RCD with built-in display?

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Richard Russell

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Jul 20, 2007, 12:32:06 PM7/20/07
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Does anybody make an RCD breaker with a built-in display of fault
current? It strikes me that with 'current' technology (ouch) adding a
small LCD wouldn't hugely increase the price, and the value in tracing
the cause of nuisance trips, or simply knowing how close it is to
tripping, would be invaluable. I'd buy one!

Richard.
http://www.rtrussell.co.uk/
To reply by email change 'news' to my forename.

John Rumm

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Jul 20, 2007, 2:36:28 PM7/20/07
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Richard Russell wrote:
> Does anybody make an RCD breaker with a built-in display of fault
> current? It strikes me that with 'current' technology (ouch) adding a
> small LCD wouldn't hugely increase the price, and the value in tracing
> the cause of nuisance trips, or simply knowing how close it is to
> tripping, would be invaluable. I'd buy one!

Yes that would be a rather nice idea, but alas I don't think I have seen
such a thing.

(It would probably have a limited market, since I guess the majority of
people don't know what a RCD does or how it works)

--
Cheers,

John.

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Graham

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Jul 20, 2007, 4:32:42 PM7/20/07
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"Richard Russell" <ne...@rtrussell.co.uk> wrote in message
news:1184949126.0...@o61g2000hsh.googlegroups.com...

> Does anybody make an RCD breaker with a built-in display of fault
> current? It strikes me that with 'current' technology (ouch) adding a
> small LCD wouldn't hugely increase the price, and the value in tracing
> the cause of nuisance trips, or simply knowing how close it is to
> tripping, would be invaluable. I'd buy one!
>

I must say that would be well down on my wish-list
Further up would be for the standard electric meter
to display the kW load being used as well as recording
kWh

--
Graham
%Profound_observation%


Andrew Gabriel

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Jul 20, 2007, 6:06:58 PM7/20/07
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In article <f7r659$lf3$1...@news.datemas.de>,

"Graham" <m...@privacy.com> writes:
>
> "Richard Russell" <ne...@rtrussell.co.uk> wrote in message
> news:1184949126.0...@o61g2000hsh.googlegroups.com...
>> Does anybody make an RCD breaker with a built-in display of fault
>> current? It strikes me that with 'current' technology (ouch) adding a
>> small LCD wouldn't hugely increase the price, and the value in tracing
>> the cause of nuisance trips, or simply knowing how close it is to
>> tripping, would be invaluable. I'd buy one!

It would be quite easy to make one using a current transformer
(which is how the RCD works in the first place).

> I must say that would be well down on my wish-list
> Further up would be for the standard electric meter
> to display the kW load being used as well as recording

Been standard in France for at least 20 years. My dad's
meter has a button which enables you to cycle around
about 10 different measurements. I won't recall them all
precisely, but they're something like Volts, Current,
Power, Power factor, VA, Energy usage peak and off-peak,
Peak Power demand, etc. They are all also read real-time
remotely which is used both for billing, and for trend
analysis to predict future national demand on the grid
(no one ever comes to read the meter). EDF also signal
back to the meter to switch between peak and off-peak,
and I think can also loadshed the high demand off-peak
output if they need to.

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]

Andy Wade

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Jul 20, 2007, 6:31:59 PM7/20/07
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Richard Russell wrote:
> Does anybody make an RCD breaker with a built-in display of fault
> current?

Not that I know of, but you can get sensitive clamp meters for the same
purpose: http://www.martindale-electric.co.uk/clamp.htm#cm67

--
Andy

Pete C

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Jul 21, 2007, 7:47:10 AM7/21/07
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On 20 Jul 2007 22:06:58 GMT, and...@cucumber.demon.co.uk (Andrew
Gabriel) wrote:

>>> Does anybody make an RCD breaker with a built-in display of fault
>>> current? It strikes me that with 'current' technology (ouch) adding a
>>> small LCD wouldn't hugely increase the price, and the value in tracing
>>> the cause of nuisance trips, or simply knowing how close it is to
>>> tripping, would be invaluable. I'd buy one!
>
>It would be quite easy to make one using a current transformer
>(which is how the RCD works in the first place).

Better still just disembowl a cheap plug in RCD, and add a socket for
reading the voltage from the current transformer to the trip relay.

cheers,
Pete.

Andrew Gabriel

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Jul 21, 2007, 8:06:01 AM7/21/07
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In article <gcs3a3h8g6566job4...@4ax.com>,

I guess I should have included a warning that current transformers
can generate lethal voltages if you don't know how to use them
(i.e. don't try measuring the voltage, and don't leave the winding
open-circuit).

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