Ecmweb 8692 Nec Office Spaces Pr
Ecmweb 8692 Nec Office Spaces Pr
Ecmweb 8692 Nec Office Spaces Pr
Ecmweb 8692 Nec Office Spaces Pr
Ecmweb 8692 Nec Office Spaces Pr

Critical Code Requirements for Commercial Office Spaces

Dec. 15, 2016
In seeking to maximize leasable square footage, office space designers sometimes make dangerous choices.

It’s amazing that more commercial spaces don’t erupt into flames, considering the Code violations commonly committed in them. What’s not amazing is that many of these spaces have equipment problems that Code compliance likely would have prevented.

monkeybusinessimages/iStock/Thinkstock

Below are half a dozen of the many violations found in a single equipment closet in a commercial office building. Actually, it was the only equipment closet, and that in itself is a Code violation.

1. All “electrical” in one equipment closet. This means the phone panel, two 45kVA dry-type transformers, two 120/208V distribution panels, two Ethernet patch panels, and the security system control box.

2. No lock on closet door.

3. Air vent on closet door covered with cardboard “to block that awful humming.”

4. One transformer was mounted with its vents turned toward wall; the other was mounted with its vents facing the other transformer. Each transformer was only a couple of inches from the wall.

5. The Ethernet patch panels were supported by plastic straps screwed to the case of one dry-type transformer (one panel on either side!).

6. No bonding jumpers between any metal enclosures.

So where does the NEC identify these as actual violations? And why do these violations matter?

All in one

Why can’t you have all the electrical equipment in one closet? You probably have a gut feeling this isn’t allowed, but why?

1. It’s impractical. Let’s say an IT tech wants to replace an Ethernet router, but the room also contains a 75kVA transformer. Because of that transformer, the job falls under NFPA 70E. How many IT techs do you know who are trained in NFPA 70E?

2. It actually is banned by the NEC. Switchboards, panelboards, and so forth must be in dedicated spaces with no equipment foreign to the electrical installation [110.26(E)].

3. Where this situation exists, it’s almost always the case that equipment is jammed into far too little space, and violations of the clearance requirements in Art. 110, Part II are everywhere. Note that this part of the NEC is replicated in the OSHA regulations, giving it the status of federal law.

4. Doing such a thing creates a hotbed for other Code violations. In this very closet, two electrical engineers counted more than 40 NEC violations. And they worked in that building!

5. You create an inherently unsafe situation for workers who are not qualified as electrical workers but must enter that room anyhow to do their jobs.

No lock on closet door

It’s sad that some building administrators feel they actually need “proof” that this is required. Anyone exercising common sense would do this anyhow. It’s worth noting that the janitorial closet in our example office building did have a locked door.

In one facility, an office manager had the locks removed (by an outside locksmith) on two nearby electrical rooms so that office personnel could store files in those rooms. The reason given? So much “wasted space.”

The NEC requires that the room be accessible only to qualified persons [110.27(A)(1)] and OSHA repeats this rule, giving it the force of federal law. Since a lock is the only way to fulfill this requirement, the doors to these rooms must be locked. The lock makes the room inaccessible to all but qualified persons [110.26(F)].

Door not vented

The ambient temperature in the equipment closet we’re focusing on measured at between 117°F and 132°F on various days. This high heat was obviously causing efficiency losses, but was it a Code violation to not vent the door?

Aside from the fact this high heat made it nearly impossible to be in the room long enough to conduct maintenance and other activities, Art. 450 does have ventilation requirements for rooms containing transformers — and they would apply to this room. The door contained the only venting the room had. So, yes, blocking those vents violated the NEC.

The real discussion should center on how to keep an equipment room cool enough. In this particular room, the door vents meant a noise problem in the occupied spaces. A correct solution would not involve taping flammable material over the vents.

A smart way to fix both the noise and the heat problems is to install a forced air intake duct from the outside to that room and a forced air exhaust duct from that room to the outside. Then replace the existing vented door with an insulated door (to deaden the sound). Putting the fans on thermostatic speed controls could make this arrangement more energy efficient. Of course, the two ducts should be widely separated.

Misaimed transformer vents

Does this problem really need a Code rule? Obviously, the vents are there to ventilate the transformer and cannot do that when airflow to it is effectively cut off. A qualified electrician would not have connected a transformer that was facing a wall only a few inches away. For those who want a Code rule despite the obvious, it’s in 450.9 (which specifically mentions not being blocked by walls) and it’s in 110.13(B).

Compounding this poor transformer’s heat problems by aiming the vent of another transformer at it violates basic engineering principles. There are such things as “craft capability” and “engineering judgment.” The NEC does not weigh in on these required attributes of installers [90.1], and the heat emanating from the other transformer certainly is not the natural air flow required by 110.13(B).

Patch panels supported by plastic straps screwed to transformer. Those screws modify the case of the transformer, violating its listing. Because those patch panels are barred from being in this room in the first place, it doesn’t make sense for the NEC to have rules governing whether this equipment can be affixed to transformers by any means.

No bonding jumpers

So an IT tech goes into this room to do some reconfiguring at the patch panel. He’s got one hand on the metal frame of the patch panel and reaches for one of the tools he set on top of the transformer case. Due to a difference in potential, he gets a very nasty shock.

All metallic objects that don’t carry current must be bonded per Art. 250, Part V. This is the only way to put them all at the same potential. With no voltage between those objects, no current can flow, so no touch shock hazard exists. The danger of flashover is also eliminated by proper bonding.

Misconceptions make mistakes materialize

These examples are from a single equipment closet. Just one. Crowded equipment closets are a fairly common problem for office spaces, due to the misconception that all electrical equipment is ugly, wastes space, and should be shoved into the same undersized room with anything else that can be shoved in there.

People can really get creative when they decide to “save money,” “maximize space,” or in some other way pretend that Code compliance is fine if it doesn’t get in the way of other, presumably more important goals.

One facility managed to save leasable space by storing spare fluorescent lamps and other items in an electrical equipment room. This freed up a “wasted” double door storage closet that was repurposed to hold a copying machine. Guess where they stored the removed double doors?

Another facility made use of “all that wasted space” in an electrical room by installing shelves for storing paper file boxes. They saved a few bucks on shelf hangers by using the tops of two transformers, too.

What to do

What if you encounter Code violations in project drawings or specifications? Bring these to the attention of the project manager. Work cannot proceed until these are reconciled in a way that results in Code compliance.

When you encounter something like the equipment room doubling as a storage area, what happens if you stay silent about it? Perhaps nothing, but if there’s an incident, don’t be surprised if you’re named in a lawsuit. Protect yourself by making a list of the Code violations you find and citing the applicable Code requirement(s). Then ask the facility manager to sign a statement that he or she has been made aware of each violation.

If the facility manager won’t sign and/or doesn’t want the problems fixed, you need to decide whether to work the job or not. Usually, you are better off walking away.

Also, the violations you found are warnings that more serious problems probably exist. You could find yourself strapped to a money-hole project or, even worse, put your crew in an unsafe situation.

Lamendola is an electrical consultant located in Merriam, Kan. He can be reached at [email protected].

About the Author

Mark Lamendola

Mark is an expert in maintenance management, having racked up an impressive track record during his time working in the field. He also has extensive knowledge of, and practical expertise with, the National Electrical Code (NEC). Through his consulting business, he provides articles and training materials on electrical topics, specializing in making difficult subjects easy to understand and focusing on the practical aspects of electrical work.

Prior to starting his own business, Mark served as the Technical Editor on EC&M for six years, worked three years in nuclear maintenance, six years as a contract project engineer/project manager, three years as a systems engineer, and three years in plant maintenance management.

Mark earned an AAS degree from Rock Valley College, a BSEET from Columbia Pacific University, and an MBA from Lake Erie College. He’s also completed several related certifications over the years and even was formerly licensed as a Master Electrician. He is a Senior Member of the IEEE and past Chairman of the Kansas City Chapters of both the IEEE and the IEEE Computer Society. Mark also served as the program director for, a board member of, and webmaster of, the Midwest Chapter of the 7x24 Exchange. He has also held memberships with the following organizations: NETA, NFPA, International Association of Webmasters, and Institute of Certified Professional Managers.

Voice your opinion!

To join the conversation, and become an exclusive member of EC&M, create an account today!

Sponsored Recommendations

Electrical Conduit Comparison Chart

CHAMPION FIBERGLASS electrical conduit is a lightweight, durable option that provides lasting savings when compared to other materials. Compare electrical conduit types including...

Fiberglass Electrical Conduit Chemical Resistance Chart

This information is provided solely as a guide since it is impossible to anticipate all individual site conditions. For specific applications which are not covered in this guide...

Considerations for Direct Burial Conduit

Installation type plays a key role in the type of conduit selected for electrical systems in industrial construction projects. Above ground, below ground, direct buried, encased...

How to Calculate Labor Costs

Most important to accurately estimating labor costs is knowing the approximate hours required for project completion. Learn how to calculate electrical labor cost.