Where does it say in the code that when service conductors enter the building that needs to be encased in concrete if it was more than 10' run before it lands on the first disconnecting means? if those conduits were run inside a chase (the switchgear is on the second floor), do they need to be encased in concrete? Thank you
Service Entrance conductors
- Thread starter sam34
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jwelectric
Senior Member
- Location
- North Carolina
Re: Service Entrance conductors
230.6 Conductors Considered Outside the Building.
Conductors shall be considered outside of a building or other structure under any of the following conditions:
(1) Where installed under not less than 50 mm (2 in.) of concrete beneath a building or other structure
(2) Where installed within a building or other structure in a raceway that is encased in concrete or brick not less than 50 mm (2 in.) thick
(3) Where installed in any vault that meets the construction requirements of Article 450, Part III
(4) Where installed in conduit and under not less than 450 mm (18 in.) of earth beneath a building or other structure
230.6 Conductors Considered Outside the Building.
Conductors shall be considered outside of a building or other structure under any of the following conditions:
(1) Where installed under not less than 50 mm (2 in.) of concrete beneath a building or other structure
(2) Where installed within a building or other structure in a raceway that is encased in concrete or brick not less than 50 mm (2 in.) thick
(3) Where installed in any vault that meets the construction requirements of Article 450, Part III
(4) Where installed in conduit and under not less than 450 mm (18 in.) of earth beneath a building or other structure
- Location
- Logan, Utah
Re: Service Entrance conductors
230.70 (A) (1):The service disconnecting means shall be installed in a readily accessible location either outside of a building or structure or inside nearest the point of entrance of the service conductors.
The code does not address any length for the "nearest the point of entrance" so each AHJ can interpret this different.
230.6: Conductors shall be considered outside of a building or other structure under any of the following conditions
(2) Where installed within a building or other structure in a raceway that is encased in concrete or brick not less than 2 inches thick.
Chris
230.70 (A) (1):The service disconnecting means shall be installed in a readily accessible location either outside of a building or structure or inside nearest the point of entrance of the service conductors.
The code does not address any length for the "nearest the point of entrance" so each AHJ can interpret this different.
230.6: Conductors shall be considered outside of a building or other structure under any of the following conditions
(2) Where installed within a building or other structure in a raceway that is encased in concrete or brick not less than 2 inches thick.
Chris
- Location
- Logan, Utah
Re: Service Entrance conductors
Wow jwelectric I was slow in typing good post.
Chris
Wow jwelectric I was slow in typing good post.
Chris
jwelectric
Senior Member
- Location
- North Carolina
Re: Service Entrance conductors
I didn't type. The joys of the NEC on CD, just copy and paste.Originally posted by raider1:
Wow jwelectric I was slow in typing good post.
Chris
- Location
- Lockport, IL
- Occupation
- Semi-Retired Electrical Engineer
Re: Service Entrance conductors
In Washington State, the disconnecting means has to be within 15 feet of where the conductors enter the building. The existence of that WAC rule confirms (to my mind, at least) the absence of a similar distance requirement within the NEC itself. Of course, if you do keep the conductors below 2 inches of concrete (as Mike pointed out), you can run them to the other side of the building. I have used that design. The conductors don't "enter" the building until they come up from beneath the concrete barrier.
In Washington State, the disconnecting means has to be within 15 feet of where the conductors enter the building. The existence of that WAC rule confirms (to my mind, at least) the absence of a similar distance requirement within the NEC itself. Of course, if you do keep the conductors below 2 inches of concrete (as Mike pointed out), you can run them to the other side of the building. I have used that design. The conductors don't "enter" the building until they come up from beneath the concrete barrier.
Re: Service Entrance conductors
Hello, I'm new to this forum. This is my first post! This discussion caught my attention. Just wanted to add my 2 cents.
1) 230.6 Conductors Considered Outside the Building
If the installation meets the requirements of 230.6 the conductors are not considered to be inside the building.
2)This is copied from the 2002 NEC Handbook.
VI. Service Equipment ? Disconnecting Means
230.70
Hello, I'm new to this forum. This is my first post! This discussion caught my attention. Just wanted to add my 2 cents.
1) 230.6 Conductors Considered Outside the Building
If the installation meets the requirements of 230.6 the conductors are not considered to be inside the building.
2)This is copied from the 2002 NEC Handbook.
VI. Service Equipment ? Disconnecting Means
230.70
- Location
- Massachusetts
Re: Service Entrance conductors
Hi EG, welcome to the forum.
It is true that 'USE' is not for interior use.
SE or the other hand is flame retardant and can be used inside.
[ September 29, 2005, 05:35 AM: Message edited by: iwire ]
Hi EG, welcome to the forum.
It is true that 'USE' is not for interior use.
SE or the other hand is flame retardant and can be used inside.
[ September 29, 2005, 05:35 AM: Message edited by: iwire ]
- Location
- Lockport, IL
- Occupation
- Semi-Retired Electrical Engineer
Re: Service Entrance conductors
True. But if you have it under concrete, it's not "interior" until it leaves the concrete. I think that the reason Washington has a 15 foot requirement is to limit the risk of accidental damage to the conductors. A long cable, even if in conduit, is more likely (than a short cable) to get bumped by a forklift (or some other WMD).
Re: Service Entrance conductors
iwire,
Thanks for the welcome. And for the correction.
I looked into this a little bit. The 338.2 (2002)
DEFINITION of SE and USE cables confirms just what you stated. So I got bit by the dangers of making a blanket statement. Thanks for pointing that out.
charlie b,
Right, that's the first thing I pointed out. If the conductors meet 2002, 230.6, they're considered to be outside the building.
I agree with you though. The purpose of the interior service conductor length limitation is to prevent unprotected (No O.C.P.D.) interior conductors from being damaged. Service conductors coming into a building without an exterior disconnect/breaker, pose a special risk. Where else would we have that much energy available without an O.C.P.D. in case of a fault?
EG
iwire,
Thanks for the welcome. And for the correction.
I looked into this a little bit. The 338.2 (2002)
DEFINITION of SE and USE cables confirms just what you stated. So I got bit by the dangers of making a blanket statement. Thanks for pointing that out.
charlie b,
Right, that's the first thing I pointed out. If the conductors meet 2002, 230.6, they're considered to be outside the building.
I agree with you though. The purpose of the interior service conductor length limitation is to prevent unprotected (No O.C.P.D.) interior conductors from being damaged. Service conductors coming into a building without an exterior disconnect/breaker, pose a special risk. Where else would we have that much energy available without an O.C.P.D. in case of a fault?
EG
- Location
- Massachusetts
Re: Service Entrance conductors
In this thread they are service conductors and the inside length should be limited.
However keep in mind that SE is can be and often is used inside as feeder conductors. In that case it is installed using the rules in 334 for NM cable.
In this thread they are service conductors and the inside length should be limited.
However keep in mind that SE is can be and often is used inside as feeder conductors. In that case it is installed using the rules in 334 for NM cable.
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