Hello:

I live in a 230V area but need to use a 120V fan to repair an amplifier.
I can only get 230V fan motors here, so i was wondering if i can simply
remove turns from a 230v shaded pole motor to make it into a 120v one?

Thank you.

On 24/06/2010 3:04 PM, Steve Sousa wrote:
Hello:

I live in a 230V area but need to use a 120V fan to repair an amplifier.
I can only get 230V fan motors here, so i was wondering if i can simply
remove turns from a 230v shaded pole motor to make it into a 120v one?

Thank you.



No. It's highly unlikely that the wire used in the motor is more than
100% overspecified, so if you remove turns from it to make it run at the
same speed on 120v, it will overheat, because the current will
approximately double.

Sylvia.

On Thu, 24 Jun 2010 15:29:35 +1000, Sylvia Else
wrote:

On 24/06/2010 3:04 PM, Steve Sousa wrote:
Hello:

I live in a 230V area but need to use a 120V fan to repair an amplifier.
I can only get 230V fan motors here, so i was wondering if i can simply
remove turns from a 230v shaded pole motor to make it into a 120v one?

Thank you.



No. It's highly unlikely that the wire used in the motor is more than
100% overspecified, so if you remove turns from it to make it run at the
same speed on 120v, it will overheat, because the current will
approximately double.

Sylvia.

There is one high labor alternative that might work...

Take the current wire on the motor, and find the center, break it at
that point, so you have two 120 volt windings. Put in parallel for 120
volts, and series for 240 volts.

But, IMHO, hardly worth the effort, but technically feasible.

In article s.com,
"Steve Sousa" wrote:

Hello:

I live in a 230V area but need to use a 120V fan to repair an amplifier.
I can only get 230V fan motors here, so i was wondering if i can simply
remove turns from a 230v shaded pole motor to make it into a 120v one?

Thank you.



Hmm, I always thought you could get anything on the planet to any other
place on the planet. How could you not be able to get a 120V fan?

On 24/06/2010 9:46 PM, PeterD wrote:
On Thu, 24 Jun 2010 15:29:35 +1000, Sylvia Else
wrote:

On 24/06/2010 3:04 PM, Steve Sousa wrote:
Hello:

I live in a 230V area but need to use a 120V fan to repair an amplifier.
I can only get 230V fan motors here, so i was wondering if i can simply
remove turns from a 230v shaded pole motor to make it into a 120v one?

Thank you.



No. It's highly unlikely that the wire used in the motor is more than
100% overspecified, so if you remove turns from it to make it run at the
same speed on 120v, it will overheat, because the current will
approximately double.

Sylvia.

There is one high labor alternative that might work...

Take the current wire on the motor, and find the center, break it at
that point, so you have two 120 volt windings. Put in parallel for 120
volts, and series for 240 volts.

But, IMHO, hardly worth the effort, but technically feasible.

I'm not sure it's advisable either. There's every chance the enamel will
be damaged in the process. If he's lucky, any short will appear as soon
as he turns it on. If he's unlucky, it will occur when he's not looking.

Sylvia.

On Jun 23, 10:04*pm, "Steve Sousa" wrote:

I live in a 230V area but need to use a 120V fan to repair an amplifier.
I can only get 230V fan motors here, so i was wondering if i can simply
remove turns from a 230v shaded pole motor to make it into a 120v one?

Rewinding the mains-powered parts of a fan is a bad idea.
Better ideas: get a 120V fan motor, find an alternate power
source (there's a DC supply somewhere in the amplifier,
can it drive a DC fan?), use a small boost transformer or
autotransformer.

Quickest solution might be to use a 'standard' computer-parts
fan (takes DC power) with a 230VAC wallwart power brick.

On Jun 23, 10:04*pm, "Steve Sousa" wrote:
Hello:

I live in a 230V area but need to use a 120V fan to repair an amplifier.
I can only get 230V fan motors here, so i was wondering if i can simply
remove turns from a 230v shaded pole motor to make it into a 120v one?

Thank you.

do you have room for other components? use two identical fans wired in
series?
or, use a 120/120 isolation transformer with 230 across both [properly
phased] and tap off the 115 for the fan,
or, add a series inductor? some transformers are built very well and
can be abused. 120/12.6 filament transformer. place the 12.6Vac
winding in series. That will put 120+ across the secondary, but might
take it, plus the inductance is smaller looking into that winding and
you might get the right voltage drop, experimentation required.
or, use a series cap? something like 22uF to 33uF AC cap [note: AC
cap, not some electrolytic, unless rated for it, they're not made to
have this much AC current go through and electrolytic requires
nonpolar, or two back to back] - require experimentation.

or, if there is enough DC power: buy a DC fan rated for the same air
flow against head pressure and use it.

"Robert Macy"
"Steve Sousa"


I live in a 230V area but need to use a 120V fan to repair an amplifier.
I can only get 230V fan motors here, so i was wondering if i can simply
remove turns from a 230v shaded pole motor to make it into a 120v one?


do you have room for other components? use two identical fans wired in
series?

** Read the question - idiot.

The OP needs a 120 volt fan and has not got one.


or, use a 120/120 isolation transformer with 230 across both [properly
phased] and tap off the 115 for the fan, or, add a series inductor?

** Read the question - idiot.

The OP needs a 120 volt fan and has not got one.

Jeez wot a macaroon.


..... Phil

On Thu, 24 Jun 2010 23:04:00 +1000, Sylvia Else
wrote:

On 24/06/2010 9:46 PM, PeterD wrote:
On Thu, 24 Jun 2010 15:29:35 +1000, Sylvia Else
wrote:

On 24/06/2010 3:04 PM, Steve Sousa wrote:
Hello:

I live in a 230V area but need to use a 120V fan to repair an amplifier.
I can only get 230V fan motors here, so i was wondering if i can simply
remove turns from a 230v shaded pole motor to make it into a 120v one?

Thank you.



No. It's highly unlikely that the wire used in the motor is more than
100% overspecified, so if you remove turns from it to make it run at the
same speed on 120v, it will overheat, because the current will
approximately double.

Sylvia.

There is one high labor alternative that might work...

Take the current wire on the motor, and find the center, break it at
that point, so you have two 120 volt windings. Put in parallel for 120
volts, and series for 240 volts.

But, IMHO, hardly worth the effort, but technically feasible.

I'm not sure it's advisable either. There's every chance the enamel will
be damaged in the process. If he's lucky, any short will appear as soon
as he turns it on. If he's unlucky, it will occur when he's not looking.

Sylvia.

Advisable, probably not, but a theoritical solution, however! bg

"Steve Sousa"

I live in a 230V area but need to use a 120V fan to repair an amplifier.
I can only get 230V fan motors here, so i was wondering if i can simply
remove turns from a 230v shaded pole motor to make it into a 120v one?


** That idea is never gonna work - have you ever seen the insides of such a
fan ??

One possibility is to connect a capacitor in * series * with the fan of
such a value that it causes the inductance of the motor to resonate at the
supply frequency. This will increase the voltage across the fan above the
incoming supply.

A 230 volt, 120mm fan I tried resonates with about 3uF in series.

With 120 volts AC input, the voltage across the fan became 165 volts and the
speed was then close to that with 230 volts.
Worth a try.

Use a cap rated for 240 volt AC operation.


..... Phil

On 25/06/2010 10:37 AM, PeterD wrote:
On Thu, 24 Jun 2010 23:04:00 +1000, Sylvia Else
wrote:

On 24/06/2010 9:46 PM, PeterD wrote:
On Thu, 24 Jun 2010 15:29:35 +1000, Sylvia Else
wrote:

On 24/06/2010 3:04 PM, Steve Sousa wrote:
Hello:

I live in a 230V area but need to use a 120V fan to repair an amplifier.
I can only get 230V fan motors here, so i was wondering if i can simply
remove turns from a 230v shaded pole motor to make it into a 120v one?

Thank you.



No. It's highly unlikely that the wire used in the motor is more than
100% overspecified, so if you remove turns from it to make it run at the
same speed on 120v, it will overheat, because the current will
approximately double.

Sylvia.

There is one high labor alternative that might work...

Take the current wire on the motor, and find the center, break it at
that point, so you have two 120 volt windings. Put in parallel for 120
volts, and series for 240 volts.

But, IMHO, hardly worth the effort, but technically feasible.

I'm not sure it's advisable either. There's every chance the enamel will
be damaged in the process. If he's lucky, any short will appear as soon
as he turns it on. If he's unlucky, it will occur when he's not looking.

Sylvia.

Advisable, probably not, but a theoritical solution, however!bg

That I agree with.

Sylvia.

On Jun 24, 5:12*pm, "Phil Allison" wrote:
"Robert Macy"
"Steve Sousa"



I live in a 230V area but need to use a 120V fan to repair an amplifier..
I can only get 230V fan motors here, so i was wondering if i can simply
remove turns from a 230v shaded pole motor to make it into a 120v one?

do you have room for other components? use two identical fans wired in
series?

** Read the question - idiot.

*The OP needs a 120 volt fan and has not got one.

or, use a 120/120 isolation transformer with 230 across both [properly
phased] and tap off the 115 for the fan, or, add a series inductor?

** Read the question - idiot.

*The OP needs a 120 volt fan and has not got one.

*Jeez wot a macaroon.

.... * Phil

No excuse, just braindead this afternoon! Wait that's an excuse!

On Fri, 25 Jun 2010 11:00:46 +1000, "Phil Allison"
wrote:


"Steve Sousa"

I live in a 230V area but need to use a 120V fan to repair an amplifier.
I can only get 230V fan motors here, so i was wondering if i can simply
remove turns from a 230v shaded pole motor to make it into a 120v one?


** That idea is never gonna work - have you ever seen the insides of such a
fan ??

One possibility is to connect a capacitor in * series * with the fan of
such a value that it causes the inductance of the motor to resonate at the
supply frequency. This will increase the voltage across the fan above the
incoming supply.

A 230 volt, 120mm fan I tried resonates with about 3uF in series.

With 120 volts AC input, the voltage across the fan became 165 volts and the
speed was then close to that with 230 volts.
Worth a try.

Use a cap rated for 240 volt AC operation.


.... Phil





Ooh, interesting potential solution!

"Steve Sousa" wrote in message
anews.com...
Hello:

I live in a 230V area but need to use a 120V fan to repair an amplifier.
I can only get 230V fan motors here, so i was wondering if i can simply
remove turns from a 230v shaded pole motor to make it into a 120v one?


**That would be the insane solution. And one which won't work. You don't say
where you are, but obtaining 120VAC fans is simply not that difficult,
regardless of where you are. Alternatively, you could source a suitable DC
fan (say: 48 Volts) and use that, connected to a DC supply line within the
amp.


--
Trevor Wilson
www.rageaudio.com.au

Trevor Wilson wrote:

"Steve Sousa" wrote in message
anews.com...

Hello:

I live in a 230V area but need to use a 120V fan to repair an amplifier.
I can only get 230V fan motors here, so i was wondering if i can simply
remove turns from a 230v shaded pole motor to make it into a 120v one?



**That would be the insane solution. And one which won't work. You don't say
where you are, but obtaining 120VAC fans is simply not that difficult,
regardless of where you are. Alternatively, you could source a suitable DC
fan (say: 48 Volts) and use that, connected to a DC supply line within the
amp.


How about using a 1:1 small xformer and doing series boost on the
secondary with the primary connected to the 120 side.. This way, a
240 volt fan can be used in a 120 volt area..

etc..
Jamie.

"Sylvia Else" wrote in message
...
On 25/06/2010 10:37 AM, PeterD wrote:
On Thu, 24 Jun 2010 23:04:00 +1000, Sylvia Else
wrote:

On 24/06/2010 9:46 PM, PeterD wrote:
On Thu, 24 Jun 2010 15:29:35 +1000, Sylvia Else
wrote:

On 24/06/2010 3:04 PM, Steve Sousa wrote:
Hello:

I live in a 230V area but need to use a 120V fan to repair an
amplifier.
I can only get 230V fan motors here, so i was wondering if i can
simply
remove turns from a 230v shaded pole motor to make it into a 120v
one?

Thank you.



No. It's highly unlikely that the wire used in the motor is more than
100% overspecified, so if you remove turns from it to make it run at
the
same speed on 120v, it will overheat, because the current will
approximately double.

Sylvia.

There is one high labor alternative that might work...

Take the current wire on the motor, and find the center, break it at
that point, so you have two 120 volt windings. Put in parallel for 120
volts, and series for 240 volts.

But, IMHO, hardly worth the effort, but technically feasible.

I'm not sure it's advisable either. There's every chance the enamel will
be damaged in the process. If he's lucky, any short will appear as soon
as he turns it on. If he's unlucky, it will occur when he's not looking.

Sylvia.

Advisable, probably not, but a theoritical solution, however!bg

That I agree with.

Sylvia.

Hello:

Thanks you for the reply. I wasn't sure about the current doubling,
but i guess is just like a transformer.

I'll just add a relay and be done with it.

Best regards

"Smitty Two" wrote in message
news
In article s.com,
"Steve Sousa" wrote:

Hello:

I live in a 230V area but need to use a 120V fan to repair an amplifier.
I can only get 230V fan motors here, so i was wondering if i can simply
remove turns from a 230v shaded pole motor to make it into a 120v one?

Thank you.



Hmm, I always thought you could get anything on the planet to any other
place on the planet. How could you not be able to get a 120V fan?

Hello:

The problem is cost. The OEM doesn't have it, people who have it are selling
for 130$ +, that's too much for the original. Customs takes a lot of time
"inspecting" and figuring how much to charge (about 30% on top of that).

Best Regards

"Trevor Wilson" wrote in message
...

"Steve Sousa" wrote in message
anews.com...
Hello:

I live in a 230V area but need to use a 120V fan to repair an amplifier.
I can only get 230V fan motors here, so i was wondering if i can simply
remove turns from a 230v shaded pole motor to make it into a 120v one?


**That would be the insane solution. And one which won't work. You don't
say where you are, but obtaining 120VAC fans is simply not that difficult,
regardless of where you are. Alternatively, you could source a suitable DC
fan (say: 48 Volts) and use that, connected to a DC supply line within the
amp.


Hello:

I could eventually get a 120V fan for a much higher cost, but the original
was probably disposed of because of that, i'm just going to add a relay,
and put a 230v fan with the minimum amount of modification, that way is
future proof.

Thank you all for your help

Best regards

Steve Sousa

"Steve Sousa"


The problem is cost. The OEM doesn't have it, people who have it are
selling
for 130$ +, that's too much for the original. Customs takes a lot of time
"inspecting" and figuring how much to charge (about 30% on top of that).


** What electronics backwater are you living in ??

Here in Sydney, one can get a 115 VAC, 120 mm fan from spare parts dealer
( WES Components) for $18.75.



..... Phil