Are you sure you're talking about rcd's/ rccd's ( residual current device) ? The usual trips you see ( should) in the fusebox are called mcb's. (Micro circuit breakers.) And they replaced one's that used fuse wire

You only need one RCD per premises.
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Your right, but if you have one on every circuit is easier to track down where you have a problem ,, and if you have one with a meter, [ as shown ],, to each room or air-co , you know how much electricity is being used on that circuit.


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Are you positive that's an rcd Duncan? Because it's only 10 amp and looks like an mcb.
If you find you haven't got an rcd installed it's worth putting one on the main supply where it comes in, before it goes into the fuse box. It should say rcd or rccd on it.
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There is another 30 amp ? on the main fuse box with all the other fuses and main switch. [ inside the house .]

AE86 wrote: ↑Mon May 29, 2017 3:13 pmSo all in with "high quality" components I'm in about $170 for the parts, not including the voltage stablisier and battery backup inverter.

For those wondering, the 5KVA stabiliser was $90 (Chinese brand), and the battery backup was around $500 I believer, $340 for the batteries and $160 or $180 for the inverter (3000 watt) I think, maybe a 5000.

Oh, NOW it gets more interesting - are you running that backup system inline, or switching on demand?

^^The inverter is an auto switching unit like in a UPS, fed from the mains. It's only going to be hooked up to one room though and isn't meant to supply the entire building if that's what you mean by inline.

AE86 wrote: ↑Mon May 29, 2017 4:49 pm ^^The inverter is an auto switching unit like in a UPS, fed from the mains. It's only going to be hooked up to one room though and isn't meant to supply the entire build if that's what you mean by inline.

An Australian guy tried to sell me his setup for $600, including an inverter/regulator/conditioner from Australia, and a bank of truck batteries, but it was only a switch-on-demand system. For the amount of computer gear I run I was looking for a whole-house solution. I'd also have had to rewire the whole house, or much of it, to make it work. Good luck with your build.