Extension power wires for long term use

[ecc83]

Attached is a birds eye of my local sub station, that grey building between the two houses.

UK wiring is pretty conservative. Outlets arte wired in 2.5mm sq about 13 AWG but also as a 'ring'. At the fuse board (aka 'Consumer Unit) 2.5 mm goes out to a ring of sockets, typically ground floor say then returns to the same breaker point in the CU. Thus each outlet is 'served' twice. Each ring is rated at 32 A giving a nominal rating of around 7.5kW but then each appliance has it own fuse in the plug of 13 or 3 amp rating.

Heavy drain devices, cookers, showers are spurred back to the CU in heavier, 6 or 10mm cable.

Dave.

 

[Farview]

The 20 amp with the horizontal slot are supposed to be used on outlets that are dedicated 20 amp outlets. In a commercial building, that's how you can tell the difference between an outlet on a shared circuit and an outlet that that is the only one on the circuit.

If it's orange, it will tend to mean that it is on the generator, when the power goes out.

 

[bLUiVORY]

Well...everything I ever bought at Home Depot in 20Amp...came with the horizontal slot. Maybe those without are older manufacture...? Even the ones in my house...all 20 Amp have the horizontal slot.

And yeah...I wired all my own shit too, including a 15Kw permanent generator & transfer switch...
...and as I mentioned earlier, the 20 Amp studio lines were done with heavier, gauge wire...I actually went with 10 gauge.
A bit of a PITA to work with, but I wasn't going to go light for the studio lines.

I stand corrected.

You are absolutely correct, sir (not that you need me telling you). And furthermore, apparently there has never been a time when existed a 20A duplex receptacle that did NOT include the horizontal ground slot, which presently has morphed into the familiar "T" slot.


Oy. 10 gauge! I can't imagine. 12 is painful enough.

 

[ecc83]

Er? Is that 10g, in a twin and earth common sheathe ? If so prospective wirers might like to investigate 'tri-rated conduit cable in plastic conduit.

I was charged with wiring our first 'proper' workshop/lab (B's) and told to do it in mini trunking and 2x2.5 mil. Tricky, not a lot of room!

BTW. That W/S/Lab was served by a sub which was wrongly tapped. We found turning on 2 or 3 1kVa Variacs would pop a breaker, turned out we were getting 254 volts most of the time and sometimes 10% over that!

Dave.

 

[bLUiVORY]

'Been looking into this...

Here's the deal in the 'States: Code allows for 15a rated receptacles on a 20a circuit, the only mandate being that there must be more than one(1) outlet - and a duplex receptacle qualifies as two(2) outlets. The thinking, apparently is that the draw on any one outlet is going to be far less than 20a. So, it's perfectly acceptable and by-the-book to wire-up a circuit thusly - 20a breaker; 12/2G cable; multiple 15a receptacles.

 

[ecc83]

'Been looking into this...

Here's the deal in the 'States: Code allows for 15a rated receptacles on a 20a circuit, the only mandate being that there must be more than one(1) outlet
Hmm, in UK IIRC, you can have as many 13A double outlets on each ring as you want (called the 'diversity' factor) since each plug is fused. You are also allowed on spur to a double outlet.

Mind you, UK wiring regs' change every few years.

Dave.

 

[Farview]

'Been looking into this...

Here's the deal in the 'States: Code allows for 15a rated receptacles on a 20a circuit, the only mandate being that there must be more than one(1) outlet - and a duplex receptacle qualifies as two(2) outlets. The thinking, apparently is that the draw on any one outlet is going to be far less than 20a. So, it's perfectly acceptable and by-the-book to wire-up a circuit thusly - 20a breaker; 12/2G cable; multiple 15a receptacles.

Yes, the 20 amp outlets with the horizontal plug are for dedicated 20 amp circuits. (where there is only one outlet on a circuit)