RCCB not tripping
ac1951
split load)
Just got power and the main earth (6mm earth from incomming cable lead
sheath to be replaced later by PME) connection onto it at the moment
but the test button on the RCCB (30mA) does not cause it to trip.
Anyone know of any reason, other than it's DUFF, for it not to
function ?
thanks
Ady
John Stumbles
> Anyone know of any reason, other than it's DUFF, for it not to
> function ?
If it calls itself an RCCB it's probably pretty ancient. Yes if it doesn't
self-test it's faulty, at least per the regs. It *could* be that the test
circuit is faulty - you'd have to test it with an RCD tester (or suitable
resistor from live to earth) but either way it's not for production use.
--
John Stumbles
Ohnosecond
Instant in time when you realise that you've just made a BIG mistake.
Dave Osborne
the test button creates a current imbalance between the "input" side and
the "output" side of the RCCB. Usually, if the RCCB does not trip on
the test button, it will not trip on a "proper" earth fault either.
This is because the little itty bitty (technical term ;-) ) solenoid is
"stuck" and will not trip the mechanism on the available fault current.
It's duff; Send it back for a replacement.
HTH
Rumble
Dave Osborne
> On Tue, 01 Jul 2008 10:00:18 -0700, ac1951 wrote:
>
>> Anyone know of any reason, other than it's DUFF, for it not to
>> function ?
>
> If it calls itself an RCCB it's probably pretty ancient. Yes if it doesn't
> self-test it's faulty, at least per the regs. It *could* be that the test
> circuit is faulty - you'd have to test it with an RCD tester (or suitable
> resistor from live to earth) but either way it's not for production use.
>
includes RCCBs and RCBOs, but the industry is inconsistent in its use of
the terminology. ISTM you're thinking of an ELCB, which would be ancient.
Category: RCD (Residual Current Device)
Sub-Category: RCCB (Residual Current Circuit Breaker)
Sub-Category: RCBO (Residual Current Breaker with Overcurrent protection)
ELCB: Earth Leakage Circuit Breaker (Obsolete terminology for obsolete
technology).
Cheers,
Rumble
Andy Wade
> Nah, RCCB is the proper term. RCD is actually an umbrella term which
> includes RCCBs and RCBOs, but the industry is inconsistent in its use of
> the terminology.
True, and EN 61008-1 does refer to RCCBs, but UK market devices have
long since been labelled "RCD" (or "RCBO") and not "RCCB". I think it's
an industry agreement to simplify the message for the general public.
John's words "calls itself an RCCB" were significant since one that does
is probably be quite old and to the old BS 4293 standard. In mentioning
ELCBs you've introduced a red herring - I see nothing to suggest that
it's one of those.
--
Andy
meow...@care2.com
Its faulty, replace it.
If for some reason you want to mess with it, you could add an external
test button, which is a push to make button + a resistor that passes
30mA. Connect from live in to neutral out, and test using that. If it
trips on that test it will trip on a real world fault ok, if not its
stuffed.
NT
Dave Osborne
Hager (to name but eight) all know what an RCCB is, and some even label
their product accordingly.
e.g. http://preview.tinyurl.com/4p32ww
http://www.toolstation.com/images/library/stock/webbig/60967.jpg
http://www.sigmaelectrocontrol.com/IMAGES/RCCB.JPG
http://www.dz98.com/tp/cd27-1.jpg
Sadly, the reason there is confusion over the nomenclature is simply
because Wylex and MK marketing people don't know the difference.
In introducing the term ELCB I have not introduced a red herring at all.
I'm not suggesting for a moment that the op's device is an ELCB, I was
merely trying to show where Mr Stumbles may have been barking up the
wrong tree.
Cheers,
Rumble
Andy Wade
> Well, ABB, MEM, Siemens, Moeller, Merlin Gerin, Crabtree, Square D and
> Hager (to name but eight) all know what an RCCB is, and some even label
> their product accordingly.
Fair enough.
> Sadly, the reason there is confusion over the nomenclature is simply
> because Wylex and MK marketing people don't know the difference.
As I said, I think it's deliberate rather than done out of ignorance.
The term "RCB" was also used at one time.
--
Andy
John Rumm
Either its knackerd, or you have not actually got power going to it yet...
(would not be the first time I had a new out of the box split load CU
with the internal bus wires in the wrong places (one would have shorted
the main supply if installed as supplied!))
--
Cheers,
John.
/=================================================================\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\=================================================================/
Andy Wade
> (would not be the first time I had a new out of the box split load CU
> with the internal bus wires in the wrong places (one would have shorted
> the main supply if installed as supplied!))
That reminds me of a story involving a generator transfer switch, two
300 amp fuses and a somewhat red-faced electrician. . .
--
Andy
ac1951
I checked the internal wiring before installing the CU and can confirm
it's wired correctly (but thanks for the advice)
Regarding RCD or RCCD, I was aware of the confussion but in posting I
decided to follow the naming convention used by Contactum and also as
advertised (currently) on TLC's web site.
I've arranged for a replacement to be shipped from TLC and will post
again on that experience (hopefully no issues)
Thanks to all for the advice..
Andy
ac1951
>
> - Show quoted text -
OOPS didn't mean to introduce more confussion I did mean to say RCB
and RCCB (must wake-up before making early morning posts :-)
Mike Clarke
> Nah, RCCB is the proper term. RCD is actually an umbrella term which
> includes RCCBs and RCBOs, but the industry is inconsistent in its use of
> the terminology. ISTM you're thinking of an ELCB, which would be ancient.
Just to add to the confusion, what we now know as RCD's were commonly
referred to as "current operated ELCB's" in their early days. That's
certainly the case in the 1979 MK catalogue I still have.
--
Mike Clarke
John Rumm
> OOPS didn't mean to introduce more confussion I did mean to say RCB
> and RCCB (must wake-up before making early morning posts :-)
or even RCD and RCCB ;-)
Andrew Gabriel
ELCB covered both types:
"current operated ELCB's" are what we now call RCDs as you say,
"voltage operated ELCB's" are the older ones with two separate earth
terminals which monitor the voltage between the CPC and real ground.
RCD comes from a campaign by Which? and That's Life! to get the
industry to agree on a common name. When these started appearing
as consumer products (initially in the form of 13A plug-in types),
every manufacturer started calling them something different, which
made it impossible for consumer organisations to talk meaningfully
about the devices and their safety advantages. Which? and That's
Life! got together with the industry and persauded the industry to
adopt a single term name, and the industry decided on RCD.
--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]
Andrew Gabriel
Dave Osborne <rum...@nospam.invalid> writes:
> ac1951 wrote:
>> In the process of installing a new Consumer unit. (Contactum 10way
>> split load)
>> Just got power and the main earth (6mm earth from incomming cable lead
>> sheath to be replaced later by PME) connection onto it at the moment
>> but the test button on the RCCB (30mA) does not cause it to trip.
>> Anyone know of any reason, other than it's DUFF, for it not to
>> function ?
>>
>> thanks
>> Ady
>>
>>
>>
> You don't need an earth for the test button on the RCCB to operate, as
> the test button creates a current imbalance between the "input" side and
> the "output" side of the RCCB.
Unfortunately, that's not universally true. There are some that
generate an earth leakage by the test button, and cause upstream
tripping too. There are some that have a monitoring earth connection
and will deliberately fail a test if it's not connected, even though
they don't use it to generate the differential test current.
Some use their earth connection to operate the trip mechanism if
the neutral becomes disconnected, which will also trip upstream.
> Usually, if the RCCB does not trip on
> the test button, it will not trip on a "proper" earth fault either.
> This is because the little itty bitty (technical term ;-) ) solenoid is
> "stuck" and will not trip the mechanism on the available fault current.
> It's duff; Send it back for a replacement.
They contain electronic circuitry which can cease working too.
Had that with a powerbreaker one.