On Dec 18, 2007, at 4:23 AM, n1jez@burlingtontelecom.net <n1jez@burlingtontelecom.net
wrote:
One other thing we do is use a bypass system around the UPS in case that fails. Pulluzzi makes a nice one, but quite expensive. We've had a scenario where a UPS came on line, ran for a while, but then failed 'in circuit'. By that time, AC power had returned, but there was no way to restore power because of the UPS failure. With the Pulluzzi switch, power can be routed around a failed unit automatically.
I've had some direct contact with Pulluzzi gear for -48VDC power switching, and found it was, hmm.. how to put this nicely... somewhat unreliable. (That's being kind.)
Server Technology out of Utah makes some (also expensive) but robust gear for similar purposes and we've had great performance out of a number of their units.
This equipment is used for mountaintop transmission systems, so not the typical Ham application, but the ideas apply to most emergency type situations.
Yeah, sorry if it's off-topic for AMSAT-BB, but you don't see power switching and re-routing talked about too much in ham circles other than the repeater-building gang.
Probably lots of hams who don't know what's "out there" nowadays for nifty power-switching/monitoring/bypass toys! Too bad many are rather spendy for hobby use. They're really quite nice to use at work, though. Telnet to the box, go into a menu, turn off power switch #23 and #30... all from somewhere else.
Toys are good. Reliable toys are even better. When you can find them surplus and integrate them into your station, it's always nice.
-- Nate Duehr, WY0X nate@natetech.com