230.2 Number of Services

A building or other structure served shall be supplied by only one service unless permitted in 230.2(A) through (D). For the purpose of 230.40, Exception No. 2 only, underground sets of conductors, 1/0 AWG and larger, running to the same location and connected together at their supply end but not connected together at their load end shall be considered to be supplying one service.

Additional services shall be permitted to supply the following:

1. Fire pumps
2. Emergency systems
3. Legally required standby systems
4. Optional standby systems
5. Parallel power production systems
6. Systems designed for connection to multiple sources of supply for the purpose of enhanced reliability

By special permission, additional services shall be permitted for either of the following:

1. Multiple-occupancy buildings where there is no available space for service equipment accessible to all occupants
2. A single building or other structure sufficiently large to make two or more services necessary

Additional services shall be permitted under any of the following:

1. Where the capacity requirements are in excess of 2000 amperes at a supply voltage of 1000 volts or less
2. Where the load requirements of a single-phase installation are greater than the serving agency normally supplies through one service
3. By special permission

Additional services shall be permitted for different voltages, frequencies, or phases, or for different uses, such as for different rate schedules.

Where a building or structure is supplied by more than one service, or any combination of branch circuits, feeders, and services, a permanent plaque or directory shall be installed at each service disconnect location denoting all other services, feeders, and branch circuits supplying that building or structure and the area served by each. See 225.37.