When troubleshooting T163339 with @Papaul, I was logged into https://ps1-a1-codfw.mgmt.codfw.wmnet and could see that tower A had a full load, while tower B had next to no load.

This is typically caused when the bios of the servers is improperly set for power redundancy, and puts the secondary psu into standby rather than active/active. It is non-ideal, as the PSU doesn't experience a full load, and it makes balancing power between the phases more difficult (as each system takes a larger amount of amperage on that tower).

I've created this task so I'll go back and audit all of the racks, and note which racks seem to have improper balance between towers A and B. We also may want to add monitoring for this, since we monitor for phase imbalance (between x/y/z phases in a tower) but not tower imbalance.