Help Please With Bollard Light Circuit.

[Marvo]

Hi Trainees. I'd like some help please with an existing bollard light circuit at one of my clients.

I'll give you some history first. Initially the client wanted a circuit of bollard lights between two buildings on the same property. The 150 meter circuit was supplied from an existing outdoor power kiosk and run entirely in 2.5mm by 4-core SWA with the armour used as CPC. At the first and last bollard there was a 2-way switch installed.

The original arrangement looked something like this;

Sure enough, a year later they wanted a second, completely separate run of bollard lights to continue up another path. This circuit was installed very similar to the original circuit and was supplied from a sub-DB in the middle of the circuit and also had a 2-way switch at each end.

 

[Marvo]

The client has now decided they want all the existing bollards on a single circuit. They want to be able to switch on and off at all points where you enter the paths so a 3-way switching arrangement will be required.

My question is whether it can be done by just removing the supply from the sub-DB and installing a short cable to link the circuits or will it involve a 200 meter cable to be installed between the switches to allow an intermediary switch to be in the middle of two 2-way switches?

 

[Marvo]

Here's a wiring schematic of the original bollard circuit. The schematic for the second circuit that was added is almost identical so I'm not going to draw it out.

 

[ElectricALAN]

Great question. For me the problem is adding that intermediate, the link to take the power from the original circuit is no problem. I can't see a way to add the third switch without the huge cable run. Looking forwards to some more experienced replies

 

[Marvo]

I'm also looking forwards to some replies, I don't have a definitive answer and it's possible that it can't even be done. It's a real-life job I've got to do later this week so I'm hoping for an easier solution. Just thought it might be a nice problem for the trainees to have a bash at.

 

[Marvo]

If I remove one of the supplies and link the circuits this would be what I'm left with.

Obviously the switching arrangement won't work with three 2-way switches.

 

[Marvo]

If one of the Mentors has a genius idea please feel free to post some comments to point the trainees (and myself) in the right direction.

 

[Sparky_Wario]

How about making one of the switch intermediate. Will the volts drop exceed the 3% permissible?

 

[davesparks]

I can think of two ways to achieve a switch at each position without running a new cable for the whole route. Both options I can think of require additional components to be installed.

 

[Marvo]

How about making one of the switch intermediate. Will the volts drop exceed the 3% permissible?

Voltdrop will be fine, it looks like a lot of lights but they're 5 watt LED E27 lamps so the load is minimal. It's 95 watts total @ 230 volt which is about 0.42 Amps. Even with the longish cable lengths, likely appauling power factor and high inrush current the voltdrop won't be an issue.

Replacing one of the switches with an intermediate with the wiring as shown will not work. The intermediate switch needs to be in the middle of the two 2-way switches to work properly, with the wiring as it is all three switches are at the ends of the circuit, none are in the middle..

 

[Marvo]

No more ideas? Anyone?

 

[Loki]

im out at work now but:

Ok so you say VD etc is ok & its really how about switching them.


What about wireless switches & receivers
Like


Quinetic Wireless Switches - https://www.tlc-direct.co.uk/Main_Index/Wiring_Accessories_Menu_Index/Quinetic/index.html#Quinetic_Controllers

AFAIK you can have multiple switches to multiple receivers?

& you can link multiple receivers.

So maybe 3 receivers & 3 switches on same circuit?

 

[Marvo]

Thanks Loki. I did consider a wireless switching option but the terrain is rugged with very thick forrest. There's no 'line of sight' between any of the switches. A wireless solution is likely to require installing repeaters or amplifiers mid-way between the switches so it would be a last resort in this particular case.

 

[Silly Sausage]

No more ideas? Anyone?

Are we allowed to re-cable the feed from the kiosk?
I'm assuming it's only a short run.

 

[Marvo]

Are we allowed to re-cable the feed from the kiosk?
I'm assuming it's only a short run.

The feed from the kiosk is a short cable to the nearest bollard, maybe around 15 meters. It could be re-cabled easily....what you got in mind?