On Mon, 31 Mar 2008, William Jackson wrote: > The 6000W-DC power supply takes four pairs of 4AWG PWR cables, my > question is the following.
> Which way is this setup cabled? > > 1. all 4 pairs of cables going back to a single circuit breaker of > ( 6000/48 = 125Amp ) > 2. each pair of cables going back to a separate circuit breaker of > ( 6000/4 = 1500/48 = 31.25 Amp ) > > I am not an electrical guy but I would have thought that the idea is > that the breaker trips before the cable burns, so I would assume option > 2? I can't speak specifically to the needs of DC, but in the AC world, that same power supply takes two 208V or 240V 20A circuits to fully energize the unit. Since the AC distro plant is centered around 120VAC 3-phase power, each one of those circuits will take up two breaker positions and each pair will be phased the same way. The 6500s are fitted out with dual power supplies, with one being fed with a pair of circuits from one output panel and the other pair from another panel. I would think in a DC environment you'd want all of the circuits for one power supply to come from one breaker panel, but separate breakers, then feed the second supply from another breaker panel. The reason for this is that if you feed one supply from more than one breaker panel, the power supply might be taken out of service if it's only partially energized. I'd think you would want the feed from the rest of your DC distro plant to the breaker panel to be sized and fused high enough to handle the combined draw of all of your output circuits, or whatever margins are dictated by your local building/electrical codes. jms _______________________________________________ cisco-nsp mailing list [email protected] https://puck.nether.net/mailman/listinfo/cisco-nsp archive at http://puck.nether.net/pipermail/cisco-nsp/
