Is this allowed for a radial circuit?

[John]

This may be a stupid question but hey, what the hell, I'll ask it anyway.

In almost every diagram I've ever seen regarding ring or radial circuits, the cable comes into one socket and then on to the next, from there it goes on to the next and so on, in a daisy-chain sort of arrangement.

Would the circuit layout shown below be acceptable? If I can put the junction box where I want to, it'll sure save me hours of sweat, frustration and tears :o)

TIA John

Single

2.5T&E-----------DS-------JB----------FCU (300W load) from CU (700W) ¦ (20A MCB) max ¦ ¦ 2.8kW load

[Bob Watkinson]

It would be fine. Options to consider though are, 1.Use a fused connection unit instead of a JB, 2. Bring a cable back from FCU to the MCB creating a ring which will allow 30A instead of 20A and allow for future expansion

[Andrew Gabriel]

That's fine (providing my correction of your drawing to use a fixed width font is what you really intended). The 2.8kW load needs to be on an FCU, but the FCU can be at the appliance end of the branch. If it is a water heater over 20 litres (IIRC) or the main room heating for some area of the house, or some other fixed load which is likely to remain on at full power for long periods, then it needs to be on a dedicated circuit with no allowance for diversity.

Subject of course to meeting other regs (JB remains accessible, cable not routed through thermal insulation or a warm area without uprating it, cable not too long for voltage drop or earth fault loop impedance, etc).

[John]

Thanks Bob. You raise some good points but they're exactly what I'm trying to avoid :o) The house will probably be completely rewired in two or three years anyway (when we build an extension on the back) so I don't want to have to go to all that extra trouble now if I don't need to.

The radial circuit (DS------FCU) already exists so I just want to lift the one floorboard at each end of the room and tee-off the existing cable to provide a new point for the new load. As long as that's an OK way of doing things, it'll do me for now.

Thanks again, John.

[Andy Wade]

That's better.

15 litres.

Also the floor area served by a 20 A radial circuit shouldn't exceed 50 m^2.

[John]

Thanks Andy and Andrew but I'm very puzzled. What have you done to my little piece of ASCII art and why do you think it's better?? :o)

When I drew it (if that's what you can call it), I had the 2.5T&E, the DS, the JB and the FCU all in a straight line, with an almost vertical line going down from the JB to the 2.8kW load. When I look at it now, the first two downward lines have moved to the left to be somewhere between the DS and the JB and the third downward line - along with the "2.8kW load" - has moved even further to the left and is now inbetween the 2.5T&E and the DS! How on earth can that look better to you?

Barman, I'll have a pint of whatever these two good chaps are drinking please :o)

Cheers, John.

[Andrew Gabriel]

You are presumably using some proportional spaced font to write and read articles. Since most people won't be using the same font as you, most people won't see what you intended. Use a fixed width font (e.g. courier) for Usenet, at least when horizontal positioning in things like ASCII art, tables, etc is expected to be readable by anyone else. Also a good idea to avoid tabs (which wasn't a trap you fell into, but people often do).

[John]

Aha, it's all clear now :o) I'm just using Outlook Express on the default settings that are used when installing WinXP for the first time (which appears to be Times New Roman for Usenet, although I do prefer Arial for email). I've just looked in "View" > "Text Size" and seen an option for "Fixed" and I now understand!

Cheers mate,

John.

[John Cartmell]

[Chip]

On Sat, 08 Oct 2005 18:05:48 +0100,it is alleged that John Cartmell spake thusly in uk.d-i-y:

Aww there are worse things.

Comic Sans anyone?

[John Cartmell]

But not produced by desecrating such a beautiful font like Helvetica.

It's OK. At least it does an everyday job of filling a gap in the market. Arial just fools the unwary into accepting bad design.

duck! ;-)