Mark P Posted October 29, 2013 Report Share Posted October 29, 2013 Okay I?ve been down this road before but I can?t find anything in either the NEC, or the ?Electrical Inspection of Existing Dwellings (By Hansen) that gives me a clear definition of when a panel is a sub-panel. I know I?m going to get push back on an issue and I want supporting reference material. The house was built in 1972 with several additions. Scenario 1 ? There is a disconnect on the outside of the house next to the meter. Directly on the other side of the wall, inside the garage, there is a panel filled with breakers, but with no single disconnect. Is this a sub-panel requiring the separation of the grounds & neutrals? Scenario 2 - There is a disconnect on the outside of the house next to the meter. Somewhere in the garage there is a panel filled with breakers and also has a single disconnect (in addition to the disconnect on the outside of the house). Is this a sub-panel requiring the separation of the grounds & neutrals? Scenario 3 - There is a disconnect on the outside of the house next to the meter. Way way far away on the other side of the house there is a brand new garage. There is a panel with breakers and a single disconnect (in addition to the disconnect on the outside of the house). Is this a sub-panel requiring the separation of the grounds & neutrals? Quote Link to comment Share on other sites More sharing options...
Chad Fabry Posted October 29, 2013 Report Share Posted October 29, 2013 Yes, yes, yes Quote Link to comment Share on other sites More sharing options...
Mark P Posted October 29, 2013 Author Report Share Posted October 29, 2013 Yes, yes, yes Thank you. Can anyone provide a reference supporting this. Quote Link to comment Share on other sites More sharing options...
Jim Katen Posted October 29, 2013 Report Share Posted October 29, 2013 You won't find a definition of a sub panel in the NEC because they don't use that term. The NEC reference you're looking for is 250.142(B). In Electrical Inspection of Existing Dwellings, check sections 3.7.3 and 4.3.1 for an in-depth discussion and some other NEC references. Quote Link to comment Share on other sites More sharing options...
Marc Posted October 29, 2013 Report Share Posted October 29, 2013 250.24 (A) 1 thru 5 give detail on where the grounded service conductor and electrode grounding conductor can be connected. Basically, it says, among other things, that the grounded service conductor - AKA neutral - cannot be connected to equipment grounding conductors or to equipment enclosures on the load side of the main service disconnect. So, you have to carry your equipment grounding conductor from the line side of the disconnect to the load side with a 4th conductor because you can't use the neutral for that after the main disconnect. Mains have 3 wires, subs have 4. Marc Quote Link to comment Share on other sites More sharing options...
Chad Fabry Posted October 29, 2013 Report Share Posted October 29, 2013 ?250.24 (5) Load-Side Grounding Connections. A grounded conductor shall not be connected to normally non?current-carrying metal parts of equipment, to equipment grounding conductor(s), or be reconnected to ground on the load side of the service disconnecting means except as otherwise permitted in this article. ?250.142 (A) Supply-Side Equipment. A grounded circuit conductor shall be permitted to ground non?current-carrying metal parts of equipment, raceways, and other enclosures at any of the following locations: (1) On the supply side or within the enclosure of the ac service-disconnecting means (2) On the supply side or within the enclosure of the main disconnecting means for separate buildings as provided in 250.32(B) (3) On the supply side or within the enclosure of the main disconnecting means or overcurrent devices of a separately derived system where permitted by 250.30(A)(1) Quote Link to comment Share on other sites More sharing options...
Chad Fabry Posted October 29, 2013 Report Share Posted October 29, 2013 Geez. Take a minute to look up a reference and two geeks beat me to it. Quote Link to comment Share on other sites More sharing options...
Tom Raymond Posted October 29, 2013 Report Share Posted October 29, 2013 So does that make you slower, or less geeky? Quote Link to comment Share on other sites More sharing options...
Marc Posted October 29, 2013 Report Share Posted October 29, 2013 ?250.142 (A) Supply-Side Equipment. A grounded circuit conductor shall be permitted to ground non?current-carrying metal parts of equipment, raceways, and other enclosures at any of the following locations: (1) On the supply side or within the enclosure of the ac service-disconnecting means .... Does this mean that it's ok to ground an AC condenser disconnect enclosure and air handler disconnect enclosure to the neutral but not the condenser unit itself or the air handler itself? Marc Quote Link to comment Share on other sites More sharing options...
Nolan Kienitz Posted October 29, 2013 Report Share Posted October 29, 2013 So does that make you slower, or less geeky? Nope ... Chad just got "geeked" [:-slaphap Quote Link to comment Share on other sites More sharing options...
rkenney Posted October 29, 2013 Report Share Posted October 29, 2013 ?250.142 (A) Supply-Side Equipment. A grounded circuit conductor shall be permitted to ground non?current-carrying metal parts of equipment, raceways, and other enclosures at any of the following locations: (1) On the supply side or within the enclosure of the ac service-disconnecting means .... Does this mean that it's ok to ground an AC condenser disconnect enclosure and air handler disconnect enclosure to the neutral but not the condenser unit itself or the air handler itself? Marc They mean alternating current not air conditioning. But you knew that didn't you? Quote Link to comment Share on other sites More sharing options...
Marc Posted October 29, 2013 Report Share Posted October 29, 2013 ?250.142 (A) Supply-Side Equipment. A grounded circuit conductor shall be permitted to ground non?current-carrying metal parts of equipment, raceways, and other enclosures at any of the following locations: (1) On the supply side or within the enclosure of the ac service-disconnecting means .... Does this mean that it's ok to ground an AC condenser disconnect enclosure and air handler disconnect enclosure to the neutral but not the condenser unit itself or the air handler itself? Marc They mean alternating current not air conditioning. But you knew that didn't you? Jeez.[:-paperba Marc Quote Link to comment Share on other sites More sharing options...
Mark P Posted October 29, 2013 Author Report Share Posted October 29, 2013 Thanks Chad, Jim Marc I appreciate it. It would make life easier if we all used the same language. Reading the code is like translating Japanese sometimes. Quote Link to comment Share on other sites More sharing options...
John Kogel Posted October 30, 2013 Report Share Posted October 30, 2013 Thanks Chad, Jim Marc I appreciate it. It would make life easier if we all used the same language. Reading the code is like translating Japanese sometimes. It's done for job security.If everyone understood the rules and why they were written, there'd be no need for enforcers. Quote Link to comment Share on other sites More sharing options...
Nolan Kienitz Posted October 30, 2013 Report Share Posted October 30, 2013 Thanks Chad, Jim Marc I appreciate it. It would make life easier if we all used the same language. Reading the code is like translating Japanese sometimes. It's done for job security.If everyone understood the rules and why they were written, there'd be no need for enforcers. OK ... you guys set this up all by yourselves ... and I can't resist!! +++++ And then you add in the dialects from a Canadian and someone from Louisiana you really have some potato and ham soup or gumbo. +++++ [][] Quote Link to comment Share on other sites More sharing options...
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