According to William Wixon :
"Jean-Paul Roy" wrote in message
Could you show us your findings?
Jean-Paul
yes, thanks for your interest Jean-Paul. i wanted to post a drawing asking
for advise as to whether or not i wired it correctly. i made a drawing and
uploaded it to...
http://www.frontiernet.net/~wwixon/fwd-rvse.jpg
first i wired up the drum switch only just to the 4 wires coming from the
motor, i didn't hook the wires up to the pins inside the motor. got a
"hum/buzz" sound, obviously something wrong.
Yes -- you were getting power only to the start winding -- not
to either of the run windings. If you left it powered up, you would
either burn out the start winding -- or far more likely, you would blow
the innards out of the start capacitor. (If that happens, you will be
able to tell by the smell -- and start capacitors are cheap, at least. :-)
gambled that i needed to hook
the "hot" and "neutral" wires up to their respective pins (white-4
orange-1). i did that and it ran, whew, wow, yay!
my concern now is that because i didn't hook up the red and black wire to
any of the pins i'm doing something wrong and either will burn up the motor
or it won't generate it's rated horsepower.
Those extra pins (2) and (3) are isolated, and are there just
for convenience in connecting a remote switch or for connecting for 240V
operation.
It should give full rated horsepower -- but there are
significant problems here.
can anyone confirm that i did the wiring correctly? as far as i can see
none of the wires have any numbers printed on them or little numbered tags,
etc. (i've seen this in other electric motors).
1) You are switching the neutral That should not be done in US
practice, as it leaves parts of the motor floating high.
2) You have hot and neutral carried through to pins 1 and 4
Unswitched. This is also not how it should be done. The
unswitched hot is another safety problem, leaving the internals
of the motor hot while it is switched to stop -- and if a widing
grounds to the motor frame inside, it could either render the
motor housing and the lathe hot, thus risking shocking you. Or
-- if you have safety grounds connected (which you have not
shown) it can leave the motor drawing current, and perhaps burn
the (already damaged) windings up -- and possibly start a fire.
I spent some time posting a text description of how to wire for
240V -- but I don't see it yet, so I can't expect you to have seen it
either.
The first thing that I need to stress here is that you need to
run a safety ground wire from the motor to the case of the switch, to
the frame of the lathe, and on to the safety ground pin in the wall
plug. This wire should be green, and there are probably screws inside
the motor wiring box with their heads painted green, and maybe one in
the drum switch box (though that may be old enough so they didn't paint
the screw head green.)
If you really want to run on 120V (I forget what horsepower
rating this motor is, but a 1-1/2 HP motor run on 120V can sometimes
trip the circuit breaker on starting surges. 240V is by far the better
choice for something which you will be starting and stopping frequently
Your wiring shown probably would run -- but it is unsafe.
thanks.
(it does run forward and reverse and it *sounds* ok, but i'm no expert at
all.)
b.w.
(oh, trying to hook it up to 220 totally boggled my mind, i gave up on 220
and went with the 110.)
(even after reading the excellent information in the link provided by Glenn
i was still unable to figure out how to wire it up to 220.)
Check out what I wrote in the other article. I think that
should do it for you.
If you still have questions -- or can't find the article -- send
me an e-mail and I'll dive back into it.
But -- if you *really* want to run at 120V, let me describe how
to do it *safely*. I'm going to be assuming that the power is brought
into the drum switch as you have shown in your fwd-rvse.jpg image.
I'm also going to label the switch terminals as follows:
(A) (B)
(C) (D)
(E) (F)
so I can talk about them, and you can sketch them out on paper if you so
desire.
1) First -- connect the black motor wire to motor terminal(3), and
the Red motor wire to motor terminal (2). There is nothing else
in the motor connected to these pins -- they are there only for
your convenience in such things as this. These two wires are
the start winding -- internally connected to the actual winding,
the capacitor (under the bulge), and the centrifugal switch.
This winding is 120V only -- though there is a trick which makes
it work in the motor wired for 240V.
2) Run wires from these two terminals to switch terminals (A) and
(D).
3) Connect the motor's orange wire to the motor's terminal (1) and
the motor's white wire to the motor's terminal (4). These get
left connected. They complete the connection of the two run
windings in parallel for 120V operation. You don't need to run
them out of the motor case at all.
3) Run the hot power line wire to switch terminals (C) and (E).
4) Run the neutral power line wire to switch terminal (B) and to
motor terminal (4).
Yes -- I said not to switch neutral -- but this is necessary to
reverse the start winding in 120V mode -- and at the same time,
the other side of the start winding is also disconnected from
the hot.
5) Run the switch terminal (F) to motor terminal (3).
And this should give you reversing operation at 120V. (As
suggested above -- 240V operation would probably be a better choice, and
that would be covered in my other article -- which you may be reading as
I type this one. :-)
Part of the problem here is that the motor's wiring scheme is
tailored to cookbook instructions, and actually hides the information
about what is inside. I wonder whether they have wiring instructions
for each brand of drum switch in addition to what instructions you found,
which were assuming that you either wanted the motor to always run
clockwise or always wanted it to run counter-clockwise -- and had no
need to switch it between those (which is what three-phase motors are
for, after all. :-)
Let's try to sketch what is actually in that motor -- using "(#)"
to indicate a numbered terminal, and "(C)" to indicate a colored wire.
Note also that I use only numbers 1 though 4, so 'O' is a letter --
orange wire, not a number.
+----------------------------------------+
| |
| (1)+WWWWWWWWW-(W) |
| |
| (2) |
| |
| (3) |
| |
| (4)-WWWWWWWWW+(O) |
| |
| (B)-WWWWWWWWW--)|-o/o-(R) |
| |
+----------------------------------------+
"-)|-" is the capacitor
"-o/o-" is the centrifugal switch.
"-+WWW-" is a motor winding.
The '+' in a motor winding shows the start of the winding, which
is important when connecting them in series or in parallel.
(Part of what is hidden by the design of the motor's terminal
plate.)
Note that terminal (2) and (3) show *nothing* connected to them.
This is exactly how it is. They are there so you don't have to
splice wires together and wrap it all in electrical tape.
So -- when you connect to the (W) and (O) wires, and nothing to
the (1) and (4) terminals, other end of each winding is
connected to nothing, so no current is flowing.
If you connect (W) to (4), and (O) to (1), then the two run
windings are connected in parallel, and they both get full 120V
from connections to (1) and (4).
If you connect (W) and (O) together, the two run windings are
connected in series for 240V operation. This is done in the
motor drawings which you posted by connecting both of these to
terminal (3), which is otherwise doing nothing. This still
leaves terminals (1) and (4) for the incoming power.
However -- this center point (3) also has a voltage which is
120V different from either end of the incoming power, so it can
be used to power that 120V start winding. And each of these
windings has only 120V across it, even though you have 240V
connected to the motor.
I hope that this helps.
Enjoy,
DoN.
--
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