10KvA Transformer

[SparkRight]

Hi. Can anyone please tell me how much a 10KvA 3P transformer pulls per phase on the primary side

 

[Darkwood]

Are you enquiring for the fuse rating at full load?..... as the demand would be proportional to the secondary side load connected.

 

[SparkRight]

I just need to know what type and size MCB to use on a 10KvA site transformer, and what would be the maximum pulled if the secondry side was fully loaded.

Thanks

 

[Darkwood]

This is one where calcs dont help but you need tech data from manufacturers of mcbs but to help you out on this one 10kva for a merlin gerin mcb is either 50A type C, or 25A type D. The recommendations are pretty much level across the playing field for different brands but i recommend you get a products book for each make of board as the info is in the back and a god-send at times. They ref' recommends for different lighting, motors transformers etc and more often than not its higher than you think so unless you checked first you may find supply cabling too small.
Its something often overlooked at college but alot of people fall foul of it and end up with nuisence tripping to which they are puzzled.

 

[SparkRight]

Sorry,
I think we are talking about different things here, Let me be more clear.

400v to 110v 10KvA Site Transformer for the use of hand tools and festoon lighting.

I was under the impression that it should have a D type mcb and pulled around 16A per phase at full load. I was just looking for confirmation.

Thanks

 

[Darkwood]

Sorry,
I think we are talking about different things here, Let me be more clear.

400v to 110v 10KvA Site Transformer for the use of hand tools and festoon lighting.

I was under the impression that it should have a D type mcb and pulled around 16A per phase at full load. I was just looking for confirmation.

Thanks

Sorry my typo error it is type D i realised my mistake and changed it but the loading per phase is only part of the equation the inrush of a low voltage/low voltage transformer is usually 10 to 15 times its rating and thus must be accounted for when selecting an mcb, so the recommendation still stands 50amp type c or 25amp type d.

 

[SparkRight]

So if the transformer was running fully loaded what do you suppose the Amps would read on the primary side

 

[Darkwood]

You about right at 16a primary side but its usually hard to overload these things as the secondary side has mcb protection on the outputs but be cautios of fitting anything less than 25A type D as nuisense tripping will be a pain in the arse when turning the unit on.

 

[ICE]

Hiya Bud,

I use 10KvA transformers all the time and always use 25D type and have never had a problem with them, as for what they pull, well it is down to the loading on the secondary side but if you are concerned for the amount of supply you have available to you I would work on 20A per phase...


ICE

 

[SparkRight]

Thanks for your advice it has been most helpfull

 

[Mac]

Hiya Bud,

I use 10KvA transformers all the time and always use 25D type and have never had a problem with them, as for what they pull, well it is down to the loading on the secondary side but if you are concerned for the amount of supply you have available to you I would work on 20A per phase...


ICE

You seem to have answered your own question ICE

 

[Darkwood]

You seem to have answered your own question ICE

You seem to under the impression that ice ask the original question???? or am i missing something

 

[Mac]

You seem to under the impression that ice ask the original question???? or am i missing something

Yes mate

 

[Dave]

Hiya Bud,

I use 10KvA transformers all the time and always use 25D type and have never had a problem with them, as for what they pull, well it is down to the loading on the secondary side but if you are concerned for the amount of supply you have available to you I would work on 20A per phase...


ICE

Thanks for your advice it has been most helpfull

You not talk at home then..?

 

[sparks1234]

Some thing that also happens with site transformers quite a lot is when the chippy or who ever turns up with his 3Kva tranny plugs it in to the office ring main and all the computers go out because the circuit is on a B rated breaker, sparky normally gets blamed