50m extension cable

[JohnW2]

How about, for example, a storage heater? I was told that a FCU was not suitable for one with 3x 850w elements, as if the voltage dropped, the current would increase and blow the fuse (potentially). (Sorry I am going a little off topic here.)

A storage heater uses entirely resistive heating elements, at least every one I've seen. Ohm's law will hold with a simple resistive load, and the current will drop as the voltage reduces.

Indeed so.

Of course, if the resistive load is, say, thermostatically controlled, then the lower voltage (hence lower current) will result in the current flowing for a greater proportion of the time - potentially (if the control is perfect and the capacity of the heater adequate) to the extent of consuming the same amount (e.g. kWh) of electricity as would been the case with a higher voltage and current (but 'switched on' for less of the time).

Kind Regards, John

 

[DrGonzo]

would 4x10mm2 cable be ok just to run a few lights, phone charger, fridge?

 

[winston1]

Yes, but 1.5KW is the running current. the pump will pull more than double that when it starts up.

Just to put this into context. 1.5mm² cable is what is used in many houses just for the lighting circuits.

3000W/240V = 12.5A?
So it may or may not burn the fuse in the actual plug?

This is Spain. The voltage is 220v, not 240v (if you are lucky). Assuming Spanish devices 3000/220=13.64amps.
No fuses in the plugs either. It is probably on a 16amp MCB.