Fluorescent Fixtures

I have five two-tube fluorescent fixtures in my garage/shop.

Being lazy I leave them on 24/7 rather than groping for the switch.

How much power do those typically pull?

If it's significant I'll add motion-sensor turn-on. ...Jim Thompson

-- | James E.Thompson | mens | | Analog Innovations | et | | Analog/Mixed-Signal ASIC's and Discrete Systems | manus | | San Tan Valley, AZ 85142 Skype: Contacts Only | | | Voice:(480)460-2350 Fax: Available upon request | Brass Rat | | E-mail Icon at

| 1962 |

I'm looking for work... see my website.

4' tubes? Sounds like 68W or 80W per fixture, so 340W to 400W. That would be the lower limit. It's probably somewhat more.

I'd just reach for the switch. If it's in a bad place, just a little rewiring will fix the problem. ...or even an X10 or smarthome switch.

Need a bit more information. What is the diameter of the bulbs? The t5 bulbs are the most efficient with the T8 size being close. The T12 are being phased out. The number after the T is the diameter in 1/8' of an inch. T8 is one inch in diameter.

Dan

depends on efficiency of ballast used and size of tubes?

assuming 32 watt tubes and maybe 90% efficient at best, =

352 watts.. But i'd go for 375W.

Not without guilt/cost, if they are as bright as the fluorescents. There is not a big efficiency difference between modern (T5) fluorescents and affordable LEDs. Even T8 are not that bad if you use electronic ballasts. Yes, you could put in dim LEDs that only use a few watts, but then you couldn't see as well as with the old fluorescents.

So, around 8 kWh per day. Don't know how much Jim pays for his energy, but that would mount up quite quickly where I live, and automating the switching off would certainly be economically worthwhile.

Sylvia.

Certain fluorescent tubes die very quickly on motion switches. I've had to swap in LED replacement "tubes" in fixtures at both work and church wherever motion sensing bas been installed.

Steve

Certainly I'd expect that Jim would want a substantial delay before the lights turn off, not least to avoid them turning off just because he's not been moving around a lot.

Sylvia.

When air conditioning is used, the extra heat load also increases the power drawn by the air conditioner.

I would also suggest a motion switch but in addition to this some relative low power LEDs burning 24/7 if the main lights are switched off when in that room (e.g. out of reach to the motion sensor).

Garage has no A/C. ...Jim Thompson

--
| James E.Thompson                                 |    mens     | 
| Analog Innovations                               |     et      | 
| Analog/Mixed-Signal ASIC's and Discrete Systems  |    manus    | 
| San Tan Valley, AZ 85142   Skype: Contacts Only  |             | 
| Voice:(480)460-2350  Fax: Available upon request |  Brass Rat  | 
| E-mail Icon at http://www.analog-innovations.com |    1962     | 

             I'm looking for work... see my website.

Yep. I don't move around a lot >:-} ...Jim Thompson

--
| James E.Thompson                                 |    mens     | 
| Analog Innovations                               |     et      | 
| Analog/Mixed-Signal ASIC's and Discrete Systems  |    manus    | 
| San Tan Valley, AZ 85142   Skype: Contacts Only  |             | 
| Voice:(480)460-2350  Fax: Available upon request |  Brass Rat  | 
| E-mail Icon at http://www.analog-innovations.com |    1962     | 

             I'm looking for work... see my website.

stick a neon across the switch

a watt 24/7 is around 1GBP a year

NT

Isn't it written on each tube?

Or a motion detector

Jim would have to take the tubes out of the fixtures to find out - posting an off-topic query here is less like hard work. Jim isn't slim and lugging a ladder out to his garage, and clambering up it get to the fixtures would probably exhaust his weekly physical effort budget.

--
Bill Sloman, Sydney

Lol! Waste is waste. Does it matter if you are wasting half as much although I don't think the LEDs are half the power of a fluorescent bulb.

--

Rick C

unlikely really.

NT

g an off-topic query here is less like hard work. Jim isn't slim and luggin g a ladder out to his garage, and clambering up it get to the fixtures woul d probably exhaust his weekly physical effort budget.

ion=41455

"NOTE: When connected to compact fluorescent lamps or LEDs, the bulb may fl icker while switch is in the off position."- not gonna happen with 5x fixtu res.

With the old style choke ballasts, the overall consumption is somewhat higher due to losses in the choke, but yes, the nominal wattage written on the tubes is a good first estimate.