2 x 500 watt floodlights in series.

scooby1 · 22 Jul 2011

New house going up and I'm in a static while the build is going on. I have installed a 30ft telegraph pole on the site and I want to place 2x500 watt floodlights wired in series at the top of it. They won't have a PIR, they will be wired to a socket in the static that I can switch on when I need to.

Distance down the pole and to the static is 20 metres. What cable do I require. I assume twin with earth. 1 or 1.5mm ? Armoured ?

TIA.

flameport · 22 Jul 2011

scooby1 said:
2x500 watt floodlights wired in series

Why in series - they will either be really dim, or the lamps will have to be half the voltage. If one breaks, neither works.

JohnD · 22 Jul 2011

you mean in parallel, running in a chain.

BTW you might consider a modern floodlight with one or more compact fluorescent tubes in it. The new ones start fast, use much less electricity and (important for you if they are on top of poles) last five times as long.

CFLs are also very tolerant of voltage, and with the current draw being about 80% less this will save you having to buy a greater gauge of cable to overcome voltage drop.

The other advantage of the floods with several tubes is that when one starts to flicker or die, the others will probably still be working for long enough for you to be warned and find your ladder and fix them on a convenient day.

an ordinary TH tube will fail completely and you will be left in immediate darkness.

scooby1 · 22 Jul 2011

flameport said:
scooby1 said:

2x500 watt floodlights wired in series

Click to expand...

Why in series - they will either be really dim, or the lamps will have to be half the voltage. If one breaks, neither works.

Yes, sorry. I meant in parallel. Both wired into a waterproof connector somewhere on the pole. Then a cable from the connector to the static.

Thanks for your help.

sparkticus · 22 Jul 2011

scooby1 said:
New house going up and I'm in a static while the build is going on. I have installed a 30ft telegraph pole on the site and I want to place 2x500 watt floodlights wired in series at the top of it. They won't have a PIR, they will be wired to a socket in the static that I can switch on when I need to.

Distance down the pole and to the static is 20 metres. What cable do I require. I assume twin with earth. 1 or 1.5mm ? Armoured ?

TIA.

Do you mean wired in parallel?

That would be 1KW about 4.5 amps. 1mm would be fine from a current carrying capacity but this is outdoors right? You should really be using something better protected. Can you clarify series/parallel and also describe the cable routing exactly?

scooby1 · 22 Jul 2011

JohnD said:
you mean in parallel, running in a chain.

BTW you might consider a modern floodlight with one or more compact fluorescent tubes in it. The new ones start fast, use much less electricity and (important for you if they are on top of poles) last five times as long.

CFLs are also very tolerant of voltage, and with the current draw being about 80% less this will save you having to buy a greater gauge of cable to overcome voltage drop.

The other advantage of the floods with several tubes is that when one starts to flicker or die, the others will probably still be working for long enough for you to be warned and find your ladder and fix them on a convenient day.

an ordinary TH tube will fail completely and you will be left in immediate darkness.

Hadn't heard of these CFLs. I'll Google them. The main reason for the lights on a pole is for security while the build is going on. I hear a noise from the alarm and I switch the light(s) on. Then I can deal with the situation.

Thank you for the ideas and help.

scooby1 · 22 Jul 2011

sparkticus said:
scooby1 said:

New house going up and I'm in a static while the build is going on. I have installed a 30ft telegraph pole on the site and I want to place 2x500 watt floodlights wired in series at the top of it. They won't have a PIR, they will be wired to a socket in the static that I can switch on when I need to.

Distance down the pole and to the static is 20 metres. What cable do I require. I assume twin with earth. 1 or 1.5mm ? Armoured ?

TIA.

Click to expand...

Do you mean wired in parallel?

That would be 1KW about 4.5 amps. 1mm would be fine from a current carrying capacity but this is outdoors right? You should really be using something better protected. Can you clarify series/parallel and also describe the cable routing exactly?

I have been corrected. I should have written parallel. The routing will be from the two lights down to a common waterproof connector box somewhere below them on the 30ft pole. Then strung across to the static. The temporary telephone cable takes the same route.

Thank you for your help.

JohnD · 22 Jul 2011

CFL = Compact Fluorescent Lamp = Energy saving bulb

Except that in a flood they will usually be tubes with pins at one end instead of bulb-shaped. Probably have a few 12W or 18w or something tubes.

If you use 3-core and earth cable you can have a switched supply to the floods, and also PIR lamps on the same poles, for very little extra cost or effort.

edit
http://www.screwfix.com/p/energy-saving-flood-wall-light-matt-black-2-x-26w/51601
look at the bottom of the page for special offers. The cheaper ones only seem to have one lamp inside.

remember the light output from these is 4 or 5 times what you would get from a conventional lamp of the same wattage.

scooby1 · 22 Jul 2011

JohnD said:
CFL = Compact Fluorescent Lamp = Energy saving bulb

Except that in a flood they will usually be tubes with pins at one end instead of bulb-shaped. Probably have a few 12W or 18w or something tubes.

If you use 3-core and earth cable you can have a switched supply to the floods, and also PIR lamps on the same poles, for very little extra cost or effort.

edit
http://www.screwfix.com/p/energy-saving-flood-wall-light-matt-black-2-x-26w/51601
look at the bottom of the page for special offers. The cheaper ones only seem to have one lamp inside.

remember the light output from these is 4 or 5 times what you would get from a conventional lamp of the same wattage.

Thank you. But definitely don't want lamps with PIRs. They trigger them for all sorts of reasons. I have alarms round the place (rural property) and know if anyone is about. Then I am in command of the situation. I can switch them on or choose to leave them off.

ban-all-sheds · 22 Jul 2011

JohnD said:
remember the light output from these is 4 or 5 times what you would get from a conventional lamp of the same wattage.

You must work in the marketing department of a CFL manufacturer.

4-5x?

NFC.

JohnD · 22 Jul 2011

ban-all-sheds said:
You must work in the marketing department of a CFL manufacturer.

4-5x?

NFC.

the packaging on the 20W CFL pearl-envelope I am looking at now says
"1152 lumen"

a typical soft white 100W filament bulb is 1165 lumen.

20x5=100
20x4=80

what do you think the figures are then?

ban-all-sheds · 22 Jul 2011

2-3x in my experience.

JohnD · 23 Jul 2011

"Which" carried out thorough long term tests, and say

"A common complaint about early energy-saving light bulbs was that they overstated their light output, however this is no longer the case. Most of the energy-saving light bulbs in our test produced light output close to, or matching, manufacturers claim."

also

Lumens are the unit used to measure light output, or brightness. So it's the lumens figure you need to have in mind when buying a new bulb.

Our table shows lumen ratings on the left, the equivalent wattage of incandescent bulb next, and then the equivalent wattages for CFL, halogen and LED energy-saving bulbs. The packaging of each bulb usually display three figures:

lumens
wattage
equivalent incandescent bulb wattage.
Wattage and maximum lumen output comparison
Maximum light output measured in our tests Incandescent bulb wattage CFL wattage Halogen energy saver wattage LED wattage
200-300lm 40W 7, 8 and 9W n/a 5 & 6W
300-400lm 40W 7, 8 and 9W 28W n/a
400-500lm 40W 8, 9 and 11W n/a n/a
500-600lm 60W 8 & 11W 42W n/a
600-700lm 60W 11W 42W n/a
700-800lm n/a 11 & 15W 52 & 53W n/a
800-900lm n/a 15W 53W n/a
900-1000lm 100W 15W n/a n/a
1000-1100lm 100W 15 & 20W n/a n/a
1100-1200lm 100W 20W n/a n/a
1200-1300lm 100W 20W n/a n/a

martinxxxxxx · 23 Jul 2011

Let's face it CFL's are crap.

The light they give is rubbish if you want to use it to read or do any activity under them like have a BBQ. I suppose if you are just lighting up a bit of field to see if you have peasant invading then they should be ok

I prefer filaments bulbs for indoors and LED Stienel or out doors in domestics.

scooby1 · 23 Jul 2011

I am getting a bit confused here. We use 500w floodlights around other properties and they do a good enough job. We switch them on when we want them and switch them off when we don't.

But aren't these "CFLs" a) less bright and b) slow to start ? When we need bright lights we need them instantly and not wait for them to warm up. Or do these have different characteristics to the ones used inside domestic properties ?

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2 x 500 watt floodlights in series.

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