Power supply is a very important part of an instrument system, the 3500/15 Power Supply in Bnetly Nevada can be ordered for ac or dc input power, equipped with a standard line noise filter. Rack 3500 can operate from a single supply, or multiple Power Supplies can provide redundancy for situations where power interruptions cannot be tolerated.
Source : 3500 System Overview, Specification and ordering information, Bentley Nevada
Each Power Supply is individually able to provide power to all shelves and modules. When excessive inventory is used, one acts as the main power for the rack while the other acts as a backup, ready to directly and automatically operate as the main rack inventory if the other modules fail, without disrupting the shelf function.
The 3500/15 Power Supply module has a self-monitor function that allows it to determine whether all output voltages meet specifications. This module announces this via the "Supply OK" green LED on the Power Supply front panel.
Reference : 3500 System Overview, Specification and ordering information, Bentley Nevada