Honeywell HPM, Сервисная инструкция

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4 Fault Isolation
4.14 Power System Voltage Checks
R688 HPM High-Performance Process Manager Service 385
December 2020 Honeywell
AC Only Power System
Introduction
There are two LED indicators on the AC Only Power System and no test points. The two green LED
indicators are located on the AC/DC Distribution assembly and provide a visual indication of the primary
and redundant Power Supply Modules’ operational status. When the LED is illuminated, its associated
Power Supply Module is functional. The locations of the indicators are illustrated in Figure 184.
CMOS batteries
The three alkaline batteries on the AC/DC Distribution Assembly provide backup power for the CMOS
Memory in the HPMM. They are not rechargeable and must be replaced periodically. The period should
not exceed 6 months, provided there is no sustained loss of power to the CMOS Memory. If there is,
replace the batteries after dc power is restored to the HPM.
Alarm Annunciator contacts
Connection points for two sets of annunciator contacts that signal the status of the primary and redundant
Power Supply Modules are provided by terminals on TH3. See Figure 188. Terminals 3 and 4 are
connection points for the secondary Power Supply module. The annunciator contact connection terminals
are normally wired in series to a monitoring 24 Vdc Digital Input FTA.
4.14 Power System Voltage Checks
Introduction
ATTENTION
Redundant power cables normally provide power to a card file or Power Distribution Assembly,
so a single power cable can be disconnected for voltage measurements at the Power System
connector without affecting the performance of the equipment. However, sometimes an
insufficient number of Power System connectors are available and only a single cable provides
power to the card file or Power Distribution Assembly.
SHOCK HAZARD
Troubleshooting, opening this equipment and removing any panels or covers will expose the
user to the risk of a shock hazard. There are no user serviceable parts inside this equipment.
Refer all servicing only to qualified service personnel .
Before disconnecting a power cable for voltage measurements, be sure power to a card file or Power
Distribution Assembly will not be interrupted.