Jmad757
New member
- Location
- Chesapeake,va,usa
So I got a 200amp 3phase 120/208 meter with a fused disconnect with rk5200a 200000 fuse and a 200 amp 10000 aic panel ... Max fault current is 59000 ..are my fuses good for let thru current ???
Current let thru?
- Thread starter Jmad757
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- San Francisco Bay Area, CA, USA
- Occupation
- Electrical Engineer
Welcome to the forum.
If what you are trying to get at is determining whether or not the let-through current of a Class RK5 fuse is sufficiently low to allow you to use a 10kAIC panel when the line side AFC is 59kA, that is not a relevant question. You are looking to do a "series rating" of that panelboard on your own, and ONLY the manufacturer of the panelboard can answer that question for you, based on their having TESTED and LISTED that panel in series with RK5 fuses.
That said, it is PROBABLY going to be OK because many if not most panel mfrs have done this, but you can't do that on your own, it must be part of the panel's listing process.
The fuses would not need to be "good for let thru", they just need to have an AIC rating at or higher than the Available Fault Current, which yours do. Let-through it what gets PAST the fuses to the devices down stream before they clear a fault.
If what you are trying to get at is determining whether or not the let-through current of a Class RK5 fuse is sufficiently low to allow you to use a 10kAIC panel when the line side AFC is 59kA, that is not a relevant question. You are looking to do a "series rating" of that panelboard on your own, and ONLY the manufacturer of the panelboard can answer that question for you, based on their having TESTED and LISTED that panel in series with RK5 fuses.
That said, it is PROBABLY going to be OK because many if not most panel mfrs have done this, but you can't do that on your own, it must be part of the panel's listing process.
kwired
Electron manager
- Location
- NE Nebraska
- Occupation
- EC
Are you sure you have 59 kA available at the end of a conductor supplying what you describe as particular 200 amp supply?
If this is a subfeeder off a pretty large service and located pretty much adjacent to the larger service, maybe you do, most anything else I doubt your available current is that high. Resistance of a 200 amp conductor will drop the available fault current pretty significantly in just a 50 foot run of conductor.
If this is a subfeeder off a pretty large service and located pretty much adjacent to the larger service, maybe you do, most anything else I doubt your available current is that high. Resistance of a 200 amp conductor will drop the available fault current pretty significantly in just a 50 foot run of conductor.
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