Pedestal Service

[GoLonghorns]

We have a 200 amp main disconnect at remote pedestal. PVC underground to house w/ 4 wire to house panel.

Questions:
1) Since pedestal has main disconnect, is exterior panel at house considered SUB which requires isolation on EGC & Nuetral and pedestal considered Main ?

2)Regardless if house is considered Main or SUB, is electrode required at house with 4 wire ?

3)If 3 wire had been sent would requirements also change ?

Clarity on this much appreciated .

 

[charlie]

Re: Pedestal Service

You need to talk to your electrician and electrical inspector. There are several ways of interpreting this area and it is up to the inspector as to which way the interpretation goes. In fact, your electrician may already know how it is done in your area.

 

[GoLonghorns]

Re: Pedestal Service

Charlie,
As you said there seems to be ENORMOUS confusion around this question. I am stuck in the middle as the Builder and see both sides. The AHJ wins but I beleive my Electrical contractor is right and was looking for direction by a nuetral source that may help us solve the dispute.

Unfortunately when discussing this with other contractors and inspectors we get 10 answers when asking 5 people and the answers are all as clear as mud.

 

[bphgravity]

Re: Pedestal Service

Its my opinion that it makes some sense, not much, but some sense to ground electrical services. Why we ground at separate structures is beyond me. So with that being said, it would I would conclude that it would be safe and effective to ground the service pedestal and run 4-wire to the house panel, keeping the neutral and grounds separated.

Treating the the pedestal as a structure and the house as a separate structure, both requiring a grounding electrode system is pretty wasteful and useless.

So to answer your specific questions, 1. yes 2. no 3. 3-wire wouldn't be permitted as 250.32 wouldn't apply.

 

[don_resqcapt19]

Re: Pedestal Service

Q1) Since pedestal has main disconnect, is exterior panel at house considered SUB which requires isolation on EGC & Nuetral and pedestal considered Main ?

A1) The post says that a four wire wire feeder is being intalled. The grounded conductor must be isolated from the neutral at the house in this case.


Q2)Regardless if house is considered Main or SUB, is electrode required at house with 4 wire ?

A2) In my opinion, 250.50 requires a grounding electrode at the house in all cases.


Q3)If 3 wire had been sent would requirements also change ?

A) The only change is now bonding of the neutral and the grounding conductor is required at the house.

Don

 

[iwire]

Re: Pedestal Service

Originally posted by charlie:
You need to talk to your electrician and electrical inspector. There are several ways of interpreting this area and it is up to the inspector as to which way the interpretation goes.

Charlie I am going to put you on the spot, please do not take it personal.

I have seen you say many times that you do not think a meter pedestal qualifies as a separate structure and that you should ask the AHJ.

IMO, given the NEC definition of structure I do not see any gray area to interpret.

Now when someone asks how far they can go 'inside' with service conductors I get the impression your feeling is no distance you must have the service disconnect 'nearest the point of entrance'. I have even seen you mention what might happen in court if an EC goes in 5' even if that is local custom.

230.70 ~ Disconnecting Means

How far inside a house can you mount a Loadcenter

IMO, there is intentional gray area in 230.70 and no gray area in 250.32.

So....my question is whats up with this double standard?

It seems to me that choosing not to treat a meter pedestal as a separate structure is a direct violation of the NEC and could be as much as a problem to defend in court.

My questions are entirely related to the NEC not the need or effectiveness of grounding.

Edit to add links.

[ September 03, 2005, 12:40 PM: Message edited by: iwire ]

 

[johndeereman]

Re: Pedestal Service

Art,100 - "Definitions" States a "structure" That which is built or constructed. Now that being said. Look at Art,225.30 feeding from one structure to another then go to Art,250.32 & look @ what is required when an equipment grounding conductor is ran with the supply conductors what needs to take place is that the grounds & neutrals need to be separated but you need to install a grounding electrode @ that separate structure & that G.E.C. is to land with the equipment grounds not to the grounded/neutral conductor. But also under this Art, if the equipment grounding conductor is not ran with the supply conductors than the G.E.C. is to land on the same bus as the grounded/neutral conductor. now with all of this being said the meter ped with the breaker installed in it needs to be LISTED & LABELED as suitable for use as service equipment & in turn it will need to be properly grounded & bonded @ this location.

 

[charlie]

Re: Pedestal Service

Good morning, Bob, I would take it personal if you had an issue with my point of view and you didn't take me to task with it.

There is no grey area in either situation. 250.32 permits you to use one of two methods and it is cut and dried. The problem comes with the definition of a structure and how the AHJ interprets a structure. Johndeereman has posted the definition from Article 100. Now consider a pole with a riser on it that serves a home, is that a structure that requires service equipment on it? OK, now the same pole with a meter fitting on it, is that a structure that requires service equipment on it? I believe most of us would agree that in both cases that the answer is no.

The Code is clear in stating that metering equipment is not service equipment; therefore, placing a meter in a riser does not make a service location. If I install a post, rise up on it with conduit to a meter fitting and back down to serve a home, is this now a structure to require a service?

With all that said, this argument could be taken a bit further with the addition of service equipment at the post we just installed. This is the call of the AHJ and, I believe in most cases, this will indeed be called a structure and everything downstream will fall to Article 225.

As far as 230.70 is concerned, I agree that is not grey at all. However, it is written into some local rules that a service may be inside a building for a certain number of feet. There are other areas where it is normally recognized that the AHJ "will permit" a certain distance and the electricians may use that distance to their advantage. If it is in writing and in the local amendments, I have no problem with any distance other than it is dangerous. If it is not in the amendments, I would not violate that section.

 

[iwire]

Re: Pedestal Service

Good Morning Charlie

Originally posted by charlie:
Good morning, Bob, I would take it personal if you had an issue with my point of view and you didn't take me to task with it.

Originally posted by charlie:
Now consider a pole with a riser on it that serves a home, is that a structure that requires service equipment on it? OK, now the same pole with a meter fitting on it, is that a structure that requires service equipment on it? I believe most of us would agree that in both cases that the answer is no.

Well I guess I am not 'most of us' thats OK I am used to that.

Bob

 

[George Stolz]

Re: Pedestal Service

My vote: Structure definition.

One other 'defense' of Charlie's statement: About a month ago, I received a memo from the head building inspector in Cheyenne WY. Basically, it was to state that from now on, there needed to be a switch ahead of the "service disconnect" on large services.

The problem was, the large mains have a fuse in them. The Power Company locks up the service switch to prevent tampering. Then the fuse blows at three in the morning, and the POCO suddenly has the responsibility of of being available to unlock the equipment to replace the fuse 24/7.

So they've made the decision to formally amend their local code to 'fix' the 'problem'. It changes the rules: The first means of disconnect is to be ignored, and the second switch in the line is the "service disconnect" where grounding rules take place, etc.

There were more specifics, that would probably make this make more sense, but at the end of the day, one thing is clear: They have made a big change to the NEC that affects 230, 250, etc. Only by communicating with the AHJ would we have known.

Glad I'm not up there, I thought the whole thing was pure folly. It might have been only in relation to hot sequence or something.

 

[iwire]

Re: Pedestal Service

Originally posted by georgestolz:
My vote: Structure definition.

I am thinking that will end up effecting to many other uses of the word structure.

What you described is a meter disconnect as referenced in 230.82(2).

There seems to be an endless difference in power companies.

Here I do not see power company locking up disconnects even if they are ahead of the meter.

Here the position of the meter in relation to the service disconnect depends on the power company, the amperage and / or voltage of the service.

We definitely have to verify all this before buying the equipment.

 

[pierre]

Re: Pedestal Service

From Bob

"We definitely have to verify all this before buying the equipment."

Some contractors install according to their past experience and then have problems after the installations. They should heed this information for all installations.

 

[johndeereman]

Re: Pedestal Service

Charlie,
Under Art,225.1 - States that a POLE is a structure how ever there is nothing stating that it is required to have service equipment installed on it but if you do install service equipment on that pole & then "feed another structure" then this is were it would be required to fallow all requirements listed in Art,225.30 & Art,250.32 for grounding.

 

[iwire]

Re: Pedestal Service

Originally posted by johndeereman:
Under Art,225.1 - States that a POLE is a structure

John as much as I agree a pole is a structure 225.1 does not state a pole is a structure.

The way 225.1 is worded it list buildings, structures and poles as separate items.

225.1 Scope.
This article covers requirements for outside branch circuits and feeders run on or between buildings, structures, or poles on the premises; and electric equipment and wiring for the supply of utilization equipment that is located on or attached to the outside of buildings, structures, or poles.

[ September 04, 2005, 07:04 PM: Message edited by: iwire ]

 

[George Stolz]

Re: Pedestal Service

Originally posted by iwire:
What you described is a meter disconnect as referenced in 230.82(2).

Thanks, Bob.

 

[charlie]

Re: Pedestal Service

We require either a service disconnecting means or a meter disconnect installed in front of our meters in our downtown area. If it is service equipment, we will meter the feeder. If it is a meter disconnect, we will lock and seal it.

It is up to the engineer to serve it up the way he wants to do the installation.

 

[charlie]

Re: Pedestal Service

For what it is worth, the NESC considers a pole to be a structure. Also consider that the NEC covers all premises wiring on the load side of the service point, even if it is on an electric utility's pole.