I have an electrical panel supplied with 415V, 3 phase and earth, no
neutral. I need to have a 240v powered switch mode PSU installed in
the same panel. Can it be done without a neutral?

Thanks

On 24 Mar, 18:51, BodgeIt wrote:
I have an electrical panel supplied with 415V, 3 phase and earth, no
neutral. *I need to have a 240v powered switch mode PSU installed *in
the same panel. Can it be done without a neutral?

Thanks

I suggest a 400/230 volt transformer to power the PSU. You may need to
earth one leg of the 230 volt output to provide a neutral depending on
the requirements of the PSU.

BodgeIt wrote:
I have an electrical panel supplied with 415V, 3 phase and earth, no
neutral. I need to have a 240v powered switch mode PSU installed in
the same panel. Can it be done without a neutral?

Thanks

Yes, but you would need to buy a 415v/230V transformer.

An autotransformer will do and may be cheaper than an isolating
transformer, but you are more likely to get 415V to 110V, so check if
your switch mode is dual voltage.

If the power is 50VA or less, you could use eBay item 170461492064

link to eBay: http://preview.tinyurl.com/ycnas4d

Connect the primary of the transformer between any two 415V phases with
a 2-phase MCB, e.g. http://www.tlc-direct.co.uk/Products/CM9806D.html

Thanks for your advice, I hadn't even thought about a step down
transformer having got so focused on going across a phase and my non
existent neutral.

Cheers



On Wed, 24 Mar 2010 20:11:17 +0000, Dave Osborne
wrote:

BodgeIt wrote:
I have an electrical panel supplied with 415V, 3 phase and earth, no
neutral. I need to have a 240v powered switch mode PSU installed in
the same panel. Can it be done without a neutral?

Thanks

Yes, but you would need to buy a 415v/230V transformer.

An autotransformer will do and may be cheaper than an isolating
transformer, but you are more likely to get 415V to 110V, so check if
your switch mode is dual voltage.

If the power is 50VA or less, you could use eBay item 170461492064

link to eBay: http://preview.tinyurl.com/ycnas4d

Connect the primary of the transformer between any two 415V phases with
a 2-phase MCB, e.g. http://www.tlc-direct.co.uk/Products/CM9806D.html