Protective Device Coordination - Lessons Learnt

[NickParker]

What are the common situations where coordination is not possible/difficult?
Any lessons learnt would be appreciated!

 

[mparenteau]

1) Thermal mag breakers w/ instantaneous only adjustments.
2) Ground Fault protection...main circuit breaker only.

Mike

 

[wbd]

I would add in fuse and mccb coordination.

 

[Parchie]

Coordination at the instantaneous portion of faults.

 

[LionelHutz]

Setting a breaker to instantaneously trip at 1kA doesn't mean it limits the fault current to 1kA.

 

[jraef]

Old gear with no data on the devices. I used to say old gear by now defunct manufacturers, but lately even the big 4 (now 3?) are abandoning documentation on their old gear.




" We are all here on earth to help others; what on earth the others are here for I don't know." -- W. H. Auden

 

[thermionic1]

Understanding what I2t in/out means on a main breaker Gnd setting