IBM @server xSeries 343, Product Manual

Page: 18 / 193

6 Safety
If DC power supplies are installed:
Connection with a DC source should only be performed by trained service
personnel. The server with DC input is to be installed in a Restricted
Access Location in accordance with articles 110-16, 110-17, and 110-18 of
the National Electric Code, ANSI/NFPA 70. The DC source must be
electrically isolated by double or reinforced insulation from any hazardous
AC source. The DC source must be capable of providing up to 650 Watts
of continuous power per feed pair.
Main DC power disconnect: You are responsible for installing a properly
rated DC power disconnect for the server system. This mains disconnect
must be readily accessible, and it must be labeled as controlling power to
the server. The circuit breaker of a centralized DC power system may be
used as a disconnect device when easily accessible and should be rated no
more than 10 amps.
Grounding the server: To avoid the potential for an electrical shock
hazard, you must reliably connect an earth grounding conductor to the
server. The earth grounding conductor must be a minimum 14AWG
connected to the earth ground stud(s) on the rear of the server. The safety
ground conductor should be connected to the chassis stud with a Listed
closed two-hole crimp terminal with a maximum width of 0.25 inch. The
nuts on the chassis earth ground studs should be installed with a 10 in/lbs
torque. The safety ground conductor provides proper grounding only for
the server. You must provide additional, proper grounding for the rack
and other devices installed in it.
Overcurrent protection: Overcurrent protection circuit breakers must be
provided as part of each host equipment rack and must be incorporated in
the field wiring between the DC source and the server. The branch circuit
protection shall be rated minimum 75Vdc, 10 A maximum per feed pair. If
the DC power system for the equipment rack is installed with more than 10
amperes of protection, you must provide supplemental protection for the
server. The overall current rating of a server configured with two power
supplies is 8 amperes.