Allied Telesis AT-8550SP - Manual (Page 68)

Installation
68
7. Secure the tray supply 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 with the first one located
within six inches of the terminal block.
Note
This system works with a positive grounded or negative grounded
DC system.
 20
8. Ensure that the circuit breaker is in the Off position.
9. Connect the DC wires to the circuit breaker. (Refer Power
Specifications on page 79 for power requirements.)
10. Power on the circuit breaker.
11. Verify that the PWR LED on the front of the unit is green. If the PWR
LED is OFF, refer to Troubleshooting on page 72.
The switch runs a series of self-diagnostic tests, which take a few
seconds to perform. After the self tests are complete, the switch is
ready for normal network operations.
Warning
This unit might have more than one power cord. To reduce the risk
of electric shock, disconnect all power cords before servicing the
unit.