rcd tripping after smoke alarm fitted.

[DC-backfrom the past]

EDIT: If it trips when you attach the smoke alarm - did you use the existing bases or fit new ones?

I tried it with brand new base and new alarm and it still trips. I stripped back the circuit to the original cable and new base /alarm and it still trips (ie back to original state). To say I am demented is an understatement. I appreciate that its hard to advise without being there.
I just wondered if I was missing something glaringly obvious

 

[Wilko]

I tried it with brand new base and new alarm and it still trips. I stripped back the circuit to the original cable and new base /alarm ... To say I am demented is an understatement ... I just wondered if I was missing something glaringly obvious

Glass of favourite and the installation instructions, who knows? I've had domestic blindness more than once

 

[Pete999]

I tried it with brand new base and new alarm and it still trips. I stripped back the circuit to the original cable and new base /alarm and it still trips (ie back to original state). To say I am demented is an understatement. I appreciate that its hard to advise without being there.
I just wondered if I was missing something glaringly obvious

Swap the N over to the other Nbar

 

[DC-backfrom the past]

Swap the N over to the other Nbar

to the one covered by the other rcd ?

 

[Pete999]

to the one covered by the other rcd ?

Yep

 

[DC-backfrom the past]

to the one covered by the other rcd ?

Yep

Apologies I'm missing the point to doing this... apart from thinking the rcd might be too sensitive or to check it trips the other one ?

 

[Ian1981]

How have you installed the 3 core and earth cable. Could you have possibly damaged(drilled/screwed) an existing cable located in the fabric of the property such as the wall?

 

[Pete999]

Apologies I'm missing the point to doing this... apart from thinking the rcd might be too sensitive or to check it trips the other one ?

It could be you have the L and N across 2 different RCDS I'm clutching at straws but worth proving a point, hence borrowed N

 

[Ian1981]

Is your cable supplying the smoke detectors the white 2.5 LSOH cable?

 

[Octopus]

Are you 100% sure you used the same cores in the interconnecting cable the same in each leg?

If you did IR at the board this wouldn't include the interconnecting cable so I suggest that you dis the smoke base and do IR across all 4 cores and see what comes back - and at the same time double check the colours and consistency.

 

[Pete999]

It could be you have the L and N across 2 different RCDS I'm clutching at straws but worth proving a point, hence borrowed N

I understood you supplied the new detector straight from the CU

 

[DC-backfrom the past]

Is your cable the white 2.5 LSOH cable?

That's the original cable that was connected to the first smoke alarm. I took the photograph prior to removing any cables for testing

 

[DC-backfrom the past]

Are you 100% sure you used the same cores in the interconnecting cable the same in each leg?

If you did IR at the board this wouldn't include the interconnecting cable so I suggest that you dis the smoke base and do IR across all 4 cores and see what comes back - and at the same time double check the colours and consistency.

yes Murdoch I had checked using a wander lead for each cable at the different areas.
This was before connecting to any equipment.
I also visually checked the cable and connections as well in case of loose connection,... although any faults should have been picked up in the initial IR / test.
I cant understand how even reverting it back to the original circuit it now still trips.

All the new cabling can be seen as there are no cable drops for the new circuit and the only part that is hidden is the drop to the consumer unit (this is the original cable which was operating beforehand).

 

[DC-backfrom the past]

I understood you supplied the new detector straight from the CU

I used the original cable and used that as a supply for the original smoke alarm then linked the other two via three core and earth cable.

 

[Octopus]

I am trying to help here!

So there was originally 1 smoke alarm, fed by T&E from the fuseboard.

You've added another smoke and a heat alarm to the existing smoke.

Now either 1 or the other RCD will trip.....

You've used 3 core cable for the new smoke & heat?

Or have I missed something?