Motor running the wrong way
 

A friend asked me to come and help him swap the motor on a small table
saw today. Anway the new motor was already in when I arrived - much the
same location as the previous one, with pullys and belt suitably set and
adjusted. So I wired it up via a NVR switch with built in adjustable
current trip, plugged it in, pushed the button, and it all sprang into
life.

Then we noticed the saw blade was going round the wrong way!

The motor is about 1.5hp I would guess looking at the size of it. It was
reclaimed from something else and hence the original plate lable is now
mostly unreadable.

I am not sure what type of motor it is, but there is no external start
capacitor visible. Also when it spins up I could not hear a click from a
centrifugal switch (not that this is any guarentee that it does not have
one).

So taking the cable entry plate off reveals six connection studs - one
of which is earth. The others are arranged thus (the letters are those
marked by each stud):

# Z # T


# S


# A # Az

The incoming mains is currently connected to A (Neutral) and Az (Phase)

In addition there are also wires that emerge from the motor body and
connect to the terminals:

A Red and Black (+ mains in Neutral)
Az Red and Red/Blue linear stripe (+ mains in phase)
S 2 of Red/Green radial stripe
Z Black and 2 of Red/Green radial stripe
T Red/Green radial stripe and White

The red and black wires have a little slack in them and look as if they
could be repositioned to alternative connection points.

Sugestions for an alternate wiring pattern to get it spinning in the
other direction?


--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

Motor running the wrong way
 

John Rumm wrote:

Sugestions for an alternate wiring pattern to get it spinning in the
other direction?



Is there room for a longer belt and twist it through 180 degrees between
the pulleys?

--
Howard Neil

Motor running the wrong way
 

Howard Neil wrote:

John Rumm wrote:

Sugestions for an alternate wiring pattern to get it spinning in the
other direction?



Is there room for a longer belt and twist it through 180 degrees between
the pulleys?

We did consider that, and I guess it will be the practical solution if I
can't find an electrical one. It would mean rotating the motor a bit
though to prevent the belt rubbing on itself though.

--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

Motor running the wrong way
 

"John Rumm" wrote in message
...
Howard Neil wrote:

John Rumm wrote:

Sugestions for an alternate wiring pattern to get it spinning in the
other direction?



Is there room for a longer belt and twist it through 180 degrees between
the pulleys?

We did consider that, and I guess it will be the practical solution if I
can't find an electrical one. It would mean rotating the motor a bit
though to prevent the belt rubbing on itself though.

Try asking in uk.rec.models.engineering. Lots of people in there who play
with lathe motors and it must be a common enough problem.
--
Dave Baker
www.pumaracing.co.uk
"Why," said Ford squatting down beside him and shivering, "are you lying
face down in the dust?"
"It's a very effective way of being wretched," said Marvin.

Motor running the wrong way
 

John Rumm wrote:

In addition there are also wires that emerge from the motor body and
connect to the terminals:

A Red and Black (+ mains in Neutral)
Az Red and Red/Blue linear stripe (+ mains in phase)
S 2 of Red/Green radial stripe
Z Black and 2 of Red/Green radial stripe
T Red/Green radial stripe and White

The red and black wires have a little slack in them and look as if they
could be repositioned to alternative connection points.

Hmm, I've not seen one like that before. Sometimes there's a wiring
diagram on the rating plate or inside the terminal box. Any
manufacturer's name?

Failing that I'd be inclined to disconnect everything (having first
carefully noted ...) and sit down with an ohmmeter and identify which
pairs are the ends of individual coils. You seem to have 11 'ends' - so
there must be at least one tapped winding or double lead-out (possibly
before and after a thermal fuse or PTC device at the end of one winding,
if it's modern enough to have such things).

Essentially/usually there will be two windings (possibly made up of
multiple coils in series) across the mains - one permanently and one via
the centrifugal switch and/or series capacitor. If you reverse either
of the two it should run in the other direction. (HTH, IME, YMMV.)

--
Andy

Motor running the wrong way
 

"John Rumm" wrote in message
...
A friend asked me to come and help him swap the motor on a small table saw
today. Anway the new motor was already in when I arrived - much the same
location as the previous one, with pullys and belt suitably set and
adjusted. So I wired it up via a NVR switch with built in adjustable
current trip, plugged it in, pushed the button, and it all sprang into
life.

Then we noticed the saw blade was going round the wrong way!

The motor is about 1.5hp I would guess looking at the size of it. It was
reclaimed from something else and hence the original plate lable is now
mostly unreadable.

I am not sure what type of motor it is, but there is no external start
capacitor visible. Also when it spins up I could not hear a click from a
centrifugal switch (not that this is any guarentee that it does not have
one).

So taking the cable entry plate off reveals six connection studs - one of
which is earth. The others are arranged thus (the letters are those marked
by each stud):

# Z # T


# S


# A # Az

The incoming mains is currently connected to A (Neutral) and Az (Phase)

In addition there are also wires that emerge from the motor body and
connect to the terminals:

A Red and Black (+ mains in Neutral)
Az Red and Red/Blue linear stripe (+ mains in phase)
S 2 of Red/Green radial stripe
Z Black and 2 of Red/Green radial stripe
T Red/Green radial stripe and White

The red and black wires have a little slack in them and look as if they
could be repositioned to alternative connection points.

Sugestions for an alternate wiring pattern to get it spinning in the other
direction?

That is why I like three phase. Every motor is guaranteed to start up in the
wrong direction, but you only have to swap any two wires to get it going the
right way.

Colin Bignell

Motor running the wrong way
 

"John Rumm" wrote in message
...
A friend asked me to come and help him swap the motor on a small table saw
today. Anway the new motor was already in when I arrived - much the same
location as the previous one, with pullys and belt suitably set and
adjusted. So I wired it up via a NVR switch with built in adjustable
current trip, plugged it in, pushed the button, and it all sprang into
life.

Then we noticed the saw blade was going round the wrong way!

The motor is about 1.5hp I would guess looking at the size of it. It was
reclaimed from something else and hence the original plate lable is now
mostly unreadable.

I am not sure what type of motor it is, but there is no external start
capacitor visible. Also when it spins up I could not hear a click from a
centrifugal switch (not that this is any guarentee that it does not have
one).

So taking the cable entry plate off reveals six connection studs - one of
which is earth. The others are arranged thus (the letters are those marked
by each stud):

# Z # T


# S


# A # Az

The incoming mains is currently connected to A (Neutral) and Az (Phase)

In addition there are also wires that emerge from the motor body and
connect to the terminals:

A Red and Black (+ mains in Neutral)
Az Red and Red/Blue linear stripe (+ mains in phase)
S 2 of Red/Green radial stripe
Z Black and 2 of Red/Green radial stripe
T Red/Green radial stripe and White

The red and black wires have a little slack in them and look as if they
could be repositioned to alternative connection points.

Sugestions for an alternate wiring pattern to get it spinning in the other
direction?



It may sound silly but, is it possible you have fitted the saw blade the
wrong way around?

--

Neil

Motor running the wrong way
 

John Rumm wrote in message
...
A friend asked me to come and help him swap the motor on a small table
saw today. Anway the new motor was already in when I arrived - much the
same location as the previous one, with pullys and belt suitably set and
adjusted. So I wired it up via a NVR switch with built in adjustable
current trip, plugged it in, pushed the button, and it all sprang into
life.

Then we noticed the saw blade was going round the wrong way!
snip

when I had this problem and after spending hours with a dvm and hundreds of
bits of paper diagrams,
I gave up and took it to an electricmotor re-winders, 10sec later and two
swapped wires job done.
http://tinyurl.com/okeen



-

Motor running the wrong way
 

Mark wrote:
John Rumm wrote in message
...
A friend asked me to come and help him swap the motor on a small table
saw today. Anway the new motor was already in when I arrived - much the
same location as the previous one, with pullys and belt suitably set and
adjusted. So I wired it up via a NVR switch with built in adjustable
current trip, plugged it in, pushed the button, and it all sprang into
life.

Then we noticed the saw blade was going round the wrong way!
snip

when I had this problem and after spending hours with a dvm and hundreds of
bits of paper diagrams,
I gave up and took it to an electricmotor re-winders, 10sec later and two
swapped wires job done.
http://tinyurl.com/okeen



-

Though I cannot answer your question I have a garden shredder, a switch
reverses the motor, so I guess it is a wiring error.

Motor running the wrong way
 

"John Rumm" wrote in message
...
A friend asked me to come and help him swap the motor on a small table saw
today. Anway the new motor was already in when I arrived - much the same
location as the previous one, with pullys and belt suitably set and
adjusted. So I wired it up via a NVR switch with built in adjustable
current trip, plugged it in, pushed the button, and it all sprang into
life.

Then we noticed the saw blade was going round the wrong way!

The motor is about 1.5hp I would guess looking at the size of it. It was
reclaimed from something else and hence the original plate lable is now
mostly unreadable.

I am not sure what type of motor it is, but there is no external start
capacitor visible. Also when it spins up I could not hear a click from a
centrifugal switch (not that this is any guarentee that it does not have
one).

So taking the cable entry plate off reveals six connection studs - one of
which is earth. The others are arranged thus (the letters are those marked
by each stud):

# Z # T


# S


# A # Az

The incoming mains is currently connected to A (Neutral) and Az (Phase)

In addition there are also wires that emerge from the motor body and
connect to the terminals:

A Red and Black (+ mains in Neutral)
Az Red and Red/Blue linear stripe (+ mains in phase)
S 2 of Red/Green radial stripe
Z Black and 2 of Red/Green radial stripe
T Red/Green radial stripe and White

The red and black wires have a little slack in them and look as if they
could be repositioned to alternative connection points.

Sugestions for an alternate wiring pattern to get it spinning in the other
direction?



I assume this is a single phase motor with a capacitor housed in a power
bulge. Can you confirm?

If so there'll be 2 windings, 1 powered directly with mains the other
indirectly through a capacitor. If the 2 windings are identical then the
capacitor may be swapped from one winding to the other. If they are not
identical it can't be reversed without overheating and/or loss of
performance.

Motor running the wrong way
 

Fred wrote:

I assume this is a single phase motor with a capacitor housed in a power
bulge. Can you confirm?

Yes, single phase. In fact it has two "power bulges" on the top at 11
and 1 o'clock.

If so there'll be 2 windings, 1 powered directly with mains the other
indirectly through a capacitor. If the 2 windings are identical then the
capacitor may be swapped from one winding to the other. If they are not
identical it can't be reversed without overheating and/or loss of
performance.

I presume reversing the supply to either one of the windings would also
do it...

--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

Motor running the wrong way
 

"John Rumm" wrote in message
...
Fred wrote:

I assume this is a single phase motor with a capacitor housed in a power
bulge. Can you confirm?

Yes, single phase. In fact it has two "power bulges" on the top at 11 and
1 o'clock.

If so there'll be 2 windings, 1 powered directly with mains the other
indirectly through a capacitor. If the 2 windings are identical then the
capacitor may be swapped from one winding to the other. If they are not
identical it can't be reversed without overheating and/or loss of
performance.

I presume reversing the supply to either one of the windings would also do
it...


Ooops yes it would! Best way to do it.

Motor running the wrong way - resolved
 

Mark wrote:

when I had this problem and after spending hours with a dvm and hundreds of
bits of paper diagrams,
I gave up and took it to an electricmotor re-winders, 10sec later and two
swapped wires job done.

My mate did as you suggested, and they swapped over the red wires on A
and Az - sorted.


--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

Motor running the wrong way
 

In message , John
Rumm writes
Fred wrote:

I assume this is a single phase motor with a capacitor housed in a
power bulge. Can you confirm?

Yes, single phase. In fact it has two "power bulges" on the top at 11
and 1 o'clock.

If so there'll be 2 windings, 1 powered directly with mains the other
indirectly through a capacitor. If the 2 windings are identical then
the capacitor may be swapped from one winding to the other. If they
are not identical it can't be reversed without overheating and/or
loss of performance.

I presume reversing the supply to either one of the windings would also
do it...

I have it on good authority that if you took it south of the equator, it
would turn the other way

--
geoff

Motor running the wrong way
 

John Rumm wrote:
Fred wrote:

I assume this is a single phase motor with a capacitor housed in a
power bulge. Can you confirm?

Yes, single phase. In fact it has two "power bulges" on the top at 11
and 1 o'clock.

If so there'll be 2 windings, 1 powered directly with mains the other
indirectly through a capacitor. If the 2 windings are identical then
the capacitor may be swapped from one winding to the other. If they
are not identical it can't be reversed without overheating and/or loss
of performance.

I presume reversing the supply to either one of the windings would also
do it...

yes.