Rv site planning-understanding article 551

[Necnerd]

I’m looking to get confirmation I am interpreting the nec correctly, and the plan I have came up with for a 4 space possibly in future 6 space rv site doesn’t have any faults…

My plan is to put a 200amp feed through 8 space panel at the pole under the poco meter.
I would use the feed through lugs and run 3-250aluminum, 1-3/0aluminum quad plex in 2-1/2 pvc to first RV pedestal and then jump out the next three using the lugs at the bottom… (all 4 sites are equipped with 50,30,20amp receptacles)

There will also be a main lug 100amp remote distributing panel fed from a 100amp breaker at the service. The 100amp remote distribution panel will be fed with 3-1/0 al and 1#2al quad plex in a 2” pvc conduit. This panel will be feeding a 2hp well and possible heater.

I was told well motor is 3 phase, and they will be adding a phase converter. I will need to supply wire rated at 1.25% of the well motor. 2 hp 3 phase 230 volt motor should pull 6.8amps

6.8amps x 1.25 = 8.5amps. After looking at Franklin aims Manuel. I thought I could run 2pole 20a ocod with #12 copper conductors down to the well pressure switch/ phase converter. Ocpd to pressure switch is less than 25 ft, and the well is 200ft down. I’m assuming we’ll company will run #10 or larger down to well motor and pump.

I used the aims Manuel to come up with this for voltage drop.

#12 copper is good for 510 feet according to there chart
#10 copper is good at 810 ft

25ft/510=0.588 in .0438 branch circuit distance
220ft/810ft =0.2716 well leads
If you add these numbers together and multiply by 100 you get 31% so I would still have another 69% to go before I’m over the 5% voltage drop….

Do I need to
Include the feeder wires coming from main disconnect to remote distributing panel?




I came up with this by using the demand factors listed in 551.73(A)

12,000va X 4sites = 48,000va
48,000va X .75%demand= 36,000va
36,000va / 240 volts = 150 amps

If they end up adding two more sites in future
72,000va X 60% demand= 43,200va
43,200va / 240volt = 180 amps

Questions:
Is my 200 amp service big enough for 4 sites and the well. If they add a total of 6 site will my service still be big enough?

Do my tv pedestals need to be rated 200 amp to feed through 4-6 pedestals. This is the model I’m thinking of telling the rv site owner he needs to get. M675CP6010 I will provide de cut sheet in the pictures. RV pedestals will not have main breaker


Thank you to all on this page that inspire to learn and teach! I appreciate you very much!

 

[Necnerd]

sorry in advance im not the best at drawing…

 

[Necnerd]

Or possibly this model depending on what we can find and cost difference

 

[Necnerd]

Says loop splitter connector lines rating 310amp cu and 250a aluminum max

 

[suemarkp]

Don't know much about the RV stuff, but your well pump calc doesn't seem right. If this is a single phase service, the phase converter is going to have to make up for that by drawing more amps on the single phase side in order to generate your ~7 amps 3 phase. Not sure what factor should be used with efficiency and power factor considerations, but I could see the phase converter pulling 14A or so. Then your 125% and now recalc your voltage drops.

 

[Necnerd]

I Haven’t done an rv site nor a well like this, but that’s what I was confused on too. As far as I know seer ode should be 240/120 single phase… The well guy said it’s a Vfd, but I think he meant phase converter because then he said it would be 2 hp 3 phase motor…

 

[Necnerd]

I Haven’t done an rv site nor a well like this, but that’s what I was confused on too. The well guy said it’s a Vfd, but I think he meant phase converter because then he said it would be told me it would be 2 hp 3 phase motor…

 

[Necnerd]

Her is how the well calculation is listed in the aim manual .

 

[Necnerd]

A single phase 2 hp motor at 240 will pull 22 amps according to 250.245
12 X 1.25 =15amps
Aim chart calls for a 25a max ocpd

 

[Necnerd]

I also believe the “0hase converter” I talked about to be an actual Vfd that takes single phase Input and changes it to 3 phase output

 

[jap]

I would think you would need the UN metered version of the pedestals.

These are being fed by a Feeder from the customer owned panel, not Service Conductors from the Utility Company.

Jap>

 

[Necnerd]

I would think you would need the UN metered version of the pedestals.

These are being fed by a Feeder from the customer owned panel, not Service Conductors from the Utility Company.

Jap>

So there is a meter above service disconnect. I would be running 4 wires to the pedestals and isolating grounded/ grounding conductors at each perdestal. Customer would like to meter each rv site so they can pay monthly electrical bill for each site…. As far as I know the meter at the pedestal will only track each site and the meter above service would track rv sites and the well panel…

 

[jap]

Not sure about your area but around here the Power Company wouldn't be putting one of their meters in the customer's pedestal since those would be customer side Feeders at that point.


They would only be supplying the meter on the line side of the Service Disconnect.

Jap>

 

[Necnerd]

I figured out that I need to size my conductors 1.25% of the max rated in out current per 430.122.

Say the single phase input rating of a Franklin subdrive 20 is 19 amps (19x1.25)=23.75

so according to 310.16 #12 copper would satisfy this… now I need to take into consideration for voyage drop but per the drive manual chart of this drive is 85 ft or less supplied by 230volts I could get away with using 12 as a branch circuit in a 20 amp fuse/ breaker. Per Vfd manual

 

[Necnerd]

Not sure about your area but around here the Power Company wouldn't be putting one of their meters in the customer's pedestal.
They would only be supplying the meter on the line side of the Service Disconnect.

Jap>

These will be customer owned meters, not supplied through the Po co company. Thank you for the response though I’m looking for any input I can get!

 

[jap]

Interesting.


Jap>

 

[Necnerd]

Interesting.


Jap>

Something like this I believe… that way the guy with a 30 amp plug and small ac isnt paying what the guy with 50 amp plug and 2 ac units is paying. And the owner of the rv site has a way to track each sites usage… That was thought anyway. Maybe I’m missing something in the nec that this install would violate?

 

[jap]

I'm just interested in how this actually works.
Most Rv sites charge a standard fee per night which covers all of the utilities used.

This may be more like a Trailer Park scenario for long time use.

Regardless of the type metering they use, I personally wouldn't want that charge to be an unknown until I arrived at the gate to pay my bill and leave.

But that's just me.

Jap>

 

[Necnerd]

I'm just interested in how this actually works.
Most Rv sites charge a standard fee per night which covers all of the utilities used.

This may be more like a Trailer Park scenario for long time use.

Regardless of the type metering they use, I personally wouldn't want that charge to be an unknown until I arrived at the gate to pay my bill and leave.

But that's just me.

Jap>

Yeah basically it’s for long term rv for a wind farm workers… they take picture of beginning and end of month and pay there own each individual meter reading. I believe they are working out like 12 month lease per site instead of just day use…

 

[tortuga]

As far as the article 220 service calcs go, I think the RV service load calc is correct.
As far as these farm size well pumps that have 3-phase motors and a factory matched VFD / motor controller / phase converter, I would tend to ignore the 3-phase motor and go with 125% of the single phase input nameplate of the combo VFD / controller / phase converter as it probably falls under 430.120 or Article 455 phase converters or both.
My rationale would be its a single phase service, and the well pump controller is more like an appliance than a 'motor'. Much like many other VFD driven appliances these days that may use a three phase motor internally, but are single phase input.