Meter and disconnect remote from residence

Merry Christmas
Status
Not open for further replies.
J

jimbaird

Member
Local electrician tells me (local inspector)that a residential customer has talked local utility into removing meter base and outside disconnect from side of residence (log cabin) and relocating them to a pedestal 120 ft from the building.
He asks me if the feeder to the main panel in the house needs to be four wire type.
I tell him it sounds like we have a design question to answer.
Comments?
 
Re: Meter and disconnect remote from residence

Yes, you do have options. See section 250.32. If you define the pedestal as a structure, this section applies. If the AHJ doens't consider the pedestal a structure, then I feel the feeder must be 4-wire.
 
Re: Meter and disconnect remote from residence

I believe this is an issue to be addressed with the AHJ.
In the state of Massachusetts a disconnect located greater than ten feet from the structure is not considered as the building disconnect (check local requirements).The NEC does not set s specific distance and it has been a well discussed topic for some time. In your case a disconnect at the pedestal would seem moot unless required by the utility for cold sequence metering.If a meter is not necessary at the pedestal then one could be installed in the load-center at the dwelling???? and in such a case an EGC is not required from the pedestal location.

Also as bphgravity has correctly stated if this can be considers as one structure supplying another (and it just may) and there is no interconnecting metal between the two structures then the EGC is also not required.read 250.32 as suggested


Charlie
 
Re: Meter and disconnect remote from residence

Jim ask your AHJ if you just mount a meter at the remote location if you can use a main breaker in the panel inside of the house for your service disconect. If you can then only a 3 wire service entrance conductors would be needed to be ran from the meter to the house. Of course if there is a requirment for outside disconnects or the panel is to far inside then this wouldn't work.

By Charlie: In the state of Massachusetts a disconnect located greater than ten feet from the structure is not considered as the building disconnect
Click to expand...
Wow Charlie that's not very far? Even the NEC and HUD allows 30' for trailers.
 
Re: Meter and disconnect remote from residence

I agree ten is not far but a good portion of Mass is 10,000 foot lots or smaller.

We have been accused many times of thinking small geographically.

This distance was established because of the meter disconnects in the 02 NEC

Charlie
 
Re: Meter and disconnect remote from residence

Jim ask your AHJ if you just mount a meter at the remote location if you can use a main breaker in the panel inside of the house for your service disconnect.
Click to expand...
Wayne, the permission of the AHJ is not be required unless there are some local amendments to the Code. The cash register is not service equipment. Therefore, the meter fitting is permitted to be installed just about anywhere the serving electric utility agrees is acceptable. Without a service disconnecting means and overcurrent protection, you would continue the service entrance conductors to the home and then meet 230.70. :D
 
Re: Meter and disconnect remote from residence

Yes Charlie but what if the AHJ classifies the pole the meter is on as a structure? And then requires a disconnect to be also on this structure?
Wouldn't that require input from the AHJ? :p
 
Re: Meter and disconnect remote from residence

I did an Indian church in Oklahoma last year the POCO,Installed a 200 amp meter and unfused disc on a pole 150 ft away.We used use to a 3R disconnect back to backed to a MLO panel.Since it was on a reservation there were no insp`s ;)
 
Re: Meter and disconnect remote from residence

Wayne, would a disconnect be required if you just ran a service drop to the pole, hit the top of a customer riser and went underground with no equipment on the pole? IMO no, a disconnecting means would not be required, that is done all the time. All we are doing is adding our cash register to the conduit. Remember, our cash register is not service equipment. Look at it as a pulling C or an LB. :D
 
Re: Meter and disconnect remote from residence

Charlie I agree with you ,same as if there was a meter and an underslab to inside the residence doesn`t matter how far inside the panel goes.Main breaker panel after the meter,all it amounts to is an extended back to back.The code says 1st point of entry :D
 
Re: Meter and disconnect remote from residence

I was wondering about an installation where the disconect is contained in the meter socket, can you stub PVC inside the meter socket to location of ML panel?
 
Re: Meter and disconnect remote from residence

All the rules change and you are now dealing with a feeder from a structure. The rules in Article 225 apply to the home and you will have to meet 225.32.
 
Re: Meter and disconnect remote from residence

The meter still has to have overcurrent protection reasonably close to the meter to limit the effects of a short circuit. A 200 amp packaged meter socket and service disconnect would be suitable for this.

You still need a local disconnect at the house as well as local grounding electrodes. The local electrode takes care of what happens when a little bit of lightning strikes near the house.

When one building is feeding another NEC allows 2 different grounding methods provided that service ground fault protection is not needed and there is no parallel path for neutral current in water pipes and so forth. These are:

1. Run 3 wires from the meter/disconnect device to the service switch in the house. Install grounding electrodes at both locations and bond the electrodes to the heutral and service swithc enclosures at both locations. Downstream of the second disconnect use separate neutrals and equipment grounds. There must not be any metal underground pipes that can form a parallel path for neutral current. Gas pipes are not a problem if the gas company requires a dielectric union before the gas pipe goes into the house.

2. Run 4 wires from the meter/disconnect device to the service switch in the house taking care to size the equipment ground for adequate performance because of the distance. Install grounding electrodes at both locations. At the met/disconnect bond the electrode, neutral, and equipment ground to each other. At the 2nd service switch DISCONNECT the bond from neutral to equi;ment ground and connect the local grounding elctrodes to the equipment ground, not the neutral. This method may be impractical if the service panel in the house is suitable ONLY for use as service equipment.
 
Re: Meter and disconnect remote from residence

The meter still has to have overcurrent protection reasonably close to the meter to limit the effects of a short circuit.
Click to expand...
Not if it is a meter disconnect. In fact, it is prohibited from having overcurrent protection in that case. It will be for the exclusive use of the serving electric utility. Also the meter does not get overcurrent protection in most cases.

If you are installing the main service disconnecting means, then "the service overcurrent device shall be an integral part of the service disconnecting means or shall be located immediately adjacent thereto" as stated in 230.91.
 
Re: Meter and disconnect remote from residence

Art 225 does not apply to services. The NEC does permit remote pole meter mounting with the service disconnect located at the building - with no minimum/maximum distance requirements from the pole to the building.
 
Re: Meter and disconnect remote from residence

Originally posted by imacheezhd:
I was wondering about an installation where the disconect is contained in the meter socket, can you stub PVC inside the meter socket to location of ML panel?
Click to expand...
Answer is yes ,we have one builder that specs no SER cable to be used and always has per print .Panel located on stud wall usually in a laundry or mechanical room.Meter can ,disconnect outside pvc to MLO panel.We factor this into bid and away we gooooooo. :D
 
Re: Meter and disconnect remote from residence

Pierre, I think I am a little dense this morning.

Art 225 does not apply to services. I agree.

The NEC does permit remote pole meter mounting with the service disconnect located at the building I disagree, it is done all the time and is not a violation.

- with no minimum/maximum distance requirements from the pole to the building. I don't understand what distance has to do with it. :D
 
Re: Meter and disconnect remote from residence

I was NOT mentioning a meter disconnect at all. I was talking about packaged meter/service switch combination service entrance devices. Around here in Ohio I have to have a service disconnect WITH overcurrent protection immediately downstream of a meter socket. That is the interpretation of every AHJ and power company around here. This is to keep the meter from exploding if the downstream wiring should short circuit.

In the case of meter switches that are connected to urban networks First Energy REQUIRES current limiting fuses in the meter disconnect of higher rating than the overcurrent protection in the downstream service switch. The is no NEC prohibition against this.

In New Jersey, a central or remote meter without overcurrent protection is absolutely prohibited.

Besides, would you want the underground run to have no overcurrent protection? The customer will probably want to connect things like post lights to this underground run, maybe even a power gate. A combination service entrance device that has a main breaker, branch breaker positions, and full current power takeoff lugs will do this.

A meter switch that is part of a so called safety socket is in actuality a safety hazard because the power supply in an electronic sometimes explodes when energized, particularly on 480 volts.
 
Re: Meter and disconnect remote from residence

I was NOT talking about a meter disconnect. I was talking about a packed combination service device with a main breaker immediately downstream of the meter socket.

Here in Ohio, a meter socket MUST have service overcurrent protection as immediately downstream of the socket as practicable. This is the interpretation of every AHJ and power company. This is to keep a short circuit that is beyond the switch from blowing up the meter.

In New Jersey, a central or remote meter without overcurrent protection is absolutely prohibited.

In urban network areas First Energy requires a meter disconnect with current limiting fuses that are of larger rating than the downstream service overcurrent protection. There is no NEC prohibition against this.

Besides, would you want that 150 feet of wiring to have no overcurrent protection? With a redundant service switch at the meter, it is possible to hook up post lights, a shelter for kids waiting for the school bus, or even a power gate.

Also, so called safety sockets that have an unfused disconnect ahead of the meter are in actuality highly unsafe. The reason why is that the power supply in an electronic meter sometimes explodes when energized, particularly on 480 volts. Go over to www.themeterguy.com .
 
Status
Not open for further replies.
Top