VI. Service Equipment ? Disconnecting Means
230.70 General
Means shall be provided to disconnect all conductors in a building or other structure from the service-entrance conductors.
(A) Location The service disconnecting means shall be installed in accordance with 230.70(A)(1), (A)(2), and (A)(3).
No maximum distance is specified from the point of entrance of service conductors to a readily accessible location for the installation of a service disconnecting means. The authority enforcing this Code has the responsibility for, and is charged with, making the decision as to how far inside the building the service-entrance conductors are allowed to travel to the service disconnecting means. The length of service-entrance conductors should be kept to a minimum inside buildings, because power utilities provide limited overcurrent protection. In the event of a fault, the service conductors could ignite nearby combustible materials.
Some local jurisdictions have ordinances that allow service-entrance conductors to run within the building up to a specified length to terminate at the disconnecting means. The authority having jurisdiction may permit service conductors to bypass fuel storage tanks or gas meters and the like, permitting the service disconnecting means to be located in a readily accessible location.
However, if the authority judges the distance as being excessive, the disconnecting means may be required to be located on the outside of the building or near the building at a readily accessible location that is not necessarily nearest the point of entrance of the conductors. See also 230.6 and Exhibit 230.15 for conductors considered to be outside a building.
See 404.8(A) for mounting-height restrictions for switches and for circuit breakers used as switches.
(1) Readily Accessible Location The service disconnecting means shall be installed at a readily accessible location either outside of a building or structure or inside nearest the point of entrance of the service conductors.
(2) Bathrooms Service disconnecting means shall not be installed in bathrooms.
(3) Remote Control Where a remote control device(s) is used to actuate the service disconnecting means, the service disconnecting means shall be located in accordance with 230.70(A)(1).
(B) Marking Each service disconnect shall be permanently marked to identify it as a service disconnect.
(C) Suitable for Use Each service disconnecting means shall be suitable for the prevailing conditions. Service equipment installed in hazardous (classified) locations shall comply with the requirements of Articles 500 through 517.
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 Nos. 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 disconnects per service grouped in any one location. For the purpose of this section, disconnecting means used solely for power monitoring equipment, transient voltage surge suppressors, or the control circuit of the ground-fault protection system or power-operable service disconnecting means, installed as part of the listed equipment, shall not be considered a service disconnecting means.
Section 230.71(A) covers the maximum number of disconnects permitted as the disconnecting means for the service conductors that supply the building or structure. One set of service-entrance conductors, either overhead or underground, is permitted to supply two to six service disconnecting means in lieu of a single main disconnect. A single-occupancy building can have up to six disconnects for each set of service-entrance conductors. Multiple-occupancy buildings (residential or other than residential) can be provided with one main service disconnect or up to six main disconnects for each set of service-entrance conductors.
Multiple-occupancy buildings may have service-entrance conductors run to each occupancy, and each such set of service-entrance conductors may have from one to six disconnects (see 230.40, Exception No. 1).
Where service-entrance conductors are routed outside the building (see 230.6 and Exhibit 230.15), each set of service-entrance conductors is permitted to supply not more than six disconnecting means at each occupancy of a multiple-occupancy building. See Exhibit 230.2 through Exhibit 230.13 for examples of permitted service configurations.
Exhibit 230.26 shows a single enclosure for grouping service equipment that consists of six circuit breakers or six fused switches. This arrangement does not require a main switch. Six separate enclosures also would be permitted as the service equipment. Revised in the 2005 Code to also include switches that disconnect power to transient voltage surge suppressors and power monitoring equipment, the last sentence of 230.71(A) specifies that the disconnect switch for such equipment installed as part of the listed equipment does not count as one of the six service disconnecting means permitted by 230.71(A). The disconnecting means for the control circuit of ground-fault protection equipment or for a power-operable service disconnecting means are also not considered to be service disconnecting means where such disconnecting means are installed as a component of listed equipment.
Exhibit 230.26 An enclosure for grouping service equipment consisting of six circuit breakers or six fused switches.
(B) Single-Pole Units Two or three single-pole switches or breakers, capable of individual operation, shall be permitted on multiwire circuits, one pole for each ungrounded conductor, as one multipole disconnect, provided they are equipped with handle ties or a master handle to disconnect all conductors of the service with no more than six operations of the hand.
FPN: See 408.36(A) for service equipment in panelboards, and see 430.95 for service equipment in motor control centers.
230.72 Grouping of Disconnects
(A) General The two to six disconnects as permitted in 230.71 shall be grouped. Each disconnect shall be marked to indicate the load served.
Exception: One of the two to six service disconnecting means permitted in 230.71, where used only for a water pump also intended to provide fire protection, shall be permitted to be located remote from the other disconnecting means.
The water pump in 230.72(A), Exception, is not the fire pump covered by the requirements of Article 695; rather, it is a water pump used for normal water supply and also for fire protection. This application is common in agricultural settings and permits separation of the water pump disconnect so it can remain operational in the event of a problem at the location of the other service disconnecting means.
(B) Additional Service Disconnecting Means The one or more additional service disconnecting means for fire pumps, emergency systems, legally required standby, or optional standby services permitted by 230.2 shall be installed remote from the one to six service disconnecting means for normal service to minimize the possibility of simultaneous interruption of supply.
The intent of 230.2(A) is to permit separate services, where necessary, for fire pumps (with one to six disconnects) or for emergency, legally required standby, or optional standby systems (with one to six disconnects), in addition to the one to six disconnects for the normal building service. Article 230 recognizes that a disruption of the normal building service should not disconnect the fire pump, emergency system, or other exempted systems. Because these services are in addition to the normal services, the one to six disconnects allowed for them are not included as one of the six disconnects for the normal supply. These separate services are permitted by 230.2 and are required to be installed in accordance with all the applicable requirements of Article 230.
(C) Access to Occupants In a multiple-occupancy building, each occupant shall have access to the occupant's service disconnecting means.
A multiple-occupancy building may have any number of dwelling units, offices, and the like that are independent of each other. Unless electric service and maintenance are provided by and under continuous supervision of the building management, the occupants of a multiple-occupancy building must have ready access to their disconnecting means, as required by 240.24(B).
Exception: In a multiple-occupancy building where electric service and electrical maintenance are provided by the building management and where these are under continuous building management supervision, the service disconnecting means supplying more than one occupancy shall be permitted to be accessible to authorized management personnel only.
WHEW!!!
Having "listed" all that I still recall a 10 story hospital I helped wire that had the "pent house" up on the tenth floor. All the fire panel rooms were not readily accessible. There were no remotes.
And of course, no one would want to "disconnect" a hospital, would they?
My point: It depends on the occupancy.
