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[Robin Hood]

Just bought a “volt free” clock/programmer to replace my combi’s internal mechanical one.
 
Thermostat gives the connections; Common = Live, Normal Open = Neutral & Normal Closed = no connection.  Boiler has a terminal block (currently shorted) with two identical feed wires and no labelling.

Am I right to assume that being little more than an on/off switch, the wiring from the clock to the boilers terminal block can be either way round?

Thanks

[nick v6]

i wouldn't risk messing about with it
i changed the thermostate that is on the wall and had nothing but greef afterwards
i ended up giving a electriction a ring

[Entwood]

nickandann .. you post is unreadable .. completely blocked by a MASSIVE avatar ... 1010*758 !!!! ... site limits are about 1/10 of that !!

[Robin Hood]

i wouldn't risk messing about with it
i changed the thermostate that is on the wall and had nothing but greef afterwards
i ended up giving a electriction a ring

Need the thermostat to be remote to better balance the system.  

[Marks DTM Calib]

If you get stuck, I can pop over and connect it up for you

[Robin Hood]

Thanks for the offer Mark.  Hopefully I can find the info I need on the web and sort it, as it’s just the two wires to the boiler left to connect.  The Installation & Service manual is ambiguous on this – written by Haynes ?  

[Marks DTM Calib]

what boiler is it and what is the control setup....is it a combi or system boiler?

On a standard setup the stat would be connected to the diverter valve feed.

[Robin Hood]

The boiler (combi) is an Ariston microGenus HE with integral mechanical controls.

http://www.ariston.co.uk/uploads/doc47f9ff54cf602.pdf

Page 22 of the online Installation Guide shows connection to the boiler via a terminal block which carries no labels.  This terminal block (A15 on page 26) also connects to PCB by two similarly coloured wires.  Am I right therefore, to assume that polarity through the thermostat/clock is not important?

[Lizzie_Zoom]

The boiler (combi) is an Ariston microGenus HE with integral mechanical controls.

http://www.ariston.co.uk/uploads/doc47f9ff54cf602.pdf

Page 22 of the online Installation Guide shows connection to the boiler via a terminal block which carries no labels.  This terminal block (A15 on page 26) also connects to PCB by two similarly coloured wires.  Am I right therefore, to assume that polarity through the thermostat/clock is not important?

Personally I would test which, if any, of the two terminals are "live" simply using a mains tester.  It is never a good idea to casually connect wire up without actually knowing the polarity of the terminals.  As I understand there is a "live" and a "neutral" side to those clocks.  

The clear polarity on the thermostate would seem to indicate the importance of connecting this up in a set, standard, electrical feed order.

[Marks DTM Calib]

Dead easy then.

Simple case of remove the wire link and connect the C and NO contacts on the stat to the terminal block.

And yes, you are right because you have volt free contacts (a relay) in the stat that polarity is not important (although there is no such thing as a specific polarity on AC anyway!)

[Lizzie_Zoom]

Dead easy then.

Simple case of remove the wire link and connect the C and NO contacts on the stat to the terminal block.

And yes, you are right because you have volt free contacts (a relay) in the stat that polarity is not important (although there is no such thing as a specific polarity on AC anyway!)

Ok Mark, AC may be operating on a 50 alternating cycles per second, but surely the direction of feed is very often important with most electrical installations and much delicate electronic equipment can be buggered if you get this wrong!

That is why most appliances are wired "live", "neutral", with the added element of many requiring an "Earth".  It is not done just for fun, and that is why the wiring colour coding exists of red, black, green (old) or brown, blue, Green/Yellow (new) . 8-) 8-)

[Robin Hood]

Thanks for the confirmation Mark, will sort it now.  

Have to admit Lizzie, it was the wiring instructions on the thermostat that caused me to hesitate.

[Marks DTM Calib]

Dead easy then.

Simple case of remove the wire link and connect the C and NO contacts on the stat to the terminal block.

And yes, you are right because you have volt free contacts (a relay) in the stat that polarity is not important (although there is no such thing as a specific polarity on AC anyway!)

Ok Mark, AC may be operating on a 50 alternating cycles per second, but surely the direction of feed is very often important with most electrical installations and much delicate electronic equipment can be buggered if you get this wrong!

That is why most appliances are wired "live", "neutral", with the added element of many requiring an "Earth".  It is not done just for fun, and that is why the wiring colour coding exists of red, black, green (old) or brown, blue, Green/Yellow (new) . 8-) 8-)

You would think that....but you may be surprised to hear that 99% of kit is connection averse....in as much as it will work either way round without affecting the safety or the operation.

All the colour coding realy tells you is which is live, which is a neutral (remote earth) and which is a safety earth.

The classic example is europe where most plugs can be inserted into the wall socket either way!

And yes....still no polarity.....nothing more than as stated....a single phase live.

In this case....it matters not what wa its connected as the rely contacts are doing nothing more than simulating the wiring short circuit.  

[Lizzie_Zoom]

Dead easy then.

Simple case of remove the wire link and connect the C and NO contacts on the stat to the terminal block.

And yes, you are right because you have volt free contacts (a relay) in the stat that polarity is not important (although there is no such thing as a specific polarity on AC anyway!)

Ok Mark, AC may be operating on a 50 alternating cycles per second, but surely the direction of feed is very often important with most electrical installations and much delicate electronic equipment can be buggered if you get this wrong!

That is why most appliances are wired "live", "neutral", with the added element of many requiring an "Earth".  It is not done just for fun, and that is why the wiring colour coding exists of red, black, green (old) or brown, blue, Green/Yellow (new) . 8-) 8-)

You would think that....but you may be surprised to hear that 99% of kit is connection averse....in as much as it will work either way round without affecting the safety or the operation.

All the colour coding realy tells you is which is live, which is a neutral (remote earth) and which is a safety earth.

The classic example is europe where most plugs can be inserted into the wall socket either way!

And yes....still no polarity.....nothing more than as stated....a single phase live.

In this case....it matters not what wa its connected as the rely contacts are doing nothing more than simulating the wiring short circuit.  

Ok Mark, thanks!

[Marks DTM Calib]

Lol....its been a week of electical questions!

I spent 2 hours on the phone to an installation technician talking about the benefits of circuit breakers over fuses and how to rate them etc.

Not done stuff like that in anger since I was working on HVDC in Stafford!