How can I convert 240v to 220v

I bought some electrical sensitive equipment from overseas which runs
on 220v. I tried to run it on 240v in Australia and some of the
resistors have been burned. I know it will damage the equipment to run
on 240v but cannot find a transformer to convert from 240v to 220v.

Any advice on this?

Thank you.

 

[John Fields]

On Tue, 8 Apr 2008 23:50:19 -0700 (PDT), timho_au@yahoo.com.au wrote:

I bought some electrical sensitive equipment from overseas which runs
on 220v. I tried to run it on 240v in Australia and some of the
resistors have been burned. I know it will damage the equipment to run
on 240v but cannot find a transformer to convert from 240v to 220v.

Any advice on this?

---
View in Courier

240>----+--+ +--->216
| O| |O
| P||S
| R||E T1
| I||C
| | |
| | +--->216
O| |O
P||S
R||E T2
I||C
| |
240>----+--+

T1 = 240P 240S

T2 = 240P 24S




JF

 

[John Fields]

On Wed, 9 Apr 2008 06:34:56 -0700 (PDT), Mike Silva
<snarflemike@yahoo.com> wrote:

On Apr 9, 7:33 am, "Richard Seriani" <richard_s...@cox.net> wrote:

Use an autotransformer.

Or a bucking transformer with a secondary that produces 20VAC at (at
least) the primary current, connected so that the 20VAC secondary
bucks the 240VAC, producing 220VAC at the input of the equipment.

---
news:8t9pv3dmhoipmq1silgjlmerkab6d1iu00@4ax.com

JF

 

[Mike Silva]

On Apr 9, 7:33 am, "Richard Seriani" <richard_s...@cox.net> wrote:

Use an autotransformer.

Or a bucking transformer with a secondary that produces 20VAC at (at
least) the primary current, connected so that the 20VAC secondary
bucks the 240VAC, producing 220VAC at the input of the equipment.

 

[terryS]

On Apr 9, 4:50 am, timho...@yahoo.com.au wrote:

I bought some electrical sensitive equipment from overseas which runs
on 220v. I tried to run it on 240v in Australia and some of the
resistors have been burned. I know it will damage the equipment to run
on 240v but cannot find a transformer to convert from 240v to 220v.

Any advice on this?

Thank you.

Find it rather hard to believe;
a) The equipment is THAT sensitive to voltage? Variation from 240 to
220 is less than 10%. Mains supplies in many countries can vary more
than that on a regular basis. Are we sure there is not something else
to this question?????
b) That that in checking around no one has mentioned the two most
obvious means of reducing voltage in such a situation. As described by
other posters here; 1) An auto transformer 2) A bucking (voltage
opposing) transformer; either of which can be used to knock off
approximately 20 volts or so.
c) Less sophisticated means could include sticking a large lamp (or
several lamps in parallel) to knock off the unnecessary voltage,
probably on the cut and try method.
d) Several other odds and ends of reducing voltage come to mind,
depending on whether keeping the waveform as close to a sine wave or
not? Is it a constant load or a varying one. Hooking up one winding of
transformer in series with the 240 supply and varying the load in one
of its 'other windings' so as to modify line voltage.
e) A Variac; sized depending on the wattage to be handled!
Appears that more information, as not unusually, is needed to give a
detailed answer!

 

[terryS]

On Apr 9, 9:37 am, John Fields <jfie...@austininstruments.com> wrote:

On Tue, 8 Apr 2008 23:50:19 -0700 (PDT), timho...@yahoo.com.au wrote:
I bought some electrical sensitive equipment from overseas which runs
on 220v. I tried to run it on 240v in Australia and some of the
resistors have been burned. I know it will damage the equipment to run
on 240v but cannot find a transformer to convert from 240v to 220v.

Any advice on this?

---
View in Courier

240>----+--+  +--->216
        | O|  |O
        |  P||S    
        |  R||E T1
        |  I||C
        |  |  |
        |  |  +--->216
       O|  |O
        P||S
        R||E T2
        I||C
        |  |
240>----+--+              

T1 = 240P 240S

T2 = 240P 24S

JF

Another thought. Is the eqipment designed to run on some other
frequency such as 60 hertz (as in the Americas) and in Australia the
supply is AFIK 50 hertz?
Also the type of eqipment it is could be crucial! For example it was
reported on one news group that those 60 cycle portable fridges and
ice boxes coolers don't work well, if at all on 50 hertz and have to
be mechanically modified/retuned!

 

[terryS]

On Apr 9, 1:35 pm, terryS <tsanf...@nf.sympatico.ca> wrote:

On Apr 9, 4:50 am, timho...@yahoo.com.au wrote:

I bought some electrical sensitive equipment from overseas which runs
on 220v. I tried to run it on 240v in Australia and some of the
resistors have been burned. I know it will damage the equipment to run
on 240v but cannot find a transformer to convert from 240v to 220v.

Any advice on this?

Thank you.

Find it rather hard to believe;
a) The equipment is THAT sensitive to voltage? Variation from 240 to
220 is less than 10%. Mains supplies in many countries can vary more
than that on a regular basis. Are we sure there is not something else
to this question?????
b) That that in checking around no one has mentioned the two most
obvious means of reducing voltage in such a situation. As described by
other posters here; 1) An auto transformer 2) A bucking (voltage
opposing) transformer; either of which can be used to knock off
approximately 20 volts or so.
c) Less sophisticated means could include sticking a large lamp (or
several lamps in parallel) to knock off the unnecessary voltage,
probably on the cut and try method.
d) Several other odds and ends of reducing voltage come to mind,
depending on whether keeping the waveform as close to a sine wave or
not? Is it a constant load or a varying one. Hooking up one winding of
transformer in series with the 240 supply and varying the load in one
of its 'other windings' so as to modify line voltage.
e) A Variac; sized depending on the wattage to be handled!
Appears that more information, as not unusually, is needed to give a
detailed answer!

Another: Just a wild idea?
Not possibly a misprint of 220 volt for 120 volt? In some 'Chingrish'
instructions?
Having seen some things that can happen when eqipment was shipped to
the Middle East, from the Far East, ostensibly of the right voltage.
Then finding out the voltage rating was for a single phase instead of
a 3 phase supply. Oops!
With memories of dealing with an Indian technician, working for an
Arabic company, purchasing from China equipment that was partially
manufactured in S.Korea. Anyway just a thought!