Star Delta motor problem.

[IrishSparks]

So I have a 55kw Star Delta starting motor. The motor was moved about 10feet from original position so I had to put new cabling in from Isolator to Motor. That's all was changed.
When I went to start it it blew a fuse when kicking into Delta.
Changed fuse and it happened again only this time it was a different phase fuse blew.
Have checked operation of star Delta contactors with no load and they are working. Have also done an insualtion resistance test on motor windings and new cables and all ok.
Is it possible when it's going into Delta that it's also going into reverse?
Anyone any ideas of what else it could be?

 

[Bobster]

Usually,someone decides to manually operate one of the contactors,whilst the other is energised,to "see if it changes the outcome" .....eye protection,obligatory

Any SD starter built or modified since 2004 needs a mechanical interlock along with an electrical interlock to the contactors to stop that from happening.

 

[Andy-1960]

Any SD starter built or modified since 2004 needs a mechanical interlock along with an electrical interlock to the contactors to stop that from happening.

Hi Rob, which regulations are you referring to that states mechanical interlocking is mandatory?

 

[Bobster]

I'll dig it out when I get back to my office on monday.

It's not specifically stated in 60204-1 but a standard that it quotes. I'll dig out an post the section.

 

[Pete999]

I'll dig it out when I get back to my office on monday.

It's not specifically stated in 60204-1 but a standard that it quotes. I'll dig out an post the section.

Thanks Rob I would be interested as well, whilst not doubting you in any way, just for my own curiosity.