Current Limiting Breaker

[phil_edwards123]

What exactly is current limiter?
Is every breaker equipped with a current limiter? If not, how can I determine if the breaker has current limiter element?
Let say there is a 600V/200A breaker, configured with 10x instantaneous tripping, and 80kA interrupting rating.
Where does the current limiting feature fit into the picture??

 

[augie47]

The term "current limiter" is applied to many devices.
There are electronic current limiting diodes.\
There are cable limiters designed to protect cables (not over current devices)
There are current limiting fuses designed to limit fault currents.

Since you mentioned breakers, here's an older tread that might help.


http://forums.mikeholt.com/showthread.php?t=138123

 

[templdl]

What exactly is current limiter?
Is every breaker equipped with a current limiter? If not, how can I determine if the breaker has current limiter element?
Let say there is a 600V/200A breaker, configured with 10x instantaneous tripping, and 80kA interrupting rating.
Where does the current limiting feature fit into the picture??

All circuit breakers are current limiting to some degree which is why when the proper testing is done series- combination protection can be achieved.
But there are specific requirements for breakers are per the definition for a current limiting breaker per UL489 which is the breaker is to open fast enough to limit the let through current (I2t) to less than 1/4 cycle. The breaker manufactures have used all sorts of magic in their design of the moving and stationery contacts, slot motors, and even integral fuses to achieve their current limiting capabilities.