Recent content by bonebill

I'm putting in a hot water tank with an immersion heater. The hot water tank will be located in a loft. I want to put an on/off switch on the wall in the utility room, so I have an MK 20A 'water heater' switch. But I figure the immersion heater should have a local isolator right next to...

To be sure, I cannot say whether an isolator would be required in this case (or even whether the whole idea is doable within the Regs). For The Avoidance Of Doubt, I am not an electrician. Usual provisos apply; unless you are confident in your own ability, consult a professional.

Is this a new installation, or are you adapting an existing installation? Will you be running power to the luminaires with (2 x brown) control pairs coming down to the switch domain, or running power to the switch domain and running a full switched-live and neutral feed up to the luminaires...

What about a DPCO (double-pole changeover) relay with the N/O (normally open) and N/C (normally closed) contacts cross-wired? Your 2 'in' terminals are the relay's common terminals, and your 2 'out' terminals are the relay's N/C terminals. (Alternatively, you could use the N/O terminals...

If you use relays, you will have to put them all in an enclosure, and this enclosure will need to be (properly!) accessible for servicing. I think in this case trying to cobble together a solution with relays when there is already a simple answer on the shelf is going to be more trouble than...

Sounds like a hard way of doing it. If you do it in MK Grid Plus, you can get intermediate switch modules. I think the intermediate switches only come in 20A. For the 2-way switches at each end, you will likely want to use 10A switches, assuming that this is a 6A lighting circuit. As well...

CT100 a.k.a. "Satellite cable". It's not hard to find. I doubt you'd need to go very far down the list of B&Q, Screwfix before you found a roll of it. If you currently have Sky (not +) you will likely have one cable. You will need a total of two cables for Sky+, so you will likely need to run...

Eh? All the push wire connections I have seen do not exert much in the way of a force on the normal to the surface of contact; it's just a spring pressing against the wire, with the shape of the spring end forming a barb pointing in such a way as to prevent withdrawal of the wire. Compare...

In my new house it turns out I have 11 light fittings which take ES / E27 lamps (8 wall fittings & 3 ceiling fittings), and 3 (pendant) fittings which take BC lamps. Now all of these locations take what would otherwise be identical lamps, apart from the ES / BC fitting. It occurred to me...

Answering my own question: The point is that, in essence, the regs say that your protective thing must either (a) be a CPC in and of itself, or (b) if it does not qualify as a CPC, be mechanically strong enough to stop nails and screws going through. The regs specifically prohibit the use...

Looking at the 16th ed, I think I can answer my own question here. Flexible steel conduit is specifically prohibited for use as a CPC by 543-02-01. But under 522-06-07, we see that, subject to certain other provisos, the protective thing does not need to be a CPC: "... or by mechanical...

So ... flexible steel conduit about as much use as a chocolate teapot then. Is it the same story for an RCD-protected circuit, buried less than 50mm, outside safe zones? i.e. Flexible steel conduit no good, but can use rigid steel conduit, SWA or (if you can find any) BS8436?

I think I need to understand what Consumer Protective Conductor is meaning here. When we say that flexible steel conduit would not be suitable as a CPC, what are we saying? Is it that the conduit would not, on its own, be suitable for making the earth connection between the two endpoints...

Flexible steel conduit any good? (The stuff that looks like shower hose coated in black rubber.)

17th edition question I was thinking to have a fixed wall-mount 30mA RCD at a location other than the CU (call this the Remote RCD). I am not sure if it is actually worth doing now, but it begs a question: The wiring to the Remote RCD would ordinarily be buried less than 50mm deep, in safe...