Discussion in 'Electricians' Talk' started by Alan/, Sep 27, 2021.
The socket that you plugged into ,is it on a circuit protected by the same RCD as the boiler mcb ?
No it on a different curcuit
Does the RCD that trips , protect the following circuits..
A lighting circuit
Any other circuits besides these ?
kitchen sockets and boiler, smoke detector, lighting, and shower but shower is on mcb but on the same RCD
sockets for other rooms stay on
That doesn't make a lot of sense, the shower bit ??
I will try to ask the same question a different way.
The RCD that trips....tell me ONLY those circuits that it protects. Not interested in the circuits that the second RCD protects.
Smoke detector, kitchen sockets, boiler, lights
Thanks. Your test with plug etc is inconclusive.
RCD' s trip when there is earth leakage ,
And a small amount of earth leakage ,typically 30 miliamps +.
So ,you have 4 circuits and if there is that amount of leakage across some or all of them it will trip. Try your test using a kitchen socket to plug into ,if RCD trips ,it points toward the new switch being duff
The thermo has no earth on it is the type that does not use a earth
I don't understand where I could get a earth leak from could you explain a bit more thanks
Nothing to do with the earth conductors being connected to the thermostat.
Earth leakage can be from cables ,accessories,appliances ,switches,sockets,ovens etc etc.
Tiny amounts of electric current can
"escape" out of a circuit via any of the above,that's called earth leakage ,is the easiest way to explain it in layman's terms.
i have put old thermostat back on that works still if it was leakage how does it not affect the old thermostat
this is how they have said to wire it the way i did it 3 and 2 are other way round just scared to try it in case it damages something
Looking at your picture it seems to be:-
Old – New – Colour – Use
4 – 1 – NC – empty
3 – 2 – NO – Grey
2 – 3 – Neutral – Black
1 – 4 – Line – Brown
Earth – Earth – Earth – Green/Yellow
This seems to be what you have, you say RCD trips with new and not with old, so only difference between new and old is likely to be the power used line to neutral, the old thermostat would work if no neutral connected, never measured the size of the anti-hysteresis resistor, but likely a very high resistance, so if the new thermostat uses more power and it has the wrong neutral supplying the thermostat that would cause the problem.
the way i wired it was
old -new -colour
4 - 1 empty no wire
2 - 3 grey with blue sleeve on it
3 - 2 black
earth to screw on metal back box
the company said try switching black and grey round i just dont know if i was to try that would it damage anything
this how they said wire it
every where i have looked videos and chat say 3 is switch on a honeywell which is black and if i use a tester when honeywell is turned to on there is 240v reading at black and 0v when it is turned to off
so if i was to try it the way you have wrote it which is how the company said do it if it is wrong will it just trip electric again.
i keep thinking i must have a neutral wrong as it trips straight off the new1 does not even get to light up ,
i can put a cable with a plug on live and neutral to 4 and 3 on new1 and all lights up and works that way
The old stat doesn't have a fault causing earth leakage ,the new one does.
Just re read all your posts ,when doing voltage measurements I assume the wires were connected to the old stat.
If so ,get 4 seperate connector blocks ,remove wires from stat and put each wire in its own terminal block, so they are not in contact with each other .then take voltage measurement as follows.
Brown to earth.
Black to earth.
Grey ( blue sleeve) to earth.
Brown to black.
Brown to grey.
Black to grey.
will do that and post readings
but can i ask about the earth leak ,as posted the old stat uses a earth and does not have a earth leak
where i get confused is the new stat does not have an earth attached use a earth wire like old 1 so where does the earth leak come from
Mate it's too long winded to explain. Try googling earth leakage in electrical circuitry.
Essentially electric current leaks out of a circuit and finds a way to go to ground in a route it is not intended to take .
ok i will google
this earth leak i have could come from fuse being in on position but not in use i have 2 fuse on the same RCD which are to the on position but are not going to anythink
I think you mean MCB's ,not fuses ,don't you ? You can't switch a fuse off you would remove it.
If you are telling me that 2 MCB's are in on position ,but nowt connected to them ,it's of no consequence whatsoever
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