Notes on power distribution

June 8, 2017

The CSC/CCS server room is powered by 225 Amps of 3 phase, 120V power, or 46.7 KVa.

The 225 Amp circuit breaker for this is on the 1st floor, labeled PNL-SR 3rd Floor. It is located at the bottom of the breaker box, not along the two columns of lower amperage breakers; in a box situated behind the printers. The feed to this box is from a transfer switch that can cut over to generator power if FPL power fails.

The control of the transfer switch is from 1st floor operations, and is the same transfer switch that feeds all first floor machines.

The feed enters the server room at the back panel, with a 200 Amp breaker (not sure why they went down to 41.6 KVa here) where it feeds a number of spare outlets, the two row Lieberts, and the UPS, known as Fatty Arbuckle.

Fatty Arbuckle is a 45 KVa Liebert APM UPS. In the server room next to fatty is a distribution cabinet/transfer switch.

The transfer switch that can cut the APM in an interlocked fashion (too avoid shorting across the phase shifted output of the APM and its input), and is the distribution box to the racks.

The distribution consists of 10 30 Amp 3-phase breakers and three 30 Amp 1 phase breakers. Each of 5 racks has a left and right PDU and runs back to one of the 10 breakers. The three single phase breakers are run to networking rack where there are three PDU’s along the bottom, one for each phase.

The rack PDU’s are 3-phase Leiberts using C13 style connectors. They are arranged to load balance across the 3 phases.

Connect dual power supply servers one to the left and one to the right provides power redundancy all the way back to the UPS, through the individual breakers in the distribution cabinet.

posted in Uncategorized by admin

 
Powered by Wordpress and MySQL. Theme by Shlomi Noach, openark.org