1984 building with 9 disconnects

Status
Not open for further replies.

mwm1752

Senior Member
Location
Aspen, Colo
look at NEC 1014 handbook exhibits 230.6 is what the op shows. 1981 was no different in this concept -- one more time -- one service drop or lateral to a building is one service -- parallel laterals bonded together at transformer & structure is defined as a single lateral -- more than one service would be parallel laterals not bonded at the structure -- one service has a max six switch rule to disconnect service power to building. --- code does allow for more than one service for a structure. tapping a single service on a structure does not make is two services -- look at NEC 1014 handbook exhibits 230.8 thru 230.11 -- quick note 230.10 does not state that the laterals are bonded in the j box so do not be confused with the illustration.
 

tortuga

Code Historian
Location
Oregon
Occupation
Electrical Design
Thank you for your explanation. This here seems to be the crux of the issue:
tapping a single service on a structure does not make it two services
So they are allowed additional sets of service conductors permitted by 230.2, Exception No 3(b) (to be "tapped" from ONE service drop), however they cant be tapped to anything other than the service drop itself? I.E. NOT other overhead service entrance conductors?

So each set of "overhead service entrance conductors" shall start at a service drop (As defined in the 1981 NEC) and not a tap?
The Art 100 Definition's of Service-Entrance Conductors, Overhead System.
2014 NEC said:
Service-Entrance Conductors, Overhead System. The service
conductors between the terminals of the service equipment and a
point usually outside the building, clear of building walls, where
joined by tap or splice to the service drop or overhead service
conductors.
1981 NEC said:
The service conductors between the terminals of the service equipment and a point usually outside the building, clear of building walls, where joined by tap or splice to the service drop.
It does not say "a tap" or one tap. I dont see a tap from a tap being prohibited.
1981 NEC said:
230.71 Maximum Number of Disconnects
(A) General. The service disconnecting means for each service or for each set of service entrance conductors
permitted by 230.2, Exception No 3(b)
. Shall consist of not more than six switches or six circuit breakers mounted in a single enclosure, in a group of separate enclosures, or in or on a switchboard.

So they (in 1981) could have ran from 54 disconnects in 9 enclosures, 9 risers to 9 weather heads and had 9 taps to one service drop at one location and that would comply with the 1981 NEC. But 9 mains in 3 enclosures does not.
Once they used one mast they are no longer meeting the definition?
I await the 1984 code book in the mail..........
Thanks in advance!
 

newservice

Senior Member
look at NEC 1014 handbook exhibits 230.6 is what the op shows. 1981 was no different in this concept -- one more time -- one service drop or lateral to a building is one service -- parallel laterals bonded together at transformer & structure is defined as a single lateral -- more than one service would be parallel laterals not bonded at the structure -- one service has a max six switch rule to disconnect service power to building. --- code does allow for more than one service for a structure. tapping a single service on a structure does not make is two services -- look at NEC 1014 handbook exhibits 230.8 thru 230.11 -- quick note 230.10 does not state that the laterals are bonded in the j box so do not be confused with the illustration.

I like that explanation very much. Does seem to be too many discos in the OP's case imo.
 

kwired

Electron manager
Location
NE Nebraska
Mike holt has a interesting recent EC&M article
http://ecmweb.com/code-basics/articl...ervices-part-1
Where he states



The rule is six disconnecting means for each service, not six service disconnecting means per building. If the building has two services, you can have a total of 12 service disconnects (six disconnects per service).

"If the building has two services" has to factor in conditions where more then one service is permissible. Outside the exceptions for fire pumps, emergency equipment, etc. if there is only a single utility source there usually is only one service permitted. Different voltage, number of phases or larger service then the utility will supply are the more common cases where you are more likely to have more then one service to a building.

We also have very similar requirements in art 225 for buildings supplied by feeders. Not sure though what may have been different in 1984 on the feeder supplied buildings.
 

tortuga

Code Historian
Location
Oregon
Occupation
Electrical Design
"If the building has two services" has to factor in conditions where more then one service is permissible. Outside the exceptions for fire pumps, emergency equipment, etc. if there is only a single utility source there usually is only one service permitted. Different voltage, number of phases or larger service then the utility will supply are the more common cases where you are more likely to have more then one service to a building.

We also have very similar requirements in art 225 for buildings supplied by feeders. Not sure though what may have been different in 1984 on the feeder supplied buildings.

Well just thought I would follow up I spoke with the senior Inspector for that area. He said he remembered the "tap box + meterpack" more than one service for multi occupancy was permissible in the 80's.
I got my hands on a 1984 code handbook and the condition in 230-2 Ex No. 3b. more than one service for multi occupancy buildings is in fact gone in that cycle. It was permitted to have multiple services to multi occupancy buildings till '84. After 84 it would require special permission.
 
Status
Not open for further replies.
Top