CapeBuild Build Journal

[bdosborn]

So there's code and there's reality.

Code:
It's always bad electrical practice to have big chunks of conducive metal at a "floating" voltage. Any voltage source that happens to contact the metal can raise the its voltage and current flows when there's a voltage difference. So grounding the frame does two things, it ensures that the frame is at the same ground potential as the charger case and provides a fault current return path to open the breaker if 120V does happen to energize the frame. Otherwise the frame will stay at 120V and will conduct current through you if you touch the frame. Your body has a lot of internal electrical resistance so it's unlikely that the breaker would see the current flowing through you as a fault and open. Most NEC code requirements are added as a result of someone getting hurt so its very likely this scenario has occurred.

Reality:
Yes it's required to bond the charger to the frame IF you are a commercial RV builder. You don't have to as hobbyist and no one is going to do an electrical inspection of your trailer. Your charger will work just fine without the case ground. The Victron Charger was designed in the Netherlands and may not be equipped with a case ground for US markets, especially if it is IP67 marine rated. So grounding the case comes down to safety and not functionality. Weighing the odds; how likely is it that your charger hot wire will touch the frame somehow? That's your call but I think its pretty unlikely and I've never seen it happen on the Teardrop forums. Your safety efforts are probably better served by testing campground outlets you plug in to and making sure you don't connect the neutral to the ground in your trailer.

Bruce

P.S. the charger in my teardrop had a plastic case with no ground provision so I didn't ground it. The charger in my standy had a metal case with a ground lug so I grounded it to the frame.

[tony.latham]

and no one is going to do an electrical inspection of your trailer...

John:

Well... If I ever get a chance to inspect your fine camper, I'm going to scrutinize the hell out of it. Your tear-tour may take an hour or so.



Tony

[bdosborn]

Well... If I ever get a chance to inspect your fine camper, I'm going to scrutinize the hell out of it. Your tear-tour may take an hour or so.

I'll come and I'll bring beer.

Bruce

[lfhoward]

I always look forward to CapeBuild updates!

Note: On my build the electrical system was floating and not grounded to the chassis for about 5+ years. I had no issues at all with it. When I added my Propex heater 2 years ago it created a new ground point to the chassis through the propane pipes and tank bolted to the frame. So the electrical was no longer floating. However, the +/- wires from the battery to the heater were not beefy enough to take that kind of grounding current, should it ever be needed. At that point I got serious and made a dedicated chassis ground point for my electrical system and inverter, using beefy wires, near the fuse box.

[mnswamp]

John, as usual, I'm simply in awe of the craftsmanship that's going into your build!

Regarding grounding - perfect timing for this discussion. I'm laying out my wiring now.
I will have a ATS managing the AC feed between shore power and the 2500W inverter, plus AC outlets for AC and the galley (probably the ubiquitous InstaPot), plus the aforementioned IP-67 charger for topping up the batteries when solar isn't doing its job
Based on what I think I know and the above thread, I plan to bond/ground the AC components to the Chassis. All of my trailer light runs are home runs back to the chassis Jbox for the 7 pin connection to the TV - should this be grounded to the same ground plane as the AC?
Same question goes for the house battery and components. I assume I should have anything with a ground connection grounded to the Chassis?

Thanks

marsh

[Capebuild]

The Victron Charger was designed in the Netherlands and may not be equipped with a case ground for US markets, especially if it is IP67 marine rated.

Bruce, thanks for your thoughts and the follow up. I don't see a "ground" screw on my charger. I think I'll just leave things as they are, for now. If I get an inkling to look into grounding the charger
to the frame (at a later date) I'll think about it a little more. For now, I think it will be okay...I'm not planning on an inverter and no 120 outlets in the trailer. The only 120 would be IP67 for the shore power charging..... thanks again, Bruce.

Well... If I ever get a chance to inspect your fine camper, I'm going to scrutinize the hell out of it. Your tear-tour may take an hour or so.

"Inspection". Hmmm... makes me a little nervous, Tony. You'd wind up seeing all my mistakes and imperfections. That being said, thanks. I'd look forward to traveling your way sometime. Never been to Idaho. At some point I'm looking to do a trip to California, making our way up to Vancouver and traveling back through the Canadian side. Hope to meet some of my TNTTT friends along the way. I don't think I've actually ever been in a teardrop before (other than the one I'm building). You don't see very many of them on the road here in the Northeast. I live 2 miles from Nickerson State Park and this past summer I rode my bike through the park many times looking for teardrops to see. Nothing.

And thanks for your comments LF and Marsh. Nice.
LF.. .I still have it my mind to revisit your great and extensive thread on using the Victron components.... soon as I get this thing built

On another note.... preparing to install the large side sheets of aluminum tomorrow. I remember seeing another thread how the poster used magnets to locate the holes in the trailer where the wires extended from and to transfer where those holes are to be cut in the aluminum. That was/is a great idea and I've saved that thought for this next task. I was unable to stuff both the wires back into the holes in the cabin AND insert the neodymium magnet in the hole....so cut another recess and rested the wires there, freeing up space for the magnets. Will fill the holes with bondo prior to final install of the aluminum. But whoever it was that provided that technique, beer on me for the tip. Good one!
John

[Tom&Shelly]

I live 2 miles from Nickerson State Park and this past summer I rode my bike through the park many times looking for teardrops to see. Nothing.

John

How do the campsites look at Nickerson SP John? (Clean, well spaced, etc?) Camping at MA state parks for non-residents is a bit pricey, so we stayed in neighboring states most of the time last Summer, but we haven't been to Cape Cod yet...

As Shelly and I think about it, we agree there seem to be more tears out here than in the Northeast. Saw a few in Arizona last week.

Tom

[Capebuild]

How do the campsites look at Nickerson SP John? (Clean, well spaced, etc?)

'

Hi Tom. Nickerson is a really beautiful park. It's quite huge with a lot of natural space that is left undeveloped and not used for camping. Lots of bike trails and walking/hiking trails. It's divided into 6 or 7 camping areas. The sites are not piled one on top of the other. There's a number of ponds within the park for swimming and fishing. Then of course you're on the bay side with a number of Brewster bay beaches within a short bike ride. I'd say the sites are VERY clean. I usually see rangers patrolling around the park on these golf cart type vehicles. I'm thinking our first outing will be there (even though it's a walkable distance from our house), just to test things out.... (if we can get a reservation).If you want to know anything specific, let me know and I'd be happy to investigate.
John

[Tom&Shelly]

Thank you John, the park sounds attractive. We will consider it when looking for places to go this Summer.

Tom

[Capebuild]

4.7.22

Installed the right and left side sheets of aluminum. I'll need to make some revisions to the opening for the pop open vent
(make the openings a tad larger. Better than having to make them smaller).

Once again, the technique posted by another member of using magnets to locate the openings for the wires to pass through worked great.
I'll have to do a little research and find out who that was so I can thank them.

John

[halfdome, Danny]

Looks great John, nice and tight.
Is that the plastic cover or the color of the aluminum?
Danny

[Capebuild]

Is that the plastic cover or the color of the aluminum?
Danny

Hi Danny. Thanks! The blue color is just the protective covering. The aluminum finish is clear satin anodized. Nice blue color though
I following your directions in your post and all went well.... so thank you for those "instructions". Used that J roller to press it down. My
arms are feeling it today.

John

[Onajourney]

Looks great John!! How did the contact cement go?

[Capebuild]

4.17.22

Looks great John!! How did the contact cement go?

Thanks!! The contact cement "method" was good. If I had to do it again I'd probably apply the aluminum the same way. There were some hairy moments getting around the curves. On one sheet (I think, if I remember correctly, the larger roof sheet) we (my wife and I) kind of lost control of it and it stuck down in one spot. In a panic I ripped it off. We started over. Got it down okay but then I noticed a small "imperfection", a dimple of sorts, where it stuck and I ripped it off. Luckily that spot will be covered by the solar panel. There's a few other areas where the roof sheet meets the side sheets on the curves that didn't adhere perfectly (maybe a 3/16 gap) but I'm thinking they will pull in when I get the moldings on. The overlaps with the VHB tape worked great. Glad I don't do this for a living.... but all in all..... turned out well. I used .040 aluminum and wondering if using .032 might have made life easier??

Also got the Maxxair fan installed.

Will probably look to install the hatch and hurricane hinge tomorrow and see what kind of challenges that presents. I feel I really need to get that settled before I install the moldings. Also have a bit more aluminum work (the rear roll pan and the front bump out). Should be real easy

John

[halfdome, Danny]

John, if you ever lay down contact cemented sheets again and have premature contact use either a spatula to cut the glue or a squirt bottle of lacquer thinner.
Then refresh that spot with more glue and go at again.
Been there done that, Danny