Manufacturer recommendation and Engineers Stamp

[dcooper]

I was always taught that a stamped set of drawings from an engineer or manufacturer recommendation supersedes the NEC.
This is tricky. I have a Bosch oven that trips the GFCI when it goes into preheat. I called them and they said it can not be on a GFI breaker. Now the inspector is telling me that I can not install this oven.
I know my ways around it. Thats not where I'm going with this. I was just ALWAYS in the understanding that manufacturers recommendations and engineers stamps supersede the NEC

 

[jim dungar]

I was always taught that a stamped set of drawings from an engineer or manufacturer recommendation supersedes the NEC.

Then you have been taught wrong.
Nothing supersedes the NEC except what is allowable by the AHJ.

 

[zbang]

Both the NEC and mfg's instructions are minimum requirements, you have to meet both. If Bosch no GFCI and the AHJ says you need one, I'd be back to Bosch about that.

 

[dcooper]

Then you have been taught wrong.
Nothing supersedes the NEC except what is allowable by the AHJ.

I kindly disagree with " except what is allowed by the AHJ"
They are only there to enforce the NEC. If you are abiding by the code they have no input. If you are not following the code then they dont have the power to "allow" it. It is my liability. I hold all the fault. if it fails or someone gets hurt and it was a violation I am responsible. Not the inspector.

I have had engineered drawings that didnt follow wire calculations or derating. But it was never called in question because they were engineered.
When i asked about this 'violation' i was told it has an engineers stamp.

 

[don_resqcapt19]

I kindly disagree with " except what is allowed by the AHJ"
They are only there to enforce the NEC. If you are abiding by the code they have no input. If you are not following the code then they dont have the power to "allow" it. It is my liability. I hold all the fault. if it fails or someone gets hurt and it was a violation I am responsible. Not the inspector.

I have had engineered drawings that didnt follow wire calculations or derating. But it was never called in question because they were engineered.
When i asked about this 'violation' i was told it has an engineers stamp.

90.4(C) Specific Requirements and Alternative Methods.
By special permission, the authority having jurisdiction may waive specific requirements in this Code or permit alternative methods where it is assured that equivalent objectives can be achieved by establishing and maintaining effective safety.

 

[winnie]

Certain portions of the NEC explicitly permit 'engineering supervision'; for example a suitable engineer can calculate conductor ampacity using the 'Neher McGrath' equations rather than using the tables.

The AHJ can also adopt the NEC with amendments that permit installations which would violate the 'raw' NEC, and the AHJ has certain power to allow some deviations on a case by case basis.

But it sounds like the manufacturer in the OP is building something which cannot be installed in a permitted fashion.

-Jon

 

[jim dungar]

I have had engineered drawings that didnt follow wire calculations or derating. But it was never called in question because they were engineered.
When i asked about this 'violation' i was told it has an engineers stamp.

The AHJ is often given quite a bit of leniency in allowing deviations from the Code, see Don's post #5.

As a PE, I am fully aware that I do not overrule the NEC except where allowed.

It is common to see specification language that requires the EC to follow codes regardless what the plans show.

 

[norcal]

To put it simply, what do you do when code requires GFCI protection, & manufacturer says no GFCI protection?

 

[roger]

To put it simply, what do you do when code requires GFCI protection, & manufacturer says no GFCI protection?

I was involved in a project where certain kitchen equipment had the same "do not connect to a GFCI" yet the NEC required it. After the customer and equipment supplier discussed it with the manufacturer, the manufacturer stood firm that they could overrule the code. So all of their equipment was returned, and the contract was given to another.

 

[don_resqcapt19]

To put it simply, what do you do when code requires GFCI protection, & manufacturer says no GFCI protection?

All that manufacturer's requirement does is to simply tell you that you are not permitted to install their equipment any place where the NEC requires GFCI protection.

 

[LarryFine]

If you are not following the code then they dont have the power to "allow" it.

As mentioned above, yes, they do. I asked an inspector for permission to retain the three-wire major appliance circuits after an ATS installation. He agreed that it was all but impossible to run new cables between the panel in the garage and the house.

Only a breezeway-type roof connected the two structures, and the roof ran directly into the brick side of the two-story house. He allowed me to carefully tape white the bare SE conductors in the panel and keep them on the neutral bus as neutrals.

 

[LarryFine]

All that manufacturer's requirement does is to simply tell you that you are not permitted to install their equipment any place where the NEC requires GFCI protection.

Agreed. If your install required GFCI protection, the selected appliances must be compatible with them.

 

[zbang]

Which gets us to a kitchen appliance that can't be installed in a kitchen. (Definitely a problem for the manufacturer and architect/specifier, not for the installer.)

 

[jaggedben]

Which gets us to a kitchen appliance that can't be installed in a kitchen. ....

Well, not a kitchen in most of the US anyway.

 

[winnie]

Question: Is this a _new_ oven that is tripping the breaker?

There have been other threads describing how new oven elements absorb moisture during shipping, and trip GFCI breakers. But if you operate them up to temperature on a normal breaker you bake out the moisture, and then the over functions just fine on a GFCI breaker.

-Jon