contactors

[sarahproperty]

can anyone supply a diagram showing how to wire a contactor?

this is to be used between a thermostat and underfloorheating cables as the amps exceed the amps allowed in the stat.

i imagine that i would need "normally closed" contactor and i do have one already, but how can i check if this is a normally closed or normally open contactor?

 

[Spark123]

Does the contactor have any markings? The coil terminals might be marked as A1 and A2. Does the thermostat require a neutral? The control side is pretty simple, the (correctly fused) live supply is fed to the thermostat and the switched live contact from the thermostat connects to A1. A2 connects to neutral. The contactor should now pull in when the temperature is below the set point. A contactor with N/O contacts is the correct type for this.
For the power side the heater live connects to one side of a contact and the live supply to the other. Neutral connects to neutral, earths to earth etc. This is also regarded as a special installation and is notifiable under part p of the building regs in England & Wales.

 

[breezer]

As its electric does it not come with its own stat that should be bureied with it?

any way, this is how it should be wired

markings on relay / contactor depend on make / model of contactor / relay

 

[Lectrician]

A contator will only have N/O contacts unless you add on aux contacts to it, and these are generall not rated to the full capacity of the contactor.

You want N/O anyway - you want the stat to close the contacts to turn on the heat.