Overcurrent Device Failures

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bphgravity

Senior Member
Location
Florida
Does anyone know of a database or published study on the number of overurrent device failures due to improperly applied AIC ratings and non-compliance with 110.9 of the NEC?

I am curious to how often failures have occurred or how likely a failure would to occur if devices with insufficient AIC rating are installed on systems with higher available fault currents.
 

ramdiesel3500

Senior Member
Location
Bloomington IN
Bryan
Sorry I have no concrete info. However, I recently attended classes on arc flash. A portion of the class was taught by one of the major fuse manufacturers. They had tons of data on insufficient AIC ratings and the resultant safety hazards. They also had lots of video of exploding panels. Really makes you check AIC ratings close after you see buss bars do a hula dance! Bussman, Shawmut, etc. would be a good place to start. The class I attended was by Ferraz Shawmut.
 

kingpb

Senior Member
Location
SE USA as far as you can go
Occupation
Engineer, Registered
I think it would be a safe approach to say that all devices will fail if fault current is applied that is higher than what they are rated for. From a liability standpoint, I don't imagine any manufacturer will tell you a device is good for more than it's rated value.

Secondly, because of lawsuits, I don't think an employer is going to report failures of equipment due to improper application. This would open themselevs up to litigation.

The only source I know of for reliabilty numbers would be to reference IEEE Std 493.

Good Luck.
 
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