50m extension cable

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DrGonzo

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This is actually for Spain.
Until the electricity company reconnect our meter (taken away due to building licence expiration even though it has now been extended), we have agreed with a neighbour to temporarily use his electricity supply.

Will a 50m cable suffer any voltage drop?
We were planning to connect it from his house and use it to connect a refrigerator, 2 lights, and maybe a pool pump (1.5kW).
 
I am not up on Spanish electrics but any cable will have some volts drop across its length. You need to select a correct cable size and have the appropriate physical and electrical protection in place.

May be worth checking on local phases as well, in the UK it is very common for adjacent properties to be on different electrical phases and running cables between such is highly dangerous !
 
Cabbyfan said:
I am not up on Spanish electrics but any cable will have some volts drop across its length. You need to select a correct cable size and have the appropriate physical and electrical protection in place.

May be worth checking on local phases as well, in the UK it is very common for adjacent properties to be on different electrical phases and running cables between such is highly dangerous !
Click to expand...

ould 2 of the 25m ones work?
http://catalogo.aki.es/electricidad/alargos_bases-y-enrollacables/enrollacables

re:phases they are both new houses installed by same electrician so likely to be the same
 
DrGonzo said:
re:phases they are both new houses installed by same electrician so likely to be the same
Click to expand...
That will be the choice of the supply company. NOT the electrician! You get what you are given. My house is on a different phase to the house next door.

Back to your original query. ALL cables suffer volt drop, it is a factor of the thickness of the cable, the length and the current being drawn.
The less the curent is, then the less will be the voltage drop.

The cables you have linked to are 1.5mm² and that's not very thick at all. It would probably be OK for your lighting + the fridge but a 1.5KW pump might be OTT - and you don't want the Cervezas to get warm, do you?
 
Taylortwocities said:
DrGonzo said:
re:phases they are both new houses installed by same electrician so likely to be the same
Click to expand...
That will be the choice of the supply company. NOT the electrician! You get what you are given. My house is on a different phase to the house next door.

Back to your original query. ALL cables suffer volt drop, it is a factor of the thickness of the cable, the length and the current being drawn.
The less the curent is, then the less will be the voltage drop.

The cables you have linked to are 1.5mm² and that's not very thick at all. It would probably be OK for your lighting + the fridge but a 1.5KW pump might be OTT - and you don't want the Cervezas to get warm, do you?
Click to expand...

1.5kW should only be about 6/7A though so what thickness cable do I need for that? Surely a standard 13A would cover it?
Would put pump on for a few hours, then plug fridge back in.
 
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.
 
Taylortwocities said:
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.
Click to expand...

3000W/240V = 12.5A?
So it may or may not burn the fuse in the actual plug?
 
Cabbyfan said:
May be worth checking on local phases as well, in the UK it is very common for adjacent properties to be on different electrical phases and running cables between such is highly dangerous !
Click to expand...

Not highly dangerous, just not idiot proof. Many properties on the continent have a 3 phase supply anyway.
 
phatboy said:
JohnW2 said:
It shouldn't, but 12.5A through 50m of 1.5mm² cable would result in a voltage drop of around 18V.
Click to expand...
Resulting in an end voltage of 222v 3000W/222V = 13.5A = overheating cable and possible fuse blow
Click to expand...
It doesn't work like that. Lower voltage delivered to the load would result in lower, not higher current. Anyway, don't forget that we're only talking about the very brief start-up current of the pump - running current will be about half that.

In any event, 13.5A, even if it were that, is well within the current-carrying capacity of 1.5mm² flex, and nowhere near the current that would blow a 13A fuse.

Kind Regards, John
 
JohnW2 said:
It doesn't work like that. Lower voltage delivered to the load would result in lower, not higher current.
Click to expand...

Really? I thought the end device would still require the same wattage, so the amps would increase when the voltage dropped.
 
phatboy said:
JohnW2 said:
It doesn't work like that. Lower voltage delivered to the load would result in lower, not higher current.
Click to expand...

Really? I thought the end device would still require the same wattage, so the amps would increase when the voltage dropped.
Click to expand...

That depends on what the end device is..

A simple motor, or pump, or typical light fixture, will simply use less power. On the other hand, something with an active power supply (a light fixture with a constant-power driver, a computer power supply, and so on) will end up drawing more current to compensate.
 
Monkeh said:
phatboy said:
JohnW2 said:
It doesn't work like that. Lower voltage delivered to the load would result in lower, not higher current.
Click to expand...

Really? I thought the end device would still require the same wattage, so the amps would increase when the voltage dropped.
Click to expand...

That depends on what the end device is..

A simple motor, or pump, or typical light fixture, will simply use less power. On the other hand, something with an active power supply (a light fixture with a constant-power driver, a computer power supply, and so on) will end up drawing more current to compensate.
Click to expand...

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.)
 
phatboy said:
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.)
Click to expand...

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.

Assuming those elements are rated at 230V, even if you increased the voltage to 250V, you would only be at 12A.
 
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