Hard-wire AutoFormer (and maybe EMS)

[ependydad]

I don't like how not-water-proof my AutoFormer is. I generally try to get it under the camper, but we've still been in some frog-stranglers.

I'd like to hard-wire it into the system, but I only use it when voltage is low (it's supposed to be safe to do, but I had issues where it didn't sense proper voltage and boosted me into an over-voltage situation).

I've kicked around two possible solutions (the EMS part on here is as-if I had a portable EMS):


On the right is #1 - crude but effective:

1. Mount the AutoFormer + portable EMS in a hatch.
2. Take an RV extension cord and plug it from the campsite pedestal to the AutoFormer.
3. Plug the EMS into the AutoFormer.
4. Plug the existing/standard RV power cord into the EMS
5. Plug the existing/standard RV power cord into the twist-lock shore power inlet

As I said, crude but effective. Quite a bit of extra cable and you have to fashion a way for the extension cord to go into and shore power cord to come back out of the storage hatch.

On the left is #1 - a more proper install:

I looked at the Hughes Hard-wire Installation kit:

• Male plug w/ wires
• Female outlet

I tried watching their video, but it turned out mostly to be a "here's what's in the box" video.

Trying to decipher it, it seems like the installation is to:

1. Remove the wiring from the shower power inlet (hold for later).
2. Install the new 50amp outlet directly to the shore power inlet.
3. Mount the AutoFormer + portable EMS in the same area.
4. Plug the AutoFormer to the new 50amp outlet.
5. Plug the portable EMS into the AutoFormer.
6. Wire a male plug to the wiring your removed from the shore power inlet.
7. Plug that new male plug into the EMS.

BUT, this concerns me. Having a built-in generator (and later a whole-house inverter), wouldn't turning that on make this new dangling male plug be hot and essentially a shock hazard if it isn't plugged into the EMS? And, if so... what's the solution? Seems like twist-lock connectors might be better?

[srosey]

I don't know how long you have had your autoformer, but it comes with a 2 year warranty. Mine has only boosted when it was needed, I have plug in voltmeters that I check constantly. I went the quick and easy route since I already carry an extension cord with me. The water control area in my fiver is right next to the basement so I was able to just run the cords down through the existing access. I cut a 4" hole through the divider from the water control area to the basement and done. If you RV doesn't have any access into the basement you can drill a hole into it and use one of these "4 inch Round Access Hatch Cover Deck Plate for RV" from amazon or similar to run the cords.

When using your generator the transfer switch should be automatically switching to the generator supply and there should be no power at the plug. If you are going with a whole house inverter you may need to put in a manual switch so the plug is not energized when running of your batteries.

[ependydad]

Originally Posted by srosey

I don't know how long you have had your autoformer, but it comes with a 2 year warranty.

Crud, I didn't say that- Hughes did fix it. I had to pay for shipping back (which wasn't cheap) but they fixed it once I sent them voltmeter readings from the pedestal and the output of the Autoformer.

Fulltimer friendly too- they called me to ask for a shipping address before sending it back.

[SailorSam20500]

So what is the GPM of the SHOWER power inlet??


But seriously, where in the circuit are you going to insert the generator? Are you going to add a transfer switch (auto or manual)? I'd think the switch would go downstream (back to water again!) of the EMS. That way the switch disconnects power from any plugs.


Also, you could just reverse the male/female connections on the camper side of the EMS. They really don't have to all plug in in the same direction...

[ependydad]

Originally Posted by SailorSam20500

So what is the GPM of the SHOWER power inlet??


But seriously, where in the circuit are you going to insert the generator? Are you going to add a transfer switch (auto or manual)? I'd think the switch would go downstream (back to water again!) of the EMS. That way the switch disconnects power from any plugs.

LOL, 12?

The generator already has an automatic transfer switch. I think that's where the shore power inlet goes- to one side of the ATS. The other side is the generator.

[GlowPlug]

Ependydad.
Thanks for the link to your discussion on Hardwiring a Hughes system in place.
I have the 2019 Flagstaff Classic 831CLBSS and my shore power comes into trailer where the fresh water inlet comes into the trailer. Shore power is located in bottom cabinet along with water lines and the water filtration system and the Hot water tank system.
To me I'm not sure I'd want to mount the Hughes unit in that cabinet with the water supply being in the same cabinet.
Like I said I've already Hardwired the PI EMS 50 Amp system about 10 inches back from the breaker box. I just cut the power wires at the fuse box location and tied the EMS system at that location, it's all right behind the Fireplace.
Should I try and wire in the Hughes unit just about 10 inches back from the PI EMS system and before the wiring disappears into the flooring?
That would be all the room I have because after the EMS System the electrical wiring makes it's dive into the floor of trailer and I suppose it's running back to the water supply closet where the power enters my trailer???
Do I have this all correct on how things run inside and outside my RV.
Thanks for all your help.
Gary
2019 Flagstaff Classic 831CLBSS

[Larry-NC]

Originally Posted by ependydad

LOL, 12?

The generator already has an automatic transfer switch. I think that's where the shore power inlet goes- to one side of the ATS. The other side is the generator.

Maybe redo the drawings to include the generator and ATS (and maybe the inverter). Then it will be easier to identify situations where exposed contacts are hot.

You may want to poke around at industrial supply sources like Grainger to find a connector system where 50 amp contacts on both components are not exposed.

[ependydad]

Originally Posted by Larry-NC

Maybe redo the drawings to include the generator and ATS (and maybe the inverter). Then it will be easier to identify situations where exposed contacts are hot.

If I understand things correctly, this is what it would look like.

Originally Posted by Larry-NC

You may want to poke around at industrial supply sources like Grainger to find a connector system where 50 amp contacts on both components are not exposed.

I think I like that idea no matter what.

[Larry-NC]

Originally Posted by ependydad

If I understand things correctly, this is what it would look like.

I think I like that idea no matter what.

Great drawing! It's easy to see that when the generator is running, the ATS represented by the diamond prevents power from feeding to the EMS-autoformer-pedestal chain.

Similarly, no power will be applied to the generator terminals when the camper has shore power.