Room stat understanding

[Killy Bing]

it should also be noted that some wired stats/programable stats also have batteries.[/QUOTEa
and if they have a battery they dont need a netural?

two core programmable room stats have batteries but you're a sucker for punishment fitting them

 

[AWheating]

two core programmable room stats have batteries but you're a sucker for punishment fitting them

let the sparky worry about that. unless thats you.

 

[AWheating]

it should also be noted that some wired stats/programable stats also have batteries.[/QUOTEa
and if they have a battery they dont need a netural?

maybe they do, whats the manufacturers instructions state?? afterall theres no general rules, guess once fit twice. guess twice.......... work in tesco.

 

[jase158]

the stat is the hardest thing to wire up correctly,
the instructions tell you how to do it but it all depends on which system you have, sometimes you connect the neutral, some times you don't.

 

[Killy Bing]

the way i learned

 

[AWheating]

in the end just run 3 cores, 4, five...... cover your cheeks and then nowt to worry about.

i cant see why they are teaching wiring controls at this level. Would be better to cover basic electrical principles and jog on.

 

[stevetheplumber]

If you've a live you always need a neutral.

not true john on a two wire stat
on two wires you have a feed into one side of a switch ,when the switch makes ,usually for our purpose when the room temp drops below the set point, the switch makes and the current flows to the next point of call usually a pump boiler or motorised valve there is no neutral much like a light switch
the neutral on stats is for a anticipator not being an electrician i have no idea what this does but im told it makes the stat more responsive but you still have a live in and live out to the load made by the switch
you many stats will have another terminal which makes on temperature rise often used for controlling air con or extract fans ie when the roomgets hot the fans or air con kicks in
you may also have a earth connection some stats need this as a safety feature but most stats now are double insulated and the earth terminal is actually there so the continuity of the earth circuit can be maintained when using muticore and earth cables if it was being wired with conduit and single cables theres no need to use the earth at all
here an exert on anticipators which actually refers to 24 volt stats but as we all know many 240 stats have similar
24 volt thermostats

The majority of modern heating/cooling/heat pump thermostats operate on low voltage (typically 24 volts AC) control circuits. The source of the 24 volt AC power is a control transformer installed as part of the heating/cooling equipment. The advantage of the low voltage control system is the ability to operate multiple electromechanical switching devices such as relays, contactors, and sequencers using inherently safe voltage and current levels.[SUP][9][/SUP] Built into the thermostat is a provision for enhanced temperature control using anticipation. A heat anticipator generates a small amount of additional heat to the sensing element while the heating appliance is operating. This opens the heating contacts slightly early to prevent the space temperature from greatly overshooting the thermostat setting. A mechanical heat anticipator is generally adjustable and should be set to the current flowing in the heating control circuit when the system is operating. A cooling anticipator generates a small amount of additional heat to the sensing element while the cooling appliance is not operating. This causes the contacts to energize the cooling equipment slightly early, preventing the space temperature from climbing excessively. Cooling anticipators are generally non-adjustable.
Electromechanical thermostats use resistance elements as anticipators. Most electronic thermostats use either thermistor devices or integrated logic elements for the anticipation function. In some electronic thermostats, the thermistor anticipator may be located outdoors, providing a variable anticipation depending on the outdoor temperature. Thermostat enhancements include outdoor temperature display, programmability, and system fault indication. While such 24 volt thermostats are incapable of operating a furnace when the mains power fails, most such furnaces require mains power for heated air fans (and often also hot-surface or electronic spark ignition) so no functionality is lost. In other circumstances such as piloted wall and "gravity" (fanless) floor and central heaters the low voltage system described previously may be capable of remaining functional when electrical power is

 

[Dotty]

not true john on a two wire stat
on two wires you have a feed into one side of a switch ,when the switch makes ,usually for our purpose when the room temp drops below the set point, the switch makes and the current flows to the next point of call usually a pump boiler or motorised valve there is no neutral much like a light switch
the neutral on stats is for a anticipator not being an electrician i have no idea what this does but im told it makes the stat more responsive but you still have a live in and live out to the load made by the switch
you many stats will have another terminal which makes on temperature rise often used for controlling air con or extract fans ie when the roomgets hot the fans or air con kicks in
you may also have a earth connection some stats need this as a safety feature but most stats now are double insulated and the earth terminal is actually there so the continuity of the earth circuit can be maintained when using muticore and earth cables if it was being wired with conduit and single cables theres no need to use the earth at all
here an exert on anticipators which actually refers to 24 volt stats but as we all know many 240 stats have similar
24 volt thermostats

The majority of modern heating/cooling/heat pump thermostats operate on low voltage (typically 24 volts AC) control circuits. The source of the 24 volt AC power is a control transformer installed as part of the heating/cooling equipment. The advantage of the low voltage control system is the ability to operate multiple electromechanical switching devices such as relays, contactors, and sequencers using inherently safe voltage and current levels.[SUP][9][/SUP] Built into the thermostat is a provision for enhanced temperature control using anticipation. A heat anticipator generates a small amount of additional heat to the sensing element while the heating appliance is operating. This opens the heating contacts slightly early to prevent the space temperature from greatly overshooting the thermostat setting. A mechanical heat anticipator is generally adjustable and should be set to the current flowing in the heating control circuit when the system is operating. A cooling anticipator generates a small amount of additional heat to the sensing element while the cooling appliance is not operating. This causes the contacts to energize the cooling equipment slightly early, preventing the space temperature from climbing excessively. Cooling anticipators are generally non-adjustable.
Electromechanical thermostats use resistance elements as anticipators. Most electronic thermostats use either thermistor devices or integrated logic elements for the anticipation function. In some electronic thermostats, the thermistor anticipator may be located outdoors, providing a variable anticipation depending on the outdoor temperature. Thermostat enhancements include outdoor temperature display, programmability, and system fault indication. While such 24 volt thermostats are incapable of operating a furnace when the mains power fails, most such furnaces require mains power for heated air fans (and often also hot-surface or electronic spark ignition) so no functionality is lost. In other circumstances such as piloted wall and "gravity" (fanless) floor and central heaters the low voltage system described previously may be capable of remaining functional when electrical power is

I was trying not to confuse the boy. He's trying to run before he can crawl Steve.

 

[PlumbBobBob]

now he is going to stumble even more