Power Usage Question T5 Flouros

[VenerableHippie]

Greetings!

I 'm aiming to supplement winter daylight hours with t5 lamps.

I live with a small stand alone power system and want to know the power consumption of these lamps. I have looked but cannot find.

I see these lamps are sold 2 or 4 at a time with a reflector and have a nominal wattage of 55w each.

I understand that theoretically: 55W @ 240v is apx. 0.25A
And that converting to 55W to 12 V results in a theoretical 5A.

Can anyone tell me if these Formulas are relevant to the ACTUAL power usage of these lamps?

Thanks in anticipation ...

 

[Growenhaft]

if you use a solar system, your solar module has a working voltage between 17 and 18 volts. you have to come to this tension when converting. not on 12v but on 17.5v. the working voltage of your solar module. Only then will we get the correct value for the charging current of the module. 55w at 17.5v = 3.1428 amps

 

[negative37dBA]

.
4 bulb 48" sunblaze 4 foot fixture. 432 watts of lamp and 4 amps draw at 120 volts.

 

[VenerableHippie]

if you use a solar system, your solar module has a working voltage between 17 and 18 volts. you have to come to this tension when converting. not on 12v but on 17.5v. the working voltage of your solar module. Only then will we get the correct value for the charging current of the module. 55w at 17.5v = 3.1428 amps

Thanks! Altho the sun will be low when I use the lights ... so seems to me I need to use battery voltage in my estimates.

 

[VenerableHippie]

.
4 bulb 48" sunblaze 4 foot fixture. 432 watts of lamp and 4 amps draw at 120 volts.

Thanks! Am I right in thinking you are quoting the amount drawn from a meter you have in yr system? Then the draw is higher than my theoretical estimates. Not good for my plans. OK. Thanks again ...

 

[Steviewunder]

[No message]

 

[Steviewunder]

Hope this can help, I was just wondering the same myself

 

[f-e]

Before you go much further, consider that a t5 makes 100 lumens per watt, which is pitiful besides nearly any LED.
I guess you have a 12v storage pack, so a 12v timer and 12v LED lights aimed at recreational vehicles could be a better result. The reason is electronic drivers cost 5-10% every conversion. So if you go 12v-240 you loose some, then the 240v driver looses some. You now have 85 lumens per watt. You could skip the 240 conversion and buy a 12v T5 driver. Or skip both drivers running LED's. Typically you could see 4 3v LEDs in series on a 12v supply, and these could be making 250 lumens per watt if you DIY. Or 100 seems very doable.

Your current plan seems to involve an invertor. It will need to be sinewave and too big if you want to run electronic drivers from it. The full picture isn't clear here. However, I think you have 12v so should look at using that without any lossy electronics.

 

[exploziv]

Great post above. You loose a lot in conversions. Lots of heat instead of light. Going DIY and powering leds straight from the batteries in a proper calculated and designed circuit would be best. If you don't want to go diy then maybe find some cheap RV leds to be driven from the 12 v (i guess its 12V, please check) power pack you got. They will have much better efficiency than the T5 and the lots of useless conversion you use now.

 

[VenerableHippie]

Hope this can help, I was just wondering the same myself

Thanks Cobra! I can use the quoted figures. See you around!

 

[VenerableHippie]

Before you go much further, consider that a t5 makes 100 lumens per watt, which is pitiful besides nearly any LED.
I guess you have a 12v storage pack, so a 12v timer and 12v LED lights aimed at recreational vehicles could be a better result. The reason is electronic drivers cost 5-10% every conversion. So if you go 12v-240 you loose some, then the 240v driver looses some. You now have 85 lumens per watt. You could skip the 240 conversion and buy a 12v T5 driver. Or skip both drivers running LED's. Typically you could see 4 3v LEDs in series on a 12v supply, and these could be making 250 lumens per watt if you DIY. Or 100 seems very doable.

Your current plan seems to involve an invertor. It will need to be sinewave and too big if you want to run electronic drivers from it. The full picture isn't clear here. However, I think you have 12v so should look at using that without any lossy electronics.

Thanks very much.

I can go both with Inverter for 240 volts or as you suggest, a 12 v driver.

But seems you are implying I use LED's. OK, I will look at this.

Thanks again!

 

[f-e]

Some time after I posted that, my light went on. LED car headlight bulbs. That market must be competitive enough to provide useful figures. I looked at kitchen counter top lighting strips that often come with a 12v adapter, but they didn't give good spec sheets. Likely the older mass produced stuff that's real cheap, not real good.

Keep in mind that inverters may not work with electronic ballasts. If you go that route, don't spend a lot on one go. I have a PC backup inverter, so a nice clean output. It won't run my sms fan speed controller though. It makes the motor scream. Even if your lights light, our eyes won't see 20% missing without a reference.

 

[VenerableHippie]

Some time after I posted that, my light went on. LED car headlight bulbs. That market must be competitive enough to provide useful figures. I looked at kitchen counter top lighting strips that often come with a 12v adapter, but they didn't give good spec sheets. Likely the older mass produced stuff that's real cheap, not real good.

Keep in mind that inverters may not work with electronic ballasts. If you go that route, don't spend a lot on one go. I have a PC backup inverter, so a nice clean output. It won't run my sms fan speed controller though. It makes the motor scream. Even if your lights light, our eyes won't see 20% missing without a reference.

Thanks f-e!

 

[exploziv]

Car led lights are quite expensive, still..

 

[f-e]

So... more water under the bridge..

Do you call your domestic lamps sils? They are gls here, and other areas call the e27 based on the 27mm Edison Screw fitting. Pop onto Ali/eBay and search 12v gls or whatever. They actually exist. Normal household lamps for 12v supplies. Maybe you could get a festoon string to take them down your glass-house?

How the first post is worded, makes me think of night-break lighting. If a 12 hour day needs to be 18 hours, you put the lights on for a little while, 6 hours after dark. Then the only sleeps they get are 6 hours long.

 

[VenerableHippie]

So... more water under the bridge..

Do you call your domestic lamps sils? They are gls here, and other areas call the e27 based on the 27mm Edison Screw fitting. Pop onto Ali/eBay and search 12v gls or whatever. They actually exist. Normal household lamps for 12v supplies. Maybe you could get a festoon string to take them down your glass-house?

How the first post is worded, makes me think of night-break lighting. If a 12 hour day needs to be 18 hours, you put the lights on for a little while, 6 hours after dark. Then the only sleeps they get are 6 hours long.

e27's in my dwelling.

Yeah, first post. This is what I 'm looking for. Just to ease plants thru the shorter daylight hours. No glasshouse. Rarely have frost here. Festoon string good idea!

For EXPLOSIV: The thing about using automotive stuff is that there's 'after-market' when items become much cheaper when the brand name is removed.

I will seek further. Thanks everyone!