Forum Discussion

Explorer

Sep 27, 2013

Hughes Autoformer question

I just purchased a used 50 amp Hughes RV220-50 Autoformer on Craigslist for $200.00. Plugged it in today, but the park I'm in has good power so even with both a/c's running we still show 118 v on my digital readout. When I plugged it in the lights did the flashing test they are supposed to do and settled on the orange light because the power is good.

What concerns me is that although it is not supposed to be boosting the power, with the Autoformer plugged in, we are now showing 121-122 v on the meter. Is this normal? Seems like it should still show the 118 v from before me plugging in. Obviously it is not boosting 10%, it is only up 3v, but I am wondering why....

Thanks,
Brian

13 Replies

Roadpilot
Explorer
Sep 27, 2013
Here's an excerpt from their web site:

"Autoformers are used in industries to stabilize voltage and lower the operating cost of equipment. The Autoformer has 5 windings: 2 primary and 3 secondary. All models have surge and spike protection. When the unit is in Automatic and the park or input voltage is 116 volts or below, the output is 10% over the input. When the input is over 118 volts, the output is 2% over the input. "

Looks like yours is working correctly.
Big_Katuna
Explorer II
Sep 27, 2013
My understanding is that it doesn't boost unless the input is low. Mine doesn't.
westend
Explorer
Sep 27, 2013
It may be that the source voltage has increased, line voltage can vary quickly and by 5%. It also may be that the Hughes has a threshold voltage that boosts power when reached. I'm not familiar with Hughes autoformer, maybe an inquiry to Hughes would bring the best answer. BTW, 122 V is a good value to be at, IMO. That is typical for my residential line voltage.