Not only that, find a good ratchet crimp tool. There are some poor rachet crimp tools about - the street market specials don't give consistancy either. I bought twice, the replacement from Maplin was OK ...
Hmm. My place has an 80mA RCD protecting the 13A sockets. It's a standalone RCD feeding the CU which contains only a double pole 100A isolator. Is that (still) acceptible?
Lecky board raised no eyebrows and, in fact re-located it to a more convenient location relative to the new CUs that were subsequently installed, when installing my dual rate meter 8 years ago.
Richard
80A is a common contact rating found on RCDs, but 80mA isn't a common trip rating. Are you sure you read that right?
It is probably a 30mA trip RCD with 80A switching capacity. If that is the only CU, then no it is not an acceptable solution these days, since one fault loses you all power and lights.
They would be unlikely to comment since it is a common arrangement, and for a time (15th edition) was considered an appropriate way of doing things. (since it was (rightly) believed that the RCD would result in a reduction of serious electric shock accidents, but the consequences of plunging a house into darkness unexpectedly had not been understood).
In the 15 years we've lived here, our similar arrangement has only ever lost us "all power and lights" when some idiot (me) drilled through a ringmain. OTOH, the power compnay plunges us into darkness several times a year. Sometimes several times a day. So I'm not going to lay awake nights worrying about it, and I suggest the OP does likewise.
There are two issues here really. One is the nuisance factor in day to day life, and the other is the genuine fault scenario.
Peoples perception of problems with the single RCD setup seem to be governed by the former, while it is the latter that in many cases has more potential to bite you.
Some single RCD setups (like yours, or the setup at my mum's previous place) never trip unexpectedly, and hence can lead you to assume there is little or no risk. Others, like that which was here when we moved it, tripped any time a horse farted or so it seemed[1] and was a right royal pain in the arse. Hence there was a big motivation to fix it for that reason alone.
(The supply also goes off with some regularity here as well - hence why I am fitting emergency lights in strategic places. Having navigated my way back to the CU in total darkness on a few occasions when it was just a RCD trip, it was apparent that to get the whole family out, possibly in the presence of smoke, in the same situation would be very difficult)
However the fact that you get no nuisance trips does not mitigate the problem of being left in an awkward situation in complete darkness when the RCD does its job protecting you from a real fault. This may be an exceedingly rare event. How much of a problem this actually is will vary greatly on circumstances. Someone in a well street lit road, young and mobile enough to find their way back to the CU with no difficulty is not really under any risk. Old, infirm, out in the sticks, up a couple of flights of awkward stairs etc and the picture is very different.
So my advice would in some circumstances concur with yours, but only after one has assessed their circumstances and thought through what factors are going to come into play.
[1] Combination of ten circuits including several outdoor ones all protected on one over sensitive 30mA trip RCD.
I suspect it is more to do with 'reasonable' cost. When the 15th regs were being prepared (and these things take time to be approved and issued) the RCD was an expensive device. To require people to have 2 or
3 was probably not reasonable, and losing all the lights was compared to electrocution. However they are so cheap that by the time the next regs come out they will probably require 2 for lights and 2 or 3 for everything else - just my guess
Quite right. I miss-remembered the rating. It's an MK LN6180 item:
100mA trip, rated at 80AFor the benefit of later contributors, and with apologies for being economical with the information earlier, this is the setup:
LN6180 feeds one CU which supports kitchen, GF, 1F and attic ring mains, and oven, immersion heater and outside socket.
Second CU (no RCD) supports GF and upstairs lighting, freezer and fridge supplies, boiler and garage (via it's own 30mA RCD CU).
I suspect that the LN6180 was installed by the previous owners because of frequent nuisance tripping - but I cannot be certain.
Richard
Yeahbut, many split load setups still only have one RCD...
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