I have a bit of a block when it comes to mains transformer wirings. ;-)

Device is factory set to 120v AC 60Hz, it says on the gubbins.

It has an analogue PS with a mains transformer.

It has two primary windings wired in parallel. Red and black go to neutral
on the IEC connector, brown and orange to the on/off switch output.

Obviously, they go to series for 240v - I assume the transformer will be
ok at 50 Hz.

What would be the best way to re-connect them for 240v?

Ie, link brown to red and 240v goes between black and orange?

--
*Fax is stronger than fiction *

Dave Plowman London SW
To e-mail, change noise into sound.

On Wed, 26 Feb 2014 18:19:58 +0000 (GMT), "Dave Plowman (News)"
wrote:

I have a bit of a block when it comes to mains transformer wirings. ;-)

Device is factory set to 120v AC 60Hz, it says on the gubbins.

It has an analogue PS with a mains transformer.

It has two primary windings wired in parallel. Red and black go to neutral
on the IEC connector, brown and orange to the on/off switch output.

Obviously, they go to series for 240v - I assume the transformer will be
ok at 50 Hz.

What would be the best way to re-connect them for 240v?

Ie, link brown to red and 240v goes between black and orange?

Once you have the wires apart you need to identify the colours that
are opposite ends of the same winding. Use an ohm meter for that.

Assuming that the black is connected to the same winding as the brown,
connect black to neutral, then connect red to brown, leaving orange
for the live connection.

d

Don Pearce wrote:
On Wed, 26 Feb 2014 18:19:58 +0000 (GMT), "Dave Plowman (News)"
wrote:

I have a bit of a block when it comes to mains transformer wirings.
;-)

Device is factory set to 120v AC 60Hz, it says on the gubbins.

It has an analogue PS with a mains transformer.

It has two primary windings wired in parallel. Red and black go to
neutral on the IEC connector, brown and orange to the on/off switch
output.

Obviously, they go to series for 240v - I assume the transformer
will be ok at 50 Hz.

What would be the best way to re-connect them for 240v?

Ie, link brown to red and 240v goes between black and orange?

Once you have the wires apart you need to identify the colours that
are opposite ends of the same winding. Use an ohm meter for that.

Assuming that the black is connected to the same winding as the brown,
connect black to neutral, then connect red to brown, leaving orange
for the live connection.


Above will give correct phasing as will following...

If black is connected to orange when tested then brown to live, black to
neutral, red to orange for series connection.

In article ,
Don Pearce wrote:
On Wed, 26 Feb 2014 18:19:58 +0000 (GMT), "Dave Plowman (News)"
wrote:

I have a bit of a block when it comes to mains transformer wirings. ;-)

Device is factory set to 120v AC 60Hz, it says on the gubbins.

It has an analogue PS with a mains transformer.

It has two primary windings wired in parallel. Red and black go to
neutral on the IEC connector, brown and orange to the on/off switch
output.

Obviously, they go to series for 240v - I assume the transformer will be
ok at 50 Hz.

What would be the best way to re-connect them for 240v?

Ie, link brown to red and 240v goes between black and orange?

Once you have the wires apart you need to identify the colours that
are opposite ends of the same winding. Use an ohm meter for that.

Assuming that the black is connected to the same winding as the brown,
connect black to neutral, then connect red to brown, leaving orange
for the live connection.

I did wonder if there were standard colours in the US for this - as there
does tend to be in the UK, or at least with some makers.

However, I found a interior pic of a bit of kit from the same maker (but
not the same device) connected for 240v. It shows red and brown linked,
black to neutral, orange to line. Which confirms things - but I'll check
each winding for continuity when I take it apart anyway. To be sure to be
sure. ;-)

--
*Frustration is trying to find your glasses without your glasses.

Dave Plowman London SW
To e-mail, change noise into sound.