50-AMP Hookup for a Truck Camper?

[roamlab]

Hi everyone! We just stripped a vintage truck camper and are rewiring it from scratch. I have tons of questions, but I thought I'd start with a big picture one: is there ever a case where it would make sense to wire a truck camper to support 50-amp shore power instead of 30-amp?

From what I've read, 30-amp hookups are pretty standard on truck campers. It's not as if we need to power two air conditioners or anything so demanding. But if one ever were to come across a scenario where there are only 50-amp hookups, it is much safer to step down from a 50-amp to a 30-amp than step up from a 30-amp to a 50-amp. Have you ever come across cases where you've hooked up to 50-amp shore power? Or am I just getting distracted by hypotheticals?

Alternatively, does anyone know a resource for completely rewiring a camper? Most blogs and forums only address swapping out one component for a more modern version. I've been researching for days, but this is all I've collected thus far: ***Link Removed***

[deltabravo]

ScottG wrote:
Without a washer/dryer or second AC, there's just no use for it and the added weight and complexity.

Ditto.

[mkirsch]

Since a 50A is two hots, a neutral, and a ground, it would be 8/4 cord, and 8/3 if you are wiring a single leg.

I know this because I have done it. In fact I have a custom adapter cord that splits out a 50A into two 30A to run two separate RVs at the same time. This is extremely useful at a crowded campground where most people are using the 30A and 20A plugs, and only 50A are available.

[Kayteg1]

Boatycall wrote:
I'll chime in on this, I'm an electrical engineer and I'm planning on upgrading to 50a single-leg.

Now, to some of the points made -
cord size--
Almost all 50a RV cords are 8/3. I will conceed that you don't likely need both legs, so you can buy/make your own 50a 8/2 plug instead. I intend on making my own.

Who needs it? Me....
Even though most 50a plugs are 50a 2-leg, I'll just use 1.
Why? Making breakfast in the summer.
Coffee maker - 900 watts, ~9amps.
Microwave going, 1500 watts, ~15a.
Electric hot water heater is going because I just took a shower, 400w, 4amps
Fridge on electric, 400 watts, 4a.

That right there is 32a.
Toaster - 900w, ~9a

And then, the AC kicks on....

I can only imagine how you turn all those things on with your 6 hands 😉
I often operate my camper on 20 amp and can have AC and small appliance at the same time + fridge that I don't bother to observe. The only thing that will not work with AC is 1000W microoven. Do they really take 1500W?
1500W takes 12.5 amp BTW
Full 50 amp service would require double leg electric panel in the camper. That opens whole can of worms on its own, beside carrying 50 lb of extension.

[Bedlam]

Unless you are a heavy electric user, 30A will be sufficient. If you want to wire in 50A, use one leg for fridge, AC, heat, water heater and battery charger while using the other leg for every thing else. This will allow you to run your espresso machine, while toasting and still leave enough power to microwave. If you fuse each leg on its own breaker and do not gang it, overloading your second leg will not take down your essential circuits within the camper.

[roamlab]

996Pilot wrote:
Sent you an e-mail with a detailed schematic for camper wiring attached. I hope it helps.

Thanks! I did read and respond (though I know that emails from new addresses sometimes wind up in spam...?)

Boatycall wrote:
I'll chime in on this, I'm an electrical engineer and I'm planning on upgrading to 50a single-leg.

Thank you Boatycall! I know it's a fringe case but I have been curious. We intend to be living in our camper full time, so it's not as if we only need to accommodate weekend or occasional road trip use.

[Boatycall]

I'll chime in on this, I'm an electrical engineer and I'm planning on upgrading to 50a single-leg.

Now, to some of the points made -
cord size--
Almost all 50a RV cords are 8/3. I will conceed that you don't likely need both legs, so you can buy/make your own 50a 8/2 plug instead. I intend on making my own.

Who needs it? Me....
Even though most 50a plugs are 50a 2-leg, I'll just use 1.
Why? Making breakfast in the summer.
Coffee maker - 900 watts, ~9amps.
Microwave going, 1500 watts, ~15a.
Electric hot water heater is going because I just took a shower, 400w, 4amps
Fridge on electric, 400 watts, 4a.

That right there is 32a.
Toaster - 900w, ~9a

And then, the AC kicks on....

Now of course, any of us can just simply do a little basic power management/use propane instead of electric, but if the plug is there, and you're paying for it, why not just upgrade? You can always use a 50-30 adapter for the sites that only have 30a.

[996Pilot]

Sent you an e-mail with a detailed schematic for camper wiring attached. I hope it helps.

[Clarryhill]

Clarryhill wrote:
Personally, I always carry a 50 - 30 pigtail adapter just to cover the situation.

Have you used it much?
I wouldn,t say "much", but have run into a number of 30 amp receptacles that were sketchy enough to use the 50 amp available.

[wnjj]

DWeikert wrote:

ScottG wrote:

Properly done, the RV will have a 30A breaker in its own panel. so even though the outside panel is 50A, your still protecting your own wiring with a 30A breaker.

Agreed. Regarding the camper's wiring on the load side of the camper's electrical box, this discussion is irrelevant. But the wire between the camper's internal box and the shore power breaker should be sized for the breaker feeding it, not for the load it serves. You can save weight if you want. But if the OP is rewiring the camper anyway, and anticipates camping where only 50 amp service is available, why not be safe?

Though your point is valid, I don't completely agree with it. What about a small appliance in your house? It has a cord sized for itself but plugs into 15 or 20A receptacle backed by a 15 or 20A breaker. The appliance wiring likely going to handle 20A but it's not a problem to use it that way.

With the camper supply cord being the only thing "exposed" to 50A, I don't see any practical way it can draw between 30A and 50A for any length of time. Too much load in the camper will trip its 30A main. A direct short within the cord will trip the pedestal 50A breaker, even with 30A-sized wire.

[roamlab]

DWeikert wrote:
Sure, you can use an adapter to plug a 30 amp plug into a 50 amp outlet but that outlet is still going to have a 50 amp breaker. Just make sure your internal wiring up to the camper's breaker panel can handle the 50 amps should a fault occur.

That's pretty much what I meant by "step down" but I didn't specify what was being stepped down. Thank you for clarifying.

Great point regarding wiring. From the responses, it does seem like having a 30-amp system that can handle a 50-amp fringe case is an option....

ScottG wrote:
Properly done, the RV will have a 30A breaker in its own panel.

Good point! I guess my challenge is to get it "properly done." 😉

ScottG wrote:
Here are two 25' power cords.

Ooff! Point taken! Space certainly is a concern.

996Pilot wrote:
I don't know your current location or the location of the camper (is it mobile?) but I could help you out and help you make all of the decisions you need based on your intended use

Wow! Any input you can offer is most appreciated. Unfortunately, we are stuck in Tennessee at the moment while we replace the rotted out floor and wings. We do intend to head west but not until November / December.

Clarryhill wrote:
Personally, I always carry a 50 - 30 pigtail adapter just to cover the situation.

Have you used it much?

DWeikert wrote:
the wire between the camper's internal box and the shore power breaker should be sized for the breaker feeding it, not for the load it serves. You can save weight if you want. But if the OP is rewiring the camper anyway, and anticipates camping where only 50 amp service is available, why not be safe?

I'm really unsure that to anticipate as far as hookups. My thinking, though, was: given the fact that I am rewiring the system and we want to keep our options open...is supporting 50 amps a contingency worth pursuing. I'm getting the impression that it is not.

[DWeikert]

ScottG wrote:

Properly done, the RV will have a 30A breaker in its own panel. so even though the outside panel is 50A, your still protecting your own wiring with a 30A breaker.

Agreed. Regarding the camper's wiring on the load side of the camper's electrical box, this discussion is irrelevant. But the wire between the camper's internal box and the shore power breaker should be sized for the breaker feeding it, not for the load it serves. You can save weight if you want. But if the OP is rewiring the camper anyway, and anticipates camping where only 50 amp service is available, why not be safe?

[Clarryhill]

Personally, I always carry a 50 - 30 pigtail adapter just to cover the situation.

[996Pilot]

roamlab wrote:

Alternatively, does anyone know a resource for completely rewiring a camper? Most blogs and forums only address swapping out one component for a more modern version. I've been researching for days, but this is all I've collected thus far: ***Link Removed***

Read your blog and there's just too much to comment on via this forum or back and forth via e-mail. I don't know your current location or the location of the camper (is it mobile?) but I could help you out and help you make all of the decisions you need based on your intended use. Additionally I have reverse engineered several RV electrical systems and created full schematics of all of the AC/DC systems. Happy to do the same for your application after a few conversations about your use.

BTW your blog regarding charging from the alternator (simple one wire) is not so straight forward. You may want to look into an isolator in that system. Also - battery disconnect would be nice. Battery monitor (brand) I'd recommend a different (better) one. Lots of other comments.

Dan -- North San Diego County

[ScottG]

Here are two 25' power cords. The first a 50A and the second, a 30A.

You'll have to decide if the space taken by the 50a, which is easily twice the size, is worth it.