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Converting an 'intermediate' (DPCO)switch to a 2-way (SPDT)?

440Hz is waaaay too low for a SMPSU. They operate in the KHz range - around 40kHz being a common switching frequency.

Another way would be to have a central (mega) junction box (like the good old Hartley Octopus from years gone by) at some central point (or one per floor). From here run 3C+E to each switch & to each light point. You now have many options - a neutral can be made available at each switch point &...

A quick question for those with the maximum investment ... what happens to the prize money after you reach the max invested? Do you have to take it in cash or can the pot still continue to grow but only by re-investment of prize monies?

There should be a fibre washer between the tap connector & the bottom of the tap. It looks like its missing? Without it, you won't get it to seal. Easy enough to buy another washer & replace it.

I agree this would be true with a an item of equipment in isolation on the test bench..... BUT with something like Erics central heating boiler .... you cant guarantee the green & yellow wire in the supply cable to the boiler isnt also connected to the installation earth by some other means eg...

I can see were you are going with this BUT ...... While this might work as a debugging aid to something that you can put on the test bench & ensure that its has NO connections to anything else, that's so easy with the central heating. The cpc to the heating system is almost certainly connected...

I have to agree with this. We are having similar issues at work. Around 5 years ago the whole installation (roughly 200 5' single & twin fittings) was bulk replaced with IP65 LED battens. These started failing after a couple of years. At first we purchased the same fitting & swapped the gear...

I can confirm that "SDW" = South Derbyshire Water. I have the same one outside my house. The current day supplier is SevernTrent Water.

Did you read post #7 ???? :sneaky:

For a 3 phase motor, started direct-on-line, you can expect the starting current to be in the region of 6 times the motor rating plate current (ie. 6 x full-load-current)

22kW & 11kW are standard IEC motor sizes. If the OP is trying to determine the current for such motors then our methods above are too simplistic. The formulae that we have all used assumes a balanced resistive three phase load (ie. pf = unity hence kW=KVA & efficiency = 100%). This method...

22kW = 22/3 = 7.33kW per phase. At 230V 7.33 kW requires 7330/230 = 31.88A. So 22kW = 32A per phase.

And if you fit it..... you'll regret it the first windy night when is banging open & closed all night.... You'll be ripping it out in the morning! Spend the cash & buy a fan with an electrically operated shutter!

Yeah, but then it takes off..... If the low voltage causes the SMPS's to pull more current...... then the bigger current leads to a greater volt drop............

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Back in my Uni days (oh my THAT long ago!) we had 2A 3 pin sockets in the Halls of Residence. Each room had two sockets & they were grouped, I think, 4 rooms onto a 5A MCB. This was back in the late 1980s (!!!!!!!!) so no big PC setups, large screen TVs etc. The room came 'complete' with an...

On the MV & upward network exist numerical protection relays. These are too expensive to justify use on anything below about 33kV. A protection relay can be considered, in simple terms, as a sophisticated programmable "fuse". As well as clever over current protection they can often be configured...

Well you could, but I think you're gonna be disappointed with the performance. An immersion heater is 3kW. Your oil boiler - you'd have to tell us what size it is but probably in the regions of 15 - 20kW.....

Definitely! For my "day job" my employer builds & ships educational equipment to many countries, including the Philippines. Our standard config is 220V single phase & 220V L-L 3 phase for the Philippines. We are spoilt here in the UK in that we've all grown up with a system where is...