Installing and Using a 50 Amp 220v Hughes Autoformer

[gordonsick]

I just had my son pick up a 50 amp Hughes RV Autoformer Voltage Booster with surge protection from Camping World for $519.84, "regularly $732.99". Catalog item #102450, Hughes part #RV220-50-SP https://www.campingworld.com/hughes-...-amp?rrec=true
I think it is a good purchase, but I'm trying to decide how and where to put it in my 2015 Berk 34QS. I'd appreciate insights from people who've got these. I'm not going to be able to use it until early April, since I'm in Calgary and everything else is in Tucson.

1. The Autoformer can be plugged into the campground post and the RV power cord plugged into it. That is the default installation, but it leaves the Autoformer exposed to rain and theft (I'll lock it, but...). I understand that some ill-informed campground managers think that this causes problems to their electrical system and "outlaw" them.

2. I could put it into my electrical bay, but then I'd have to leave my existing power cord wrapped around it, plugged into the Autoformer, and then connect to the power post with my extension 50 Amp cable. I'm not sure if my electrical bay has room for all of this, and ventilation might not be very good with all that equipment installed. My inverter is in the same bay, on a different rack and there is a fan installed in the bay for the inverter. I assume the fan would come on if the bay gets hot for any reason, and the inverter wouldn't be generating much heat except battery charge current when on campground power.

If people have done this, is there an overheating problem?

3. I could open things up and remove the 7 foot power cord from the Autoformer with its male plug, and replace the current power cord that is connected to the transfer switch with this shorter. Then, I could take the current long power cord and wire it into the Autoformer in place of the 7 foot cord. This would let me keep the Autoformer in the electrical bay, while I feed the long power cord out to the post. This would leave more room in the bay for the Autoformer and it would have more space from cooling.

Have people done this and is there any residual overheating problem? That would be situations with both AC's running, along with other applicances like the microwave and fridge.

Note that I plan to continue using my current surge protector in the power post. It would catch power spikes before the Autoformer is asked to catch power spikes, and it is easier and cheaper to replace if I hit a power spike. I can't see any problem with running two surge protector units in series.

Finally, I notice that Camping World lists a more expensive 50 Amp Hughes Autoformer, catalog #72455 https://www.campingworld.com/50-amp-...rmer?rrec=true Hughes part #RV220-50 for a sale price of $792.99. I can't see what is the real difference between these two that justifies a higher price on the latter. They both have 50 Amp 220 V and surge protection. The less expensive one has more diagnostic lights.

Is the more expensive model old stock that is replaced by the newer unit?

–Gordon

[Oscarvan]

I put the Autoformer in the shore power bay. I left it as is, which allows me to change my mind down the road. I did have to remove the handle to fit it in on it's back. I did not want the whole shore power cord in there to, so I shorted it to about 3 feet and put one of these on there.

https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

I put the female version of same on the removed 22' section of shore power cord. I also have a 50' shore power extension cord I carry. I have both in a tub forward in the storage.

So now, depending on the situation I use the long or the short cord, and the compartment is relatively uncluttered.

There is one caveat. Whereas the female end on my 50' is the fused on one and nice and compact, these yellow screw on plugs are too large to fit through the pass through in the bottom of the compartment. So if I want to use the 22' cord (The original male with a screwed on yellow female, I have to feed the male and all of the cord through the hole. I don't mind that, you may feel differently.

As you can see I also stuffed the surge guard in there. Lately it's been acting up and I've not used it for a while. Took it out and put it in the tub with the cords. The Hughes should do everything the Surge Guard does.

[gordonsick]

Thanks Oscar. Nice to see your approach. Your electrical bay looks like mine in size, but I've lost some space by putting in a solar charge control on the front wall. I was thinking that I'd also have to move some things to a separate storage bay.

I agree that it is nice to be able to have the Autoformer so that it is plugged in and removable from the system. But, I'm not sure why there is a need to use the extra yellow Camco plug ends. It seems to me that I can use the wires and male plug ends that are already in the coach and the Autoformer, as in my solution 3. Unless it is not possible to open the Hughes unit and the transfer switch to change the wires that are connected there.

I'll have a closer look at your solution at the rally in late April.

– Gordon

[Herk7769]

I "semi-permanently" installed my 30 amp Franks Autotransformer just behind where the power cord enters the camper.

I cut the wire between the back of the wall socket and the power center and installed a male/female plug/socket (that could be connected to each other when the autotransformer was out of the camper) and installed the autotransformer inside the camper.

You can do a similar "insert" with a 50 amp setup.

Here are some photos of my install that you may be able to adapt to your motor home.

That way the "big cord" is not effected at all.

[Herk7769]

The cheaper unit will constantly boost 2% of the incoming voltage (even when its "good") and then boost up to 10% of the incoming voltage when it drops to 113 volts. So it will always be boosting at least 2% even when not needed.

If the incoming voltage is 122 volts, that unit will output 124.5 volts. Still safe (below 127 volts) but on the higher side.

The better one will ONLY boost 10% when the incoming voltage drops below 115 volts and will stop the voltage at 95 volts incoming.

[gordonsick]

Originally Posted by Herk7769

The cheaper unit will constantly boost 2% of the incoming voltage (even when its "good") and then boost up to 10% of the incoming voltage when it drops to 113 volts. So it will always be boosting at least 2% even when not needed.

If the incoming voltage is 122 volts, that unit will output 124.5 volts. Still safe (below 127 volts) but on the higher side.

The better one will ONLY boost 10% when the incoming voltage drops below 115 volts and will stop the voltage at 95 volts incoming.

Herk,
That is useful to know.
Is there some electrical standard that specifies that equipment designed for 110v circuits must be able to handle up to 127 v safely, but no requirement that it handle higher voltage?

–Gordon

[gordonsick]

Answering my own question, Wikipedia on the subject of Mains electricity says:
In the United States[8] and Canada,[9] national standards specify that the nominal voltage at the source should be 120 V and allow a range of 114 V to 126 V (RMS) (−5% to +5%).

This is at https://en.wikipedia.org/wiki/Mains_electricity

–Gordon

[Herk7769]

Originally Posted by gordonsick

Herk,
That is useful to know.
Is there some electrical standard that specifies that equipment designed for 110v circuits must be able to handle up to 127 v safely, but no requirement that it handle higher voltage?

–Gordon

UL and other testing agencies make sure that things will operate in the "safe range". Outside that; all bets are off.

[ependydad]

Do *not* modify the AutoFormer, they’ll void your warranty. Their owner’s manual also specifically calls out hard-wiring it in. You can do like shown above and plug it in permanently, but don’t hard-wire it.

And, they do fail. Mine did. It was boosting good voltage and throwing my hard-wired EMS into an “over voltage” shutdown. I did some diagnostics with them over email and they sent me return info. I think I paid for shipping back to them.

They’re also fulltimer friendly and made sure to get a shipping address before returning it.

[cavie]

Originally Posted by gordonsick

Answering my own question, Wikipedia on the subject of Mains electricity says:
In the United States[8] and Canada,[9] national standards specify that the nominal voltage at the source should be 120 V and allow a range of 114 V to 126 V (RMS) (−5% to +5%).

This is at https://en.wikipedia.org/wiki/Mains_electricity

–Gordon

US is 108 to 132

[gordonsick]

Originally Posted by ependydad

Do *not* modify the AutoFormer, they’ll void your warranty. Their owner’s manual also specifically calls out hard-wiring it in. You can do like shown above and plug it in permanently, but don’t hard-wire it.

And, they do fail. Mine did. It was boosting good voltage and throwing my hard-wired EMS into an “over voltage” shutdown. I did some diagnostics with them over email and they sent me return info. I think I paid for shipping back to them.

They’re also fulltimer friendly and made sure to get a shipping address before returning it.

Ependydad,

Good point.

None of my solutions would hardwire the unit to the RV. The only change to the Autoformer (and that is solution 3) would be to replace the 7 ft whip cable (on the Autoformer) that has a male end with the 25 or 30 foot cable that comes with the motorhome and is currently connected to my transfer switch.

Now, maybe Hughes would be upset about that, but if I did have to send it to them for warranty, I'd just switch the wires back. It would be just as they delivered it.

To be squeaky clean and never open the Autoformer case, I could remove the existing long cable from the RV Transfer case (out of warranty) and cut off a short whip. Then, I'd put a male plug on the whip that would plug into the Autoformer in my electrical bay. Then put a female plug on what is left of the long cable that was the original supply cable. The Autoformer would plug into it. This might leave a cable that has to be stored in my regular storage bay and not the electrical bay. That means it would be simplest to put the female end through my existing 4" electrical hole. If the female plug doesn't go through my 4" hole between the electrical bay and the outside, I'd have to run my existing male end, which does go through – lots more to drag as Oscar notes. I do have an extension 50 A cable that has ends that are small enough to go through the hole, and that could become my main cable in use.

Oscar's suggestions of how to get male and female ends from Amazon look good.

–Gordon

[gordonsick]

Originally Posted by cavie

US is 108 to 132

Cavie, that is a pretty wide range that is useful to know. Is there a source I can get for that? Is it a UL standard?

–Gordon

[waybeck2018]

Originally Posted by gordonsick

Answering my own question, Wikipedia on the subject of Mains electricity says:
In the United States[8] and Canada,[9] national standards specify that the nominal voltage at the source should be 120 V and allow a range of 114 V to 126 V (RMS) (−5% to +5%).

This is at https://en.wikipedia.org/wiki/Mains_electricity

–Gordon

In addition to Wikipedia, it would be prudent to check the National Electrical Code (NEC). Your local Fire Department may have a copy and the Library normally has a copy as well. You may not find it on line in it's entirety as it is a subscription service. NEC is the US Authority on these type questions.

[Herk7769]

Originally Posted by ependydad

Do *not* modify the AutoFormer, they’ll void your warranty. Their owner’s manual also specifically calls out hard-wiring it in. You can do like shown above and plug it in permanently, but don’t hard-wire it.

And, they do fail. Mine did. It was boosting good voltage and throwing my hard-wired EMS into an “over voltage” shutdown. I did some diagnostics with them over email and they sent me return info. I think I paid for shipping back to them.

They’re also fulltimer friendly and made sure to get a shipping address before returning it.

I essentially made the "Hughes Install Kit" for a fraction of their cost and that included the plastic junction boxes.

https://hughesautoformers.com/produc...ll-kit-30-amp/

NO modification of the unit was needed.

[gordonsick]

I'm answering my own question by looking at two sources:
SPGS America (Safety Protection Grid Solutions) https://www.spgsamerica.com/informat...voltage-ranges
and
Pacific Gas and Electric Company
https://www.pge.com/includes/docs/pd..._tolerance.pdf

They both indicate that the national standard in the US for voltage regulation is ANSI C84.1. The ANSI store sells the PDF for a mere $111.24, so I'll stick with what others report after seeing it. These are recommendations and not a requirement, but let's assume that our equipment (AC units, refrigerators and microwave ovens, for example ) is designed with this specification in mind.

The ANSI C84.1 spec has two ranges for a 120 volt nominal system: Range A and Range B

As PGE puts it "Basically, the Range A service voltage range is plus or minus 5% of nominal. The Range B utilization voltage range is plus 6% to minus 13% of nominal. For range A, the occurrence of service voltages outside of these limits should be infrequent. Utilization equipment shall be designed and rated to give fully satisfactory performance throughout this range (A)."

PGE goes on to say "Range B includes voltages above and below Range A limits that necessarily result from practical design and operating conditions on supply or user systems, or both. Although such conditions are a part of practical operations, they shall be limited in extent, frequency, and duration."

Range A has a Service Voltage of 114 v to 126 v, and a Utilization Voltage of 110 v to 124.5 v (I'm reading a graph for this.)

Range B has a Utilization Voltage of 104.4 to 127.2 v, according to their discussion, although there are some inconsistencies in what is written.

PGE says that NEMA (National Electrical Manufacturers Association) goes outside ANSI C84.1 and "recommends that all electrical appliances and motors should operate at nameplate plus or minus 10% satisfactorily, however not necessarily at an optimum condition." That would be 108v to 132v. Note that it is a recommendation and not a requirement.

SPGS America has a similar but not identical spin on the standard. They take a Service Entrance Voltage Range A from 114v to 126v. This is the +/- 5%, but they are making it clear that this is the voltage that should be going into our units, which would be the voltage supplied by an Autoformer. Voltages inside our units could vary because of line losses in the wiring while heavy loads (AC and microwave) are applied. Their Range B is 110v to 127v. And they have a Utilization Range B from 104 v to 127v. I interpret the Range B utilization to be the voltage we measure inside our units that is available for an AC unit to start. It would be the outside voltage less line losses while the heavy load is applied.

OK, I'm not a lawyer nor an electrical engineer, even though I've worked with and taught both of them, but not about law or electricity. My take is that 126 to 127 volts at the upper end is safe for our equipment. That would be what we would get with 115 input and a 10% boost from an Autoformer. The boost drops to 2% if the input falls below 115. So, that is how they set their transfer point.

The low end of the voltage is where big loads burn out because they can't start. The standards seem to say that a brief period of 104 v is OK, but don't go lower. That would be an input voltage of 95 v that the Autoformer boosts to 104 v. That explains why some of the Autoformer units cut out below an input voltage of 95v.

So, if I had a voltmeter inside my RV reading below 104v (after the Autoformer does its thing, if I have one), I better turn off some appliances and/or turn on the generator.

Sorry for the long post. I'm sure that only the dedicated nerds have read to the bottom.

–Gordon

[cavie]

Originally Posted by gordonsick

Cavie, that is a pretty wide range that is useful to know. Is there a source I can get for that? Is it a UL standard?

–Gordon

Sorry some confusion on my part. 108 to 132 is Progressive EMS protection range .

Electric delivery range is 112 to 127.

[Oscarvan]

You calling me a nerd?

In addition to the V/A meters I added to my AC distribution panel I have the plug in volt meter that came with the Autoformer. It's right there in the galley in plain sight. If I see 108-109 I watch it closely.... If I see 104 I start shedding for protection.

That would mean a campground voltage, like you said, of 95 or less. There's only one place I go where I suspect that could happen and so far it's not.....

I assume cutting out on the part of the Autoformer means it no longer passes the current. As in we go dark.

[raidernation]

Originally Posted by gordonsick

Ependydad,

Now, maybe Hughes would be upset about that, but if I did have to send it to them for warranty, I'd just switch the wires back. It would be just as they delivered it.

–Gordon

The unit is is sealed with rivets. Good luck opening it up without them being able to know.

You probably are not the first person to think of that.

[Oscarvan]

And they are NOT cheap rivets. I took the handle off mine and they put up a hell of a fight. Of course I was doing this in a campground with a hacksaw instead if at home with an angle grinder.....

[itat]

We just upgraded to a new 5er that has a 50A service. Unfortunately, the Hughes Autoformer that I bought for our previous TT was a 30A unit. The 50A models are very pricey. The new 5er only has one A/C and we had no problems managing with just 30A before, so I figure I can still use it with a dog bone at times when everyone in the park has their A/Cs running or in the event that park voltage is not reliable. I will have a Progressive Industries EMS-HW50C installed to protect the electrical system and equipment.