Horizontal tilt angle of R7s halogen

Cheers everyone.

I'm here trying to install a pair of outdoor R7s floodlights and reading the manual (who does that? I do.) it mentions multiple times the horizontal tilt of the fixture should be "Ideally 0º or <5º" because otherwise the lamp will "burn too fast" with no more clarifications

Lights are 78mm 250W.

My questions are
a) is the manual right?
b) why would the lamp burn if tilted exactly at a >5º angle?

I'm thinking uneven heat dissipation with one of the sides getting hotter and damaging the filament inside, but isn't the lamp designed for that? getting hot that is, that's how it emits light after all.

Planning to leave them on for at least 8 hours, is that OK? no PIR, I've seen this kind of lights paired with PIRs before
I live in a rural area and basically we've been having trouble with wild cats attacking our roosters, and it's said they won't sneak in that much if there are lights on outside, otherwise when we go to sleep and the indoors lights are off it's a pitch dark place, perfect for these night predators. I like cats too but not when they're trying to kill our animals

Halogen tubes are particularly fragile… and I think if it sits at an angle… the higher up end of the filament will heat up more… heat rises, and all that.

I wouldn’t know exactly how much shorter a lifespan the lamp would have compared to perfectly horizontal.

The instructions also say no to touch lamp with bare hands??
That’s down to an oil on your skin being transferred to the glass making a hotspot when lamp is on, and can cause it to shatter.


Halogen R7 lamps are old style now.
The LED equivalents are only a 1/10 of the power consumption.
You can buy LED lamps that fit an R7 connection.



Just as an extra note.
Don’t change a halogen lamp, up a ladder, without first checking the power is off.
I did when I was much, much younger and the tissue I was using so I didn’t touch the lamp with bare hands…… set on fire.

Half a kilowatt for 8 hours every day - that's a lot of energy being used! Definitely consider LEDs. I wouldn't use halogen.

The instructions also say no to touch lamp with bare hands??

esp. if it's still lit.

As above, LED lights have a much longer life time and much lower running cost. I don't know how it would work out in your region of the world but here in the UK an LED equivalent (something like 40-50W) would pay for its self over a 250W halogen unit in electricity use alone in around 3 months of 12 hour per day operation.

Using a PIR sensor to only turn it on when something is moving is another option, but if your worry is small animals like domestic cats then most sensors won't pick them up unless really in the middle of the detector's view.

littlespark said:

Halogen tubes are particularly fragile… and I think if it sits at an angle… the higher up end of the filament will heat up more… heat rises, and all that.

I wouldn’t know exactly how much shorter a lifespan the lamp would have compared to perfectly horizontal.

The instructions also say no to touch lamp with bare hands??
That’s down to an oil on your skin being transferred to the glass making a hotspot when lamp is on, and can cause it to shatter.

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Hi, thanks for replying.

Yes it says not to handle the glass with bare hands as skin oils might heat up, so I used a clean rag to fit them, similar to what I do with capsules for AR111.

littlespark said:

Halogen R7 lamps are old style now.
The LED equivalents are only a 1/10 of the power consumption.
You can buy LED lamps that fit an R7 connection.

Click to expand...

DPG said:

Half a kilowatt for 8 hours every day - that's a lot of energy being used! Definitely consider LEDs. I wouldn't use halogen.

Click to expand...

pc1966 said:

As above, LED lights have a much longer life time and much lower running cost. I don't know how it would work out in your region of the world but here in the UK an LED equivalent (something like 40-50W) would pay for its self over a 250W halogen unit in electricity use alone in around 3 months of 12 hour per day operation.

Click to expand...

I got the floodlights from a friend, and already have a box full of lamps for them... it's a long story, I hunt deals on closing stores, or stores that want to get rid of NOS/discontinued products fast and put very low prices on the goods.

LEDs do exist and I've seen them online but I couldn't find them in my country, all I've seen was whole floodlights being sold, once the LEDs burn or start flickering you have to replace the whole unit, that's pretty bad imo, also expensive compared to the old halogens. I know how to fix them, but still.

I can still pay for the bill and plan to install a few solar panels next month, mainly to cope with the constant outages, I'll skip the inverter and go 12V for a small circuit powering a few lights in order to avoid running a generator all the time, good news is I have 12 volt R7s lamps as well so I might run these instead, rewiring is easy. I know running domestic DC wiring might be illegal in the UK but I'm basically free to do so as long as I don't mess up the wire sizes, fuses and switches and create arcing. I've asked a few questions on DC here already and everyone's been helpful so if problems arise I'll start a new topic

littlespark said:

Just as an extra note.
Don’t change a halogen lamp, up a ladder, without first checking the power is off.
I did when I was much, much younger and the tissue I was using so I didn’t touch the lamp with bare hands…… set on fire.

Click to expand...

telectrix said:

The instructions also say no to touch lamp with bare hands??

esp. if it's still lit.

Click to expand...

Heh ^^ Switch should be always off, my rule of thumb is to wait for at least 5 minutes if the light was on at the time.

pc1966 said:

Using a PIR sensor to only turn it on when something is moving is another option, but if your worry is small animals like domestic cats then most sensors won't pick them up unless really in the middle of the detector's view.

Click to expand...

Even if the sensor detects the cats wouldn't switching on/off multiple times reduce the lifespan of the bulbs?

Carolina said:

Even if the sensor detects the cats wouldn't switching on/off multiple times reduce the lifespan of the bulbs?

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It should not for LED, but halogens do suffer a bit on start-up. You can get NTC surge reducers for that sort of thing, and using a zero-crossing SSR to switch also slightly reduces the surge, but that it is a whole lot of extra trouble if you have a box cheap lights!

The overall electricity bill savings would pay for a new LED fitting.

Make it easy to change them over..

Sometimes changing the lamp in an old halogen R7 is even more hassle with rusty screws.
That is in the UK’s moisture laden environment.

pc1966 said:

It should not for LED, but halogens do suffer a bit on start-up. You can get NTC surge reducers for that sort of thing, and using a zero-crossing SSR to switch also slightly reduces the surge, but that it is a whole lot of extra trouble if you have a box cheap lights!

Click to expand...

I like the NTC idea to soft-start the lamps, switches have a little spark in them due to inrush, peaks at 3.6 amps according to my clamp meter.

It's not too much trouble tbh, I'd like the lights to last as long as possible, if wiring a simple thermistor can achieve that then I'll do it ^^

littlespark said:

The overall electricity bill savings would pay for a new LED fitting.

Make it easy to change them over..

Sometimes changing the lamp in an old halogen R7 is even more hassle with rusty screws.
That is in the UK’s moisture laden environment.

Click to expand...

New tech is good but I really don't like the single-use floodlights.



If I could only swap the module containing the LEDs, they're convenient but being honest they're just a waste of resources once the LEDs burn, can't use them for anything else, well, I could get all new LEDs and replace them one by one, but not most people.

These replacements exist, but nobody sells them near me, and I can't order them say on Amazon and have them imported.



So, guess I'll have to make use of what I have available for now, it's enough, lamps emit a nice warm light too.

Carolina said:

I like the NTC idea to soft-start the lamps, switches have a little spark in them due to inrush, peaks at 3.6 amps according to my clamp meter.

It's not too much trouble tbh, I'd like the lights to last as long as possible, if wiring a simple thermistor can achieve that then I'll do it ^^


New tech is good but I really don't like the single-use floodlights.

View attachment 101816

If I could only swap the module containing the LEDs, they're convenient but being honest they're just a waste of resources once the LEDs burn, can't use them for anything else, well, I could get all new LEDs and replace them one by one, but not most people.

These replacements exist, but nobody sells them near me, and I can't order them say on Amazon and have them imported.
View attachment 101818


So, guess I'll have to make use of what I have available for now, it's enough, lamps emit a nice warm light too.

Click to expand...

I find it hard to believe you are worried about LED lamps being a waste of resources when you are going to burn through half a kilowatt of electricity constantly for over 8 hours a day!

DPG said:

I find it hard to believe you are worried about LED lamps being a waste of resources when you are going to burn through half a kilowatt of electricity constantly for over 8 hours a day!

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Eh, I'm not the worst offender here, the power plant is going to burn the coal anyway, and other people install 5kW air conditioners and run them 24/7 during summer, we don't have A/C but still get 160V instead of 240 so our ceiling fans barely spin, but at least I've found an inexpensive way to boost my mains -thanks to the forum- and get the pedestal fans running somewhat decently.

A few busted cheap UPS turned out to be useful after all, I've rewired a couple for us and added some more protection, if V is >250 it'll trip the protection to prevent the motors from catching fire. I've also installed a bypass that goes directly to the mains with a MOV across, not the best of protections but it'll do for now.