RCD with RCM

[ericmark]

I saw in a trade mag a RCD with built in RCM which changed LED colour and started to warn at around 50% and did not trip until between 90% and 100% but can't find it.
Any ideas what make they are? And where to get them?

 

[bernardgreen]

http://www.fdb.uk.com/docs/VDA2.pdf

http://www.moeller.net/en/products_...rol/measuring_relay/earth_leakage_monitor.jsp


Both are motor orientated. The first one has an "offset" adjustment for nulling out existing and acceptable earth currents caused by filtering of the supply. In a domestic situation that nulling out feature could be more of a hazard than a benefit

 

[ericmark]

Thanks but not what I was looking for. The mag I read showed a RCD which had RCM built in so giving a warning that leakage was getting high. And instead of tripping between 50% and 100% as normal it tripped between 90% and 100%. But can't remember where I saw it or what make.

 

[ban-all-sheds]

In a domestic situation that nulling out feature could be more of a hazard than a benefit

I haven't got time to look, but I have a feeling that in a domestic installation such a feature would contravene the regulations....

Anyway....

this found me this on the first page of results....

 

[ericmark]

Spot on it was what I was looking for. I had tried loads of googles but had not tried the phrase you used.

"The system is in a state of alarm and the digital RCD will only trip if the residual current increases beyond 90% of the IΔN." still complies with tripping between 50% and 100% so can't see a problem.

Anyway want for my own house so it's not for use of ordinary person so until I move it will comply.

Once you put me in right direction also found this but as yet can't find a price. I thought this

Untitled

• ericmark
• 6 Dec 2008
• 34

was great until I found the price at around £350 each I think I can walk out to garage and reset manually.

 

[ban-all-sheds]

I've often wondered about those auto-resetting devices. How quickly do they reset? How often before they stop? If some poor gardener has accidentally bitten into his hedge clipper cable does he lie there repeatedly getting short 30mA zaps?

 

[bernardgreen]

I think the device shown is only a monitor and does NOT provide disconnection of the supply

From the description

The PDIM residual current monitor, which is just four module units wide, is a remedial measure. If such a monitor is connected in series before or after a Moeller residual current device, it makes it possible to always monitor the current system status.

The reset applies to remove the alarm condition on the alarm contacts.

Auto resetting of an RCD in a domestic situation is extremely hazardous given the many reason for an RCD to trip and the lack of electrical knowledge in the average occupiers.

 

[ericmark]

The idea of both knowing when getting near to tripping and to reduce the thunder storm problem is good.

RCD's

• ericmark
• 4 Jan 2011
• 1

OK look the part but the B16 rating may present a problem would want B32 for ring main.
The other two seem to be 25A and 40A both a bit too low to use in a consumer unit.
But price is the main thing. What do they cost and where can you get them.

 

[ELZ4742]

Moeller is Eaton/MEM so most wholesalers should be able to sort you out