Multiple Security Lights / Multiple Motion Sensors

[sparkypenguin]

Hi all,

I am a self builder with some electrical knowledge and I am hoping someone can provide me with some guidance on wiring my security lights.
In total I have 8 lights and 8 separate motion detectors, however in the example below I have only stated 6 as if someone can help me with this I am sure I can work out the extra 2.

Location of 6 Lights (L), South Light = SL, South West Light = SWL, SEL, NWL, NEL, NL
Location of 6 separate PIR Motion Detectors (MD), SMD, SWMD, SEMD, NWMD, NEMD, NMD
Hope that makes sense.

Ideally I would like the ..
SMD to activate SL, SWL and SEL.
NMD to activate NL, NWL and NEL.
Nice and simple so far however I would also like the...
SEMD to activate the SL, SEL and NEL.
SWMD to activate the SL, SWL and NWL.
And finally the...
NEMD to activate the NL, NEL and SEL.
NWMD to activate the NL, NWL and SWL.

This configuration means that I cannot wire any of the lights together.
On top of this I would also like to be able to manually deactivate or turn on any individual light by the way of a switch.

My initial thoughts are to wire the MD's to a contactor for each light.
Hence the SL contactor would have wires into it from 3 MD's, the SMD, SEMD and the SWMD.
I would then feed the switched live from this contactor via a switch to the light.
This switch would be configured so that the switched live could be allowed to continue to the light or not and would also have it's own permanent live feed that could be used to turn on the light manually. Or this could be completely wrong and / or a much easier solution exists?

Any help would be much appreciated and just to confirm I will have all electrical work signed off by an appropriately qualified electrician.

Thanks.
Mark.

 

[SUNRAY]

So you want 8 MD's, 8L's & 8 switches in a fairly complex arrangement which (without being nasty or insulting) probably more than 50% of qualified electricians would not be able to cope with.
You don't have a clue how to wire it up yourself and you expect to come to a DIY help forum where there may be a selection of different options offered, some will work, some will not work and those in the middle may be converted to work. It will require a control system of some sort (you mention contactor so part way there)

Then after all that you expect an electrician to sign a document stating he has designed, installed and tested the installation.

If the electrician you employ for your building work is capable (again not an insult) then he is the person you should be asking to do the job.

My apologies for sounding very negative on this reply but this is not a DIY question, to get it right without being a horrible mess it is verging on a controls person rather than an electrician.

 

[FrodoOne]

SUNRAY has expressed more than enough of the problems which you are posing.

While you are being a bit "coy" concerning the "Upgrade" from 6 to 8 "lights", that which you are specifying seems to be an exercise in "logic".
However, if you intend to carry out this "logic" into the world of 240 V operation, it may be necessary for you to provide "Interface" devices (such as Relays) from the devices which can operate and provide the "Logic" concerned at the now usual "Extra Low Voltage" levels - while maintaining "Safety" at 240 V.

It would be quite easy to provide a "program" which would operate an Arduino (or similar) to perform all of the functions which you require (at an Extra Low Voltage level) - via a "Remote Control" - using only 10 keys.
Translating this to Low Voltage (240 V) could be a problem.
The fact that you may wish that "switches" should be involved could also be a problem in the "realization" of your project, as you have described it.

 

[plugwash]

I would argue that for something this simple it's not worth interfacing from the world of 240V to the world of logic levels and back again. Probably simpler to just implment the whole thing with relays.

I would look for relays with 3 sets of contacts, each motion sensor would trigger a relay and then different contacts on that relay would be used to turn on different lights.

Something along the lines of https://cpc.farnell.com/relpol/r3n-...rial-relay-10a-3pco/dp/SW05441?st=240v relays , you would need to get the corresponding mounting bases, some din rail and a suitable enclosure.

For the manual overrides I would suggest two way center off switches.

 

[oceansoul]

For this application I would suggest a smart relay (smart relay as in a small PLC, not WiFi gadget). Something like this
https://uk.rs-online.com/web/p/plcs-programmable-logic-controllers/4684488/ would be ideal. 8 relay outputs so each light can be directly wired (assuming they are LED or fairly low current). 12 100-240VAC inputs so your PIRs can be wired directly also, plus any switches you might need (this assumes they are all fed from the same supply). Programming is done on the LCD screen so no PC software or leads needed. The only downside with this arrangement is that all your wiring needs to come back to the same place.

My apologies for sounding very negative on this reply but this is not a DIY question, to get it right without being a horrible mess it is verging on a controls person rather than an electrician.

I'm a controls guy, and tend to agree. Most electricians will struggle with this kind of setup, let alone your average DIYer, but if able to pull it off, you can get some good results.

 

[plugwash]

The other downside is the price, that box of tricks is £200, relays seem to work out to about £8 each for relay and base and he needs 6 of them or about £50 worth of relays.

Either way you will need to add an enclosure, din rail etc.

 

[oldbutnotdead]

Fun project.
A central control box is a must unless you go full IoT with WiFi devices all round and pay for a subscription on IFTTT, do the logic there on the cloud & hope your internet never fails.
Lowrent option is relays (I'd use 24v Telco types with a diode matrix for the logic), fun option is Arduino, Pi etc, all of them will cost a few quid and some hours. Doable but do not expect a domestic electrician to create it.

 

[sparkypenguin]

Hi all,

Thanks to everyone for their input, all appreciated and certainly more friendly than some of the trade specific forums I have been on for other things where you often get slated for even suggesting you may try something that fringes on that particular trade. .

From the above I have decided to initially investigate the use of the 3 contact relays to see if it's possible as it appears that this will be the easiest / cheapest option.

I have uploaded a basic photo showing how I think a 3 sensor, 4 light system would work.....

To expand it up to the full 8 sensor / light system I would just keep adding sensors and lights until it goes full circle.

Would this work?
Are the 3 contacts on the relays totally separate?
If not then my first thought is that in the example that the SEMD / SER were activated would the electric from the 3 activated lights, SL, SEL and NEL, travel back up from the light to the SR and the NER and then back down to include the SWL and the NL.

Thanks again for all the help.
Mark.

 

[plugwash]

Yes, each contact on a relay is seperate, that's why you use relays with multiple contacts.

 

[sparkypenguin]

Thanks plugwash!
So I am thinking that all I need to do is then join the relevant lights switched lives from the 3 separate relays together and then treat this as any other light switched live?
And to turn off the light completely use a centre off switch or I recall seeing a 2 gang switch wired in such a way that one of the gangs isolates the light.

 

[oldbutnotdead]

If you use DC relays you can use diodes to prevent backlinking, allows single pole relays which are cheaper and smaller. Your schematic is pretty much there...

 

[sparkypenguin]

If you use DC relays you can use diodes to prevent backlinking, allows single pole relays which are cheaper and smaller. Your schematic is pretty much there...

Thanks for suggestion but everything is 240VAC so I am assuming that I would need to convert to DC which would complicate and add cost?

 

[sparkypenguin]

Still based on the 8 Motion Detector / Relay / Light system can I ask if this is an OK wiring POA....
2.5mm T&E power supply cable to the Relay enclosure from the CU.
0.5mm T&E ring circuit power supply to all Motion Detectors from the Relay enclosure.
8 core 0.5mm control cable in a physical ring around the house to feed back the switched lives from the Motion Detectors to the Relays within the enclosure.
10 core 0.5mm control cable from the enclosure in a physical ring around the house to take the earth, neutral and switched lives from the relays to the 50W LED lights.
I am using the control cable in an attempt to keep it nice and tidy.

And could I use 8 core alarm cable to feed back the switched lives from the Motion Detectors?

 

[oldbutnotdead]

First thing- if your motion detectors have volt free contacts in them (which my only standalone detector has) then you can run 24v through the switch circuit.
Or for ease of wiring you can use 240v relays on the output of the detectors to switch 24v DC to the relays for the lights (via diode matrix).
Your control multicore has to be rated at 240v or greater and routed properly (safe zones etc). Alarm cable, CAT5 etc may not be rated- check the spec. If it is rated then you can use it but why you need it I don't know, much easier to use 1mm T & E to each lamp and do your switching in the relay box.

 

[Adam_151]

First thing- if your motion detectors have volt free contacts in them (which my only standalone detector has) then you can run 24v through the switch circuit.

Theres also some stand alone PIR sensors that can run off 24v with only minor modifications