"DoN. Nichols" wrote in message
...
According to Chris :

"JohnM" wrote in message
...

[ ... ]

Use an electric motor, you won't have the fumes and won't have to stop
for
fuel. Just unroll the extension cord as you go to work and roll it back
up
again as you come home.

A variable frequency drive would allow you to use a 3phase motor and
have
speed selection, this would be an asset in traffic.

John

John,
Hate to bring up the normal response, but...

What gauge wire would that need to be for the extension?

The obvious response is:

How long does the extension cord need to be? :-) I figure just
over 15.5 A at a full 5 HP with a 240V line. You probably want no more
than a 10V loss over the length of the extension cord, so you want less
than 0.041 Ohms. So -- 4-0 wire would be pretty close at 1000 feet
total length (that is 500 feet away from the outlet).

0000 1000' total or 500' loop
#8 66' total or 33' loop
#6 104' total, or 52' loop
#16 10.3' total or 5.2' loop

If you insist on having 5 HP, you had probably better plan to
stick pretty close to home. :-)

Oh yes -- 4-0 (0000) is 640.5 pounds/1000 feet. :-)

Now -- you can reduce the current, and thus increase the
distance or reduce the gauge by stepping the voltage up high and
reducing it with a transformer on the bike -- but that would add enough
weight to neutralize the benefits. (Not to mention the extra cost of
high-voltage insulation on your extension cord. :-)

OK so since we are limited to 500Ft and a distance of 18miles I think I have
a solution. Granted the option of using a higher transmission voltage
cannot be used with this solution; neighbors do not have a high voltage lug.

What I am thinking is making friends with the neighbors. Granted not all
would be willing, but you could win them over with "I am saving the
environment". Better yet if the OP is in a liberal area as he will
definitely find some suckers there.

So:
18 miles * 5280 feet = 95040 feet
95040 / 500 (length of extension) = 190.08 neighbors.

For the sake of simplicity I think it is safe to assume at least one down
hill run and we can round the neighbors down to 190.

So 500 feet of cable and 190 kind neighbors allowing him to plug his bike
in. This now brings up the problem of cable return (How does he get the
cable back to plug it into the next house) . I would think some type of
geared rig to compensate for the 640lbs of cable and associated friction
could be rigged to the 5hp motor to coil the wire back up. Allowing him to
plug into the next house.

Problem is if the OP lives in a rural area with no or few neighbors. Than I
would suggest contacting the local power company. See if they would let you
climb the pole and hookup. This would also allow the use of a higher
voltage, thus a longer run. More info would be needed from the OP as to the
actual supply voltage along the streets on his route.


VFD would be nice, but lose about 1/3 of the HP on the motor. RPC might
be
a better choice.

Huh? How do you expect to lose 1/3 of the motor's horsepower
with a VFD? With a so-called "static" phase converter (which in reality
is a starting capacitor and the necessary switching to take it out once
the motor is started), yes -- you would lose about 1/3 of the motor's
horsepower rating.

OPPS Brain slip. I got static converters and VFDs confused. Good thing I
am not designing this thing.


Now -- you might want to over-rate the VFD a bit if you are
going to be drawing full rating from it for long. But even a 7.5 HP VFD
will weigh a lot less than the 5HP motor. I know, because I've got an
old one on my shop wall.

Enjoy,
DoN.

Tried looking up some rulings in the old NEC book, but cannot find any
reference to powered bicycles at all. At least the insurance company cannot
refuse ya if you get hurt on the thing.


--
Chris

If you can read this, thank a teacher. If it is in English, thank a
soldier. If it is in ebonics, thank your Congressman.