Number of service conductors

[trojans4]

Here is the situation. Residential service. There is a meter pedestal in the yard about 50 ft from the house. There is a 200A breaker in the panel but no branch circuits run from it. Service conductors run from there to 200A panel in the house. Do you need 3 wire or 4 wire from the pedestal to the house for this type of service? I think you only need three wires from previous experiences but can't find anything in the NEC in 230 that directly expresses that. I am not doing this job but was asked about size and number of conductors by a friend who is buying the wire for his house.

 

[augie47]

Since there is a breaker at the meter pedestal most inspectors would view the conductors from that breaker to the house as a feeder and per 250.32 require a separate equipment grounding conductor along with the power conductors.
That requirement was not always in the Code so existing installations may be installed differently;y.

 

[Dennis Alwon]

I agree with Gus. The code prior to 2008 did not require 4 wires from one structure to the other. Today , of course, we need it but art. 230 will not help you it's in 250 as Gus stated. Gus is a pretty smart guy....

 

[augie47]

Apparently you got the gift certificate

 

[trojans4]

Thanks guys. I agree that you need it from one structure to another but think our state inspector has ruled in the past that the meter pedestal is a power distribution point and you only need three wires to the residence. That being said, I agree with you after reading article 250 that it indicates you would need the grounding conductor. I will contact the state inspector to make sure.

PS - This came up several years ago and since I have done very few underground services I can't remember what he ruled. My memory is fading faster than my bank account did when I was married to my ex-wife.

 

[ActionDave]

Here is the situation. Residential service. There is a meter pedestal in the yard about 50 ft from the house. There is a 200A breaker in the panel but no branch circuits run from it. Service conductors run from there to 200A panel in the house. Do you need 3 wire or 4 wire from the pedestal to the house for this type of service? I think you only need three wires from previous experiences but can't find anything in the NEC in 230 that directly expresses that. I am not doing this job but was asked about size and number of conductors by a friend who is buying the wire for his house.

Check with the local inspector. Here, where I live the meter pedestal is property of the utility, so as far as my inspector is concerned it doesn't exist.

 

[kwired]

Check with the local inspector. Here, where I live the meter pedestal is property of the utility, so as far as my inspector is concerned it doesn't exist.

We run into some of that around here as well. If the meter pedestal (or other disconnecting means) is provided by the utility, we generally treat anything that leaves that as service conductors. Customer may actually own the disconnect but POCO installs and maintains it, and if it goes bad or gets upgraded it may or may not have overcurrent protection in whatever they replace it with - so it is to be considered service conductors leaving that disconnect.

 

[augie47]

We run into some of that around here as well. If the meter pedestal (or other disconnecting means) is provided by the utility, we generally treat anything that leaves that as service conductors. Customer may actually own the disconnect but POCO installs and maintains it, and if it goes bad or gets upgraded it may or may not have overcurrent protection in whatever they replace it with - so it is to be considered service conductors leaving that disconnect.

Just amazes me how the electrons know the difference and can decide which conductor to use depending on who owns the equipment.

 

[kwired]

Just amazes me how the electrons know the difference and can decide which conductor to use depending on who owns the equipment.

Actually this sort of unwritten rule started before the changes in 2008 that required us to use an EGC with feeders.

I had a situation where I was connecting a couple mobile home services, POCO had a meter/main that they supplied on a pole that was right next to the home. Inspector would not let me use that disconnect as the required service disconnect because of the fact that POCO's providing such equipment can change that equipment out for various reasons. The typical service from rural POCO's in this region usually leaves you with a disconnect from their source but is not always something with overcurrent protection. For that reason they wanted me to provide an additional 200 amp service disconnecting means between the POCO disconnect and the mobile home.

Rural POCO's are also known to commonly provide an unlisted unit containing a meter and double throw switch (transfer switch) if customer wants to pay extra for it - this is most common thing you currently do see that contains no overcurrent protection that often is replacing a meter/main. It cost extra but they can still install it for less then I can install a NEC compliant manual transfer switch, and is in a nice looking single cabinet instead of multiple items cobbled onto the pole. I have one on my service pole myself - at the time it cost me nothing because of electric heating incentives out there at that time. I think today it would cost me something - but still less then I could buy transfer equipment for.