Blast in Siemens LT busbar

What does "laira" mean?

This is all I could find...

http://en.wikipedia.org/wiki/Laira_(comics)

Generally, when a "blast" occurs in bus bar systems, it is related to a short circuit event.

Laira means (female) power connector. The system is 415V system. No moisture & dust.Still flashover happened.

Yes, what is laira means?

This I could offer, probably you have an insulation breakdown? during the high surge of current, a pin hole in the the insulation is enough condition for the breakdown. Loseness, carbonized contact or connection and dust would also contribute to your problem.

You haven't said all the parameters of your problem. (voltages) Anyway,

Check also ambient humidity and temperature requirements for your system. Enough moisture in the air will also ruin your system.

What is your application?, Is soft starting can be done? so that current surge will be dramatically controlled? or Variable Frequency Drive applicable?

Question?

Does your voltages drift down significantly during starting? Have you check its transient response time? Just asking...

Hope this help.

Hi there,

You need to check your busbars for the correct torque. You must have no loose connections etc. I also suggest you get someone out who will check your MCC bus bars for you with an injection set. This will tell you if there is a problem with the insulation, shorting, hot spots, resistance etc etc.

Good luck

Craig

Your problem seems to be in the insulation. Check individually the bus insulators if they are leaking.