Allied Telesis AlliedWare Plus Installation Manual page 140

Chapter 9: Wiring the DC Connector on the AT-PWR250-80 Power Supply
140
6. Connect the +48 VDC (RTN) feed wire to the terminal block marked
+ (plus).
7. Connect the -48 VDC feed wire to the terminal block marked - (minus).
Warning
Check to see if there are any exposed copper strands coming from
the installed wires. When this installation is done correctly there
should be no exposed copper wire strands extending from the
terminal block. Any exposed wiring can conduct harmful levels of
electricity to persons touching the wires.  E12
8. Secure the tray cable near the rack framework using multiple cable
ties to minimize the chance of the connections being disturbed by
casual contact with the wiring. Use at least four cable ties, separated
four inches apart. Locate the first one within six inches of the terminal
block.
Note
This system will work with a positive grounded or negative grounded
DC system.  E13
9. Verify that the circuit breaker is in the OFF position.
10. Connect the supply-cable wires to the circuit breaker.
Note
Do not power on the switch at this time.
11. If the switch has two AT-PWR250-80 Power Supplies, repeat this
procedure to wire the second DC connector.
12. Repeat this procedure to wire the DC connectors on the AT-PWR250-
80 Power Supplies in the other switches of the stack.
13. After wiring all of the AT-PWR250-80 Power Supplies, go to Chapter
10, "Displaying the AlliedWare Plus Version Number" on page 141.
Warning
This unit might have more than one power source. To reduce the
risk of electric shock, disconnect all power cords before servicing the
unit.  E30