On Jun 14, 7:11*pm, "Steve Walker" wrote:
GC wrote:
Guys

Posting from sunny New Zealand. Getting a spa pool delivered soon and
just had wiring done.

Specs say it needs 32amp. It has 2 pumps rated at 2.25KW each. *A
blower at 700w and a circ pump at 0.25 kw. Reckon that should be
everything if all switched on at same time...

Importer who sold it to me said his was running on a 40amp MCB and 6mm
square cable....Sparkie who just did a homer used 4mm square cable
instead saying it was ample. Two core and earth - PVC sheathed.

That's the optional underpatio heating version.... *)

Voltage not mentioned but assuming it's 230 volts? Single phase?
Using some North American design tables for the wire gauge closest to
4mm diam. it looks like voltage drop (with everything on) will be
about 2% or roughly 5 volts. Wire length being twice 23 metres
(roughly 140 feet).
However a 40 amp breaker seems to be 'close to the wire' (pun
intended!).
Cos if you add up all the normal running wattages, ignoring start up
surges of pump motors and also that heaters until warmed up draw more
current one gets something of the order of 8.5 kilowatts? That's
around 37 amps!!!!
So if a 50 amp breaker then needed, to avoid trip outs, it may be
necessary to comply with local wiring/insurance codes to use another
(heavier gauge) of wire?
Seems wise that you are checking. Not sure what's the legal or
insurance liability outcome of knowingly installing inadequate wiring,
to local code, would be, in your part of the world.