Can someone please tell me what the difference is between RCS mains sockets with active control circuits and those which are passive?
I was looking at this MK one for our garage:
Many thanks for your help.
For outdoor use (and indeed in most domestic circumstances) 10mA will be a nuisance; it's used in hospitals for obvious reasons. My 30mA on the main board trips at 25mA but not at 20mA and hasn't suffered from over-sensitivity, but 10mA in the garden probably would.
Many thanks Peter I'll get the 30mA. They certainly not cheap are they?
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Adam
Active needs mains power to stay untripped, so it will trip on loss of mains. That's useful if you don't want appliances to start up after a mains failure (such as garden machinary), but would be a disaster for anything that should be running continuously such as fridge/freezer/central-heating/fish-tank...
10mA is fine for a single (or very few) appliances, which is what you're likely to have running from a single socket. 10mA would be a pain in the arse for a circuit which is running many appliances, such as a standard ring circuit.My outdoor socket circuit is run from a 10mA RCBO in the consumer unit, and has never false tripped. It has however tripped very nicely as I sliced through the hedge cutter cable, without me feeling a thing. (When a neighbour waves to you, don't wave back with a running hedge cutter ;-)
10mA is traditionally required for restricted conductive locations, such as if you are working inside a large metal pipe where you can't easily move or jump out of way, or let go of the metalwork you're laying on. It's also useful for poor grounding situations, such as working outdoors where an earth leakage through you might be limited to a small current due to resistance of dryish ground, damp footwear, leakage through tree branches, etc, which might mean you are taking a sustained 20mA which isn't tripping your particular 30mA RCD/RCBO.One other comment I'd make is to avoid installing RCD's outdoors or in damp/condensating places like garages. You do want RCD protection there, but have the RCD indoors remote from the power outlet, where it isn't going to suffer from any condensation issues which eventually kills them.
"active" means it has a "No Volt Release" (NVR) facility that will result in the RCD opening on power loss, and then needing a manual reset when power is restored.
30mA will usually offer adequate protection - certainly for in the garage.
MK generally aren't - other brands may be more to your pockets liking.
An alternative would be to use a din mount RCD in a small enclosure to protect a radial with a number of sockets. You could do this for £20 all in.
They're quite complex electro-mechanical devices.
From another thread, looks as if MK is expensive and not the best.
Screwfix has some, e.g.
I did a GFs garage, mainly for a mower, by using a twin socket RCD (with a cover and metal-clad, as it was close to the door) and ran an extension to a double socket extension for the bench.
In my shed I ran the supply from the 100mA RCD on the main board, split it to the lights via a 5A MCB and via a 30mA RCD for the sockets. This was so that the lights don't go off if there's a fault.
Surprised you can get the thing to reset if there is a decent extension cable on the circuit. I have a plug in 10mA RCD, it's 50:50 if it will stay in if you try to reset with it still connected to the supply. It's a PITA so don't use it, thus can't remember if it will latch without a supply. I think not otherwise it wouldn't be such a PITA...
Until I installed a new CU, I used a 10ma RCD for several years to feed the garden socket without /any/ spurious trips.
I would say that there's either something wrong with your RCD or with the extension lead.
My outdoor circuit has a few metres of singles in conduit indoors, either 15m or 25m (can't recall now) of SWA outdoors, a couple of sockets, and when I'm using the hedge trimmer, its own 5m lead plus an 18m extension lead, all of which is 3-core. No problems with that. I have tested the 10mA RCD and it trips at 10mA but not at 5mA (not actually tested where between 5mA and 10mA it trips). It's a TT circuit (own earth rod, not the house earthing), although that shouldn't make any difference.
The RCD socket I want to fit is for the lawnmover, strimmer, garden shredder, pressure washer, etc. This site has the MK one on special offer listed at =A319.99:
I think I'll get the Volex one from Screwfix that Peter posted the link to.
Cheers!
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