What is the disconnect rule?
The six disconnect rule has been the requirement since the 1933 NEC for residences and the 1937 NEC for all occupancies. Requiring a separate enclosure with a main for each enclosure or a main for each panelboard will affect single- and two- and multifamily dwellings and commercial and industrial buildings.
Where should the main service disconnect be located?
The service disconnect must be at a readily accessible location either outside the building or structure, or inside nearest the point of entry of the service conductors.
What is the maximum number of disconnects permitted per service grouped in any one location?
There shall be no more than six sets of disconnects per service grouped in any one location.
What is meter disconnect rating?
Meter disconnect switches nominally rated not in excess of 600 volts that have a short-circuit current rating equal to or greater than the available short-circuit current, provided all metal housings and service enclosures are grounded in accordance with Part VII and bonded in accordance with Part V of Article 250.
What is the 6 handle rule?
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 …
When should you use a service disconnect?
Since the 1937 edition of the NEC, the service disconnecting means used to isolate a building’s premises wiring from the utility provider’s conductors has been allowed to consist of as few as one, but as many as six switches or sets of circuit breakers.
What is a cold sequence disconnect switch?
The term cold sequence refers to a means of disconnecting power ahead of the meter socket so that the components inside are deenergized or “cold.” This method is used to allow workers to safely upgrade, replace or provide any other necessary maintenance for the meter.
Is a meter a means of disconnect?
A meter is not a disconnecting means.
What is the 6 switch rule?
The “six breaker throw rule” is a requirement in the National Electrical Code [NEC 230.71(A)]) that a service must have have a main disconnect that shuts off all power and it cannot take more than six switch throws to do it. The main disconnect or disconnects also must be clearly marked, as in the photo above.
What is the first means of disconnect?
This “main bonding jumper” that is required at the service disconnect (aka first means of disconnect, aka service equipment) that ties grounds to the neutral conductor is required in every enclosure that contains a means of disconnect (switch) for that electrical service.
Is there a maximum number of disconnects per service?
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 installed as part of listed equipment and used solely for the following shall not be considered a service disconnecting means: (B) Single-Pole Units.
Where are the service disconnects on a panelboard?
Panelboards with a main service disconnecting means in each panelboard enclosure. Switchboards where there is only one service disconnect in each separate verticle section where there are barriers separating the sections. Service disconnects in each switchgear or metering center where each disconnect is located in a separate compartment.
How many disconnects can be grouped in one enclosure?
Section 230.72 (A) of the Code addresses the grouping requirements quite specifically and simply. The general rules are that the two to six service disconnects permitted in 230.71 must be grouped in the same location, either in a single enclosure or in separate enclosures located adjacent to each other.
Where are the service disconnects in a metering center?
Service disconnects in each switchgear or metering center where each disconnect is located in a separate compartment. Section 230.72 (A) then goes on to tell the electrician to group all of these individual enclosures acting as one service disconnect, and to mark each to indicate the load being served.