Check out the "National Electrical Code Handbook" from the National Fire Protection Agency. The "handbook" has some explanations - making it a little more readable than the "code" alone. IIRC the handbook is about $75.
The big issue with a computing environment is the sizing of the neutral conductor. In normal installations the neutral current to ground should be less than that on any of the "hot" legs. Ideally it should be close to zero. As such the neutral conductor is often sized smaller than the hot legs. The switching power supplies of computer gear change all that. Due to harmonics the current on the neutral can be 150% of that on the hot legs. In a computing environment the neutral should be oversized and particular attention should be made that it has a low resistance path to ground. My source for this is documentation from Chloride UPSs and field measurements. The above is true for the US. If you live elsewhere YMMV. > -----Original Message----- > From: "Chuck Whose Road is Ever Shorter" > what amperage were your circuits? were the two power supplies > plugged into > different circuits? > > a 2500 watt PS requires a 20 amp circuit, while the 1300 can run on a > standard 15 amp circuit. If you were to plug your 2500 watt > supply into the > same 15 amp circuit as your 1300, I can see problems developing. > > Can you tell I've been reading up on electricity in response > to a customer > who apparently doesn't trust his electricians? > > in any case I would bet there is some connection with the > reload and the > numbers and draws of your line cards as well. Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=74791&t=74791 -------------------------------------------------- **Please support GroupStudy by purchasing from the GroupStudy Store: http://shop.groupstudy.com FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html
