Flush timeswitch

Depending on what you want to control, one option might be a DIN rail mounted timer in the CU and then a normal switch in the kitchen to trigger it.

If we had a DIN rail in our wooden CU with rewireable fuses ;)

But the real reason for having it in the kitchen is so that SWMBO doesn't have to go into the outhouse (where the cylinder is) to press the Boost button.

Well same logic can apply - auxiliary DIN enclosure for a timer, and a remote slim switch.

I have TimeGuard ZV700

Looking at the picture of the FST11A the depth:width ratio doesn't look right for 38:85, that's more or less 1:2... Get your ruler out and measure the image on your screen and do a bit of maths. I come out with somthing over 20 mm for the height or 1:4 which does look more like the image. Also look at the size of the fixing screw heads they are about 6 mm normally 3 or 4 of those make up the depth of the box.

Those dimensions are overall and there is something sticking out the back...

You could fit a deep backbox. There are 50mm ones available.

Bill

I'm not sure I see how that would help. The surface part of the timer would still protrude the same amount, wouldn't it?

Alex

Interesting. What I might do then is buy one of these anyway because I can always use it out of sight for the electric towel rail. Then I'll get to see it in the flesh and test how far it really will stick out.

Thanks for the advice.

Alex

How would the switch override the timer to do the boost?

Alex

Depends on the type of timer, and the type of switch. Some timers may already include a boost capability, in which case the switch only needs a push to make action to trigger it. Alternatively a normal timer could be connected in parallel with a 20A plate switch, allowing the choice of "on" or "timed".

How about:

If the timer settings will remain fairly static, how about putting a cheap timer in the outhouse and wiring something like this in parallel with it in the kitchen:

combination with your parallel conductors idea it might work though.

As it happens I was looking at the regs on parallel conductors yesterday. It's not clear to me if they allow this setup.

Having the timer and boost in parallel will not share the load. Unless the boost happened to be active during the timed period, only one of the parallel conductors would be loaded.

Alex

Oh. 523.8 goes on to say "... or special consideration shall be given to the load current sharing to meet the requirements of Regulation

Alex

Indeed - either a DIN mounted timer in an enclose elsewhere, or a conventional immersion switch somewhere less visually objectionable to provide the normal timed operation. Then this device "wire ORed" to provide an override.

Yup, load sharing only really becomes an issue when you are attempting to parallel up cables to increase available current carrying capacity. You then need to consider if they are equal resistance paths and hence will load share equally, and also whether each individual cable is adequately fault protected by the protective device at the origin which is sized to overload protect the group of cables.

For your circumstances you are not doing that, so its not a problem.

Or actually visit an electrical wholesaler to see one in the flesh before buying... If you want to be really fussy about how it will look next to the other accesories take them along on a dualbox and put them next to each other, or be really cheeky and borrow those bits at the wholesalers. B-)