When an engineer signs off on modifying equipment, i.e. adding a lug to a bus bar, does the AHJ have to accept that? Is it the same as a NRTL approving the modification? Does the AHJ have final say even if something has been listed? I recently had to do this with a P.E. and the AHJ said he would accept it this one time, but going forward he would not. The P.E. says the AHJ has to accept it. Who's right?
P.E. Signing Off On Field Modifications
- Thread starter sketchy
- Start date
- Status
- Location
- Wisconsin
- Occupation
- PE (Retired) - Power Systems
The AHJ always has the final say.
electrofelon
Senior Member
- Location
- Cherry Valley NY, Seattle, WA
- Occupation
- Electrician
No the AHJ does not have to accept, there is no provision in the NEC that a PE can can "sign off" on equipment modifications.
ron
Senior Member
- Location
- New York, 40.7514,-73.9925
I am not familiar with anything in the code that has a PE signoff provision for field modifications.
- Location
- Chapel Hill, NC
- Occupation
- Retired Electrical Contractor
That may be true but in general, I believe most authority having jurisdiction's will accept a signed form from the engineer.
- Location
- New Jersey
- Occupation
- Journeyman Electrician
I agree, an engineer cannot simply write a letter stating that the modification is now code compliant except maybe if he happens to work for the manufacturer. If the AHJ decides to accept it that's his prerogative he is not required to do so.
It didn't work that way around Asheville Dennis.
Listen for the "thud" noise when the PE gets knocked off of his high horse.
ron
Senior Member
- Location
- New York, 40.7514,-73.9925
There is very few code section that provides a PE some real leverage over a UL listing or something established by a standard. A search of engineering supervision includes 110.22(B) & 240.86(A) (series ratings), 110.71 (manhole / vault strength), 235.202 (Over 1000 Volts ac, 1500 Volts dc, Nominal), 245.26(A), 250.194(A) (Metal Fences), 310.14(B) & 310.15(A) (conductor sizing), 337.10 (Type P Cable), 371.18(A) (flex bus), 705.12(B) Busbars and 705.76 (Interconnected Electric Power Production Sources)
- Location
- Chapel Hill, NC
- Occupation
- Retired Electrical Contractor
Was your buddy being a Pita. lol
I know in Chapel Hill if you got a sig from an ee that was acceptable.
gadfly56
Senior Member
- Location
- New Jersey
- Occupation
- Professional Engineer, Fire & Life Safety
Speaking from a fire alarm perspective, NFPA 72 has more wiggle room than the NEC. You can either follow the prescriptive requirements, or you can do a ground up design that meets the intention of the code. For example, you can use listed notification appliances with the prescriptive spacing, or you can put together your own design that meet the candela requirements. That's just one example. The key is that you need to get AHJ buy in beforehand not afterward.
A lot of our areas have a "variance board". If it doesn't meet Code (Building, Electrical, etc) you can present your case to the board and if they accept it that's the ruling. A PE letter goes a long way toward gaining acceptance.
Similar to an AHJ call but not putting the final word in one person' hands plus there is a public record
Similar to an AHJ call but not putting the final word in one person' hands plus there is a public record
gadfly56
Senior Member
- Location
- New Jersey
- Occupation
- Professional Engineer, Fire & Life Safety
I think the OP's case is a little more nuanced, as it deals with the modification of listed equipment, not simply a departure from prescriptive design. You're point would be well taken if the discussion was about, say, using a 1-hour fire wall where the code might require a 2-hour fire wall.
Take a look at a UL publication
texie
Senior Member
- Location
- Fort Collins, Colorado
- Occupation
- Electrician, Contractor, Inspector
An engineer can't OK this in most informed AHJs just like he can't override codes either. Most informed AHJs would require a field evaluation by a NRTL for things like this.
- Location
- Wisconsin
- Occupation
- PE (Retired) - Power Systems
OSHA and NFPA70E are 'safety standards' for interacting with equipment. Both of these defer to the NEC for equipment installation.
The PE is exaggerating their influence.
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It's up to the AHJ what he will accept. I've never had an AHJ question a bus tap except for compliance with 240.21. These days I won't have anybody drill a bus but will basically look the other way if the bus already has the necessary holes, nuts and bolts. I've got two "temporary" projects with this happening right now. On both the electrician asked if he can tap the bus and I told him as long as he maintains the UL listing. Both will be returned to original condition with OEM parts eventually.
The real trick is that it doesn't take something close to drilling a bus to void a UL listing.
The real trick is that it doesn't take something close to drilling a bus to void a UL listing.
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