a non-fused disconnect is only rated for 10kA short circuit current rating. Upon my investigation of this I have found that to be true. Would you please take a look at the attached diagram that is requesting me to install a meter, non-fused disconnect, and then control cabinet that has 60 amp breaker in the cabinet. I have contacted the AHJ and have been told that the wiring is considered part of the service conductors until it reaches that overcurrent device. While I agree to an extent, I disagree due to my understanding that the service is no longer considered the service once it is terminated on the line side of the service disconnecting means. (The non-fused disconnect) Could you please clarify this and let me know if it is a legal installation. I feel that this is not legal since the disconnect is rated for 10kA and the utility fault current is 21,697 kA. If you would please shed some light on this it would be greatly appreciated.
Not sure why you are concerned with the semantics of what the conductors are called. But pursuant to your issue, as I said in the other thread a Non-Fused disconnect switch, IF RATED FOR SUSE*, is only going to have a 10kA rating, it's part and parcel to the UL98 standards to which is it designed. BUT, if coordinated with the proper circuit breaker down stream, it CAN be used at higher levels. But those higher levels vary by mfr., you are going to have to be careful. Since I posted in the other thread, this came up in my office just this week as well, and I had to do some more specifics.
My customer was using Siemens heavy Duty NF disconnects. Turns out there is NO CB SERIES COMBO available from Siemens that is good for more than 18kA until you get to 600A NF switches, in which case they are still only 25kA. So Siemens is out for you as an option.
Eaton has a series listing of their NF switches with their breakers, but they stop at 25kA for a 60A switch, so you would need to go with a 100A NF switch and use an EGH or EGS circuit breaker down stream.
Square D Heavy Duty 30-100A NF switches are good for 35kA when in series with a Sq. D Type H or J breaker.
GE... can't tell, they make it WAY too difficult to find anything and frankly, I don't use them so I didn't try too hard.
Honestly though, if you have a control panel that you didn't build and so don't have control of what breaker is used in it, just use a fused disconnect, it's a LOT simpler if you ask me...
*You will also find that only the Heavy Duty versions of everyone's NF disconnect switches will be SUSE labeled, whereas for some, you can get the General Duty switches with an SUSE label if they are fused, which will mean they are less expensive.
