Does anyone else have a problem with the IEEE 1584 incident energy equations for current limiting fuses?
Incident energy is based on the arcing fault current, not the bolted fault current. Arcing fault current is determined from the bolted fault calculation but takes several other variables...
I've been asked to evaluate a panel for SCCR labeling. The panel is fed from a 575V source. The 575V source feeds some 600V equipment, leaves the panel to an external 50kVA 575/480V transformer, then the 480V circuit comes back into the same panel and feeds 480V equipment.
So, how do I label...
Anyone have suggestions for conducting an arc-flash study on a 480V, three-wire, grounded-b system? Is this possible? If so, should it be treated as an ungrounded-delta? Not sure where to start with this one... TIA!
When you have a panel feed directly from an unprotected source (i.e., large transformer secondary) you will generally have a high arc-flash hazard at the incoming lugs of the panel. On an installation such as an I-line (or similar construction), will the selection of the main breaker settings...
I've come across an ITE device (switchgear?) labeled CR30. It's a 480V 2000A breaker in an FS-20 switchboard. Seeing as the device is older than I am, I'm having difficulty finding specs and operation on this. Does anyone have information on this device? A little more information... CAT NO...
Anyone have a suggestion of where to look for Uninterruptible Power Supply standards? Would like to review them for inclusion in specification baselines.
Thanks.
Steve
Hi everyone,
Just got back from Baghdad and off active duty and faced with the PE in October. I've gotten a copy of Granger's Power System Analysis to study up. Does anyone know the solutions to the problems???
Steve
I'm working for an engineer battalion in stationed in Baghdad working on reconstruction. I need a handy wire size comparison chart relating the common AWG to the sizes usually found here (6mm^2, 10mm^2, etc.) I don't have many technical books and I can't really get books or journals very fast...
Anyone have a favorite technical book or manual regarding underground power system cables and calculations? I'm working on a task that has piqued my interest in this subject (which I barely know anything about).
I'm looking more for a textbook type book with theory, not a quick calculation...
Can anyone explain the basis for selecting a PT fuse(or VT as some may call it) for the secondary winding?
Thanks. To whoever answers this... YOU RULE! Heh
I'm looking at a pair of B-Pro relays from NxtPhase (APT) for 2-zone protection of a 69kV substation. Would anyone care to comment on their experiences with this relay or any of the APT relays? Please no APT sales responses!! I would only like responses from those who have used the relay or...
It may seem obvious that a rectifier fuse is used with rectifiers. But why? It seems that the curves for rectifier fuses are very similar to "one-time" fuses. We have a PT setup which was designed using old KAW type fuses, and they are labeled "rectifier fuse". What makes...
