Camper Hook Up

[iwire]

If I am reading this right the 240 volt 50 amp outlet should be calculated at 9600 VA. The 120 volt 30 amp outlet with a 20 amp GFCI outlet should be calculated at 3600 VA.

9600 VA + 3600 VA = 13200 VA
13200 VA ÷ 240 volts = 55 amps
55 amps × 1.25 = 69 amps

80 amp feed breaker
Two #4 THHN hots
One #6 THHN neutral
One #8 THHN ground

In my opinion adding the 125% is not required and no need to round up 11 amps but it is certainly code compliant.

You could do a 60 amp with 6 AWG not factoring voltage drop.

 

[kda3310]

Assuming the equipment can legally have multiple outlets in use at one time, perhaps you should just ask the owner if s/he wants to pay for the larger wire and main breaker panel breaker to allow multiple use or just pay for the smaller wire/breaker single use option. (And of course any other variable expense like conduit size and added labor.)

I do not own my own business. I work for a local plant. I usually just work off of plans and do as I'm told. However, this time I was given the task to install this camper hook up for a portable hearing test booth. It was left up to me to let my boss know what I need. There will probably never be more than one thing hooked to this at a time. I just needed to know how to size to give my boss a list. Thanks for all the help. I now know the right questions to ask and how to get the right answers now.

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[kda3310]

In my opinion adding the 125% is not required and no need to round up 11 amps but it is certainly code compliant.

You could do a 60 amp with 6 AWG not factoring voltage drop.

I thought if it ran for more than 3 hours it was considered a continuous load and had to be multiplied by 125%

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[Coppersmith]

i disagree with that, do you have a source or reference stating that?

The only source I can quote you is the sign on every pedestal in every RV park I've ever stayed in that said approximately "Do not use more than one outlet at a time. Turn off breakers not in use" This is probably just the way it's done by the owners to save on wiring costs, not a NEC requirement.

If the device can be wired for all the outlets to be hot simultaneously, sure you can do it, but it's not what's expected and way more costly to do. That's why I suggested getting owner approval before doing it.

 

[iwire]

I thought if it ran for more than 3 hours it was considered a continuous load and had to be multiplied by 125%

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That is part of it, from article 100

Continuous Load. A load where the maximum current is expected to continue for 3 hours or more.

The loads in a camper cycle, the maximum load will not last 3 hours.


Now to be clear I have been posting about what I think the code minimums are. If you want to add 25% by choice there is nothing wrong with that.

When installing one pedestal it would not add much cost and I might do that, on the other hand if I was pricing a bunch of them that could mean not getting the job

 

[kda3310]

i disagree with that, do you have a source or reference stating that?



Why is that?

So you think it's a violation for me to plug my camper into the 30 amp outlet and my radio into the 20?:huh:


A camper pedestal is just a job specific panelboard, we would not be having discussions about adding up the current ratings of the breakers in a homes panel to size the service. We know we would use load calculations. The same applies here. It will require more than a 50 amp breaker at the supply.

551.73 States that all the sights will have a 120 volt 20 amp outlet and then gives you a demand ​factor of 3200 VA for the 30 amp outlet and 9600 VA for the 50 amp outlet. The 20 amp out is already counted in the demand factor. The real question is can you or should have the 30 amp and 50 amp on at the same time. I think one box one campsite. If you use both outlets then it is two camp sites running off of one box.

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[iwire]

The only source I can quote you is the sign on every pedestal in every RV park I've ever stayed in that said approximately "Do not use more than one outlet at a time. Turn off breakers not in use" This is probably just the way it's done by the owners to save on wiring costs, not a NEC requirement.

If the device can be wired for all the outlets to be hot simultaneously, sure you can do it, but it's not what's expected and way more costly to do. That's why I suggested getting owner approval before doing it.

It's a panelboard, all outlets can be on at the same time.

Unless you can show me a code or UL standard that says otherwise I will continue to believe that.

You do know some parks do allow more than one camping unit per site? I would say that is why the NEC requires a site with multiple outlets to have multiple va loads used in the calculations.

 

[iwire]

The real question is can you or should have the 30 amp and 50 amp on at the same time.

No, that is not a question.


If you go to your own homes electrical panel and add up the value of all the breakers it very likely exceeds the rating of your main breaker even taking into account single phase loads etc

Now do you concern yourself with only turning on as many breakers that add up to the mains rating?

Of course not, so why would you do it here?

 

[augie47]

It's a panelboard, all outlets can be on at the same time.

Unless you can show me a code or UL standard that says otherwise I will continue to believe that.

You do know some parks do allow more than one camping unit per site? I would say that is why the NEC requires a site with multiple outlets to have multiple va loads used in the calculations.

If you wish to take Art 551 as applicable, from 551.73:
Where the electrical supply for a recreationalvehicle site has more than one receptacle, the calculatedload shall be calculated only for the highest ratedreceptacle.

 

[iwire]

If you wish to take Art 551 as applicable,

It is not my wish, it is what the scope states.

from 551.73:
Where the electrical supply for a recreationalvehicle site has more than one receptacle, the calculatedload shall be calculated only for the highest ratedreceptacle.

Sweet, so they can back it up even less than the 60 I suggested if they wanted to.

 

[augie47]

It is not my wish, it is what the scope states.

.

I make that statement since 551.73 is in Part VI of Art 551 which is entitled "RV Parks".
By 551 definition a RV park consists of two or more RV sites. As I stated in an earlier post, I would be comfortable using 551.73 but an argument can be made that its not applicable as this is not a "park".

 

[iwire]

I make that statement since 551.73 is in Part VI of Art 551 which is entitled "RV Parks".
By 551 definition a RV park consists of two or more RV sites. As I stated in an earlier post, I would be comfortable using 551.73 but an argument can be made that its not applicable as this is not a "park".

Interesting.

In escense you are saying no code applies to the size of this feeder.

How would you calculate it?

 

[augie47]

Interesting.

In escense you are saying no code applies to the size of this feeder.

How would you calculate it?

My opinion is way back in post #8 LOL.... Unless I knew more than one receptacles was going to be in use at one time I'd feed it with a 50 amp feeder although 551 would allow a 40 amp if it were in a "park".

 

[iwire]

My opinion is way back in post #8 LOL.... Unless I knew more than one receptacles was going to be in use at one time I'd feed it with a 50 amp feeder although 551 would allow a 40 amp if it were in a "park".

I was looking for a code answer but I guess there is not one.

 

[augie47]

From a Code standpoint, since Table 551.73 shows a demand for "1" site (100%) and allows that 9600va is allowable for the 3 receptacle unit meaning, as I understand it, if it were on its own feeder it would be a 9600va load with no demand adjustment, would it not be within Code to use the same calculation if that one unit happens not to be in a park ?

 

[iwire]

From a Code standpoint, since Table 551.73 shows a demand for "1" site (100%) and allows that 9600va is allowable for the 3 receptacle unit meaning, as I understand it, if it were on its own feeder it would be a 9600va load with no demand adjustment, would it not be within Code to use the same calculation if that one unit happens not to be in a park ?

You told me 551.73 not apply.

Now we are going to cherry pick part that we want and ignore the rest?

It seems if 551 does not apply here we need to go to article 220 which seems to allow me to count each of the three receptacles at 180 va each for the feeder. So a 14 AWG with a 15?

 

[kda3310]

You told me 551.73 not apply.

Now we are going to cherry pick part that we want and ignore the rest?

It seems if 551 does not apply here we need to go to article 220 which seems to allow me to count each of the three receptacles at 180 va each for the feeder. So a 14 AWG with a 15?

There is no way I'm telling my boss that.

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[augie47]

or possibly:
220.18 Maximum Loads. The total load shall not exceed the rating of the branch circuit.....................................

I have no idea what the correct "Code" answer is

 

[kwired]

My experiences, you can get away with a lot and not have much tripping with RV's/campers. Until it gets hot outside. Then you better have at least 20 amps @ 120 volts for every air conditioner or you will have problems. The units that have a 50 amp cord have multiple air conditioners, but individual AC units are all similar in capacity. Occupants often don't use much other power when it is hot. Cooking is often done outside to keep from adding more heat inside.

 

[K8MHZ]

I do not own my own business. I work for a local plant. I usually just work off of plans and do as I'm told. However, this time I was given the task to install this camper hook up for a portable hearing test booth. It was left up to me to let my boss know what I need. There will probably never be more than one thing hooked to this at a time. I just needed to know how to size to give my boss a list. Thanks for all the help. I now know the right questions to ask and how to get the right answers now.

Sent from my XT1565 using Tapatalk

Would camper/RV calculations and/or requirements apply to a portable hearing test booth?