5. Set the power switch of the AC power source outlet to the ON (|) position.
6. Set the power switch of the AC power supply to the ON (|) position and verify that the AC OK and the DC OK LEDs
are on and steadily lit green, and the PS FAIL LED is not lit.
Connecting EX9204 to DC power
For each power supply:
WARNING:
Ensure that the input circuit breaker is open so that the cable leads will not become active
while you are connecting DC power.
1. Attach an ESD grounding strap to your bare wrist, and connect the strap to one of the ESD points on the chassis.
2. Set the power switch on the power supply faceplate to the OFF (0) position.
3. Remove the clear plastic cover from the terminal studs on the faceplate.
4. Verify that the DC power cables are correctly labeled before making connections to the power supply. In a typical
power distribution scheme where the return (RTN) is connected to chassis ground at the battery plant, you can use a
multimeter to verify the resistance of the –48 V and RTN DC cables to chassis ground:
•
Cable with large resistance (indicating an open circuit) to chassis ground is –48 V.
•
Cable with low resistance (indicating a closed circuit) to chassis ground is RTN.
CAUTION:
You must ensure that power connections maintain the proper polarity. The power
source cables might be labeled (+) and (–) to indicate their polarity. There is no standard color
coding for DC power cables. The color coding used by the external DC power source at your site
determines the color coding for the leads on the power cables that attach to the terminal studs on
each power supply.
5. Remove the nut and washer from each of the terminal studs.
6. Secure each power cable lug to the terminal studs, first with the flat washer, then with the split washer, and then with
the nut. Apply between 23 lb-in. (2.6 Nm) and 25 lb-in. (2.8 Nm) of torque to each nut. Do not overtighten the nut.
(Use a 7/16 in. [11 mm] torque-controlled driver or socket wrench.)
•
Secure the positive (+) DC source power cable lug to the RTN terminal.
•
Secure the negative (–) DC source power cable lug to the –48 V terminal.
5