Installing a -48 Vdc Power Distribution System 147
Practice 450-1011-201
Figure 17-4
Field Wiring Instructions
USE #6 AWG COPPER CONDUCTORS, RATED AT LEAST 90˚ C.
FIELD WIRING INSTRUCTIONS
-48 VOLT DC SUPPLIED DATA VOICE INSTRUCTIONS
This System has been designed to comply with the requirements for Field Wiring of stationary units in
accordance with the 1987 National Electrical Code, NFPA 70 or the Canadian Electrical Code C22.1.
This system has been provided with an opening to accommodate a 1 inch trade size fitting for the
attachment of a field installed electrical raceway, conduit or cable/strain relief. Refer to local codes and
requirements for suitable methods of attachment.
A MAIN DISCONNECT DEVICE MUST BE PROVIDED IN ORDER TO COMPLY WITH THE
REQUIREMENTS FOR PERMANENTLY CONNECTED PRODUCTS IN ACCORDANCE
WITH THE NATIONAL/CANADIAN ELECTRICAL CODE.
BRANCH CIRCUIT OVERCURRENT PROTECTION SHOULD BE PROVIDED FOR THIS
SYSTEM AT THE SOURCE OF SUPPLY. THE PROTECTION DEVICE SHOULD BE SIZED
IN ACCORDANCE WITH THE MARKED ELECTRICAL RATING OF THE SYSTEM AND
SHOULD ALLOW 150% OF THE MARKED RATINGS FOR TEN SECONDS TO COMPENSATE
FOR STARTING CURRENT DEMANDS.
The anticipated nominal current draw for -48 Vdc systems is as follows:
2 Tower System: -48 V, 17 A, DC
3 Tower System: -48 V, 25 A, DC
4 Tower System: -48 V, 34 A, DC
5 Tower System: -48 V, 42 A, DC
6 Tower System: -48 V, 50 A, DC
7 Tower System: -48 V, 59 A, DC
8 Tower System: -48 V, 67 A, DC
TERMINAL BLOCK
P0693026
-48V
-48V
Return
Gnd
450-0506
