So how much power does an oil filled radiator actually use.

Except if you turn the knob thermostate down (anti-clockwise)then it switches off to 0W and the LEDs go out.

That may be the only example of valid usage. There may be other valid usage cases but I can't think of any right now so I'll leave it to others to provide additional examples if they care enough to make the effort.

Voltage 211, it does drop more than 1 volt with just one heater switching off and on. (with 5 on the same circuit we get down to 202V)

with thermostate at highest i.e always on. LEDs always on both switches. When the thermostate is manually turned down from maxium I hear a click and the meter drops tom 0W as expected.

What I didn;t expect was that leaving the heater on for a couple of hours at full also resulted in a click and the power drops to ~700W rather than 0w like I'd expect of a cut out. At this 700 both LEDs remain on, indicating to me that 1700W would be disapated rather than the 700W measured.

Sounds like it's the upper limit stat that is cutting in and out on the bigger element (only) ... before the main stat cuts everything out? Do you have a IR thermometer? If so it might be interesting to see what surface temperatures these clicks and measurements apply to.

If they are keeping them I'd be inclined to open one up and make a wiring diagram (or see if there is one in there or in the manual).

Cheers, T i m

So it is. But, er, that one just now wasn't a conjunction. :)

However if they were to run for an extended period the socket would fail.

It's nothing to do with the B curve:-)

The same applies to C and D MCBs

I remember from my first job (a temporary one CADding up the packaging drawings and datasheets for the Volex 9000 range) that the twin sockets were rated at 29A.

If I remember, I'll ask my dad at the weekend - as he used used to run the drawing office and the test lab there. The test lab was full of plugs and sockets being run continuously, plugged in and out repeatedly or swiched on and off endlessly - all in heated boxes to accelerate ageing.

SteveW

Well I don't have the web page to hand, but I am sure it was shown a double socket failed at 19.5A after an hour or so.

I'll be delighted if you can get some old Volex info.

What is the theory behind a double socket not being able to take 26 amps total? The actual sockets and switches and terminals are identical to a one gang of the same make - which only leaves the bus bars between them.

I think it stems from the way BS1363 specified the test for temperature rise. In a single socket that was with a 14A load. In a double socket it was 14A and 6A loads. That was still true in BS1363-2:1995 but I've not checked the current currents.

Still the same for 2016 edition.

It does mention 2x 14A for unfused outlets with more than 2 sockets, but any trailing multi-way, or wall mounted outlet I've ever seen with more than 2 sockets has been fused.

B&Q sell a 3-way that's apparently unfused

to temperatury I'd expect it to disconneced with a bimetalic strip or some thing more advanced and would be 0W not 700W.

tches off to 0W and the LEDs go out.

We do have an IR thermo... good idea, providing I can find it.

What temperature would you expect say the half way up the fin should be. I know it's to hot to hold on to as I tried.

The manual is on line and has the same details as the one supplied in the b ox. When you say 'they' it is the estates department I doubt they'd like me tak ing their new stuff apart and I don't particually want to. I have an oil filled radiator at home that works as I'd expect it to, but t hen that one was over £100 rather than £35.

It would suggest it is not "fully on". It might be that the stat does not fully disconnect both elements - perhaps just the 1300W one. If that were the case it would cycle between ~2kW and 700W during normal operation.

Note also that some heaters are configurable. I found some wall mounted

n.

The ones like that I once looked after had the internal switch as a rocker switch. A couple of small 2mm holes drilled opposite the switch ends let me change them by using a small knitting needle poked through the holes in a simlar manner to the way many battery powered amber road works warning lamps used to be switched on/off using a matchstick poked through a hole.

G.Harman

;-)

I can't say for your rad but when I was experimenting with mine I think it was pretty high ... as I think the thermal trip was set at

So, if you hear something click and the wattage from 2000 to 700, but turning the main stat down sees the current drop to zero, the thought is that the upper limit stat is cutting the power to the main element (because the rad is overheating itself) before the main (room-ish) temp stat is cutting the power to it all?

So, with the IR thermometer looking say midway up the rad, and you monitoring the power drawn, see if you can work out a pattern between the clicks, lights and temperature.

I believe on 2000W and the main (room-ish) stat on max, the rad is unable to dissipate enough heat to stop it 'overheating' and therefore it's modulating the power on the 'overtemp stat'.

If you turn the stat down to just above the current temperature, you may find that (the main stat) will cut out (0W) before the overtemp stat (leaving 700W).

When you say 'apart' you just mean the plastic end cover off. ;-)

Shouldn't make any difference what it cost to how it works.

Cheers, T i m

That could explain why dave only reads a max of ~1700W (1000 + 700W) but I'm not sure how you would manage the 1300W down to 1000 (other than the low voltage supply he mentioned).

I think it's just wired incorrectly or strangely, with the 700W element not protected by the overtemp stat (because it alone would be unlikely to take the rad to overtemp and said stat couldn't handle the full ~200W)? .

I assume there is still a thermal fuse in there providing the ultimate overtemp protection?

Cheers, T i m