How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site. Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask Kevin Your Own Question
Kevin, Licensed Electrical Contractor
Category: Electrical
Satisfied Customers: 3665
Experience:  30 years Licensed Electrical Contractor in Illinois, Adjunct College Electrical Instructor, Former Electrical Inspector, Diploma: Digital Electronics, FCC Technician License
Type Your Electrical Question Here...
Kevin is online now
A new question is answered every 9 seconds

I have a small acreage. It has electricity onto the land

Customer Question

I have a small acreage. It has electricity onto the land with the electrical panel on the light pole where the electricity comes onto the property. I have a very small fishing cabin on the land about 400 ft from the electrical pole. I want to run electricity from the pole to a subpanel in the fishing cabin. The main panel (on the pole) has a 200 amp main breaker on the top in the panel. The bottom of the panel has a few 20 amp breakers that control some 110 electrical outlets they placed lower on the pole. Ther are several spaces for other breakers.
Here is what I know:
1. An electrician told me I need to run number 2 wire form the main panel on the pole to the subpanel in the fishing cabin. I assume I need 2 2 2 -4.
2. I need to buy the kind that can be buried and bury it 24 inches deep.
3. I need to stay with the same manufacturer (Square D) for all the parts.
4. I need to take the strap between the neutral and ground bars out of the subpanel (or the green screws).
5. I need at least a 100 amp subpanel.
6. I need an 8 ft ground rod in the ground (and attached to the ground in the panel).
My questions are these:
1. Do I just place a breaker (or two) in the bottom of the main panel for the feed to the cabin?
2. If so do I need:
one 100 amp breaker or
two 50 amp breakers or
two 100 amp breakers
3. Do I need tandem or 2 pole breakers?
4. Do the new breakers in the main panel have to be connected to just the red or black or to both?
5. In the cabin will the wires run to a 100 amp main breaker like at the pole?
6. If so, I assume I will connect the red hot and the black hot wires to their bars, the neutral to the neutral bar and the ground to the ground. Is that correct?
I don’t need 220 volts outlets in the cabin.
Submitted: 11 months ago.
Category: Electrical
Customer: replied 11 months ago.
Posted by JustAnswer at customer's request) Hello. I would like to request the following Expert Service(s) from you: Live Phone Call. Let me know if you need more information, or send me the service offer(s) so we can proceed.
Expert:  Kevin replied 11 months ago.

Hello and welcome to Just Answer. My name is ***** ***** I will be happy to assist you with your electrical question.

1) The NEC recommends that the voltage drop be limited to 3% or less. Unfortunately, the electrician is incorrect and did not perform a voltage drop calculation. Using 2 AWG copper results in a 6.3 % VD. Using 2 AWG aluminum results in a 9% VD. Both of these VD %'s are not recommended per the NEC as they are too high.

On a 400 foot run @ 240 volts and 100 amps, you need 4/0 AWG Aluminum which results in a 2.8% VD or 2/0 AWG copper which results in a 3.1% VD (slightly over but still OK)

2) Correct, minimal burial depth = 24 inches below final grade. URD 4 wire cable is the type used.

3) Correct, on any sub-panel, the main bonding screw or main bonding strap is never installed. The neutral must remain isolated from the panel metal enclosure.

100 amps is the minimal service allowed by the NEC for a single family dwelling.

4) A minimum of one 8 foot ground rod is required at the cabin sub-panel if you can prove the resistance using a Meggar tester is 25 ohms or less. If no Meggar available, then two 8 foot rods spaced a minimum of 6 feet apart are required at the cabin.

5) A quantity of one 100 amp full size double pole feeder breaker is required in the 200 amp panel.

6) The feeder circuit to the cabin sub-panel will be 240 volts and the feeder hots will need to be labeled as black and red.

7) Yes, the cabin will require a 100 amp main breaker panel.

8) At the cabin sub-panel, you will need a separate equipment ground bar to land the grounding electrode conductor along with any bare copper grounds from Romex cables. The neutral from the feeder circuit along with the neutrals from the branch circuits will terminate to the sub-panel neutral bus bar.

9) Sub-panels always provide a combination of 120 and 240 volts due to the 2 hots and 1 neutral from the feeder circuit.

Expert:  Kevin replied 11 months ago.

1) In addition, in all habitable areas of the cabin, arc fault circuit breakers (AFCI) for the 120 volt branch circuits are required.

2) Each bedroom and each hallway of the cabin requires inter-communicated smoke alarms.

3) If any fuel fired appliances in the cabin, then CO alarms are required outside of the bedrooms.

4) All interior receptacles need to be the tamper resistant type.

5) GFCI protection is required for the kitchen countertop receptacles, exterior receptacles, bathroom receptacles and basement receptacles (if applicable). A dishwasher also requires GFCI protection.

6) Exterior receptacles also need to be a combination of TR and WP type (tamper resistant and weather rated). Exterior receptacles also require an in-use bubble cover.

Expert:  Kevin replied 11 months ago.

1) I also recommend that you contact your local electrical building code official and run your plans past them prior to starting construction. Obtain approval from the local Authority Having Jurisdiction first.

Keep in mind that local electrical codes can always take precedence above and beyond the National Electrical Code. The local electrical inspector always has the final approval for such installations.

Expert:  Kevin replied 11 months ago.

If you have any additional questions, just let me know and I’ll be glad to answer them for you.

Otherwise, don’t forget to rate me before you log Off.