DTBarch
SAWHORSE
SITUATION: Existing vacant commercial tenant space is served by a landlord-controlled and paid for, single meter feeding (1) 480/277v panel, a transformer, and (1) 208/120V panel. Landlord wants to split space into two leasable tenant spaces. There are no more meters available in the electrical service. The electrical service is provided by the building management, but there is no "continuous" management supervision on site. They do have a building engineer, but he floats between several properties.
Per NEC Section 240.24(B), "each occupant shall have ready access to all overcurrent devices protecting the conductors supplying that occupancy unless otherwise permitted in 240.24(B)(1)"
Due to the location of the panels at the rear of the existing tenant space, creation of a shared common electrical room is not practical due to the need to maintain free egress from the electrical room to the exterior of the building (without a key or special knowledge). In the absence of a dedicated exit access hallway, a shared electrical room would, by default, allow access from either tenant space into eachother's space to egress the building, which is not feasible.
A suggestion was made to install (2) new sub-panels, fed directly out of the existing panels to the other side of the new demising wall, and re-feed all power, lights and hvac from the newly created sub-suite to those sub-panels. Since that side is only about 20% of the total existing tenant space, that would be a reasonable exercise with a reasonable cost to implement.
However, the question was brought up about the feed to the sub-panels from the existing panels. Those would be fed via a circuit breaker in the existing panels.
QUESTION:
Technically, the breaker controlling and feeding the sub-panels is an overcurrent device protecting the conductors supplying the other occupancy, right? So while the new tenant would have access to all of their individual breakers via the new panels, they would still not have access to the main breaker feeding the sub panels since it would still be in the adjacent tenant space. Is that still a violation of NEC 240.24(B)?? Does anyone know of an exemption that would allow for this configuration?
Per NEC Section 240.24(B), "each occupant shall have ready access to all overcurrent devices protecting the conductors supplying that occupancy unless otherwise permitted in 240.24(B)(1)"
Due to the location of the panels at the rear of the existing tenant space, creation of a shared common electrical room is not practical due to the need to maintain free egress from the electrical room to the exterior of the building (without a key or special knowledge). In the absence of a dedicated exit access hallway, a shared electrical room would, by default, allow access from either tenant space into eachother's space to egress the building, which is not feasible.
A suggestion was made to install (2) new sub-panels, fed directly out of the existing panels to the other side of the new demising wall, and re-feed all power, lights and hvac from the newly created sub-suite to those sub-panels. Since that side is only about 20% of the total existing tenant space, that would be a reasonable exercise with a reasonable cost to implement.
However, the question was brought up about the feed to the sub-panels from the existing panels. Those would be fed via a circuit breaker in the existing panels.
QUESTION:
Technically, the breaker controlling and feeding the sub-panels is an overcurrent device protecting the conductors supplying the other occupancy, right? So while the new tenant would have access to all of their individual breakers via the new panels, they would still not have access to the main breaker feeding the sub panels since it would still be in the adjacent tenant space. Is that still a violation of NEC 240.24(B)?? Does anyone know of an exemption that would allow for this configuration?