RCD tripped and wont reset

JohnD said:
Well, if the RCD is tripping, you clearly have an earth leakage. Did you look to see if the RCD still tripped when the MCB was off? That will tell you if it is Phase/earth or Neutral/Earth.

Did you UNPLUG all appliances in the ring? That will tell you if it is a wiring/accessory fault or an appliance fault.

Did you try halving the ring? That will help you identify where the fault is on the circuit.

Presumably you have already had a visual search for damaged wiring or accesories, including rodent damage under floors, or water ingress, and have tried disconnecting any outdoor sockets or lamps on the circuit, which are at risk of collecting rainwater.

You have probably realised now why the Installation Certificate includes spaces for a lot of test results, and why replacing a CU is notifiable work. If you say you have done CU replacements at work I presume someone else has been doing the tests.

thanks for reply john ;) well the rcd tripped leaving the mcb still on and cant reset it since.

unplugged everything on the circuit and still no reset.

no outdoor light or sockets

and yes as im an apprentice i have a guy with me at all times who tests any work i do

like i said he was going to come and test my cu on monday


this was supposed to be my big test and to be honest i thought it'd be a walk in the park but obviously something is wrong and i do not have the knowledge to know what..
 
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its a crabtree starbreaker 10 way split load board...which we use all the time in work so i am familiar with them

gimme a minute and i'll upload a photo

and thank for helping me fellas i really do honestly appreciate it ;)
 
silly question (sorry) are you sure you have the "tongues" of the Starbreaker RCD plugged in across the two halves of the busbar?

Cann you take the RCDout and see if it will reset when unconnected?
 
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image-upload-26-743864.jpg


the 6mm not connected is the cooker which i took out to test if the ring would work...gas cooker anyway so for the time being doesnt matter....

the 40A mcb is not used also obviously that would overload the rcd but as i said it doesnt have a circuit on...and i know the main earth needs upgrading and the equip. bonding...doing tomorrow ;)
 
I can't see what's wrong... except it's not very elegant.

Take out the RCD and see if it will reset on the bench.

Can you pull out all the MCBs from the RCD side and let us see a wider picture.

Check that none of those loose wires is touching anything.
 
I am not familiar with these CUs.

Are the in / out leads for the RCD the right way around?

It is easily muddled up in MK CUs. I wonder if this is the same?
 
The starbreaker RCD only has "in" and "out" terminals for N.
P is in and out through "tongues" into slots in the shielded busbar, which is divided at the Non RCD/RCD side. The RCD bridges the divide.

The main switch also has an "out" load side tongue into the busbar.

The MCBs pick up their supply through tongues.

(that's why you see few screws at the bottom)

(there was an older model of Starbreaker which had the usual terminals at the bottom of the MCBs, and an ordinary comb busbar)
 
RF Lighting said:
I am not familiar with these CUs.

Are the in / out leads for the RCD the right way around?

It is easily muddled up in MK CUs. I wonder if this is the same?

the rcd was manufacture fitted but i think its correct and have checked connections!
 
JohnD said:
Take out the RCD and see if it will reset on the bench.

Can you pull out all the MCBs from the RCD side and let us see a wider picture.
Go on, please!
 
JohnD said:
I can't see what's wrong... except it's not very elegant.

Take out the RCD and see if it will reset on the bench.

Can you pull out all the MCBs from the RCD side and let us see a wider picture.

Check that none of those loose wires is touching anything.

not very elegant haha here here!!

had to rush the torch was dimming quickly as night was falling!!

will tidy all up tomorrow when i upgrade main earth and change meter tails as they are too short and was one helluva stretch!!

i'll take out and see if it'll reset tomorrow as i cant have the power off as mum is watching charlotte church show :oops: i know, dont
ask ;)....
also to change the meter tails would it be ok to go to a 100A splitter and do it that way?? As i cant remove the service fuse and have an isolation switch to disconnect power ;)

oh and if it don't reset when removed what would be my next plan of action??
 
If it won't reset when lying dead on the bench with no supply, then it is faulty.

p.s. if you have a super MEM 100A DP Isolator, then you may find it has the "hatch" enabling you to open the Load side without exposing Supply terminals. Don't forget to switch off and test dead.
 
1878 said:
As i cant remove the service fuse and have an isolation switch to disconnect power


If you have an isolation switch fitted then you should replace the tails from the outgoing side of the isolator to the CU incommer terminals.


If it is an isolator like this, you can remove the outgoing cover without exposing the live incomming side.

memisolator.jpg
 
If you have an isolation switch just change the tails from there.

If the RCD won't reset then you have a knackered RCD.

Davy
 

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