mcb trips..

[kuksiani]

i have install 18 way CU but im so surprised why one MCB trips every time when i switch on main switch..just one of them..he does have any problem on cable installation and not trip after i switch on again..if i switch of main switch and i switch on again that MCB trips..its brand new installation , CU and MCB..another strange problem its the consumer unit make noise..its not like usually noise of transformer do..its like PIIIIIIIIIIIIIIIIIIIIII..i never heard that before..its first time for me..any sugestion why MSB trips and why CU make noise...

 

[Guest111]

That's the way, polite response always get the most help mg_smile:

maybe he didn't like our line of questioning,wonder if he's a spark?

 

[Octopus]

i ask for help not for joking..my English probably its not academic language but i think its not a problem to understand what i ask.. thanks to any one try to help but If anyone there is nothing to say the best way its to shut up your mouth..

Totally uncalled for. Looking to get ban?

If you want to use this forum you better get used to posting complete questions, not half baked scribbles.

So what are the RCD's doing?

 

[kingeri]

Shut up your mouth at once. Or don't. 'Tis up to you.

 

[kuksiani]

So what are the RCD's doing?

If the MCB trips then there is a fault in the circuit connected to it. You need to test the circuit to find the fault, since it is tripping an MCB instantly it sounds like a direct short circuit, so it should be easy to find on a continuity test.
As it is a new install this should have been caught on the inspection or testing before powering up, so repeat these again for the faulty circuit.

thank you..RCD its not trips..i have test all circuit including that who trips..its not any fault on the circuit because MCB not trip on normal time ..its trips just when i switch on and of main switch on the consumer units..its not first time to fix CU and not happened to me before..i know if its fault on the circuit MCB or RCD trips but keep trips always you try to switch on..if its fault on the circuits you newer can switch on MCB or RCD..

 

[Lucien Nunes]

...trips just when I switch on and off main switch

This is the interesting bit. Is the MCB close to the main switch? Perhaps its mechanism is faulty and the mechanical disturbance of handling the main switch is enough to dislodge the tripping link, i.e. there's no electrical fault. If you are 100% confident of the electrical soundness of the circuit, try another identical MCB? Or just see if it still trips with the circuit disconnected, or if you can make it trip by wriggling it or the busbar with the main switch off. Check the busbar anchorage!

E2A what brand of MCB / CU is it?

 

[Steve_P]

I shut up mouth after say that maybe call electrician to find fault as psychic fault finding not good idea.

Now I'm out of here.

 

[44ALLAN]

Have you tried changing Mcb with another one yet?

oops Lucien beat me to it

 

[kuksiani]

my apologies to you who are offended by my words the above post but believe me i was worry why someone on this forum always trying to mock or ignore others..im not concentrate just on my thread post but i see that on many other posts on this forum..on my experience i believe no one on this word know everything..if we know everything why we are on this forum..as i believe we are here to give our knowledge and experience and to learn from others knowledge and experiences..lets help others for what we know and let us learn from your knowledge and experiences..

 

[kuksiani]

Have you tried changing Mcb with another one yet?

im doing that on Monday because probably its MCB physical problem..

MANY THANKS TO ALL..

 

[44ALLAN]

im doing that on Monday because probably its MCB physical problem..

MANY THANKS TO ALL..

As already mentioned...........try disconnecting the circuit from the Mcb first.
If it's a mechanical problem it will still trip.
If it doesn't then try testing your circuit again

 

[SJD]

Does this MCB that trips have any loads connected, e.g. that take a surge when first powered up?

 

[Octopus]

Come on then. What tests have you done?

 

[richy3333]

Come on then. What tests have you done?

Murdoch - read back. CU has been turned on and off and MCB trips. What other tests are there to do

 

[Rockingit]

Come on then. What tests have you done?

I first do the bang test, is fine, then I do big money test is also fine.

 

[Octopus]

I was simply wondering if the testing was plugging in the kettle.

Numpties like this make the honest, decent competent sparkies job tough.

And yes I've now read the whole thread - god help the client.