The DC supply panel is used to distribute power in a rack from either a power supply or backup battery, and provide isolation and protection for each circuit, along with monitoring.

Front and back of the DC supply panel

From left to right; the first device is a main power shutoff, which connects to the power supply. An Astron RM-50BB was used, which can supply up to 50A, and also has a connection to an external battery, complete with a trickle charger. Following the main cutoff is a set of bus bars for power distribution.

Next to the main switch is a power monitor that measures the current input voltage, and the power consumption overall.

In the middle is a set of breakers, divided into two groups. The upper group has a main breaker and the rest supply 12V to the rack for subsystems. The lower group also has a main breaker, and the remaining three supply power to three independent inverters for POE applications. The meters at the top measure the voltage and amperage being supplied to those subsystems.