As a Systems Engineer who spends a fair amount of time responding to inquiries received through our Technical Support department I often hear "The PDU blew a fuse. I replaced it but it blew again. Something is wrong with the PDU. Please send me a new one." Would that we could, but the PDU is doing what it should. Following are some notes about why fuses blow and circuit breakers trip, and how to respond to re-energize the outlet branch safely and effectively.
Can a cabinet/rack based power distribution unit with a higher Ampere rating be used with a lower ampere rated power feed?
Topics: data center power
Branch circuit protection on a 20A rated power strip is not an National Electrical Code1 (NEC) requirement. Server Technology has both 20A Inlet rated CDU products with and without branch circuit protection. The presence of Bussmann SC-20 fuses on 20A units, even though not required, allows for selective coordination with short-circuit faults. Fuses react fast enough to halt a short-circuit fault nearest the fault while also reducing let-through to upstream and parallel branch gear.
Lately, we've been getting quite a few questions from customers, channel partners and just about everyone else on 3 phase power. It seems everyone is searching for an effective solution to deliver power to all of the varying devices in their high density cabinets. Rather than trying to re-invent the wheel, we invite you to explore the following resources, all of which we have found to be extremely helpful in discussing 3 phase power with customers.
Uptime or zero down time is the key driving factor in today’s data center design and operation with companies measuring downtime in thousands of dollars per minute when a system is not available. Many companies operating Tier III and Tier IV data centers also manage remote sites and co-location facilities that are just as critical as their main location. Managing both remote and co-location facilities requires new innovative solutions to ensure uptime. One such solution is using intelligent Cabinet Power Distribution Units (CDU’s) capable of providing Smart Load Shedding capabilities. Smart load shedding allows the operator to load shed based on three key operating parameters; 1) whether the UPS is on battery, 2) the temperature level or 3) the current load. These key parameters allow the user to automatically shed designated, non-critical, devices based on one or all of these conditions ensuring uptime and avoiding damage to the critical devices within the cabinet should a problem occur.