terry wrote:

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

Note we are assuming the OP means 4mm^2 cross section area and not 4mm
diameter wire here. The latter would be in excess of our 6mm^2 cable.

Perhaps comparison with the outside dimensions listed here might help:

http://wiki.diyfaq.org.uk/index.php?...n_Mains_Cables

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!!!!

Using the type of breaker we traditionally do, this would not usually be
considered a problem. It may be normal to specify a type C MCB to cope
with the motor inrush currents however.


--
Cheers,

John.

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