Author Topic: 3 Phase/Wild AC Wiring Question  (Read 2820 times)

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scaseley@eastlink.ca

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3 Phase/Wild AC Wiring Question
« on: November 25, 2014, 07:33:45 AM »
Hi, I am new to wind energy and am planning my first install.  I have purchased a 1600 watt turbine which produces 3 phase AC.  I am wondering if it is OK to use solid wire to bring the wild AC to the house where I will be installing the Rectifier and charge controllers, etc. 

I've read enough to know that DC need to use multistrand wire, but am wondering if I can use solid wire to bring the initial power to my house as I have a spool of 10/2 wire that is surplus that I would love to use for this 150 foot run to my house.

Any thoughts or suggestions will be greatly appreciated.

hydrosun

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Re: 3 Phase/Wild AC Wiring Question
« Reply #1 on: November 25, 2014, 11:24:37 AM »
The reason for multystrand wire is because low voltage dc is used in vehicles where vibration can cause solid wires to flex and break. In non moving locations it is fine to use solid wires.
chris

J0hann

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Re: 3 Phase/Wild AC Wiring Question
« Reply #2 on: November 25, 2014, 02:42:17 PM »
Just keep in mind that you need some flexibility connecting the turbine to your solid wiring.

kitestrings

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Re: 3 Phase/Wild AC Wiring Question
« Reply #3 on: November 25, 2014, 03:15:31 PM »
scaseley,

Welcome to the forum.  If you're running 3-phase from the turbine you will need three conductors.

You also didn't mention the voltage of the system.  If it is a 12V system, and 1,600w, you're looking at near 90 amps; at 24V it'd be near 46 amps, and at 48V maybe 23 amps.  In all but the latter, or if it is MPPT (where the voltage can be higher than the batteries) you will be over the ampacity of the wire.

Usually the size of the wire is determined not by limits of ampacity - #10 ga CU is good for 30 amps - but by the voltage drop over the distance you're going.  There are a number of voltage drop calculators on-line (if not on this board), you should try to limit the voltage drop to 2% ideally; and not more than 5%.

Solid or stranded wire will work with DC or AC.  Stranded is often used on vehicles as hydrosun mentioned and also on things like welding cables, battery bank wiring, and inverter (DC) wiring mainly because of flexibility, which may be why you're thinking it is associated with DC.

Hope this helps.  Good luck, ~kitestrings

tanner0441

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Re: 3 Phase/Wild AC Wiring Question
« Reply #4 on: November 25, 2014, 04:20:37 PM »
Hi

150 ft of solid wire is not a problem if it is underground in a conduit. If it is suspended on a catenery cable then swinging in the wind has to be considered, and the possibility of failure need to be considered. Also to be considered is the voltage of your system, as your just starting I would assume like most people your going for 12 V. A quick refference for copper conductors cross sectional area 2.5mm is 18mV/A/Mtr. 4mm is 11mV/A/Mtr.  6mm is 7.3mV/A/Mtr.

So you will see on the lightest cable you are going to get roughly 2.7 volts per amp on the length of your cable.

A junction box at both ends rigidly fixed with the solid wires connecting them would be OK, assuming the cable is appropriatly rated, I don't know the US wire sizes. The juction boxes could be connected with flexible cables to the local circuits.

As mentioned if the three phase wire is sent down the cables then you need three conductors if you rectify the three phase then you only need two.

Hope this helps...

Brian