Stupid Pneumatic Delay Switches

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bigalxyz

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I live in a leasehold property in London and I’m responsible (along with two others) for property maintenance.

there’s a big hallway/stairway inside the building and the lighting is controlled by about half a dozen of those white pneumatic delay switches. We’re not happy with them - they don’t work well, residents break them by pushing too hard on them etc. or wedge them in the on position with matchsticks. It’s a real pain.

Are there any good alternative delay switches that anyone could recommend - something where they’re digitally controlled so that they don’t have the moving parts? Or…should we consider using PIR sensors instead? Do they work well, and can they just sit in the same back boxes that the current light switches sit in (for easy installation)?

Unsure how best to proceed.
Thank you.
 
Loads. But given the low current consumed by led lights you might want to consider ditching the switches and leaving (led) lamps on 24/7. Each watt per year costs about £1.60

EDIT Or replace the switches with pir blobs. Google Pir light switch no neutral
 
Yeah, believe it or not, I have installed some Danlers kit but forgot the name and couldn't find it in the TLC catalogue.
 
JohnW2 said:
I have some similar in my house which do not require a neutral.

Kind Regards, John
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I have one PIR replacement for an ordinary switch, with no neutral needed, fitted in our utility room and pantry. We often go in or out of there with arms full of stuff, so it saves reaching for the switch. It works well.
 
JohnW2 said:
In fact, the first two (Danlers ones) on this TLC page do not require a neutreal.

Kind Regards, John
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and they require a minimum load, no use with LED.

I worked on a staircase a number of times over the years with 7 pneumatic switches wired in parallel life expectancy 2-3 years, origionally they were controlling about 10 bulkheads. One by one they failed and were replaced with illuminated Danlers. Then the bulkheads were changed to either 2D or 4D and each light fitting had 1 or 2 capacitors added to convince the switches to work (as advised in MI, I think it equated to 2 per switch or there abouts). Then the flou's were changed to LED and the system never did work properly and the LEDs glowed, no matter how many caps were added.

The calculations went roughly: Predicted ife expectancy of say 10 years, cost £20, labour = £50 = £7 per year X 7switches = £49 per year + The Danlars consume~0.3W =£3 p/y... Cost of running 10X 4W leds 24/365 per year = roughly the same, with their full time handyman replacing as required rather than calling in contractors. No brainer, they paid us to replace switches with metal blanks, power the switch wiring down and split the lights onto 2 different phases.

No brainer, and the residents liked the stairwell being constantly lit.
 
SUNRAY said:
and they require a minimum load, no use with LED.
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That's probably true - and, even if they did work with LEDs, I imagine that the LEDs might well glimmer, flash or whatever.

The couple I have in service which I'm pretty sure (without looking) don't have neutrals are (for historical reasons - never bother to change because so rarely used!) controlling fluoro tubes (with traditional 'ballasts'), so I imagine that its the PF correction capacitors in them which allow them to work.

Kind Regards, John
 
SUNRAY said:
and they require a minimum load, no use with LED.

and the system never did work properly and the LEDs glowed
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The MI's showed capacitors for use with loads below the minimum rated power, from memory I think it was something like 40W and one cap would allow 25W and 2 for 15W but I didn't go into too much detail, as I wasn't on the job when the fluo's were installed. I went in to help out with the LED change and one of the attempts at getting it working was removing 6 switches, leaving one with a stack of the caps in circuit. It was actually suggested they went back to pneumatics with a simple switch contact.
 
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SUNRAY said:
... I went in to help out with the LED change and one of the attempts at getting it working was removing 6 switches, leaving one with a stack of the caps in circuit.
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I presume that they are more-0or-less bound to work if the capacitor is large enough - the PF correction ones I mentioned above are typically 4 μF or 8 μF.

Kind Regards, John
 
JohnW2 said:
I presume that they are more-0or-less bound to work if the capacitor is large enough - the PF correction ones I mentioned above are typically 4 μF or 8 μF.

Kind Regards, John
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I'm sure you're correct but each switch was supplied with a cap and part number, consultation with manufacturer/distrubuter came up with the quantity to solve the problem with the flou's. I pretty sure we fitted 14 and I think they are something like 0.47μF so very much in line with your figure. The site owners seemed happy to do away with them when the calculations were done.
 
securespark said:
If there is a neutral at the switch positions, you might want to consider the electronic version of the pneumatic switch.

https://www.tlc-direct.co.uk/Products/EK560Adash1.html
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I’ve just checked the wiring behind the switches. There’s earth, red and black. Black = neutral? (Old skool wiring colours?)

wondered if I might see 4 core red live/yellow switched live/blue neutral/earth like I have inside my flat, but no.

oh and the lights are all LEDs which is good for keeping energy consumption down but does it make my choice more difficult (some switches don’t work properly with LEDs?)
 
bigalxyz said:
I’ve just checked the wiring behind the switches. There’s earth, red and black. Black = neutral? (Old skool wiring colours?)
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If there are only the two wires, red and a black - red should be live, black will be the switch wire, there will not be a neutral.
 
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