a little input here please. so the discussion goes, your neutral has to go with your ungrounded conductors down to the switch, yes it does, no it dont, so forth and so on. article says nothing specific but mentions exceptions and that not being one of them, it also throws in the where used. any outside interpretations please, seems like a slightly grey loophole that needs to be cleared up.
300.3(b)
- Thread starter MasterDic
- Start date
- Status
- Location
- Massachusetts
MasterDic said:
The neutral only has to go to the switch if used at the switch.
Read 300.3(B) and you see it says "where used".
crossman
Senior Member
- Location
- Southeast Texas
Read the section and note where it says "where used".
A "hot" wire from a lighting outlet to a switch with a "switch leg" going back to the lighting outlet does not use a grounded conductor. There is no requirement for the grounded conductor to go to a switch location in this instance.
In other instances, the neutral may need to go through the switch box. The whole point is to have the magnetic fields cancel with the same current going one way as is coming back in an individual raceway or cable.
I think another code section deals with that but am too lazy to look it up right now.
A "hot" wire from a lighting outlet to a switch with a "switch leg" going back to the lighting outlet does not use a grounded conductor. There is no requirement for the grounded conductor to go to a switch location in this instance.
In other instances, the neutral may need to go through the switch box. The whole point is to have the magnetic fields cancel with the same current going one way as is coming back in an individual raceway or cable.
I think another code section deals with that but am too lazy to look it up right now.
- Location
- Massachusetts
this is not an nec issue, but it should be noted that although the neutral may technically not be required with travellers, not installing the neutral with the travellers can often be associated with unwanted emf (ie. running the neutral with the travellers can reduce undesired flux)
- Location
- Massachusetts
nakulak said:
That is only true is your doing something very unusal.
The common ways of wiring 3 ways without a neutral still balance each other out and there will be no EMFs running around the home. :smile:
Last edited:
- Location
- Chapel Hill, NC
- Occupation
- Retired Electrical Contractor
I agree. The feed and the switch leg will cancel out and there would be no emf's.
Getting back to the OP's question, some switches such as; low voltage dimmers, motion switches, etc. require a neutral wire. This would be when you need to put a neutral wire at the switch. It is becoming more common to see special type switches like this in residential. The 2 ways of wiring that are most common are,
1) run the line conductors to the light box, then drop down to the switch with a 2 wire NM "hot & switch leg" no neutral wire.
2) run the line conductors to the switch box, then an NM "switch leg, neutral, & ground" to the light.
Both methods work and are code compliant. The second method gives you a neutral at the switch, the first method does not.
Personally I go with the neutral to the switch box, if you don't need it for the switch it hasn't cost you any more work, if you do need it you will be glad you put it there.
1) run the line conductors to the light box, then drop down to the switch with a 2 wire NM "hot & switch leg" no neutral wire.
2) run the line conductors to the switch box, then an NM "switch leg, neutral, & ground" to the light.
Both methods work and are code compliant. The second method gives you a neutral at the switch, the first method does not.
Personally I go with the neutral to the switch box, if you don't need it for the switch it hasn't cost you any more work, if you do need it you will be glad you put it there.
William1978
Senior Member
- Location
- N.C.
check out 404.2
- Status