NEC, 6 Service Disconnects

Status
Not open for further replies.
N

Npstewart

Senior Member
As im sure everyone is aware, the NEC requires the building to be shut down within 6 throws. Lets say you have a MDP with (6) breakers in it which feeds various loads & panels throughout the building, then there is a 7th 30A/3P breaker in the MDP which feeds a SPD mounted next to the panel, would this still be compliant? Sounds nit picky I know...
 
kwired

kwired

Electron manager
Location
NE Nebraska
Npstewart said:
As im sure everyone is aware, the NEC requires the building to be shut down within 6 throws. Lets say you have a MDP with (6) breakers in it which feeds various loads & panels throughout the building, then there is a 7th 30A/3P breaker in the MDP which feeds a SPD mounted next to the panel, would this still be compliant? Sounds nit picky I know...
Click to expand...

I don't know what justifies nit picky, it seems to be a clear violation to me.
 
jumper

jumper

Senior Member
Location
3 Hr 2 Min from Winged Horses
Npstewart said:
As im sure everyone is aware, the NEC requires the building to be shut down within 6 throws. Lets say you have a MDP with (6) breakers in it which feeds various loads & panels throughout the building, then there is a 7th 30A/3P breaker in the MDP which feeds a SPD mounted next to the panel, would this still be compliant? Sounds nit picky I know...
Click to expand...

Didn't you just answer your own question?:)
 
charlie b

charlie b

Moderator
Staff member
Location
Lockport, IL
Occupation
Retired Electrical Engineer
I don't have time to look it up right now. But my (fading) memory tells me that the Washington State Admin Code has a statement that a breaker ("throw") for the SPD can be in addition to the six other throws. That tells me that the NEC would not allow it, for if it did then the WAC amendment would not have been necessary.

To follow up on Bob's comment, a building could have two or more services under certain (limited) circumstances. Each of the services can have up to six disconnects. So if there are three services, you could have to throw up to 18 switches, in order to remove all power from the building.
 
qcroanoke

qcroanoke

Sometimes I don't know if I'm the boxer or the bag
Location
Roanoke, VA.
Occupation
Sorta retired........
GoldDigger said:
So, not a load and not inside the building. How say you all?
Click to expand...

I don't think I would flag it.
Some surge suppressors can be connected to the line side of a service with no disconnecting means required.
And it does not utilize power or provide power.
 
iwire

iwire

Moderator
Staff member
Location
Massachusetts
When all else fails, look at the book.

This is from the 2008 NEC and it indicates this section had changes made to it. I don't have the 2011 on my Ipad.

I made the changed text bold

230.71 Maximum Number of Disconnects.

(A) General. The service disconnecting means for each service permitted by 230.2, or for each set of service-entrance conductors permitted by 230.40, Exception No. 1, 3, 4, or 5, shall consist of not more than six switches or sets of circuit breakers, or a combination of not more than six switches and sets of circuit breakers, mounted in a single enclosure, in a group of separate enclosures, or in or on a switchboard. There shall be not more than six sets of dis-connects per service grouped in any one location. For the purpose of this section, disconnecting means in-stalled as part of listed equipment and used solely for the following shall not be considered a service disconnecting means:

(1) Power monitoring equipment

(2) Surge-protective device(s)

(3) Control circuit of the ground-fault protection system

(4) Power-operable service disconnecting means

(B) Single-Pole Units. Two or three single-pole switches or breakers, capable of individual operation, shall be per-mitted on multiwire circuits, one pole for each ungrounded conductor, as one multipole disconnect, provided they are equipped with identified handle ties or a master handle to disconnect all conductors of the service with no more than six operations of the hand.
Click to expand...

It appears under the 2011 it cannot be done in the field.
 
G

GoldDigger

Moderator
Staff member
Location
Placerville, CA, USA
Occupation
Retired PV System Designer
charlie b said:
I don't have time to look it up right now. But my (fading) memory tells me that the Washington State Admin Code has a statement that a breaker ("throw") for the SPD can be in addition to the six other throws. That tells me that the NEC would not allow it, for if it did then the WAC amendment would not have been necessary.
Click to expand...
NEC 230.71(A) [2011]
For the purpose of this section, disconnecting means installed as part of listed equipment and used solely for the following shall not be considered a service disconnecting means:
(1) Power monitoring equipment (2) Surge-protective device(s) (3) Control circuit of the ground-fault protection system (4) Power-operable service disconnecting means
Click to expand...
In the OP's case, the SPD is external to the panel, but the disconnecting means (breaker) is installed as part of listed equipment (the panel) and seems to qualify.
 
kwired

kwired

Electron manager
Location
NE Nebraska
iwire said:
When all else fails, look at the book.

This is from the 2008 NEC and it indicates this section had changes made to it. I don't have the 2011 on my Ipad.

I made the changed text bold


230.71 Maximum Number of Disconnects.

(A) General. The service disconnecting means for each service permitted by 230.2, or for each set of service-entrance conductors permitted by 230.40, Exception No. 1, 3, 4, or 5, shall consist of not more than six switches or sets of circuit breakers, or a combination of not more than six switches and sets of circuit breakers, mounted in a single enclosure, in a group of separate enclosures, or in or on a switchboard. There shall be not more than six sets of dis-connects per service grouped in any one location. For the purpose of this section, disconnecting means in-stalled as part of listed equipment and used solely for the following shall not be considered a service disconnecting means:

(1) Power monitoring equipment

(2) Surge-protective device(s)

(3) Control circuit of the ground-fault protection system

(4) Power-operable service disconnecting means

(B) Single-Pole Units. Two or three single-pole switches or breakers, capable of individual operation, shall be per-mitted on multiwire circuits, one pole for each ungrounded conductor, as one multipole disconnect, provided they are equipped with identified handle ties or a master handle to disconnect all conductors of the service with no more than six operations of the hand.







It appears under the 2011 it cannot be done in the field.
Click to expand...

I should have looked before commenting earlier, I did not know SPD's was on that list off the top of my head:ashamed1:

I was aware of control circuits for ground fault equipment and power operated disconnecting means, and even the fire pump.
 
Status
Not open for further replies.
Top