mortimer
third party inspector
- Location
- New England
- Occupation
- retired
would a sub panel be concidered service equipment?
Indeed, I have, but I feel that it can be interpreted in a way that would allow a sub panel to be treated as service equipment. For example, if a meter was changed to a meter main, would you have to change a range that was wired with #6 SE cable to a 4 wire?No, see the definition of "Service Equipment" in article 100.
Roger
Indeed, I have, but I feel that it can be interpreted in a way that would allow a sub panel to be treated as service equipment. For example, if a meter was changed to a meter main, would you have to change a range that was wired with #6 SE cable to a 4 wire?
Yes, any time you add a new main disconnect upstream, everything after should be re-wired as a sub-panel would be, including major-appliance circuits, receptacles, power cords, etc.
This is triggered when, for example, a transfer switch is added to an existing service; the T/S becomes the service, and GECs and the main bond are supposed to be relocated there, etc.
I can't see any way it can be interpreted except it is not service equipment any more. Per the NEC yes, you would have to change it.Indeed, I have, but I feel that it can be interpreted in a way that would allow a sub panel to be treated as service equipment. For example, if a meter was changed to a meter main, would you have to change a range that was wired with #6 SE cable to a 4 wire?
And to expand on that, if an inspector allowed it he would not be doing his job.Some areas may allow it to remain but you have made a service panel a non service panel and thus the se cable would not be compliant from a sub.
I can't see any way it can be interpreted except it is not service equipment any more. Per the NEC yes, you would have to change it.
And to expand on that, if an inspector allowed it he would not be doing his job.
Roger
250.140 Frames of Ranges and Clothes Dryers.Frames of electric ranges, wall-mounted ovens,counter-mounted cooking units, clothes dryers,and outlet or junction boxes that are part of thecircuit for these appliances shall be connected tothe equipment grounding conductor in the mannerspecified by 250.134 or 250.138.
Exception No. 1: For existing branch-circuitinstallations only where an equipment groundingconductor is not present in the outlet or junctionbox, the frames of electric ranges, wall-mountedovens, counter-mounted cooking units, clothesdryers, and outlet or junction boxes that are partof the circuit for these appliances shall bepermitted to be connected to the grounded circuitconductor if all the following conditions are met.
(1) The supply circuit is 120/240-volt, singlephase, 3-wire; or 208Y/120-volt derived froma 3-phase, 4-wire, wye-connected system.
(2) The grounded conductor is not smaller than10 AWG copper or 8 AWG aluminum.
(3) Any of the following:
a. The grounded conductor is insulated;
b. The grounded conductor is uninsulated andpart or a Type SE service-entrance cableand the branch circuit originates at theservice;
c. The grounded conductor is uninsulated andpart of a cable assembly and all current carrying conductors are protected by a ground-fault circuit interrupter at the origination of the branch circuit; or
d. A new 3-wire cable assembly not smallerthan the existing conductors shall bepermitted to be extended from the service toan enclosure where the existing conductorsshall be spliced together and provisions aremade so that the grounded conductors areinsulated by tape, heat-shrink or otherapproved means inside the enclosure.
(4) Grounding contacts of receptacles furnishedas part of the equipment are bonded to theequipment
Exception No. 2: For existing branch-circuitinstallations only where an equipment groundingconductor is not present in the outlet or junctionbox, an equipment grounding conductor sized inaccordance with 250.122 shall be permitted to berun separately from the circuit conductors.
Dennis, existing installations would mean nothing else has changed. There has never been an exception to allow a three wire branch circuit where it was never allowed in the first place and it was never allowed from a "subpanel".NC allows it in some situations
Dennis, existing installations would mean nothing else has changed. There has never been an exception to allow a three wire branch circuit where it was never allowed in the first place and it was never allowed from a "subpanel".
Roger
b. The grounded conductor is uninsulated and part or a Type SE service-entrance cable and the branch circuit originates at the service;
Roger I am pretty certain that the intent of the bold was added to accommodate the situation we are talking about. I can check with Joe but I seem to remember going over that with him
I think they need to work on their wording.My point was that it is allowed in some areas. Granted the NEC doesn't allow it.
Nc has gone further for an existing 3 wires run to an old service panel that is now a sub panel
Exception No. 5: It shall be permissible to groundan existing panelboard enclosure by connectionto the grounded circuit conductor for a one- andtwo-family dwelling where all the followingconditions apply:
(1) When relocating or installing an additionalmain disconnecting means;
(2) Enacting 250.142(B) Exception No. 5: (1)redefines the existing service entranceconductors as a feeder as set forth in Article100;
(3) An equipment grounding conductor in theexisting panelboard is not present;
(4) Replacement of the existing service entranceconductors either requires the removal of thebuilding finish or is deemed impractical by theauthority having jurisdiction.
(5) All grounding electrode conductors areremoved completely from the existingpanelboard; and(6) The grounded conductors are insulated bytape, heat-shrink, or other approved meansexcept where covered by the sheathing of acable assembly or as needed for joints, splices,and termination purposes.
I should have pointed to Exception 1 (3)(b) of 250.140 to accompany my post.
Roger
This is getting exciteing. All kinds of interpretationThat's an interesting point.
Seeing as how there is no branch distribution in a Meter/Main setup (unless you purchase it with it) , isn't the existing Service Panel (although now actually a subpanel) still the first "Service Panel" where a branch circuit can be taken from ?
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