I bought a used Hughes Autoformer on EBAY, it did not come with a user manual. The model number is RV36HLA, does anybody have a manual I can get a copy of?
RE: Autoformer

I go a blank page also. I think this manual is the one on the manufacturers web-site. I have that one. The unit I have is an older model and I would like to know for sure what the lights mean.
Thank You
Re: Autoformer

The manual is the one on the website. It is fairly large so it takes a bit to load. When you are looking at the blank page, it is downloading.

Anyway, why do you need a manual?
Re: Autoformer

Here's the link to upgrade your Acrobat reader for PDF's:

Adobe Reader 7.0.8 (Be sure and UNCHECK each little box before you download.)

It doesn't have anything to do with the Autoformer manual, but if you need it; you need it. Durn 'puters!
Re: Autoformer

I need the manual for a couple of reasons.....I need to know what the lights mean and I would like to know the specs. I have downloaded the manual from Their representative, Robert, told me that was not the manual I needed and he did not know where to get the correct one.
Re: Autoformer

Perhaps if enough of us called and asked about the RV36HLA then they might look into their archives for a description of the lights.

Hughes Autoformers
1189 N. Tustin Ave.
Anaheim, CA 92807
888-540-1504 Sales & Service
714-630-7609 Fax

In the mean time, why don't you describe the lights, and we can compare them to the lights on the newer models and make some logical conclusions?

For instance,

the AMBER light means the park power is SAFE TO USE.
the RED light means the park power is low and the unit is BOOSTING.
On a 30 amp model there is only one red light, and the 50 amp model there are two (each leg could be boosting independent of the other leg).

So, how does this compare with the model that you bought as far as lights that are on the unit?
Re: Autoformer

There are 3 lights...2 amber one red. When I plug it in all 3 come on a stay on. I do not know if this is correct operation or not. When I bought this unit it was advertised as "fully automatic" I need to know if this is true. I know at least one of the older models was "manual", not automatic. I need to know which one I have.
Thanks, Charlie
Re: Autoformer

Charlie, everyone that I talk to says to call Robert @ Hughes to get that information. (I know you said you already did.) One of my sources said to call before 8:30 am PT. One source said he's VERY hard to get to the phone.
Re: Autoformer is the answer I got from Robert!

This model was manufactured by the previous owner unfortunately I do not have any manuals or can I explain how to use it without seeing it you should have asked the person selling it to you to explain how it works or it to manuals from them

Have a nice day

Robert Petree
Re: Autoformer

Charlie, that's a tough lesson to learn, but don't blame Hughes for it. Its the chance you take when you buy off of Ebay.

There probably should only be one light on when the unit is operating. It logically would be the RED light. The AMBER lights (on yours) probably came on when the unit was BOOSTING. The fact that your AMBER lights are on all the time could mean that your's is boosting all the time, and that probably indicates a faulty unit. You could check the output with a voltmeter to confirm whether it is boosting or not.

My logical assumption could be completely upside down. It could be that the AMBER lights go OUT when it is boosting.

ARCHER, an autoformer is a transformer with extra "taps" that get switched into the output when the park line voltage gets below 112 volts (usually). It "boosts" the line voltage back to 117 when that happens to keep the MH at 117 volts. When the park voltage is "OK", it just passes it straight through.

LOOK OUT FOR TECHNICAL STUFF: The term autotransformer usually designates a particular type of transformer; one that has a common connection from the input to the output. This configuration allows them to make a smaller transformer for the same current handling capability. This also means that this transformer configuration does not isolate the output from the input.

I notice now that Hughes is selling a larger and more expensive tranformer. It probably is a different configuration that isolates the output from the input. I'm guessing, but if that is the case, then it won't be called and autotransformer.
Re: Autoformer

I'm not trying to "blame" anyone, I am just trying to get answers. I know the risks on EBAY I have been buying and selling for years.

I measured the output of the unit with "no" load, input voltage is 121vac. 128vac with the switch on low boost, 121vac with the switch on high boost. All three lights on in both positions.
Re: Autoformer

It would have been nice to know about the "switch" from the beginning. The newer models have automatic relay switching inside (no external manual switching).

It appears that the lamps are just pilot lights. From your measurements, it looks like the "high" boost is not boosting at all, but the low boost is boosting about 6%.

I wouldn't plug my MH into it.

DL Rupper

Senior Member
RE: Autoformer

I have a Autoformer that is about 5/6 years old. It also has a switch on it that goes from auto-to-no-boost-to-manual-boost. 3 positions; however, it is currently in my 5'er in storage about 6/7 miles away. I also have instructions with it in the box. Next time I go to check on the 5'er, about every 3 days, I'll lift the bed storage and get the instructions out and check the model #. Best case if applicable I'll send a copy of them to you (boisegolfer99). The only thing I can remember off the top of my head is that it works best in manual boost, that leaves the boost on all the time. In auto every once in awhile I will notice my voltage in the yellow (low 105v)) on my monitor. Never happens in manual boost (always above 110v). Not sure if the auto function is the top or bottom position on the switch. No boost is the middle position.

Overall I wouldn't run my A/C without having one handy in case of low voltage at the RV Park. Low voltage is fairly common on hot days with lots of campers using their A/C. Low voltage is very hard on A/C compressors. Causes them to draw more current, thus heating the intrnal circuits up.
Re: Autoformer

Thanks, I am not sure it is the same model since my switch has only 2 positions but the instructions may still help. I am not plugging anything into it until I know it is OK. I am also negotiating with the seller to return it.