Long mains cable costing money ?

threedee

Ok. While i do understand basics of electricity i need for someone with professional background to answer me some questions...

Situation is as follows.
I live in a split-off portion of the house, which has power supplied via one cable, which in turn feeds 6 sockets directly, and loads low draw tech plugged into those (laptops, routers, tv, consoles, cfl lights), as well as some high drawing stuff which are not on for long (kettle, hoover, food nuker, etc).

At any time i usually draw about 0.25-0.7 kWh if no heavy drawers are on.

Since electrics are shared (don't ask) landlord started asking about me using too much leccy (which i'm not). He asked (allegedly) qualified electrician about this and he told my landlord that unusual consumption is caused by long split line that supplies my part of the house.

Now, i know that that IS an issue with VERY LONG cables, but as far i know mine is not long enough to cause resistance/overload issues. My split is ~50 meters off the house input (actual meter)... It is a fat stiff cable, not the usual domestic "extension" sort of affair.

Am i right to suspect that electrical "expert" (whom my landlord spoke to) is a cowboy ?

(P.S. to this part, i'm not about to dispute costs of electricity, all i want to know if this situation can SERIOUSLY influence power consumption ? )

Another question in a slightly different context - how safe is 50m extension (of the domestic type) ? I need to do some work in the garden using electrical tools. Can i chain several 8m extension leads ? (granted i'm not going to use anything over 13a, far from it...)

Andy_WSM

A long mains cable will not increase consumption so long as it is not getting hot! Then the "heat" is wasted power where the cable won't cope with the load running on it - and clearly a dangerous situation.

Your post starts reading as though you are running everything on an extension lead, then you mention "fat stiff cable" which suggests it's either a proper armored cable or a 6/8/10mm cable feeding a distribution board in your flat - this will have no effect on power consumption at all.

If you are being accused of using "excessive" power then look at what is being left on or on standby. Games consoles etc all use a surprising amount of power when you add up the total standby power.

Also, ask them to define what "excessive" is - this might be a fuss over nothing. Maybe the landlady didn't expect any increase (wrongly)?

Cardew

Yes he is a cowboy, or your landlord is telling porkies.

Obviously the cable needs to be of the correct cross section to cope with the load and be properly fused(protected) at the source.

For instance the recommendation for a cable to an electricr shower drawing up to 12.5kw(approx 50 amps) is that it should be 10mm up to a distance of 35 meters from the fuseboard.

However from the point of view of extra consumption because of the cable, the appliances at the end of the cable will still only draw their rated power and the only issue is the power consumed(dissipated) by the cable itself and that is tiny.(fractions of a watt)

Re the chain of domestic extension leads, it is obviously not good practice even assuming that the supply is RCD protected. However provided the extension leads are in good condition, and the leads are not put under strain(the temptation is to pull them from the end), the risk(IMO) is minimal. However the Health and Safety brigade would outlaw the practice!!