1 ground rod 2 services

[kbrandt]

I have a question, maybe you guys can help.

I have two 100 amp services on the same pole, one feeds a trailer and the other feeds a different trailer. Power company feed on top of pole, both feed from same poco wires at top. Separate risers and feeders to service.

Do I need two ground rods, one for each service or can I use the same one for both?

Inspector says two, but he said he really didn't know. I think one--who's right.

County only requires one ground rod for one service. But there is nothing on two services on the same pole. The same x-former and same poco wire.

Thanks for any input.

 

[Dennis Alwon]

Well unless you have 25 ohms you need 2 ground rods for one service. However you can use one set of rods for both services. 250.56

250.56 Resistance of Rod, Pipe, and Plate Electrodes.
A single electrode consisting of a rod, pipe, or plate that does not have a resistance to ground of 25 ohms or less shall be augmented by one additional electrode of any of the types specified by 250.52(A)(4) through (A)(8). Where multiple rod, pipe, or plate electrodes are installed to meet the requirements of this section, they shall not be less than 1.8 m (6 ft) apart.

 

[Jim W in Tampa]

yes fine to share same rod. Not sure where your located that they would assume your under 25 with 1 rod. But of local ahj is happy you should be too. The rod does nothing unless hit by lightning

 

[Volta]

I have a question, maybe you guys can help.

I have two 100 amp services on the same pole, one feeds a trailer and the other feeds a different trailer. Power company feed on top of pole, both feed from same poco wires at top. Separate risers and feeders to service.

Do I need two ground rods, one for each service or can I use the same one for both?

Inspector says two, but he said he really didn't know. I think one--who's right.

County only requires one ground rod for one service. But there is nothing on two services on the same pole. The same x-former and same poco wire.

Thanks for any input.

One Grounding Electrode System is fine for both sets of Service Conductors, but as Dennis and Jim pointed out, you should expect to install two if the first does not have a resistance of 25 ohms to ground or less.