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Egress from and Access to Electrical Room

DTBarch

SAWHORSE
Joined
Nov 1, 2010
Messages
78
Location
Phoenix, AZ
Got nothing but crickets in the electrical forum on this rather specific and probably long-winded question, so thought I might cast my line here to see if my luck improves in this pond...

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?
 
Here is the key word in this code. ALL. All overcurrent devices means ALL overcurrent devices and the feeders coming into that unit is protected by the service disconnect, therefore, they need access to ALL overcurrent devices, which includes the service disconnect.

Your situation is not unique and must comply with the code requirements. Move the service disconnects to the outside of the building and to save money, install junction boxes where the service disconnects currently are. What the owner wants to do and what he has to do go together. If he wants to increase his profits by creating a new tenant space, he will have to comply with the code requirements.
 
jar ... I'm going to differ slightly. IMHO the purpose of tenant access to the breakers is so they can kill a circuit if they need to work on it. So if they have access to the subpanel, they can do that. If the main breaker trips, they can’t go to it to reset without call the LL so their business is interrupted, but if the main breaker trips there’s more than a little problem and they should not be resetting it anyway.
The code exists for protection, not convenience. The subpanels meet that intent.
 
I'd like to break down the actual verbiage, vs perceived intent.
240.24(B) Reads:
(B) Occupancy. Each occupant shall have ready access to all
overcurrent devices protecting the conductors supplying that
occupancy
, unless otherwise permitted in 240.24(B)(1) and
(B)(2).
(1) Service and Feeder Overcurrent Devices. Where electric
service and electrical maintenance are provided by the building
management and where these are under continuous building
management supervision,
the service overcurrent devices
and feeder overcurrent devices supplying more than one occupancy
shall be permitted to be accessible only to authorized
management personnel in the following:
(1) Multiple-occupancy buildings
(2) Guest rooms or guest suites


The feeder that supplies power to the tenant space panelboard(s) is fed by an overcurrent device that protects the conductors supplying voltage to that space as required,
The exception specifically discusses service and feeder overcurrent devices which shows that the intent of the code is to provide access unless the exception is met with continuous management supervision.

The intent may be inconvenient but it is obvious.
 
and if the electrical problem is in the sub panel feeder ???? No Jar has the correct answer and as a practical standpoint, if your business is having electrical issues that require the power to be shut down for your space, it should not affect my ability to continue doing business or require the fire department to wake me up from my beauty sleep ==== or damage my business to get access to the service panel if required.

Sorry getting older and grumpier - love my sleep.

Jim
 
Here is the key word in this code. ALL. All overcurrent devices means ALL overcurrent devices and the feeders coming into that unit is protected by the service disconnect, therefore, they need access to ALL overcurrent devices, which includes the service disconnect.

Your situation is not unique and must comply with the code requirements. Move the service disconnects to the outside of the building and to save money, install junction boxes where the service disconnects currently are. What the owner wants to do and what he has to do go together. If he wants to increase his profits by creating a new tenant space, he will have to comply with the code requirements.

Access to the service disconnects is not an issue. The tenants all have access to the meter room that contains the service disconnects and feeds their spaces. If the sub-panel solution does not work, the alternative is either creation of a common egress corridor that blazes through the tenant space to the front entry door area (no access in the rear of the building since it backs up to another tenant space), or relocation of the existing tenant's panels (2) and transformer to a space adjacent to a common corridor, which would require a complete re-circuiting of all power, lighting, and hvac for the existing suite due to voltage drop calcs and feeder sizes. Not impossible, just very expensive and invasive to resolve a practicality risk that, to the laymen's eye, is fairly low on the life-safety risk spectrum.

If a breaker trips, it's likely going to be in the sub-panel and not make it's way to the breaker feeding the sub-panel. Problem is "likely" = grey area. Having said that, it's not always black and white with the code. There are plenty of "hardship" provisions throughout the code, so therefore it's a viable discussion point.

Lastly, the owner isn't motivated solely to increase his profits, rather he is responding to a tenant prospect who is willing to sign a long-term lease, but does not want or need all of the existing space, so he's simply hoping for a reasonable solution to help him reconcile the terms of this lease negotiation. Thanks everyone for the solid feedback. That's why I love this forum. Much appreciated.
 
Small corridor though back of tenant spaces? Takes care of security issue....
You're right Steve. It would. That would be far too easy, lol! Unfortunately, the back of this tenant space is landlocked by 3 other tenant spaces, therefore, no rear access options are available.
 
Any floor plan of the area


Does the utility company care????

Here are two plan images. First is the option of relocating panels and trans to the common corridor, 2nd image is the creation of new dedicated path of egress from a new common area that contains the suite's electrical room.upload_2019-9-18_13-31-40.png upload_2019-9-18_13-30-40.png
 
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One more thought. What constitutes "continuous building management supervision"? The building management does provide the electrical service and maintenance, and they have a property manager on site during business hours, along with a roaming building operations maintenance man who services a small group of nearby buildings. He's not there all day, every day, like you might have in a high-rise, or larger office building, but between him and the property manager, they do provide what could be argued as continuous building management supervision? I don't think that's explicitly defined in the code, so is it up to interpretation? Any legs there?
 
One more thought. What constitutes "continuous building management supervision"? The building management does provide the electrical service and maintenance, and they have a property manager on site during business hours, along with a roaming building operations maintenance man who services a small group of nearby buildings. He's not there all day, every day, like you might have in a high-rise, or larger office building, but between him and the property manager, they do provide what could be argued as continuous building management supervision? I don't think that's explicitly defined in the code, so is it up to interpretation? Any legs there?

The intent of continuous supervision is essentially a facility with a full time maintenance staff 24/7. In the case of continuous building management supervision, I believe it would be the same whereas 24/7 you have someone that is present to open areas such as the one being discussed.
 
Jar, I personally think you're on the side of being right, just was honestly curious if your definition is rooted in the actual code, commentary (which is not "code"), or simple application of subjective logic? In other words, if a building official had a slightly less stringent definition in his or her mind, would he or she be wrong to accept it? Why would they not add 4 characters to the code "24/7" to eliminate subjectivity? I know, I know, this is a bigger horse that has been beaten to smithereens...
 
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