Specifications

Appendix A Specifications
DC Power Supply Safety Warnings
A-10
Content Services Switch Getting Started Guide
78-11766-01
DC Power Supply Safety Warnings
Warning The DC power supply must be installed in restricted access areas
only (for example, dedicated equipment rooms, equipment closets)
in accordance with articles 110-16, 110-17, and 110-18 of the
national electric code, ANSI/NFPA 70. Connect a DC CSS 11150 or
CSS 11800 to a -48 VDC source that is electrically isolated from the
AC power source and is reliably grounded to earth.
This equipment is designed to permit the connection of the grounded conductor
of the DC supply circuit to the grounding conductor at the equipment. If this
connection is made, all of the following conditions must be met:
• This equipment shall be connected directly to the DC supply system
grounding electrode conductor or bonding jumper from a grounding terminal
bar or bus to which the DC supply system grounding electrode conductor is
connected.
• This equipment shall be located in the same immediate area as any other
equipment that has a connection between the grounded conductor of the same
DC supply circuit and the grounding conductor, and also the point of
grounding of the DC system. The DC system shall not be grounded
elsewhere.
• The DC supply source is to be located within the same premises as the
equipment.
• There shall be no switching or disconnecting devices in the grounded circuit
conductor between the DC source and the point of connection of the
grounding electrode conductor.
Warning A readily accessible disconnect device must be provided in the
fixed wiring for a DC power supply. It must be suitable for the rated
voltage and current specified.