NEC question about number of services

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joanie

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I remember from a previous NEC edition that no facility could have two services unless those services were different voltages (example one 208Y/120V service and one 480Y/277V service but NOT two of any one). I cannot locate this particular statement in the new Code.

I have a hospital that has constructed an addition. Instead of upgrading the existing service and extending to the addition, the contractor has fed the addition from a second service, located at the other end of the whole facility (original plus addition).

Is this still a code violation and, if so, can you please provide the reference? The contractor does not seem to be aware of this.

Thanks
 
Take a look at 230.2. There are several instances in which a second service is allowable. Having different voltage characteristics is only one of them.
 
Here is the NEC section that deals with number or services.

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.
(A) Special Conditions. 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
(B) Special Occupancies. 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
(C) Capacity Requirements. 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 600 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
(D) Different Characteristics. Additional services shall be permitted for different voltages, frequencies, or phases, or for different uses, such as for different rate schedules.
(E) Identification. 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.
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As long as the service falls under one of the conditions listed in 230.2(A) through (D) you can have a second service to a single building.

Chris
 
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