Installing RV Inlet Into Junction Box
Hi everyone,
As the title says, I need to install a 50 amp (male) RV inlet into my tiny house, located on the exterior junction box.
When this was built, it wasn’t properly planned ahead for a normal inlet install…so this is what I am working with.
I would like to install an inlet like this: https://www.amazon.com/Leisure-Power-Twist-Inlet-Stainless/dp/B077ZCNHG7/ref=sr_1_2?dchild=1&keywords=50+amp+rv+inlet&qid=1632336910&sr=8-2
but the depth seems to be too long.
I have attached photos of the junction box. It is roughly 4 3/4″ x 4 3/4″ x 4 3/4″. I am having a hard time figuring out how to make this work.
It looks like the back black tube comes off on these inlets, but the manufcacturer said this isn’t what they reccomend (safety perhaps?).
Are there any other inlets that are not as deep so I could make this work? Something like this? https://www.towgear.com/products/rv-pro-50-amp-rv-inlet-white
If not, I would love some suggestions how to do this. My electrician was saying a could frame out the box on the outside with some cedar plywood. I was also thinking of buying a 2 gang Metal Square Electrical Box Extension Ring.
Thank you.
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Replies
That back tube is meant for an installation without a junction box. Since you've got a junction box, you can discard it.
You may still need or want an extension ring. I'd recommend a plastic one, because it's a bit of a pain to mix metal and plastic--each piece of metal needs its own ground. I'd get that part in-hand and then see how much if any extension you need.
Thanks! Yea I am planning to get a couple extension rings to see what works the best.
That first link is a cable body on a cover, and odd arrangement. That's not going to work for you -- it's intended to be wired onto the end of a flexible cord, not mounted into a box.
The second link is a useable connector, but probably not with a standard plate arrangement. The box you have appears to be a speciality/propreitary box meant for something specific. What I would do is to cut a piece of PVC sheet (rigid/solid PVC sheet, not the cellular core stuff), then drill it to make a custom adapter cover that will let you mount the inlet to that special box. You'll need a sheet of gasket material to seal between the two.
I don't think a mud ring will work here, and framing out the box with cedar is technically a no-no per code, since the cedar counts as a "flammable material".
Bill
Hey bill thanks for the comment. The first link is meant to be mounted onto a wall. I spoke with them today. In my case, I can mount it onto an extension ring.
Great idea about the pvc mount, but I am pretty sure I can just buy a 1.5" extension ring. To be clear, the plugin will be inside the box, not flush with it. I will be using a 50 amp power cord like this https://www.amazon.com/gp/product/B08ZMLQDBP/ref=ppx_od_dt_b_slice_asin_title?ie=UTF8&psc=1
As you can see, it is a straight plug, so will go inside the box.
Noted about the cedar.
Yes, you can get extra-deep extension rings up to at least 1.5" depth. You'll probably have to go to a commercial electrical supply house to get one of those though. If it's a metal ring, it should be grounded. I would get some of the grounding pigtails (short green wires with a ring terminal on one end and a spade lug on the other) at the same time, then use the ring terminal to create a grounding point on one of the mounting screws against the steel ring. Cut off the spade lug on the other end of the wire, strip back a bit of insulation, then connect it normally with a wire nut in the box.
I'm not sure those mounting holes in the box you have will line up with the mud ring mounting slots though. Mud rings are typically available for both 4" square boxes and 4-11/16" square boxes. 4" square boxes have the cover mounting screws in opposite diagonal corners (two locations), where 4-11/16" square boxes have four mounting hold locations, two each on two opposite sides of the box. You'll want to be sure your mud ring lines up with the mounting holes in your existing box.
Bill
Great thank you! I think this one should do? It's from the same manufacturer. Looks like holes line up.
https://www.amazon.com/gp/product/B002W6Z938/ref=ox_sc_act_title_2?smid=A1GAF1H4JQJZXC&psc=1
Hey Bill can you link me on amazon or home depot for the pvc sheet you are talking about? I only see foam.
I usually get stuff like this from either US Plastics in Ohio (I've used them for years), who will ship to anywhere, or locally at Laird plastics, which has branches all over the midwest.
I would recommend at least 1/4" thick PVC for this. Gray is more UV resistant than white. US Plastics has 12" square pieces for a little over $6/ea here:
https://www.usplastic.com/catalog/item.aspx?itemid=137311&clickid=search
BTW, you can easily work this material with wood working tools. A router can make nice edges. If you have a drill press, you can get an X-Y table and an end mill and use your drill press like a milling machine -- it's not ideal, but it will work for a small one-off project.
Bill
Thanks! THose are hard to get for me and take too long. Something like this looks the same? https://www.amazon.com/Density-Polyethylene-Plastic-Sheet-Black/dp/B071SF9M9Q/ref=sr_1_7?dchild=1&keywords=12%22+x+12%22+Gray+PVC+Sheet&qid=1632509618&sr=8-7
No, that's not the same stuff. Your link is black HDPE. It will be a bit softer than the PVC, but should be perfectly useable -- just note that it's pretty much impossible to glue to it and tape doesn't like to stick to it. Aside from that, you should be OK using HDPE instead of PVC here. I would recommend through bolting everything and not trying to tap holes in HDPE though, but I would have recommended that for the PVC too.
Bill
Why not just get one designed for surface mounting, like this one? https://www.amazon.com/dp/B095RR593N/ref=sspa_dk_detail_3?psc=1&pd_rd_i=B095RR593Np13NParams&spLa=ZW5jcnlwdGVkUXVhbGlmaWVyPUEyTkc0VloyT1pKWEgxJmVuY3J5cHRlZElkPUEwNDE0ODkxM1FPN09BTVpaODdCUiZlbmNyeXB0ZWRBZElkPUEwODAyMzAwMkROVEtEWFpTUFZLVCZ3aWRnZXROYW1lPXNwX2RldGFpbDImYWN0aW9uPWNsaWNrUmVkaXJlY3QmZG9Ob3RMb2dDbGljaz10cnVl
It's 20 bucks more but you'd spend that on fittings trying to surface mount the other one.
Hey there, because I already have a junction box with my electrical wires coming out, and I think it would look silly to mount a box over that, or attach a new one right next to it.