Rccb Keep Tripping

[Harris786]

Hello there,

            I went to a studio flat where there was a problem in the cooker circuit. The consumer unit was protected by RCCB 0.03A, I ran IR test and RCD test which came back clear, I only run L-N IR test n forgot to forgot to do with Earth. I also disconnected the cooker and disconnected all the cables from the sockets. As soon as the MCB is switched on the  RCCB trips. .Can anybody make any suggestions as to what the problem could be? 

 

[pewter]

Only testing l-n won't help

Need to test live conductors to E . Rcd detects earth leakage

 

[Harris786]

that's I was think I missed the vital test, dose normal main switch resolve this issue? and cook circuit have it's 30A MCB.

 

[steptoe]

what RCD testing did you do?

ramp?

x1/2

x1

x5

as above, need to to L-E & N-E    IR

that's I was think I missed the vital test, dose normal main switch resolve this issue? and cook circuit have it's 30A MCB.

NO it doesnt

 

[pewter]

No

 

[Harris786]

If IR test clear with L-E and N-E then what could be wrong?

half time, one time and five time, all tests. 

 

[SLIPSHOD & SLAPDASH]

Hello there,

 I also disconnected the cooker and disconnected all the cables from the sockets. As soon as the MCB is switched on the  RCCB trips. .Can anybody make any suggestions as to what the problem could be? 

Which mcb did you turn on , or do you mean the main switch ?

Did you try turning all the breakers off, turning on the rcd then turning each breaker back on separately ?

 

[steptoe]

firstly check if it is clear,

what are you testing at?

and what would your definition of clear be?

 

[SLIPSHOD & SLAPDASH]

Is the RCCB the main switch or is it seperate to the consumer unit ?

Now if only the property had had double pole rcbo's fitted  ;

 

[Harris786]

Clear means pass, I was testing IR test on 0.5 DC. yes I have tried every thing, only problem with cooker circuit.  RCCB is used as main switch. This is old consumer unit and all MCBs are the fused not autometic.

 

[Steve3948]

Probably not the cooker then.

 

[Harris786]

cooker is not connected any more but still problem in the circuit.

 

[SLIPSHOD & SLAPDASH]

Did you disconnect the cooker neutral inside the consumer unit ?

 

[Harris786]

I am think to run again IR test, if all clear then I am thinking to use normal main switch and 30A cooker MCB, what do you think?

.  

yes I have disconnect main incoming cable for cooker from  cooker switch.

 

[SLIPSHOD & SLAPDASH]

MCB means miniature circuit breaker. You said there weren't any, only fuses ? 

 

[batty]

I think he is thinking to replace RCD with a main switch and replace fuse with an MCB probably not a good idea.

 

[steptoe]

Clear means pass, I was testing IR test on 0.5 DC. yes I have tried every thing, only problem with cooker circuit.  RCCB is used as main switch. This is old consumer unit and all MCBs are the fused not autometic.

what does that mean?

what readings are you getting?

there is no cut and dried pass/fail IMHO

should this be in the DIY section?

going by the misuse of basic terminology its clearly not a post/question from an electrician.

 

[samson337]

I think batty is trying to say, that will just hide what could be a dangerous problem. A couple of minutes testing should find the fault, the cu is just doing its job by the sounds of it

 

[SPECIAL LOCATION]

Hello there,

            I went to a studio flat where there was a problem in the cooker circuit. The consumer unit was protected by RCCB 0.03A, I ran IR test and RCD test which came back clear, I only run L-N IR test n forgot to forgot to do with Earth. I also disconnected the cooker and disconnected all the cables from the sockets. As soon as the MCB is switched on the  RCCB trips. .Can anybody make any suggestions as to what the problem could be? 

that's I was think I missed the vital test, dose normal main switch resolve this issue? and cook circuit have it's 30A MCB.

If IR test clear with L-E and N-E then what could be wrong?

half time, one time and five time, all tests. 

Clear means pass, I was testing IR test on 0.5 DC. yes I have tried every thing, only problem with cooker circuit.  RCCB is used as main switch. This is old consumer unit and all MCBs are the fused not autometic.

cooker is not connected any more but still problem in the circuit.

I am think to run again IR test, if all clear then I am thinking to use normal main switch and 30A cooker MCB, what do you think?

.  

yes I have disconnect main incoming cable for cooker from  cooker switch.

From reading your posts the assumptions I am coming to are as follows...

1/ this "RCD" is protecting every circuit on the CU.. 

2/ you have assumed there is a fault on the cooker circuit, tried to isolate it but a fault is still present...

(so maybe the fault isn't actually where you think it is?)

3/ Disconnecting any cables at the cooker switch.. will still leave a cable connected to the fuse box..

(N-E can still cause an RCD to trip on this cable.)

4/ you haven't actually done the correct tests to earth..

so  you have proved very little so far..

5/ The RCD is doing its job detecting a leakage fault...

Removing the RCD is NOT the correct cure ...

YOU MUST FIND THE CAUSE..  not remove the safety device that is detecting a potentially hazardous fault! 

6/ Don't forget ...  It could be an intermittent fault that maybe shows clear during your tests.??

7/  You need to go back and start again with a fresh approach...

forget all that you have assumed so far and start back a basics and reprove everything cortectly..

Have there been any recent changes to any part of the installation?

or new appliances fitted??

 

[Sharpend]

May I suggest a copy of GN3 so that you can follow the standard procedure to testing and fault finding?

Whilst we may have a wealth of knowledge collectively to assist you, you need to do your part and provide well structured plan of approach to fault diagnosis to enable the correct answer to be ascertained.