Programmer swap question

[stewartgreen145]

Hello everybody

I had no hot water today (programmer was faulty and sending no signal to cylinder stat - tested with multimeter) - have a standard Y plan system

I am to change the programmer (Drayton Tempus 7) - for a new one - the new Drayton Tempus, but have a slight questkion that's bugging me:

The old Drayton didn't have an earth wire.... but the new one, on the backplate it has an earyh wire terminal. I could only change the face as they are compatible but am going to use the new backplate as sscrew slots are same place and want a new clean connection.

My question is: do I need to run a new earth wire, or can I ignore the earh wire terminal as the old one didn't use an earth and the programmer is plastic.

Thanks for your help


Steve

 

[heatserve]

Most programmers do not require an earth connection. If an earth terminal is provided on the back-plate it is usually purely for the customer use. The instructions should explain this.

 

[stewartgreen145]

That's what I thought, same with room stats etc - no earth required.

WHat do you mean purely for customers use? Do you mean, if a new install, customer can use an earth? I am just swapping/replaxing an original that had no earth though. So OK to just ignore the terminal rather than run a new earth wire from the back plate to the wiring centre in the airing cupbaord which would be awkward !!!!

 

[londonboy]

You should really have a 'circuit protective conductor' (cpc/earth) in every cable, and at every 'point' in the circuit, ie at every light switch, every timer, thermostat etc.

 

[stewartgreen145]

that's rubbish, most cylinder and room stats never have an earth and don't require one.

 

[londonboy]

May I suggest you post this in Electrics forum so you can see your the one talking rubbish, I wonder who the electrician is here?

 

[stewartgreen145]

ELectricians don't do plumbing electrics.... I know that for a fact!!! lol.

Most cylinder stats / room stats do not have or require an earth

 

[londonboy]

Looks like youve just met someone whos an exception then.

The cable needs a CPC incase it gets damaged, cut, ripped from the wall.

 

[heatserve]

That's what I thought, same with room stats etc - no earth required.

WHat do you mean purely for customers use? Do you mean, if a new install, customer can use an earth? I am just swapping/replaxing an original that had no earth though. So OK to just ignore the terminal rather than run a new earth wire from the back plate to the wiring centre in the airing cupbaord which would be awkward !!!!

If you require earth continuity for some reason, the terminal provided plays no part in the electrical connections to the programmers contacts. But, as I said before, the instructions will tell you all you need to know.

 

[stewartgreen145]

heatserve - so just to clarify, I just ignore the earth terminal (screw) on the new back plate as the original wiring didn't use an earth?

 

[londonboy]

He dont like my answers cos they involve doing the job properly

 

[heatserve]

heatserve - so just to clarify, I just ignore the earth terminal (screw) on the new back plate as the original wiring didn't use an earth?

As long as it is a separate terminal and the instructions say it doesn't need to be earthed.

The connections are usually N-L-1-2-3-4.

 

[stewartgreen145]

Yep got the instructions, have a booklet which lists all programmers and wiring terminals. Was just checking about the earth.

 

[stewartgreen145]

He dont like my answers cos they involve doing the job properly

You are talking madness!!!! You don't need an earth on ALL thermostats etc..... some thermostats don't even have an earth terminal... so what you on about!!!

 

[simond]

So you don't know what a CPC is, and what it is intended for?