Wiring a DP neon switch for a light

[RLB10]

Hi

Can I get a bit of advice? I have my loft lights wired to a light switch on an MK grid plate on the landing. I want to swap the switch for one with a neon, but the grid system only has DP neon switches. The lighting cable doesn't have a neutral.

I've seen a number of posts suggesting wiring the light to the Live Supply and live Load, and then running a cable between the neutral load and the earth terminal in the box in order to get the neon to come on when the lights are on.

I don't like the idea of wiring into the earth, so I want to run a different solution past you. Suppose I run the light into the Live Supply and Neutral Supply. And then bridge the Live Load and Neutral Load with a piece if insulated 1mm cable.

Doesn't that turn the DP switch into two SP switches wired in series? And the neon should work as, when the switch is closed, the current runs across the bridging wire between the live load and neutral load. Not best practise, I know. But I can't see why it wouldn't work and it seems much better than running a trailing a cable to the earth.

Any thoughts?

Thanks

 

[wingcoax]

Bridging the Live load and Neutral load would create a DEAD short. A neon should go between the Load live and Load neutral, other wise it would be on all the time.

 

[RF Lighting]

It won't work, and connecting to earth is much more dangerous than you think. It could leave every piece of metal work in your house live.

The only way to make it work is to get a neutral to the switch.

 

[EFLImpudence]

Bridging the Live load and Neutral load would create a DEAD short. A neon should go between the Load live and Load neutral, other wise it would be on all the time.

It's the Live and Switched Live being connected.

The neon won't light because both terminals are connected to the same Line.

 

[wingcoax]

Hi



I don't like the idea of wiring into the earth, so I want to run a different solution past you. Suppose I run the light into the Live Supply and Neutral Supply. And then bridge the Live Load and Neutral Load with a piece if insulated 1mm cable.

 

[EFLImpudence]

What do you want me to say?
Draw it.

If I paint a big 'N' on one side of a pylon will it go bang?

 

[RLB10]

Here is a diagram of the wiring I assumed I could use in the DP switch, and also for comparison in an SP switch. I'm still struggling to understand why it wouldn't work - have I drawn the diagram wrong?

DP switch

• RLB10
• 28 Jul 2012
• 1

 

[EFLImpudence]

My reply about drawing it was intended for wingcoax.

Your diagrams are correct.
The light will work but the neon will not so there is no point using the double pole switch.

 

[ban-all-sheds]

I've seen a number of posts suggesting wiring the light to the Live Supply and live Load, and then running a cable between the neutral load and the earth terminal in the box in order to get the neon to come on when the lights are on.

Where are these posts?

Please tell us so that we can arrange for leather-winged dæmons of the night to tear themselves, shrieking blood and fury, from the endless caverns of the nether world, hurl themselves into the darkness with a thirst for blood on their slavering fangs and search the very threads of time for the throbbing of the posters' heartbeats.

Suppose I run the light into the Live Supply and Neutral Supply. And then bridge the Live Load and Neutral Load with a piece if insulated 1mm cable.

Doesn't that turn the DP switch into two SP switches wired in series?

Yes.

And the neon should work as, when the switch is closed, the current runs across the bridging wire between the live load and neutral load.

You've got a diagram - add the neon to it and show when and how there'd be 230V across it to make it light up.

 

[RLB10]

Isn't the neon hard wired into the switch between the load live and load neutral (ie. in parallel with whatever appliance would normally be wired there)? If so, doesn't it light when the switch is closed?

 

[vibrobullit407]

Isn't the neon hard wired into the switch between the load live and load neutral (ie. in parallel with whatever appliance would normally be wired there)? If so, doesn't it light when the switch is closed?

You have no neutral at the switch. A neon will not work with out being connected to a neutral. You can use the switch as you have proposed, but the neon will not work as you have no neutral. I don't know how to explain it any simpler for you. It will not light the neon!!!!!

 

[EFLImpudence]

the neon should work as, when the switch is closed, the current runs across the bridging wire between the live load and neutral load.

This is where you are going wrong.

Drawn in a line this is what you are proposing.
I have left the switches open for clarity,

Untitled

• EFLImpudence
• 28 Jul 2012
• 1

If you still think the neon should light; well it just doesn't work like that.

 

[RLB10]

Thanks, EFImpudence. I clearly need to do some homework, as I did think it worked just as in your diagram. Thanks for explaining!