Pre-made fixture whips

[LarryFine]

Me again. How many lay-ins' worth of current can be placed on those pre-made whips? I think they contain #18 wire.

We're looking at 2 to 4 fixtures per switch in most of the rooms, but about 12 will be on each circuit in the large main room.

Do they come in #12, or must I make my own where I'll need them?

 

[quogueelectric]

Me again. How many lay-ins' worth of current can be placed on those pre-made whips? I think they contain #18 wire.

We're looking at 2 to 4 fixtures per switch in most of the rooms, but about 12 will be on each circuit in the large main room.

Do they come in #12, or must I make my own where I'll need them?

One whip one fixture is my take on them. i usually spraypaint a colord dot on the floor where a deep 4 sq box and try to lay it out where you can hit 4 fixtures per jbox and you are in the money.

 

[LarryFine]

... try to lay it out where you can hit 4 fixtures per jbox and you are in the money.

The problem with that is the roof bar joists are about 8' above the suspended ceiling grid.

 

[quogueelectric]

The problem with that is the roof bar joists are about 8' above the suspended ceiling grid.

That stinks making your own whips is not the end of the world but supporting them properly can be a pita. I would probably just daisy chain with duplex connectors in this case charge a little more for wasted wire and fastening if you can.

 

[hurk27]

The problem with that is the roof bar joists are about 8' above the suspended ceiling grid.

Install extra cieling support wires, and use them to support your conduit and boxs? see: 300.11(A) and 314.23(D)(2)

Caddy makes a nice clip for mounting the box's to the wires.

 

[jeffhornsby]

402.5 6 Amps if it 18AWG fixture wires but I believe you can only wire one light per whip because the box having to be 1 foot away is for heat dissapation. Use #12 and your whip can be longer than 6 foot and get the cieling grid guy to put up some extra wire and use batwings to support wire. The inspector might make you paint the grid wire, but I think that is only if the suspended cieling is a certain fire rating

 

[infinity]

So if you need whips longer than 6' you'll likely need to make your own since 3/8" FMC is limited to 6' in length. In that case you might be better off just using MC cable.

 

[cschmid]

the supplie house here stock whips that are #14's and you can get #12's and #10's if you order them. you can get different lengths as well but if I remember the price of the longer ones I bought the materials and made them.

lets see 15 x .8= 12 .4/12=30 So on a #14 you can run 30 ballast provided they only use .4 amps and that was just an appromimation of what a 4 bulb t8 ballast uses. You got the idea anyway and just for the record I dislike large daisy chained light sets but sometimes you gotta do what you gotta do..

ADDED...

the supply house does not stock #18 whips it only stocks #14..I did not even think you could use #18 as I thought the minumum wiring size was #14?? I am going to have to check thatout and get back to you on the section if it exists.

 

[M. D.]

If they are listed as fixture wire whips

this will take to a document from one co. that makes them ,.. if you're interested

http://www.engproducts.com/pdf/AppNote_FlexibleMetalFixtureWhips.pdf

 

[iwire]

Larry, I would forget the whips and just daisy chain the fixtures with MC. No boxes to support.

 

[gotmud]

You guys are lucky...our city ordinace says no daisy chaining.:roll:

 

[Pierre C Belarge]

If one is going to use boxes, and the junior beams are so high, them mount the boxes between fixtures as Sherman has suggested, and mount the boxes on threaded rod down close to the fixtures so the support method is the fittings. That may save a lot of time, depending on the number of fixtures involved in the installation.

 

[cadpoint]

If one is going to use boxes, and the junior beams are so high, them mount the boxes between fixtures as Sherman has suggested, and mount the boxes on threaded rod down close to the fixtures so the support method is the fittings. That may save a lot of time, depending on the number of fixtures involved in the installation.

Some might think it is a waste, I'd add a piece of 1/2" conduit over the rod dropped from ceiling, a toggle bolt at the bar joist, a couple of extra bolts and fender washers, it sure does firm up the box. MC from the switch, home run in high ceiling and drop down and still have some better conduit support down to the box off of the additional vertical conduit. Watching your fixture arragement you can usually get the correct usuage of 6 foot whips.
Dancing with the HVAC and the Sprinkler system is usually the bigger problem!

 

[renosteinke]

The fixtures are listed as one whip to feed that fixture only. If you want to 'daisy chain' them, you need to use full-size wire.

 

[iwire]

The fixtures are listed as one whip to feed that fixture only. If you want to 'daisy chain' them, you need to use full-size wire.

Got a reference for that?

 

[cowboyjwc]

Wow, you guys go through a lot of trouble to support a box. Just screw or nail a 2x4 or a steel stud and drop it down and mount the box to that or nipple a box to the top of one of the fixtures.

 

[renosteinke]

Fair point, Bob. Let's see what I can dig up.

 

[Johnmcca]

Bob,I think M.D. already did cite the code 402.11

 

[LarryFine]

Larry, I would forget the whips and just daisy chain the fixtures with MC. No boxes to support.

That looks like where I'm heading. Would you say 30 minutes per fixture including unpacking, making a whip from MC, laying in the grid, attaching, wiring, and lamping? Customer is supplying materials and the lift.

 

[iwire]

I think it is doable but not much room for any hold ups.