can i remove turns from shaded pole motor

[Steve Sousa]

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.

 

[Sylvia Else]

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.

 

[PeterD]

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.

 

[Smitty Two]

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?

 

[Sylvia Else]

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.

 

[Phil Allison]

"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

 

[PeterD]

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>

 

[Phil Allison]

"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

 

[Sylvia Else]

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

That I agree with.

Sylvia.

 

[PeterD]

"Steve Sousa"


** 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!

 

[Trevor Wilson]

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.

 

[Jamie]

**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.

 

[Steve Sousa]

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

 

[Steve Sousa]

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

 

[Steve Sousa]

**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

 

[Phil Allison]

"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