Manufactures instructions vs NEC code

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bluecollar84

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What would you follow if the manufacturers instructions went against the NEC on a certain installation requirement but then also the manufactures instructions told you to follow all local codes what would you do?


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Manufacturer's instructions can never be used to permit an installation that the NEC does not permit. They may require things in addition to what the NEC requires, but they can't remove a requirement.
 
A good point of controversy might be 250.79, and the inclusion of GEC's

an entire market erupted from the '11 change

all manufacturer driven

the prob is, manufacturers don't really care to do lunch with each other

ahj's miss the finer points

so.....depending on the manufacturer one pursues , a 110.3B may be quite the ado

~RJ~
 
Mfg requirements can be lax or more restrictive than the NEC, however they cannot contraindicate any other codes. The only one that comes to mind recently was some piece of equipment that the manufacturer language, which was poorly translated, required a fused neutral. I cannot remember what code section that violates however, it did not get installed with a fuse neutral.

There are some truly ridiculous manufacturer requirements, the worst I've seen I think was on a spa that required certain colors of wire to be connected to the terminal blocks. Needless to say on that one, the wire was already run, the homeowner did not want to pay to rerun The Wire, and assumed all liability on warranty issues arising from using the wrong color wire.....
 
Yeah I'm dealing with a bit of a conundrum myself, I'm trying to install a Dyna-Glo heat a 15,000 w in the supplier in the manufacturer and telling me that it's a 10 gauge wire with an 80 amp breaker??? So I called the GHP group directly and they say that it's 62.8 continuous amps calling for a 4 gauge wire but if I bump it up to an 80 amp I need 10 gauge wire which makes 0 sense to me..

What do you guys think how does it work when it comes to manufacturer ratings for instance I know with AC condensers they give you an MCA and MOP which we can follow according 440
 
I think your issue is that heat can only be loaded to 60 amps once you get more than that you need to have another circuit... I assume the #10 was in addition to the #6 or #4 if you use NM
 
Woem14 said:
Yeah I'm dealing with a bit of a conundrum myself, I'm trying to install a Dyna-Glo heat a 15,000 w in the supplier in the manufacturer and telling me that it's a 10 gauge wire with an 80 amp breaker??? So I called the GHP group directly and they say that it's 62.8 continuous amps calling for a 4 gauge wire but if I bump it up to an 80 amp I need 10 gauge wire which makes 0 sense to me..

What do you guys think how does it work when it comes to manufacturer ratings for instance I know with AC condensers they give you an MCA and MOP which we can follow according 440
Click to expand...
At first I thought that maybe they're saying is that the 10 is really supposed to be 1/0 but that doesn't make sense either.
 
Here is the section

424.22(B) Resistance Elements. Resistance-type heating elements in
electric space-heating equipment shall be protected at not
more than 60 amperes. Equipment rated more than
48 amperes and employing such elements shall have the heating
elements subdivided, and each subdivided load shall not
exceed 48 amperes. Where a subdivided load is less than
48 amperes, the rating of the supplementary overcurrent
protective device shall comply with 424.3(B). A boiler employing
resistance-type immersion heating elements contained in
an ASME-rated and stamped vessel shall be permitted to
comply with 424.72(A).
Click to expand...
 
Now this makes more sense. So the heater says 62.5 amps, how do I correctly subdivide that?
Is it just 62.5/2?
Then add the 125% giving me just under 40?
 
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