30A switch mystery

[jobin]

here i have a new 30 amp toggle switch with a neon glow lamp indicating ON, when lit (this for my shower heater). Inside i find ( beside earthing connection) four connectors labeled P1, P1, P3,P3 (P2 also found but no connection possible). The tiny neon wires run from P1 and P2 on the ON side so at least i know which direction the current flows. However, there is no indication which of these, P1 or P3, is Live and which is Neutral, the box has no other markings. Can anyone help? See the photos and thanks.

Untitled

• jobin
• 26 Jun 2011
• 1

Untitled

• jobin
• 26 Jun 2011
• 1

Untitled

• jobin
• 26 Jun 2011
• 1

 

[Astra99]

I would suggest that this switch is also available for 3-phase (P=phase) and as yours is for either single-phase and neutral or split-phase (where both conductors are "live" relative to earth), so P2 is "blanked off"

I would suggest you use P1 for the line (or live) wire and P3 for neutral. The incoming supply goes to the bottom set of terminals in the picture, and the load is connected to the upper set which also have the neon connected to them. Make sure all the earths go to the earth terminal, and if mounted on a metal back-box, a fly-lead is taken from the earth terminal on the switch to the terminal in the back-box.

 

[jobin]

Thanks Astra99. Do you have any basis or logic for suggesting P1 for the live wire?

 

[Paul_C]

The tiny neon wires run from P1 and P2 on the ON side

I take it that's a slip of the fingers and you mean that the neon is connected between P1 and P3 on the load side.

I would agree that it appears that the same basic switch molding is probably also used for a 3-pole version of the switch, and for the 2-pole version you have the manufacturer just uses the P1 and P3 terminals.

It really doesn't matter which way round you use P1 and P3 - So long whichever way round you connect L & N on the supply side you connect the L & N to the load to the corresponding terminals on the other side of the switch.

 

[Astra99]

In your particular case, as Paul_C says, either P1 or P3 could be used for the line conductor, just be consistent on both sides of the switch. I suggested P1 Line and P3 Neutral because L comes before N in the alphabet and one is less than three!