cmdeals

Hi there,

I am here asking for your help with this situation. This will be my first time working with fluorescent fixtures and am somewhat confused about the Wattage indicated on the ballasts of the fixtures. Please give any advice on the following situation:

Need to do:

Wire up 30 Fluorescent Light Fixtures 2' x 4' T8 4-Lamp off a single switch coming from breaker panel.

Information I can provide on the ballasts:
Each ballast states a wattage of 50-60 W. However, each lamp is rated at 32W. The ballast amperage is at most 0.97A.

My question: In order to calculate the load of the 30 Fixtures, do I use the 50-60W rating on the ballast or the 4 x 32W (128W per fixture) of the lamps?

If I need to use the wattage of each lamp, what would be the best method to get all 30 fixtures off a single switch.

As of right now, I plan on using a single 20A toggle switch as the main (assuming I am to use the 50W rating of the ballast = 1500W total).

Any help would be greatly appreciated. Thanks and take care.

Dennis Alwon

Use the ballast rating not the wattage of the bulbs.

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John

Run two circuits and use a two pole switch.

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Doubt All Before Believing Anything.......

kbsparky

That is the number you need .... it takes power factor into consideration.

With that in mind, your plan to control 30 fixtures with a 20 Amp switch won't cut it, unless you use 2 circuits and a double-pole switch, or a lighting contactor on multiple circuits.

__________________
-KB

Life is uncertain -- eat dessert first!

wildleg

your profile says residential, yet your first post is about office lighting. curious

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As President Roosevelt said: "We have nothing to fear but fear itself. And Chuck Norris. And 滿口胡言. And Grabthar's hammer. And Gort. and 江南 Style. and rotting in the street and Zombies . . . and Wayne Griffen "

cmregalado

I am a residential contractor, thats why I need the help with this scenario, it is my first time.

HARRY304E

It could be that the company he works for ,Or his company landed a commercial job so they don't deal with that stuff very much.

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electricalwiz

make sure thay are multi volt ballast and wire them in 220 volt

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noarcflash

1 amp per ballast x 30 fixtures, = 30 amps, plus the 20% rule. So now your running #8 wire off a 40 amp disconnect.
??????????????????????????????????

there is something called load balancing, across 3 phases. 10 fixtures per phase. or so many other (better) ways to do this.

Wireman191

The ballast will up the voltage is the reason the wattage on the bulbs/ballast don't make sense.
I wanna say it bumps it to 600 volts?

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Work like you don't need the money

jay_bolton

What voltage are you working with? 120/240, 120/208, 347/600?
And out of curiosity, where are you installing them? Office, warehouse?
Do they need night lights or emergency lights?

Lighting Retro

lick your fingers, stand barefooted in water, and then touch the black wire.

:P

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Big John

You can't use only the lamp wattage because there's power loss in the ballasts that gets ignored. All the heat that ballasts produce is power being consumed.

-John

oldtimer

What part of Ontario is TOROMTO in????

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Hairbone

LMAO..... Chit like this grinds my gears. I used to have to read books before the internet. Now guys with no brains can bid work and go to a professional board and get free info

Speaking of first times...... well, i could never imagine going to a chat room and asking questions about many firsts if you know what i am talkin' about

ME, LC

He's a residential all-in-one (don't like to pay fer trades if ah can do it mahself!) contractor. Plumbing, electrical, roof repair, siding... no job too big, or too small!

MELC

Rhysrich1991

i would just run one curcit in and use a four pole rotary contactor
*happy days*

AntiqueElectrician

Each fixture is about 1 amp each. I would use 2 circuits, 15 fixtures on each. Have the switch pull in a coil. Connect the 2 circuits to the starter so they turn on together.

Then again, more commercial work than residential.. Ha

Electric_Light

The lamp wattage is "nominal".
The ballast output rating is not based on lamp wattage, but based on the lamp type designation and % of catalog lumen (ballast factor). Typical ballasts are rated 87%. This means 3,000 lumen lamps are driven at 2610 lumens. T8 and T12s are tested at 60Hz.

Given the same input power, lamps gain about 10% efficacy at 10+KHz electronic ballasts drive them at but the ballast loss is about 10%, so it usually balances out like 1.00*1.1*0.9 ~1

The_Modifier

The post is also from last November.

Not to add that the OP had 2 user names- if I read it correctly. (cmdeals and cmregalado- post#6)