Determining And Balancing Current Draw On Two Circuits In One Rack - HP D5970A - NetServer - LCII Reference Manual

Chapter 3
loaded rack, see the section of this chapter entitled "Determining and
Balancing Current Draw on Two Circuits in One Rack."
4. For the sake of easy access to the rear of each component, route the
associated power cords within the same space (the same set of EIA Units)
where the component is located.
Excess cord can be handled by coiling and tie wrapping unneeded length,
and hanging it in the space at the side of the component it connects. When
doing so, be sure you allow sufficient slack for access. Also provide for
components which can be extended, ensuring the coil does not conflict.
5. Plug the PDU(s) into the UPS or into the site power receptacles. When you
are ready to power on the components, see "Power Up Sequence."
Determining and Balancing Current Draw on Two Circuits in One
Rack
NOTE Amperage ratings for use in determining and balancing loads
on the Power Distribution Unit are shown in Tables
2-6 and 2-7.
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. Plan to plug in components with smaller
power requirements and connectors so that they alternate between the circuits. In
other words, plug one component into one circuit and the next component into the
other circuit. For instance, see Figures 3-7 and 3-8.
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.
Procedure for Connecting and Routing Cables to the LXr 8500
33