MCB won't reset
 

Just had an MCB trip.

It's a 6A MCB with only 1 fluorescent fitting on it. Turned off the switch
to the light and the MCB would not re-set. I then removed the started for
the light and the MCB still won't re-set.

Anyone got an idea what the problem might be?

Just had an MCB trip.

It's a 6A MCB with only 1 fluorescent fitting on it. Turned off the switch
to the light and the MCB would not re-set. I then removed the started for
the light and the MCB still won't re-set.

Anyone got an idea what the problem might be?

As the switch is off to the light, that rules that fitting out (Unless it
has be wired to switch the neutral, rather then the live!)

If this is the only thing on the circuit, then there must be a cable fault,
or the MCB is faulty.

Does it trip immediately, or is there a delay?

Have you knocked any nails into the wall recently!?

Any other DIY work done recently?

Sparks...

Swap it with a working MCB. If that trips, you've got a fault.

As the switch is off to the light, that rules that fitting out (Unless it
has be wired to switch the neutral, rather then the live!)

If this is the only thing on the circuit, then there must be a cable
fault, or the MCB is faulty.

Does it trip immediately, or is there a delay?

Have you knocked any nails into the wall recently!?

Any other DIY work done recently?

It trips immediately. Was working fine until this evening and I've not done
any DIY work that would affect it.

I guess that means it is probably a faulty MCB. Think I will leave it until
tomorrow before I try another one ;)

"Goonerak" wrote in message
...

As the switch is off to the light, that rules that fitting out (Unless it
has be wired to switch the neutral, rather then the live!)

If this is the only thing on the circuit, then there must be a cable
fault, or the MCB is faulty.

Does it trip immediately, or is there a delay?

Have you knocked any nails into the wall recently!?

Any other DIY work done recently?

It trips immediately. Was working fine until this evening and I've not
done any DIY work that would affect it.

I guess that means it is probably a faulty MCB. Think I will leave it
until tomorrow before I try another one ;)

Try turning off the main isolator or RCD for this part of the CU, does the
MCB still trip then?

Sparks...

On Sun, 10 Jul 2005 22:25:47 +0100, "Sparks" wrote:

Just had an MCB trip.

It's a 6A MCB with only 1 fluorescent fitting on it. Turned off the switch
to the light and the MCB would not re-set. I then removed the started for
the light and the MCB still won't re-set.

Anyone got an idea what the problem might be?

As the switch is off to the light, that rules that fitting out (Unless it
has be wired to switch the neutral, rather then the live!)

If this is the only thing on the circuit, then there must be a cable fault,
or the MCB is faulty.

Does it trip immediately, or is there a delay?

Have you knocked any nails into the wall recently!?

Any other DIY work done recently?

Possibly a faulty switch, or the wiring in the switch box. Make sure
there aren't any loose wires in the switch box, such as the incoming
line, which may have jumped out and made contact with the back-box.
You don't state whether or not you have an RCD as well.

--
Frank Erskine

Goonerak wrote:
Just had an MCB trip.

It's a 6A MCB with only 1 fluorescent fitting on it. Turned off the switch
to the light and the MCB would not re-set. I then removed the started for
the light and the MCB still won't re-set.

Anyone got an idea what the problem might be?

In 95% of cases it means a fault that draws far more current than the
mcb's rating, simple as that. So faulty wiring.

NT