Determining Current Draw On Two Circuits In One Rack - HP D7171A - NetServer - LPr Manual

Chapter 2

Determining Current Draw on Two Circuits in One Rack

NOTE Amperage ratings for use in determining loads on the Power
Distribution Unit are shown in Tables 3-4, 3-5, 3-6, and 3-7.
If applicable, use two circuits (each including a Power Distribution Unit and an
optional Uninterruptible Power Supply) in one rack. Attempt to balance the
current drawn through each circuit. The HP NetServer LH 4r has redundant
power supplies but does not have redundant power cords. Therefore, both cords
of the NetServer LH 4r are plugged in to one circuit. See, for instance, Figures
2-11 and 2-12.
CAUTION Do not plug the two HP NetServer LH 4r power cords in to
two different PDUs. Doing so could result in a single
electrical circuit failure causing the whole rack to lose power.
When (in either the 208 or 230/240 VAC case) a 10-amp PDU is daisy-chained
to a 16-amp PDU, determine the load to be placed on each. Plug only those
combinations of components into the 10-amp PDU whose overall total current
draw is less than 10 amperes. Then be sure that the 16-amp PDU total load,
including the daisy-chained 10-amp PDU and any other components, does not
exceed 16 amperes.
Add more PDU-UPS circuits to support higher loads.
NOTE
Choosing a higher line voltage will reduce the number of
PDUs required.
Connecting and Routing Cables to the HP NetServer LH 4r
27