Connect Neutral to Earth?

[fortress]

Hi all,

I have a roomstat to install. It has 3 terminals: Comm, NO, and NC. But the wiring in the wall is L, Switched L (to boiler), and Earth; there is no Neutral wire.

So the question is, can I connect the roomstat's N terminal to the Earth wire?

 

[endoftheworld]

This is a volt-free contact, which means it doesn't output voltage, only switches it. Like a float switch.

Comm is the common wire (live feed wire goes here), NO is Normally Open, and NC is Normally Closed. This means with the unit not activated current passes through the Comm to the NC, and when it gets up to temperature the contacts switch, i.e. current goes to the NO. So you would connect the live wire to the heating system to the NC. Earth and Neutral are not involved, just run them straight through in a junction box.

Of course it may switch the other way round, best to check with a continuity meter which one the Comm connects to when cold.

I assume this is not a powered unit, just a bi-metallic thermal switch.

 

[petej]

The traditional room thermostats had a neutral connection to run an anticipator to make the stat more sensitive.
Common connections are
Terminal 1 = Live in from timer
Terminal 3 = Switch live to boiler and or pump
Terminal 2 = Neutral

http://i15.photobucket.com/albums/a353/NeilScarrott/HoneywellThermostatWiring.gif