You are installing two online, rack-mounted UPS units in a new server rack. Each dual-corded server will have one power supply connected to UPS-A and the other to UPS-B. Facilities has run UPS-A from branch circuit X on panel PP-1, and UPS-B from branch circuit Y on panel PP-2, which is on a different breaker and phase than circuit X. Which primary risk does supplying the two UPS units from separate branch circuits mitigate?
Battery exhaustion in one UPS during a prolonged utility outage
Mechanical fan failure inside one of the server's redundant power supplies
Harmonic distortion caused by both UPS units operating on the same phase
A single branch-circuit breaker trip or wiring fault that would otherwise cut power to both UPS inputs
Feeding the UPS pair from different branch circuits removes the branch-circuit wiring and breaker as a single point of failure. If circuit X is lost because of an overload, breaker trip or cabling fault, only UPS-A loses its upstream source; UPS-B (on circuit Y) continues to provide conditioned power, so every server still has at least one live power feed. Industry guidance for redundant power paths recommends plugging each server power supply into a separate UPS and placing those UPS units on independent supply circuits or utility sources for exactly this reason. Doing so does not double battery runtime (the batteries are still independent), eliminate harmonic distortion, or protect against an internal fan failure in a server PSU, all of which would require different controls or have no relation to the circuit choice.
Ask Bash
Bash is our AI bot, trained to help you pass your exam. AI Generated Content may display inaccurate information, always double-check anything important.
Why is it important to connect UPS units to separate branch circuits?
Open an interactive chat with Bash
What is the role of redundant power supplies in server infrastructure?
Open an interactive chat with Bash
Does using separate UPS units extend battery runtime during outages?