Juniper EX9214

3. On the power supply, rotate the metal cover away from the input mode switch to expose the
switch.
4. Move the input mode switch to posion 0 for one feed or posion 1 for two feeds.
NOTE: For a fully redundant conguraon in two-feed mode, sixteen feeds are required.
5. Set the power switch of the power supply to the OFF (0) posion.
6. Verify that the power cables are labeled before making connecons to the power supply. In a
typical power distribuon scheme where the return (RTN) is connected to chassis ground at the
baery plant, you can use a mulmeter to verify the resistance of the –48 V and RTN DC cables to
chassis ground.
• Cable with large resistance (indicang an open circuit) to chassis ground is –48 V.
• Cable with low resistance (indicang a closed circuit) to chassis ground is RTN.
CAUTION: You must ensure that power connecons 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 aach to the terminal studs on each power supply.
7. Install heat-shrink tubing insulaon around the power cables.
To install heat-shrink tubing:
a. Slide the tubing over the poron of the cable where it is aached to the lug barrel. Ensure that
tubing covers the end of the wire and the barrel of the lug aached to it.
b. Shrink the tubing with a heat gun. Ensure that you heat all sides of the tubing evenly so that it
shrinks around the cable ghtly.
Figure 54 on page 182 shows the steps to install heat-shrink tubing.
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