Overdutied Equipment Labeling

[wbdvt]

Is there any code requirement to label equipment that is found to be overdutied as a result of an electrical systems study? i have looked but have not found anything on required labeling. How do workers in the field know equipment is overdutied?

Granted it needs to be replaced but that does not always happen rapidly so there is a period of time where the equipment is known to be overdutied but still in service.

 

[Jraef]

From an AHJ's standpoint, the labeling would be a red tag ceasing operation. There is nothing in the NEC addressing your situation, because the situation violates the NEC rules from the outset. 110.3; suitable for the intended use.

One might go so far as to say this is one main REASON why the NEC exists in the first place!

 

[kwired]

What exactly do you mean by "overdutied".

I can show you several applications where if you counted every possible connected load a larger supply would be needed, but if you recorded demand data the maximum load ever seen is still less then the supply rating.

1200 amp service but utility only installs a transformer with secondary current rating of ~600 amps - they know what the real load is and won't put in a larger transformer unless there is load there to justify it.

Now if that 1200 amp service actually has more then 1200 amps of load - you are going to have overcurrent protection trips reminding people there is a problem, but the equipment is essentially protecting itself.

 

[dkidd]

What exactly do you mean by "overdutied".

I have only seen that term used where the available fault current is greater than the equipment rating.

 

[petersonra]

depends entirely on what you mean by "overdutied".

 

[kwired]

I have only seen that term used where the available fault current is greater than the equipment rating.

Never gave that aspect any thought but I guess it could be what OP is asking about.

 

[wbdvt]

Yes, the term is commonly used to indicate equipment that is not rated for the available fault current. Examples:

Circuit breaker with a 18kA AIC rating but the available fault current is 23kA

Panel rated 10kA but available fault current is 12kA

Both of these would be considered overdutied and not only an NEC violation but an OSHA violation also.

Note this has nothing to do with loading only short circuit.

 

[kwired]

Yes, the term is commonly used to indicate equipment that is not rated for the available fault current. Examples:

Circuit breaker with a 18kA AIC rating but the available fault current is 23kA

Panel rated 10kA but available fault current is 12kA

Both of these would be considered overdutied and not only an NEC violation but an OSHA violation also.

Note this has nothing to do with loading only short circuit.

Placing labels or signs warning of this IMO will not get owners off the hook should there be an injury or death as a result. Placing such labels may reduce or eliminate fines during a casual or routine inspection if there is also a plan in place to fix the problem.

If the hazard was there but you weren't aware of it, that doesn't change things when it comes to welfare of your employees in OSHA's eyes.

It is simply a situation that requires attention and how much risk is there to put it off vs doing it immediately is hard to estimate.

 

[wbdvt]

Placing labels or signs warning of this IMO will not get owners off the hook should there be an injury or death as a result. Placing such labels may reduce or eliminate fines during a casual or routine inspection if there is also a plan in place to fix the problem.

If the hazard was there but you weren't aware of it, that doesn't change things when it comes to welfare of your employees in OSHA's eyes.

It is simply a situation that requires attention and how much risk is there to put it off vs doing it immediately is hard to estimate.

As the consultant that finds the overdutied equipment, I always put in the report that it is a violation of NEC and OSHA but my concern is that this information may not get to the workers and they would no way of knowing that the device that are operating may be overdutied and should not be operated energized. But perhaps that is all I can do, highlight it with strong language in the report.

 

[kwired]

As the consultant that finds the overdutied equipment, I always put in the report that it is a violation of NEC and OSHA but my concern is that this information may not get to the workers and they would no way of knowing that the device that are operating may be overdutied and should not be operated energized. But perhaps that is all I can do, highlight it with strong language in the report.

All you can do is mention to owner, it is up to them to protect their workers. Give them some worst case stories if you want to help them decide how urgent this repair may be, but IMO suggesting such a sign possibly increases your liability should an incident occur before they make changes.

 

[petersonra]

As the consultant that finds the overdutied equipment, I always put in the report that it is a violation of NEC and OSHA but my concern is that this information may not get to the workers and they would no way of knowing that the device that are operating may be overdutied and should not be operated energized. But perhaps that is all I can do, highlight it with strong language in the report.

Just how would they operate it de-energized?

The thing about SCCR is that there is a ton of stuff out there that has been in place for many decades that is almost certainly on a system that can supply more short circuit current than the equipment is rated for. I have NEVER seen any credible research reports suggesting it has ever actually been a problem. none. Zero. I think it is a potential problem, but the fact that it is not killing people suggests maybe it is overblown as problems go.

Arc flash related stuff OTOH is a real problem that continues to kill people yet we do almost nothing about it code wise that makes any real difference. At least the Canadians mandated the separation of the main in a PB into a seperate section. Not perfect but an improvement. We just make more rules that are hard to understand and often even harder to follow and then wonder why the problem does not get all that much better. There is a reason why engineering controls are not considered a good first step in safety measures. Engineering controls are a last resort as far as safety measures go but for something as deadly as arc flash injuries that is where we are starting from.

 

[kwired]

Just how would they operate it de-energized?

The thing about SCCR is that there is a ton of stuff out there that has been in place for many decades that is almost certainly on a system that can supply more short circuit current than the equipment is rated for. I have NEVER seen any credible research reports suggesting it has ever actually been a problem. none. Zero. I think it is a potential problem, but the fact that it is not killing people suggests maybe it is overblown as problems go.

Arc flash related stuff OTOH is a real problem that continues to kill people yet we do almost nothing about it code wise that makes any real difference. At least the Canadians mandated the separation of the main in a PB into a seperate section. Not perfect but an improvement. We just make more rules that are hard to understand and often even harder to follow and then wonder why the problem does not get all that much better. There is a reason why engineering controls are not considered a good first step in safety measures. Engineering controls are a last resort as far as safety measures go but for something as deadly as arc flash injuries that is where we are starting from.

Having higher available current then equipment rating isn't a problem, until someone closes a switch into a fault, or is standing by that equipment at the right moment when it does have a failure.

I don't get into many places that have over 1200 amp supply to them, but what I have generally noticed below that level is that you generally are below max available fault current with equipment ratings if you have at least 25 feet maybe occasionally up to 50 feet of conductor between transformer and service equipment. And even if you are over the rating of branch units they usually will be series rated with the service disconnect. That don't mean there isn't going to be high arc flash energy available, just that the equipment is within acceptable ratings.

 

[jumper]

As the consultant that finds the overdutied equipment, I always put in the report that it is a violation of NEC and OSHA but my concern is that this information may not get to the workers and they would no way of knowing that the device that are operating may be overdutied and should not be operated energized. But perhaps that is all I can do, highlight it with strong language in the report.

Not an EE or any type of consultant, but I would want confirmation that report was received and a well written statement that the owner read and understands exactly the situation you are addressing.

Major CYA documentation with signatures.

I have a real healthy sense of paranoia for stuff like this.

 

[publicgood]

It happens. There should be reasonable evaluation as to why the existing equipment ratings as less than true available. Generally, utility agreements maintain a threshold of allowable increase in available fault current. That would be my first investigation.

Otherwise, one might take measures to solve this short/long term by having an engineered series rating modifications.

Otherwise, yes - there is cause for concern. However, it depends on the situation. If this equipment were in an unoccupied vault, for instance, maybe it is reasonable to continue operation for while waiting on lead time needed for replacement. Maybe the same is true for an occupied space, so long as NFPA 70E alerting techniques are followed to avoid technicians operating the equipment. Maybe you’d consider different if it were an industrial facility under single management.

We have all seen equipment with high enough AIC ratings needed, but the equipment condition itself is questionable - that same equipment continues to be in operation for many years beyond service life should be subject to the same criticisms, but they aren’t always.

Some due diligence is needed when we find these and the specific solution...depends. In all cases, owners carry high liability and OSHA is waiting in the shadows.

 

[dkidd]

There is a good discussion of the topic with sample labels here https://brainfiller.com/arcflashforum/viewtopic.php?f=24&t=4518

 

[Sahib]

Why not also send a note to OSHA as a responsible electrical professional?

 

[kwired]

Why not also send a note to OSHA as a responsible electrical professional?

Because your clients hired you to help them comply not to turn them in to be fined. Other alternative for them is to just call OSHA directly and have them come inspect things - then fine you for anything non compliant, that would save paying the middle man (the OP).

 

[Sahib]

Because your clients hired you to help them comply not to turn them in to be fined. Other alternative for them is to just call OSHA directly and have them come inspect things - then fine you for anything non compliant, that would save paying the middle man (the OP).

Either way it should deter the owners to keep an unsafe condition.

 

[jumper]

Why not also send a note to OSHA as a responsible electrical professional?

Bad idea.

I said to CYA, not shoot oneself in the foot.

 

[kwired]

Either way it should deter the owners to keep an unsafe condition.

One way of looking at it I guess.

Remember owner probably knows little about electrical - hears horror stories about others that were caught, fined, had casualties, etc. Decides to call a professional for consultation on what risk he may have.

Probably is expecting that professional to find problems and make suggestions for solutions, maybe even offer some services to correct such problems. The idea is to avoid being fined by OSHA, and being further investigated in areas other then electrical at same time. Those other areas need addressed as well - but they would likely prefer consultants and not OSHA to point out those issues, which is why they hire them.