Wiring and Connections Best Practices¶
Polarity¶
The polarity of the installed hill wire at Mammoth Mountain is inconsistent from venue to venue and sometimes from timing box to timing box. However, keeping consistent conventions for start an finish connections can cut down on some of the confusion.
The double banana plug connectors found on most wires have a protruding tab on one side. If the plug is not taped you can see ‘GND’ imprinted on this tab.
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When plugging into timing boxes or shack timing boards this tab should always go to the right. The wire will then be on the top of the plug.
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When using single plugs, the black plug should always be the ground and go on the right, and the colored plug should always go on the left.
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Securing Connections¶
Banana Plug to Timing Box¶
After inserting the plugs into the box following the polarity guidelines above, secure the cable to something solid near the box using tape. This could be a tree branch, part of the box or the hill wire, or if nothing else is available a piece of bamboo.
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Securing the cable near the box prevents the plugs from pulling out unexpectedly.
Banana Plug to Banana Plug¶
Tape the two plugs together to prevent accidental disconnection.
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Wrap tape around the exposed metal plugs to prevent shorts.
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Securing Wire Runs¶
Wire runs should be protected from weather and traffic at all times. They can be run along a fence where possible, or attached to bamboo poles if it is in an area that is safe to do so. In high traffic areas wire should be flown high on double bamboo or buried underground. Whenever possible, avoid tying knots in the wire. A clove hitch will secure a wire to a piece of bamboo, but it will also put unnecessary strain and wear on the wire, reducing its reliability.
To a fence¶
Insert a loop of wire through a top fence square just downhill of a pole.
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Loop the wire over the pole
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On bamboo¶
Use tape.
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If using bamboo, make sure it is in a safe location. Bamboo is not safe anywhere on course or in the finish area, or in an area where it could be hit by public skiers at high speed.
If there will be high foot traffic around the wire, such as in a start area, use a double stick of bamboo to allow people to walk underneath
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Under the snow¶
In high traffic areas where safety is paramount, such as a finish area, trenching the wire underground is the best. This is most easily done with a chainsaw.
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