RCD SPUR Keeps Tripping

[Geezergeezer]

Hi

Here is my problem, I had a conservatory built a while ago, the electrics for this were spurred off the ring main from the living room, the electrician came off a double socket which he fitted to a switched fuse and from there into the conservatory he fitted two sockets onto a ring circuit, all good there and no problems, recently I have had an outside pool fitted, so in order to run the pump, I fitted an rcd Spur to the ring circuit in the conservatory (which I wired the supply side into the ring circuit to maintain the ring system) the load went to an outdoor (weatherproof) socket on the external wall of the conservatory, which I plug the pump into, this all seemed to work ok, but after about 20 minutes the RCD I fitted kept tripping, I unplugged the pump and tried a reset but the RCD still kept tripping, I waited a while then did a reset, which worked, so i plugged the pump back in and it ran for a while but I noticed the pump was running slower, then it tripped after a short while, I then ran the pump from an extension lead which was plugged into one of the sockets in the conservatory and it ran at the correct speed without any problems.

Can you please advise on where I have gone wrong or on what I should do.

 

[riveralt]

Here is my problem,

Where do I begin?

I had a conservatory built a while ago, the electrics for this were spurred off the ring main from the living room, the electrician came off a double socket which he fitted to a switched fuse and from there into the conservatory he fitted two sockets onto a ring circuit,

Are you sure - really sure that he fitted an additional ring final circuit off an FCU which leads into the conservatory.

all good there and no problems,

Well actually there is if he really fitted a ring final circuit from a spur. You cannot run a spur from a spur - you can't run a ring final circuit from a spur. Are you sure its not a radial circuit.

recently I have had an outside pool fitted, so in order to run the pump, I fitted an rcd Spur to the ring circuit in the conservatory (which I wired the supply side into the ring circuit to maintain the ring system)

What do you mean the supply side - how many cables are there in the Supply side Live and Neutral?

the load went to an outdoor (weatherproof) ......I then ran the pump from an extension lead which was plugged into one of the sockets in the conservatory and it ran at the correct speed without any problems.

So the problem is the RCD/Spur which you cannot have.

RCD's constantly check the input and output balance between Live and Neutral - tripping when that balance exceeds 30mA.
Putting aside the nonsense set up you have created you may have a loose connection between the FCU/RCD and your weatherproof socket or there is a problem with the FCU/RCD itself.

What is the load of the pump?

 

[Geezergeezer]

Q
Are you sure - really sure that he fitted an additional ring final circuit off an FCU which leads into the conservatory.
A
I never saw the electrician wire it up, but the last socket has two cables wired into it

Q
What do you mean the supply side - how many cables are there in the Supply side Live and Neutral?
A
I took one cable from the last socket and wired it into the RCD Supply then run a second cable from the RCD Supply back to the last socket (to maintain the circuit/radial) so two cables in the live and neutral supply

Q
What is the load of the pump
A
The pump has a house hold 3 pin plug (13 amp fuse) so its a 220~240v

A
Putting aside the nonsense set up you have created you may have a loose connection between the FCU/RCD and your weatherproof socket or there is a problem with the FCU/RCD itself.
Q
I've double checked all the cables, they seem ok, how can I test the RCD is delivering the voltage

 

[Geezergeezer]

Untitled

• Geezergeezer
• 23 Aug 2013
• 1

[/setup]

In side conservatory

 

[riveralt]

I'm sorry but I don't think I can help you further for the reasons below.
If the electrician fitted the conservatory circuit as a ring final circuit as you believe then that is wrong and should be rectified first.
It is quite possible that he has created a bridge on the ring final circuit which could be dangerous.
The way you describe what you have done could also be described as another bridge and as I said you cannot add a spur to an already spurred circuit.
You really need to get an electrician to check/sort out the mess in the conservatory first and then get him to correctly fit the RCD/FCU.

If it were me I would firstly ensure that the circuit going from the FCU in the living room to the conservatory is a radial - this is all it can be.

I would check that the living room ring final circuit and consequently the conservatory (radial we hope) is protected by a RCD in the Consumer Unit.
If this is the case then you do not need to add another RCD in the circuit and you CANNOT add another FCU in the circuit.

Assuming there is RCD protection on the circuit then the last socket in the conservatory should be one with only one set of conductors - provided the conservatory circuit is a radial you can connect your outside socket to this socket or any of the other conservatory sockets.

If your living room ring final circuit and conservatory are not protected by an RCD then you can replace the living room FCU with the FCU/RCD you have pictured - this will provide additional protection for your conservatory radial and outside socket.

By the way the load on the pump will be measure in Watts or KW - that information will be in the pump/swimming pool manual - with 13A fused supply you are limited to around 3kw in total.

 

[Aragorn84]

Why cant you put a second FCU behind a FCU thats spurred off a ring main?

For instance, the light in the conservatory could surely be perfectly legitimately run from a switched FCU with a 3A fuse, which is attached to the conservatory radial....

 

[EFLImpudence]

I had a conservatory built a while ago, the electrics for this were spurred off the ring main from the living room, the electrician came off a double socket which he fitted to a switched fuse and from there into the conservatory he fitted two sockets

If that is the case and you mean an FCU and the conservatory is on the load side then it doesn't really matter what you add in the conservatory.

There would be no point (and it would be very silly) to wire the TWO conservatory sockets in a ring but it would not do any harm?


As for the tripping, this must (unless there are connections between supply and load wires in the RCD) be caused by something that is plugged in, i.e. the pump or its cable.
Especially if there IS an RCD in the consumer unit which does NOT trip.

Does it trip with something else plugged in?

 

[securespark]

Thing that's niggling me is the pump slowing down.

Loose connection?

Voltage drop issue?

 

[Geezergeezer]

EFLImpudence wrote
Does it trip with something else plugged in?

Well I haven't tried anything else, but after it trips with the pump running, it will not reset even when I've unplugged the pump until about 20-30 mins have lapsed


EFLImpudence wrote
As for the tripping, this must (unless there are connections between supply and load wires in the RCD) be caused by something that is plugged in, i.e. the pump or its cable.
Especially if there IS an RCD in the consumer unit which does NOT trip.

There are no connections between the supply and load, and there is a RCD at the consumer unit for downstairs sockets


Aragorn84 wrote
Why cant you put a second FCU behind a FCU thats spurred off a ring main?

For instance, the light in the conservatory could surely be perfectly legitimately run from a switched FCU with a 3A fuse, which is attached to the conservatory radial....

Aragorn84 has a point because that IS the way the electrician has wired in the fan and the lights.

riveralt wrote.
If it were me I would firstly ensure that the circuit going from the FCU in the living room to the conservatory is a radial - this is all it can be.

So I as i understand it, I need to remove the returning cable from the last socket, and disconnect all other affected returning cables to the living room FCU.

a thought has just occurred to me, I haven't checked this but, could the electrician have Run a continous length of wire from the living room RCD to the last socket first, then run a feed back to the first socket and not actually completing a circuit OR could he have gone from the living room FCU to the conservatory FCU (that run the lights), then from the conservatory FCU run a cable from the Supply side to the sockets the way I described above, because I can use the sockets without the conservatory FCU switched on OR would he have run two cables from the living room FCU, one to feed the sockets and one to feed the conservatory FCU that feeds the lights, the electrician was a contractor whom was supplied by the company who fitted the conservatory and I did get a certificate

 

[Geezergeezer]

EFLImpudence wrote
Does it trip with something else plugged in?

Well I haven't tried anything else, but after it trips with the pump running, it will not reset even when I've unplugged the pump until about 20-30 mins have lapsed


EFLImpudence wrote
As for the tripping, this must (unless there are connections between supply and load wires in the RCD) be caused by something that is plugged in, i.e. the pump or its cable.
Especially if there IS an RCD in the consumer unit which does NOT trip.

There are no connections between the supply and load, and there is a RCD at the consumer unit for downstairs sockets


Aragorn84 wrote
Why cant you put a second FCU behind a FCU thats spurred off a ring main?

For instance, the light in the conservatory could surely be perfectly legitimately run from a switched FCU with a 3A fuse, which is attached to the conservatory radial....

Aragorn84 has a point because that IS the way the electrician has wired in the fan and the lights.

riveralt wrote.
If it were me I would firstly ensure that the circuit going from the FCU in the living room to the conservatory is a radial - this is all it can be.

So I as i understand it, I need to remove the returning cable from the last socket, and disconnect all other affected returning cables to the living room FCU.

a thought has just occurred to me, I haven't checked this but, could the electrician have Run a continous length of wire from the living room RCD to the last socket first, then run a feed back to the first socket and not actually completing a circuit OR could he have gone from the living room FCU to the conservatory FCU (that run the lights), then from the conservatory FCU run a cable from the Supply side to the sockets the way I described above, because I can use the sockets without the conservatory FCU switched on OR would he have run two cables from the living room FCU, one to feed the sockets and one to feed the conservatory FCU that feeds the lights, the electrician was a contractor whom was supplied by the company who fitted the conservatory and I did get a certificate

So I may have been jus guessing about the ring circuit, so I suppose now the question is, if the conservatory wiring is correct, why does the pump slow down when I run it from the RCD I fitted and then trips the circuit, but when the pump is connected to an extension lead which is plugged into the socket which I spurred off, the pump runs all day at the correct speed and does not trip the RCD at the consumer unit.

 

[securespark]

You sure you've not mixed up neutral and earth?

 

[Geezergeezer]

securespark wrote
You sure you've not mixed up neutral and earth?

I will double check however, I did put a socket tester on the weatherproof socket and all three lights illuminated as correct

 

[JohnW2]

You sure you've not mixed up neutral and earth?

I will double check however, I did put a socket tester on the weatherproof socket and all three lights illuminated as correct

As it will probably say on it somewhere if you look carefully, plug-in testers cannot detect neutral-earth reversals.

Kind Regards, John

 

[ban-all-sheds]

[quote="Geezergeezer";p="2858911"]EFLImpudence wrote
Does it trip with something else plugged in?

Well I haven't tried anything else, but after it trips with the pump running, it will not reset even when I've unplugged the pump until about 20-30 mins have lapsed


EFLImpudence wrote
As for the tripping, this must (unless there are connections between supply and load wires in the RCD) be caused by something that is plugged in, i.e. the pump or its cable.
Especially if there IS an RCD in the consumer unit which does NOT trip.

There are no connections between the supply and load, and there is a RCD at the consumer unit for downstairs sockets


Aragorn84 wrote
Why cant you put a second FCU behind a FCU thats spurred off a ring main?

For instance, the light in the conservatory could surely be perfectly legitimately run from a switched FCU with a 3A fuse, which is attached to the conservatory radial....

Aragorn84 has a point because that IS the way the electrician has wired in the fan and the lights.

riveralt wrote.
If it were me I would firstly ensure that the circuit going from the FCU in the living room to the conservatory is a radial - this is all it can be.

So I as i understand it, I need to remove the returning cable from the last socket, and disconnect all other affected returning cables to the living room FCU.

a thought has just occurred to me, I haven't checked this but, could the electrician have Run a continous length of wire from the living room RCD to the last socket first, then run a feed back to the first socket and not actually completing a circuit OR could he have gone from the living room FCU to the conservatory FCU (that run the lights), then from the conservatory FCU run a cable from the Supply side to the sockets the way I described above, because I can use the sockets without the conservatory FCU switched on OR would he have run two cables from the living room FCU, one to feed the sockets and one to feed the conservatory FCU that feeds the lights, the electrician was a contractor whom was supplied by the company who fitted the conservatory and I did get a certificate

So I may have been jus guessing about the ring circuit, so I suppose now the question is, if the conservatory wiring is correct, why does the pump slow down when I run it from the RCD I fitted and then trips the circuit, but when the pump is connected to an extension lead which is plugged into the socket which I spurred off, the pump runs all day at the correct speed and does not trip the RCD at the consumer unit.

FGS use the Quote facility properly to make it easier to follow what you are saying in replies to others.

 

[Geezergeezer]

ban-all-sheds
Apologies for my quote issues, I'm new to forums as such and I haven't a clue how to use this facility the way it's been set up, I'm still learning, took me a while to figure out how to get the picture up there