Generator

[Tim W]

andrew wibbled on Saturday 09 January 2010 22:59

You can get bigger ones, 63A for example and I think double that too. I expect the latter would be a big bastard though.

Yes - I did mention consideration should be given to RCD protection 9and earthing, also echoed by Andrew).

Interestingly, the Briggs and Stratton transfer switch contains its own RCD.

Either have to incorporate an inline RCD into the generator lead, stick an RCD plug on the boiler feed (less desireable if the circuit is already RCD protected) or if you laid in a second socket and a dedicated feed cable to an outside hookup point, stick the RCD in that (or use and RCD socket).

[geoff]

In message , Tim W writes

I would say that its more the design of the electronics in the boiler

e.g. Lets take the good old suprima vs the worcs 24i

The Suprima uses r-c voltage dropping and not much filtering, its very susceptible to crap coming down the mains

The 24i uses a transformer -regulator LV supply which is less prone to masins variations

As to absolute sensitivity to fluctuations and transients, its not something I've spent much time investigating

[js.b1]

To add, if you go the UPS route, realise whilst SmartUPS are probably the best can not be "fiddled" by sticking bigger batteries to them. The internal components are sized accordingly (this was barely the case on the BackUPS Pro, but still applies to the SmartUPS). The XL range of SmartUPS will handle additional batteries according to specs.

You may need to set the UPS to transformer trim/boost rather than battery (or the battery might actually deplete) and set the voltage sensitivity to low (some have a push-button on the rear, others software).

Using a BS4343 appliance inlet to the house for the generator to a BS1363 socket on the inside is probably simplest and safe, just make sure the socket inside is never connected to the house wiring - otherwise the pins on the BS4343 appliance inlet plug will be live (output) vs dead (input)!

[Bob Eager]

Most (if not all) SmartUPS will also do a black start.

[Doctor Drivel]

He doesn't need UPS and they are not cheap. What I described is about the cheapest to have essential circuit backup - he is in an area prone to power cuts so well worth installing the extra CU throw over switch. Just started the genny and throw the throw-over switch for the genny to supply the essential circuits. The genny costs around £200 for a 3kW model on two wheels, and can be hung on the wall in the garage.

[Doctor Drivel]

Maxie that was fantastic. Were you playing in the Paddy Band last night? Just as well you had your turned down wellies on.

[Doctor Drivel]

A 32A throw-over switch for £36:

[Dave Liquorice]

Explain further please. Lead acid are constant voltage charge, larger (as in capacity) batteries will just take longer to charge and longer to discharge. AFAIA the UPS just monitors battery voltage to determine state of charge/discharge. Bigger batteries won't fit in the box but that's not a great problem, just bear in mind the current draw and size the cables accordingly.

Via offical add on battery packs.

[js.b1]

1 - Charge circuit is sized to the expected battery size. The charge circuit gets warmer the longer it takes to charge. 2 - Transformer etc are sized to the expected battery size. The transformer etc gets warmer the longer it is on battery.

If in doubt, email Andy Whitfield who will advise which SmartUPS you can 1) oversize batteries with 2) link several batteries to (it is not just the XL series, I think 2200 & 3000 tolerated "expansion"). I suspect the larger models with a fan.

Recent SmartUPS will black start (cold start) if the button is held down - some of the older models refused. If it refuses drop the load until it has powered up particularly if the batteries are not new.

[Tim W]

Doctor Drivel wibbled on Sunday 10 January 2010 14:06

circuits which is an excellent idea, but that will cost a fair bit if you need to pay someone to do it.

Otherwise, you will need a 60A, 80A or 100A switch (depending on your incoming circuit protection aka main cutout fuse) and they are more like

71+VAT (which you helpfully omitted) or more for a 100A.

Otherwise, to save money:

1 hacksaw blade broken in half for the two knife blades 20p 1 bit of plywood 1x1 foot approx from the B&Q scrap bin 50p 1 more blade broken into 2" lengths, heated, bent and retempered, and nailed to ply for the contacts 20p

Bit of 22mm speedfit for the handle (hint, try your scrap bin of all the bits that leaked free

Random nails bent for blade pivots and to nail contacts 1.00

Youtube video of you operating it priceless

[Bob Eager]

20p

I think copper tube would be better for Drivel. Don't need to insulate it...

[Doctor Drivel]

Essential circuits fed from a 3kW genny needs 60A switch. Another idiot.

[Andrew Gabriel]

Good point. Capacitive droppers used in things like programmers are going to pass more current, and the voltage regulator will run hotter. (I don't have one, as my heating and hot water are driven by a home automation system.) The boiler I've done this with is a Potterton Profile, and that runs fine on my cheap inverter. The pump makes a different noise, but seems to work fine (or at least well enough not to cause any problem). I guess the mid- position valve worked, but I didn't think to explicitly check.

What didn't work was the cigarette plug on the inverter - it got just as hot as the heating system;-) I replaced it with a couple of spade terminals and matching binding posts. It's hard to find good high current 12V connectors. I bought a few different ones, but on inspection they were all crap.

[Tim W]

Doctor Drivel wibbled on Sunday 10 January 2010 15:11

And the cost of segregating the essential services? Re-incarnation theory says you are going to be a bat in the next life - because you are already blind enough...

[Doctor Drivel]

Maxie, you have a thing about him don't you? Does he watch you in the Paddy band?

[Doctor Drivel]

A throw-over switch a CU and some other bits. Easy!!! If you are a rural area prone to outages it is the best bet - and the cheapest.

[Tim W]

Doctor Drivel wibbled on Sunday 10 January 2010 17:01

"and some other bits"...

Suddenly we seem to be getting as expensive as a 100A transfer switch...

But you're not great on the logic front are you?

[Doctor Drivel]

You really do not get it, you are so dumb.