al borlan
Member
- Location
- Newport, Mi.
Why do fixture whips only come in 6' lengths?
Does the NEC limit the length?
Does the NEC limit the length?
Why do fixture whips only come in 6' lengths?
Does the NEC limit the length?
2011 NEC 410.117 (C) limits tap conductors to 6ft for luminaires.
Fixture wire shall be permitted to be tapped to the branch-circuit conductor of a branch circuit in accordance with the following:
20-ampere circuits ? 18 AWG, up to 15 m (50 ft) of run length
20-ampere circuits ? 16 AWG, up to 30 m (100 ft) of run length
20-ampere circuits ? 14 AWG and larger
30-ampere circuits ? 14 AWG and larger
40-ampere circuits ? 12 AWG and larger
50-ampere circuits ? 12 AWG and larger
Sorry but I see some inconsistencies here(not from you but from the NEC) That section is for recessed/flush luminaires - so no problem with the typical use of a "whip" for a typical "troffer".
Correct, the problem is you can't have both six feet of tap conductor and six feet of raceway to put it in and still have enough free conductor at the ends. If we are to have a minimum of 6 inches of free conductor at each end then the raceway would have to be a maximum of 5 feet long or not contain "tap conductors"A troffer is a recessed/flush mounted fixture in my opinion.
My opinion is it says "AC or MC Cable".as that is what we use for our whips..that would be the entire assembly so having the cable 6' with additional 6" of conductors at each end would still be a 6' cable.Correct, the problem is you can't have both six feet of tap conductor and six feet of raceway to put it in and still have enough free conductor at the ends. If we are to have a minimum of 6 inches of free conductor at each end then the raceway would have to be a maximum of 5 feet long or not contain "tap conductors"
However I also believe most of the pre-made "whips" are a listed assembly and the listing maybe gets you around this problem.
My opinion is it says "AC or MC Cable".as that is what we use for our whips..that would be the entire assembly so having the cable 6' with additional 6" of conductors at each end would still be a 6' cable.
Agreed, tap rules apply to conductor length, nothing mentions raceway or cable sheath length, one could make a tap in a wireway, then pass the conductor through a raceway then into the enclosure containing the overcurrent device, but you only get so much allowed conductor length and do not start over just because it has a change of routing method.It seems like a stretch to say that.
I think kwired is technically correct even though I would never expect an inspector to enforce it that way.
Or are you suggesting that if I was to use MC cable for a feeder tap of say a switchgear bus that any length I have stripped and is inside the enclosure does not count towards the length of the tap conductors?
My reference is to the what is considered 6' in terms of the cable itself as it pertains to the length of whips. When the conductors are the issue (as in your example) then that is what is counted....when dealing with for example supporting requirement as in 6' of unsupported cable from the last point of support to a luminaire for example...the 6' is the cable.It seems like a stretch to say that.
I think kwired is technically correct even though I would never expect an inspector to enforce it that way.
Or are you suggesting that if I was to use MC cable for a feeder tap of say a switchgear bus that any length I have stripped and is inside the enclosure does not count towards the length of the tap conductors?
lol..the whip or the conductors in the whip....:angel:Most fixture whips are made with 3/8" FMC which has a maximum length of 6'. {348.20(A)}
lol..the whip or the conductors in the whip....:angel:
Keep in mind that "whips" can also be wire assemblies (QQYZ) that are comprised of product like Type MC that is already produced and permitted under Art. 330 as you know. We produce "whips" but none are FMC so not sure I would say most....but many indeed.