Electric Room Egress

[Mustang125]

Article 110.26 (C)(2) states "For Equipment rated 1200a or larger....." there shall be a door at each end of room.
Now it seems pretty clear but there may be room for interpretation here.

When they say "equipment rated" do they mean the rating of the bus bar or the rating of the wire/breaker that feeds the equipment?

Meaning if I have a piece of equipment with a bus rating of 1200a but I'm only feeding it with 800a, yes the equipment is "rated" at 1200a but there is only a "potential" for 800a.

what are the groups thoughts on this?

 

[gadfly56]

Article 110.26 (C)(2) states "For Equipment rated 1200a or larger....." there shall be a door at each end of room.
Now it seems pretty clear but there may be room for interpretation here.

When they say "equipment rated" do they mean the rating of the bus bar or the rating of the wire/breaker that feeds the equipment?

Meaning if I have a piece of equipment with a bus rating of 1200a but I'm only feeding it with 800a, yes the equipment is "rated" at 1200a but there is only a "potential" for 800a.

what are the groups thoughts on this?

I'd base it on the breaker rating.

 

[Rock86]

Article 110.26 (C)(2) states "For Equipment rated 1200a or larger....." there shall be a door at each end of room.
Now it seems pretty clear but there may be room for interpretation here.

When they say "equipment rated" do they mean the rating of the bus bar or the rating of the wire/breaker that feeds the equipment?

Meaning if I have a piece of equipment with a bus rating of 1200a but I'm only feeding it with 800a, yes the equipment is "rated" at 1200a but there is only a "potential" for 800a.

what are the groups thoughts on this?

2020 NEC clarifies this by saying "shall apply to either of the following conditions: ... (2) For service disconnecting means installed in accordance with 230.71 where the combined ampere rating is 1200 amperes or more and over 1.8m wide."

but if you are on 2017 NEC, they say " 110.26(C)(2) Large Equipment. For equipment rated 1200 amperes or more and over 1.8m wide that contains...." So IMO I would take that to mean whatever the equipment is rated at, not what the disconnecting means or overcurrent protection is rated at. Ask your AHJ what they would approve.

 

[infinity]

I look at it this way, if I have a 200 amp disconnect with 150 amp fuses and wire is it a 200 or 150 amp piece of equipment?

 

[Mustang125]

2020 NEC clarifies this by saying "shall apply to either of the following conditions: ... (2) For service disconnecting means installed in accordance with 230.71 where the combined ampere rating is 1200 amperes or more and over 1.8m wide."

but if you are on 2017 NEC, they say " 110.26(C)(2) Large Equipment. For equipment rated 1200 amperes or more and over 1.8m wide that contains...." So IMO I would take that to mean whatever the equipment is rated at, not what the disconnecting means or overcurrent protection is rated at. Ask your AHJ what they would approve.

I do understand this but to mean this relates only to service equipment. in my current situation its all sub-equipment all fed from same service so even if I had 2 800a panels in a room I have 2 800a panels not 1 1600a panel, to me it shouldn't be additive.

I did ask the AHJ and he said "I don't like it and I want to come out with building inspector to get his input". But the engineers didn't design the room with 2 doors and the whole room is now complete with every wall full of equipment, no good way to add a door. So I'm trying to think hard on the issue incase it escalates.

I look at it this way, if I have a 200 amp disconnect with 150 amp fuses and wire is it a 200 or 150 amp piece of equipment?

I do see your point here that the fuses could easily be changed to 200a but what is feeding the 200a disconnect? if the wire is not rated for 200a then to change the fuses you would also need to change the wire. so this is why its a bit borderline to me. i could also say that someone is able to add or change equipment at anytime and could pull that disconnect down and change it to something larger. to me the code should read " for equipment that has a current potential of 1200a or larger under normal operating conditions". But this is why I'm asking for more input....

 

[Rock86]

I do understand this but to mean this relates only to service equipment. in my current situation its all sub-equipment all fed from same service so even if I had 2 800a panels in a room I have 2 800a panels not 1 1600a panel, to me it shouldn't be additive.

I understand your situation, but I am only looking at what the code says. Because it says "Equipment rated" so if you have a 1200A rated busbar, I would argue that by they wording of the code you would need the two doors. IMO.

 

[Mustang125]

I understand your situation, but I am only looking at what the code says. Because it says "Equipment rated" so if you have a 1200A rated busbar, I would argue that by they wording of the code you would need the two doors. IMO.

Now what if the equipment is rated 1200a, fed with 800a and is only 3' wide? the way I read it, it says "equipment 1200a or more and over 6' wide" it doesn't say or. Wouldn't that mean it has to be 1200a and be 6' wide in order to be required? if it only meets 1 of those then it doesn't apply.....

 

[Rock86]

Now what if the equipment is rated 1200a, fed with 800a and is only 3' wide? the way I read it, it says "equipment 1200a or more and over 6' wide" it doesn't say or. Wouldn't that mean it has to be 1200a and be 6' wide in order to be required? if it only meets 1 of those then it doesn't apply.....

If it is only 3' wide... then sure, you should be good with 1 door. IMO