rcd tripping

[biggals]

hi everyone...

I've got a RCD tripping problem... I've put in a new split board rcd consumer unit in exchange for an fuse board.. i've found an insulation leakage problem on the downstairs ring which through this forum got advice and fixed it (thank you)... now i've energised the circuit but when i plug even a lamp into one of the sockets the rcd trips... any suggestions please? on way home i've been thinking could it be, I might have dropped the N's into the other RCD split way? (can't remember but if so is that an amateur mistake?), or does it matter i've got 3x32amp MCB in 80amp 30mA RCD? I'm back tomorrow but if i find i haven't messed up on the N's then I'm stuck!!

also on another note, whats the main differences in 1.0mm & 1.5mm cables? and why am i finding it difficult to get 4mm Twin&earth?

just a new comer so take it easy on me!!

 

[NozSpark]

TBH if your IR test are OK then you either have put the rn into the wrong N bar or if it's only on a socket or two then the sockets are wired incorrectly

1.0mm T&E have a 1.0mm L,N & E

where as

1.5mm T&E have a 1.5mm L & N and a 1.0mm E

4.0mm T&E should be easily obtained from a wholesaler... mine hold it in stock...

4.0mm T&E good for 32A radials (installation method C)

 

[sparkytim]

If N not in wrong bar at CU then you may have N-E fault some where.

Did You fix any sockets back AFTER IR tests?. Easy to pinch N in back of socket, done it myself a few times.

 

[matt.leung]

could be a doggy lamp that u r plugging into the circuit.....

 

[Hawk81]

you have said that when you plug in even a lamp so i am guessing you have tried plugging in a few different items. i dont believe it to be a neutral to earth fault on that ring as it would trip rcd all the time. it has to be that you have connected the neutrals from that ring into the wrong neutral bar in the cu.

 

[ianmacd]

Or the sockets have E&N swapped at some point.

 

[PC Electrics]

N in wrong N bar

incorrect polarity at one or more sockets

incorrect polarity in lamp plug

N-E fault in lamp

N-E fault on circuit

'shared' N from another circuit

in no particular order of likelyhood (except the first one!).

 

[sparkytim]

you have said that when you plug in even a lamp so i am guessing you have tried plugging in a few different items. i dont believe it to be a neutral to earth fault on that ring as it would trip rcd all the time. it has to be that you have connected the neutrals from that ring into the wrong neutral bar in the cu.

Only when current flows in the circuit i.e. when you plug something in and switch on.

 

[biggals]

Nice one, N was in the wrong bar.. think it was the result of a 14hr day!! fella wasn't impressed as they had no dwn sockets for the night!!

thanks again.

 

[Hawk81]

Only when current flows in the circuit i.e. when you plug something in and switch on.

i am not sure what part of my post you were responding too. if it is the part where i say about a neutral to earth fault. then i am correct. if it was a short between n+e on the circuit then it would trip all the time.

 

[sparkytim]

i am not sure what part of my post you were responding too. if it is the part where i say about a neutral to earth fault. then i am correct. if it was a short between n+e on the circuit then it would trip all the time.

Yes it would but only when current is flowing in the Nuetral

I have tested a live circuit with a Martindale plug in polarity tester with out it tripping then plugged in a fridge and it trips

i.e. the circuit requires sufficent current to flow to show the RCD an imbalance in excess of 24 mA or so before it will trip

Try it and see!

 

[ADS]

i am not sure what part of my post you were responding too. if it is the part where i say about a neutral to earth fault. then i am correct. if it was a short between n+e on the circuit then it would trip all the time.

Sorry Hawk, Sparkytim is correct

 

[Hawk81]

Yes it would but only when current is flowing in the NuetralI have tested a live circuit with a Martindale plug in polarity tester with out it tripping then plugged in a fridge and it trips

i.e. the circuit requires sufficent current to flow to show the RCD an imbalance in excess of 24 mA or so before it will trip

Try it and see!

I think that you must have misunderstood my point. What i was saying was that if the connections had of all been in the correct place (neutrals in the correct neutral bar) and there was a dead short between neutral and earth then the rcd would trip and not reset until this fault was cleared. His rcd was only tripping when something was plugged in.

 

[Lurch]

I think that you must have misunderstood my point. What i was saying was that if the connections had of all been in the correct place (neutrals in the correct neutral bar) and there was a dead short between neutral and earth then the rcd would trip and not reset until this fault was cleared. His rcd was only tripping when something was plugged in.

If no current is flowing in the circuit then the RCD cannot operate. A neutral to earth fault does not mean the RCD will operate and not reset.

Quite an echo in here.