tong of the autoformer plug. The plug blades were clean however I can not speak for the receptacle.

I sense that it was my fault (no pun intended) in that I was using in excess of 80% available amperage for long periods of time. Just wondering how and why the autoformer met it's untimely death.

I gather the pedestal receptacle slowly diminished in its capacity to withstand the heat due to excess amperage being drawn, eventually shorted and melted the autoformer. Thus the autoformer saved the converter in the motorhome , OR the autoformer tricked me into thinking I could use all this power without tripping a breaker, until the hook-up gave up, overheated and melted components.

I used to walk around at 7PM shooting pedestal connections with my IR thermometer.

One French Canadian yelled "Hey they don't even do that in the USA or Canada".

I caught more than a few at 10C higher than ambient. Didn't want old corroded plugs screwing up my receptacles.

Harbor Freight Black Friday price for the IR is $19.99

There is basically no way that I know of that your autoformer could have "Destroyed the pedestal" with one exception which I will cover, and that is not the autoformer's fault, it's yours.

ANY time you go to plug in check the plug,, Make sure the blades on the plug are clean,, If they get nasty, they cause a lot of heat, which can do serious damage both to the plug and to the socket.

However you did not say the plug was damaged, Just the Pedestal.

I have seen circuit breakers do that.. WITH MY OWN EYES.

Thankfully, I caught it before it became serious and the park maintenance man was able to swap in a new breaker before he had to replace the entire box.

tvman44 wrote:
Change the plug on the auto-former by cutting back a few inches to get to good wire & insulation. :) That will most likely get it working again. :)

I had an issue with my 50A Autoformer about a year ago - I lost one side of the power line. Mine is installed in a cabinet and is plugged in all the time. It turned out that the female plug on the unit had lost the "springiness" in the contacts. Normally I expect to see that when something is plugged and unplugged a lot, but in this case it was plugged in when I installed it in 2007 and never touched, so the metal contacts simply loosened up from age. I put a new plug in and it's been fine since.

Thank you for the replies. The electrical shop called this morning. (I did put a new plug on it) The insides are melted and in pieces.

what do I learn from this?

Do not attempt to use maximum amperage (supposedly provided) or exceed as the autoformer will allow it for an unknown time without tripping breakers? ( 80% continual use is max, thanks CA Traveler.)

the autoformer quality plugs can stand much more heat than campground pedestal receptacles, eventually burning out the campground receptacle and sending a short to the autoformer, (which destroys it)?

The innards of the autoformer could not take the heat, shorted back to the pedestal plug?

No question that clean tight connections with proper size wire is a must when attempting to maximize amperage provided. Winter camping with all the heaters going in the campground would probably exceed air conditioner use in summer.

I;m guessing that PI is progressive industries and the unit is a surge guard? No one, even at the RV place has heard of an autoformer, but I would like to get something in the line. Over the years I believe the autoformer has worked very well. Next trip South, I'll get another.

Oddly enough the front furnace seems to have a board failure, however that may be a coincidence. (new board installed 1 year ago)

Perhaps but everything that you posted begs for a good power protector like the PI unit. On the other hand you might be good for another 10 years or 10 days or ???

Hopefully with a new autoformer plug it will be OK.

I do know that consumption would be close to 30 amps and that the campground breaker is shared (2, 30 amp breakers together) with another site which must be very close to using 30 amps as well.

And this is part of the problem. Few folks know or care that the recommended continual load should be limited to 80% or 24A.

Hi,

In winter time voltage drop is not going to affect the air conditioner motor--because it won't be on. I'd simply leave the autoformer out of the circuit.