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017-882-B0-001 Rev. E (06/2018)
4.0 Maintenance, Continued
4.3 Power Supply System Maintenance
4.3.1 Preparing for Maintenance
The power supply system should be remotely monitored and physically inspected periodically. If the system has an
automatic monitoring system to gather the electrical and environmental data, the remote checks should consist of
evaluating the recorded data and visiting any site that does not meet the specifications listed in the detailed procedures
below.
Notify anyone affected by the intended maintenance or troubleshooting activity. This should include but not be limited to
anyone responsible for the status monitoring equipment at the headend or NOC.
The following maintenance procedure requires a fully functional status monitoring system capable of remotely measuring
and recording the following data from a Self Test:
Self Test Result
Percent Load
Output Voltage
Procedure:
1. If Self Test fails a site visit is required
2. If the power supply percentage load is above 100%, a site visit is required
3.
If Output voltage is below 84.5V for 89V units or 59V for 63V units, a site visit is required.
Remote Status Monitoring of Power Supply Monthly Self Test
4.3.2 Periodic Maintenance Tasks
On-Site Power Supply Preventive Maintenance
Procedure:
1. Exterior site inspection
a. Inspect power supply cabinet security and condition.
b. Inspect cabinet for integrity (securely mounted, service meter and conduit integrity, etc).
c. Check all locks and hinges for proper operation and lubricate if necessary.
d. Inspect integrity of ground wire and ground rod. Ensure wire is of acceptable gauge and proper connections are
tight at both ends, meeting NEC or Local Authority specs.
2. Interior Cabinet inspection
a. Remove any dust, debris, or rodent signs from enclosure, louvers or vents. If enclosure has filters, clean with
compressed air or leaf blower.
b. Check all interior locks, hinges and battery slide trays for proper operation and lubricate if necessary.
c. Verify that SPI (ALT Box) is tight along with coaxial connection, ensuring that power supply and sheath of coax is
grounded.
d. Verify that power supply has a Surge Arrestor that is in working condition. Replace the unit as needed.
Ensure personal preventive equipment (including rubber gloves, plastic apron, safety glasses, and face
shield) is worn prior to proceeding.
CAUTION!
