Site Preparation: Circuit Breakers - HP D7171A - NetServer - LPr Manual

Chapter 2

Site Preparation: Circuit Breakers

When you connect the HP NetServer LH 4r to an AC power source, the server
temporarily draws a large "inrush current. " This occurs even when the system is
in standby mode. Inrush current is much greater than the server's normal
operating needs. Generally, your external AC power source can handle the inrush
current.
If you install several HP NetServers on one circuit, however, precautions are
necessary. For instance, if there is a power failure and power is then restored, all
the servers immediately begin to draw inrush current at the same time. If the
circuit breakers on the incoming power line have insufficient capability, they may
trip and thus prevent the servers from powering up.
When preparing your site for installation , allow for the additional inrush current.
Consider the following before installing the server in your environment:
In North America, a 20-amp-minimum circuit is to be used with one
NEMA AB1 class 14B breaker for each 16-amp Power Distribution Unit
that is to be connected to an HP NetServer LH 4r.
In Europe:
For a single LH 4r unit in a rack, use a 16-amp-minimum circuit with
one IEC MCB C-type breaker for each 16-amp Power Distribution
Unit.
For multiple LH 4r units in a rack, use a 16-amp-minimum circuit
with one IEC MCB D-type breaker for each 16-amp Power
Distribution Unit.
NOTE Some local codes do not allow a 16-amp device to be
connected to a 16-amp service. Consult a qualified electrician
or local regulatory authority before beginning electrical site
preparation.
Connecting and Routing Cables to the HP NetServer LH 4r
15