what would happen if i ran an electicity overhead cable,20 meters long between house and garage unsupported?

Question

it would be a heavy duty cable,it meets the required standard and more.

Answer 1

Best go underground in a plastic conduit, overhead is unsightly and dangerous if not done by an experienced electrician but despite the above answers it is still used today with the correct type of cable or catenery wire

Answer 2

As mentiond by a few other respondent, there are building regulations, etc to abide by. Assuming that you meet those or don't care. Then do as was suggested and use a supporting cable, or for a much neater and simpler solution: use proper overhead high tensile cable. It has UV resitant insulation which is also weather resistant. The local power authority here regularly uses it to span over 40m. Fasten the cable at each end with the correct fasteners, ie heavy metal hooks and cable holders designed to transfer the tension from the cable to the hook without damaging the cable and it will work a treat. This type of cable is generally only 2 core, 6squ mm cross section or more. You will have to string a separate earthwire or earth the building in question separately. You should also have a mains switch and fuse box in the building being connected for safety. Likewise the source connection should have its own separate breaker or fuse.

But all of that sort of depends on what you want the power for. If its just light and to charge the battery, you might be better off with a low voltage cable, and add an inverter if you really need a bit of 240V. With a low voltage cable you avoid most of the rules and regulations.

All that being said, I have used steel carrier cables (high tensile fencing wire) to support cables and they have survived 10+ years in high winds and tropical down pours. I have on occassion also used poorly insulated separate wires, ie separated by air (3 ft apart) active, neutral and earth, over some considerable spans to power remote machinary such as bore pumps. Not elegant, but necessity is mother of invention, and when you're desparate you use what you have. Keep it well above any place any one can reach. Hey even use long extention cables to provide power on a temporary basis, not recomended as the weather gets to the insulation after a while, and they are expensive to replace.

Mind if you fail to follow local regulations and something later goes wrong you are in BIG SH*T. Even when it wasn't your fault!
Eg. Your house burns down from some other cause, but the insurance won't pay up as it might have been that illegal power connection.
Your neigbour gets cranky because of your noisy hamster so reports your illegal connection to the authorities.

Answer 3

The risk is that if not supported the cable would sag and if in a high winds undue force could be put on the connections to the electricity at either end.To be safe I would stretch a steel wire between the house and the garage and anchor it at either end. Suspend the electrical cable from this supporting it every couple of feet or so with either plastic ties or tape.This would make sure of the safety issue and should be relatively easy to do.Holding the cable up also means it is not so easy to foul when passing beneath it with perhaps a ladder or similar., or you may be driving the car beneath it.

Answer 4

the weight would tear it loose at the points where it was attached on either end
with the wind ,rain or a big bird sitting on top
you need a pole every 10 meters minimum so one pole in the centre might do it or 2 on the sides if there is a street in the middle

Answer 5

you'd be breaking the building regulations unless you were a proper electrician, also it sounds like it would be too heavy to be unsupported so it droop to the ground. Anyway why would you want to do this?

Answer 6

you would get electricity from the house to the garage

Answer 7

Try it and see. If it droops too low, take it down, if not, power it up. It isn't rocket science!

Answer 8

it will be somewhere for the birds to sit