abb calor emag Is limiter problem 1

[MohammadHanafy]

hi
we have abb calor emag Is limiter in a power plant to eliminate short circuit level
it consists of a main conductor (bursting tube) and in parallel hrc fuse
what is the benefit of the fuse ?
are there another companies makes this technology ?
are there another companies can repair a defected one neither abb calor emag?
thanks

 

[mgtrp]

G&W makes a similar product, called "CLiP" - see [URL unfurl="true"]http://www.gwelec.com/current_limiting_system.html[/url]. They also have an explanation as to how the CLiP product works (see here), which is similar to the ABB IS-limiters.

 

[MohammadHanafy]

thanks mgtrp
but are there companies can repair a defected Is limiter of abb calor emag?

 

[slavag]

ABB Only.

Clip is not same technologies, Clip is Fuse, Is is operated on di/dt principle.

 

[slavag]

ABB Only.

Clip is not same technologies, Clip is Fuse, Is is operated on di/dt principle.

 

[mgtrp]

The two are very similar - they both consist of a main conductor in parallel with a fuse. When a fault is detected, a small explosive charge is triggered, rupturing the main conductor and forcing all of the current through the parallel fuse, which quickly blows.

Unless they've made some changes to the triggering algorithms in the ten years since I last had much to do with these devices, the CLiP device is triggered by magnitude of current only, while the IS-limiter includes rate of change of current.

 

[MohammadHanafy]

what is the benifit of the fuse as the main conductor is ruptured first ?
what is the time required for Is limiter to clear the fault ?
thanks

 

[johannes60]

Hi Mohammad,

during normal operation only the main conductor is carrying current due to its lower resistance, thus drastically reducing losses within the fuse.
After having ruptured this bypass with the help of an explosive charge the resulting arc reverses the ratio of resistance in favor of the fuse.
The current commutates to the fuse, the arc in the bypass dies and the fuse is blown.
You may find some more detailled description when googleing 'calor emag is limiter'; ABB documents are to be found right above the link to this very forum.

Have fun

Johannes