Tandem Strip Light Wiring

[BTSaw]

I planning to buy four Lithonia Model # TUNS 2 32 MVOLT 1/4 GEBHL at HD. I'm assuming there is a ballast for each pair of 4' bulbs. I read in one of postings these fixtures can be wired to two separte light switches.

If so, can I use two separate 14-guage wire for hot and one single 14-guage wire for neutal? Or do I have to have a neutral for each hot leg? Thanks.

 

[lakee911]

Whether or not it has one or two ballasts depends on the fixture--you may need to open one up and check or contact the manufacturer.

Energy effciency codes many times do require two light switches in commercial or industrial spaces--half of the lamps on one switch and half on the other switch. The NEC only allows #14 wire to be used for a 15A circuit and then loaded to only 80%. So, that gives you 12A on a #14.

I don't know how many lights you're planning, but if you use the same circuit for all your lighting you can only load the circuit to 12A total--that means 6A on each hot. Because in that case current adds, you'll have 12A on the neutral--maybe a little more depending on harmonics which is dependent on how much lighting you'll have but that's likely negligible here and out my expertise anyways. Sometimes for harmonics issues, the neutral gets sized at 200%.

If you decide to use a MWBC (make sure you use a tie handle on two single pole breakers) you can load up each leg to 12A and since currents subtract here, with both lights on you'll be pretty close to 0A on the neutral.

Jason

 

[Steevo]

According to the specifications, there is a single ballast in that fixture model.

Product Details of Lithonia Lighting LITHONIA TUNS 2 32 MVOLT 1/4 GEBHL Fixture,Strip,F32T8,4 Lamp,120-277V G3539042

Description

Channel Strip Fluorescent Fixtures, F32T8 Lamp Type, Lamp Quantity 4, 32 Lamp Watts, Heavy-Duty Fixture Type, 128 Fixture Wattage, 120-277 Voltage, Electronic Ballast Type, Ballast Quantity 1, 0 to 104 Degrees F Ambient Temp. Range, Suggested Lamp Item No. 2ETU3, Description/Special Features Heavy-Duty, Tandem Strip, Ceiling Or Suspended Mounting, White Powder Paint Housing Finish, Metal Gauge 22, No Lamp Included, 96 In. Length, 4-3/8 In. Width, 3 In. Height, Standards UL Listed, Footnotes 2

 

[BTSaw]

do you know how many amps this light fixture uses? Thanks.

 

[lakee911]

do you know how many amps this light fixture uses? Thanks.

Specifications should say, because it depends on the ballast. A rule of thumb is to add 10% loss for the ballast. Cheapo magnetic ballasts might be worse ... not sure.

A = W/V

A = (32W*4)/120V = 1.07 * 110% = 1.17A per fixture lamped with four working bulbs @ 120VAC.

 

[Dave88LX]

Any input/reviews on this fixture? Looking at them as a T8 solution.

 

[akjose]

Any input/reviews on this fixture? Looking at them as a T8 solution.

I would honestly go with these instead: http://www.homedepot.com/p/Lithonia...orescent-Utility-Light-MNS5-2-28-LP/100654408

4' T5 and it comes with 2 bulbs. I would stack double them up end to end. They are much brighter than the T8.