How many service disconnects are allowed
Each service gets one disconnect, or two to six if each sits in its own enclosure, panelboard, switchboard section or compartment. Since 2020, six breakers grouped in one enclosure no longer qualify.
What the code requires
Each service is generally allowed one disconnect. Under 230.71(B), two to six service disconnects are allowed per service, or per set of service-entrance conductors that 230.40 Exception No. 1, 3, 4 or 5 allows, but only in arrangements that keep each disconnect separate.
Allowed arrangements: separate enclosures, each with a main; panelboards, each with a main; switchboard sections with one disconnect per section and barriers between sections; switchgear, transfer switches or metering centers with each disconnect in its own compartment; metering centers, each with a main; and motor control centers with one disconnect per unit, no more than 2 per MCC, with barriers.
Disconnects that are part of listed equipment and used only for power monitoring, surge protection, the ground-fault protection control circuit or power-operable service disconnects do not count toward the limit.
On the job
- In a meter stack or metering center used for multiple service disconnects, each disconnect needs its own compartment, unless the metering center has its own main disconnect.
- Washington's state electrical inspectors treat disconnects tied together by a cover-mounted interlock as two or more disconnects under 230.71, not one. Ask your inspector how they treat interlocked equipment.
- Splitting a large service into several smaller disconnects can keep each under the 1,000 A and 1,200 A sizes that trigger ground-fault protection (230.95) and arc energy reduction (240.87).
Exceptions that matter
- Existing equipment installed under an earlier code that allowed several disconnects in one enclosure may contain up to six. This applies to the panelboard, switchboard, switchgear, metering-center and motor-control-center arrangements.
What changed in 2023
The 2023 code tied the barriers between switchboard sections to the line-side contact protection in 230.62, added transfer switches, metering centers with mains and motor control centers to the permitted arrangements, and added the allowance for existing equipment; the bigger change, ending six disconnects in one enclosure, came in 2020.
Related sections
- NEC 230.40
- NEC 230.70: Where the main service disconnect must go
- NEC 230.72
- NEC 230.95: Ground-fault protection on large commercial services
- NEC 240.87: Arc energy reduction for breakers of 1,200 A and up
Where this comes from
Send a photo. Get a real answer.
Text is fastest, and a photo quote is free. Call if it is urgent, if you smell something burning, or if a breaker will not reset.
CSLB #354550 · C-10 Electrical · Licensed since 1978 · $25,000 contractor's bond