I own a lake lot & have 60 amp service to my power pole. I would like to run a buried line from the pole to my motorhome & bunk house. I would like to supply the power as such;

1 line (20 amps) to the motor home (50 to 75ft)
- to supply power to motorhome with the breaker on the power pole
1 line (40 amps) to the bunk house (100 to 150ft) connected to a sub panel in the bunk house with 2 breakers
- 1 (15amp) for 10-20 gal electric hot water heater.
- 1 (25amp) for pressure pump, fridge, lights, & outside plug for misc use around the lot.

Questions
1. can I do this?
2. what size wire for both lines?
3. can I run both lines in 1 trench?

Jim

There are really two questions here that need to be addessed first. You will need a permit for this work and your building inspector will tell you what is and is not allowed . I'd call and ask him. Second question is have your created a list of your known loads? 20 amps for an entire motor home seems low since you'd have a frig and likely a water heater. 15 amps for a small water heater in the bunk house also seems low. We can't tell you the wire size until you determine the loads which determines the breaker, that determines the wire size. This chart will help you once you know your needed breakers. Wire sizes, gauges, for breakers (http://www.greatinspector.com/faq-elec-wiresize.html)

Javelin,

From the tone of your post I would strongly suggest you get some on-site help.

There are a lot of mistakes right off the bat with most of what you are suggesting.

- A 20A circuit is not enough to effectively run a motor home. You should at least run a "travel trailer" circuit and receptacle to it.
You best bet is to run whatever size circuit the cable from the motor home has. What is the plug on the cord coming from the motor home?

- A 40A sub-panel is fine, but 120v/15a to a water heater is a mistake.
Also, you CANNOT have what you suggest on a "25a" breaker. In fact, a 25a breaker is an extreme rarity.
The things you describe can only be on a 15 or 20 amp circuit, except for the pump, which should be on it's own circuit. That circuit should be whatever size is correct for that particular motor.

There are really two questions here that need to be addessed first. You will need a permit for this work and your building inspector will tell you what is and is not allowed . I'd call and ask him. Second question is have your created a list of your known loads? 20 amps for an entire motor home seems low since you'd have a frig and likely a water heater. 15 amps for a small water heater in the bunk house also seems low. We can't tell you the wire size until you determine the loads which determines the breaker, that determines the wire size. This chart will help you once you know your needed breakers. Wire sizes, gauges, for breakers (http://www.greatinspector.com/faq-elec-wiresize.html)

1. I will need to call about the permit
2. Motor home has small fridge, gas water heater, 11000 BTU a/c. I checked max draw peaked at 19 amps & averaged around 4-5 amps most of the time without a/c.
3. manufacturer for bunk house HW heater recommends min. 15amp breaker as it's max draw is 1650w (15 amps). The lites (2-3amps), pump 750w(6.8amps), fridge(6amps max).

How did you gauge the motor home? An amp clamp meter is NOT an accurate way to check this.

If the water heater is 1650 watts it does NOT draw 15 amps. It draws 13.75 amps and requires a 20A dedicated circuit.

If you are installing a sub-panel, what is the rationale behind not having at least the fridge and pump on their own circuits??

How did you gauge the motor home? An amp clamp meter is NOT an accurate way to check this.
I have a meter that plugs into the source then you plug the load into it.New Kill A Watt EZ Electricity usage meter P4460 P-4460 - eBay (item 220260182201 end time Jul-31-08 17:31:33 PDT) (http://cgi.ebay.com/New-Kill-A-Watt-EZ-Electricity-usage-meter-P4460-P-4460_W0QQitemZ220260182201QQihZ012QQcategoryZ50625 QQcmdZViewItem)
Also Ithe mh cord is 30amp with an adapter to use 15 or 20amp connection. The a/c is not used much & if needed I can switch to my onbard gas 4k generator for that.If the water heater is 1650 watts it does NOT draw 15 amps. It draws 13.75 amps and requires a 20A dedicated circuit.
Ok so I will supply with 20amp

If you are installing a sub-panel, what is the rationale behind not having at least the fridge and pump on their own circuits???
The previous owner only ran 60amps to the power pole on the lot. So if I run 20a to MH, 20a to heater I only have 20a left which would be equal to 1 breaker no?

Am I missing something in that if I have 60amp supply I can only run 3 20a breakers, 4 15a breakers or a combination of both to equal 60amps. The other option is to have the county rewire the meter to 100amp & install a cut off switch, run a 100 amp breaker box in bunk house then distribute from there. This is going to cost a lot more money to install.

The previous owner only ran 60amps to the power pole on the lot. So if I run 20a to MH, 20a to heater I only have 20a left which would be equal to 1 breaker no?
No! This is not at all correct.
Besides, the 60A is at 240v (more accurately 120/240v), or 14,400 watts.
20A @ 120v is only 2,400 watts.
You are fixated on 20A, 60A, etc. You are forgetting that the voltage I important too.


Am I missing something in that if I have 60amp supply I can only run 3 20a breakers, 4 15a breakers or a combination of both to equal 60amps.
Yes, you certainly are. The sum of the breaker is a meaningless number. You can have 300 amps (and more) worth of breakers in a 60A panel. It is the calculated load that is the important number.

No! This is not at all correct.
Besides, the 60A is at 240v (more accurately 120/240v), or 14,400 watts.
20A @ 120v is only 2,400 watts.
You are fixated on 20A, 60A, etc. You are forgetting that the voltage i important too.


Yes, you certainly are. The sum of the breaker is a meaningless number. You can have 300 amps (and more) worth of breakers in a 60A panel. It is the calculated load that is the important number.

Ok fair enough. So I can run more breakers than I originally thought I just need to make sure my total uasage does not exceed my total coming in correct.

IE. The sub panel can have 3 or 4 breakers such as

20amp for water heater
15 amp for pump
15 amp for fridge
15 amp for lights & outlets

I just need to make sure I donot max out the breakers all at the same time. Am I on the right track now.

Also back to my orignal question, what is the recommended wire size for the wire going underground to the sub panel in the bunk house?

Can I run more than 1 wire in the trench or do they need to be separated?

Jim