Light Switch with Neon

[Wayne61]

Hi

I'm trying to use 20amp double pole switch with neon to replace a light switch (so I know when I've left the garage light on).

The only wire I have going to the original light switch are red and black with red sheaf.

The socket has N & L load terminals and N & l feed terminals.

The said it would work at B & Q but wouldn't be specific about the actual wiring.

 

[Steve]

The only way you'll get the neon to work is when the light is OFF by wiring it in parallel with the switch.

You have no neutral at the switch.

To use this switch as above, wire the live to L IN and the switched live to L OUT, and the neon to the same terminals (if you can change it). But you probably dont want this. Sorry.

If you listen to the electrician at B&Q you're asking for trouble.

 

[ajrobb]

Most light switches just have a live and switched live connection. Metal switches and junction boxes also have an earth bonding connector.

A 20A isolator is designed for live and neutral in and out. I doubt you'll get a neon going without adding a neutral wire to the switch.

 

[Wayne61]

Thanks to you both for the help

 

[OwainDIYer]

The way to do this is to wire a 230V lamp in the garage in series with a 10V lamp at the lightswitch. The current drawn by both lamps must be the same. The 10V lamp must be insulated for 240V.

 

[martinxxxxxx]

The way to do this is to wire a 230V lamp in the garage in series with a 10V lamp at the lightswitch. The current drawn by both lamps must be the same. The 10V lamp must be insulated for 240V.

Could you elaborate on the solution proposed please?
What 10V lamp? Is he to drill and add his own bulb, if so what bulb? Where does he buy this and how does he mount it in the the lightswitch?

Martin

 

[flameport]

The way to do this is to wire a 230V lamp in the garage in series with a 10V lamp at the lightswitch. The current drawn by both lamps must be the same. The 10V lamp must be insulated for 240V.

If such a dangerous mess was created, then the current in both lamps would always be the same, since they would be in series.
However if you were expecting 10V across the 10V lamp and the other 230V across the main lamp, then think again, since that would entirely depend on the relative resistances of each lamp.
Even if it somehow worked, it would cease working as soon as the main light was replaced with a different wattage (as the filament resistance would be different). If the main light isn't an incandescent lamp, then it's anyones guess as to what other bad things could happen.

The correct solution to the problem is to get a neutral wire to the switch, and connect the neon indicator between the switched live and neutral.
Replacing the switch T+E cable with 3c+E cable would be the neatest solution.

 

[ban-all-sheds]

The way to do this is to wire a 230V lamp in the garage in series with a 10V lamp at the lightswitch.

Should be fun when one of the two lamps fails.....

 

[sparkwright]

As this is a garage, is it easy to add a neutral?

Can you replace the cable with a 3 core and earth flat cable?

Using your 20 amp double pole switch, connect

Permanent live to L FEED
Neutral to N LOAD
Switched live to L LOAD

 

[ban-all-sheds]

The said it would work at B & Q but wouldn't be specific about the actual wiring.

Was this the guy you asked:

 

[silve]

Hi Wayne61

I had a similar requirement and bought this switch from B&Q (it is a weatherproof one). It is also rated 20A

http://nextday.diy.com/app/jsp/product/productPage.jsp?productId=54649

The neon is "customer configurable". You can make it light when the switch is off, or on. I think this is done by bridging the 2 wires of the built in neon between the common and L1 or the common and L2 terminals according to your preference. I actually have it wired the opposite way to you as I want to see the neon to find the light switch.

No need for any neutral to be run etc. Works for me using just the two wires as per your setup.

 

[NamelessRob]

Of course there is another way; one which is commonly used in caravans to check supply polarity.

 

[flameport]

I think this is done by bridging the 2 wires of the built in neon between the common and L1 or the common and L2 terminals according to your preference.

It's done by either connecting the neon across the switch (C and L1), or connecting it between L1 and a neutral.

Across the switch will cause the neon to be on when the switch is off, as the neon completes the circuit instead of the switch. The current flow via the neon is too small to illuminate the main light, unless it is a CFL or fluorescent tube, in which case it will probably cause the CFL to flash at regular intervals, or the starter to glow continuously.

To switch the neon indicator with the main light, a neutral is required.

 

[ban-all-sheds]

Without a neutral it will only work the way you have it.

If you want it to indicate switch on a neutral is needed.

[edit]Doh![/edit]

 

[silve]

Fair enough