MCB tripping on lighting circuit

[bleach]

Hi

Two lighting circuits (A&B) side by side, each feeding 1 gang of 2 gang switch, then onto lights.

circuit A works fine.
circuit B works fine if mcb A is off...MCB B holds ok if MCB A is on until light switch turned on for circuit B.

Yet to look at this job but thinking must be short circuit on outgoing switchline B to Neutral A. Maybe in switch or next jb if exists.

Any thoughts chaps

 

[Lucien Nunes]

My thoughts exactly. I reckon the fault is reported wrong - in an SP installation one side of all MCBs is connected together, so turning one ON can't realistically cause another to trip in the event of a cross-connection, it can only stop it tripping by shunting it, unless there are relays or similar involved which is unlikely here.

So even without any test results, we can look into the crystal ball of physics and give the OP some advice. Amazing!

 

[Octopus]

The OP does say "yet to look at the job" so he's going on what the customer has said......

 

[uksparks]

True, so it probably is the big switch thing in the board not the one with the little lever.

 

[Plonker 3]

But terminology is important in this job, if we are told MCB then we should take it as a MCB, you can't afford to guess in this job.

 

[telectrix]

why not? it works for doctors. mine told me that my back pain was caused by beer and worn-out knees due to smokes. all over the phone. brilliant.

 

[SPARTYKUS]

why not? it works for doctors. mine told me that my back pain was caused by beer and worn-out knees due to smokes. all over the phone. brilliant.

Not 40 years hard graft.....

 

[Brightspark2]

What test results did you get when you tested the circuit?

Why didn't yo carry out any tests on your initial visit to the job?

In your own words...

Try reading the whole post by the OP...

 

[Plonker 3]

In your own words...

Try reading the whole post by the OP...

OK, I have read it all again and still await the question to be answered, or in other words how are we supposed to know the answer when the job hasn't even been looked at yet?

Some proper information from the job is needed what someone has told someone down the phone it just turns into Chinese whispers and information gets left out. Or can you diagnose faults from just a phone call?

 

[7029 dave]

He needs to get to the job and do some testing.

 

[GMES]

I agree with last 2 post's some testing needs doing. this is not Mystic Meg's helpline!

 

[telectrix]

soon there'll be an iphone app to test installations over the phone. then the Electrical Trainee course will be redundant.

 

[Knobhead]

But terminology is important in this job, if we are told MCB then we should take it as a MCB, you can't afford to guess in this job.

I don’t guess, I have special powers.