Vertiv CoolChip CDU 600 - Page 59

Code Description Severity Self-Clear Latching Shutdown Shutdown
non-return valves on Pumps are not sticking open (Pump rotating slowly backwards). Reduce flow setting (or DP).
A26 Valve Fault 2 —
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Detail:
Feedback signal from cooling valve is more than 10% (default) adrift from demand signal (sampled every 15 minutes (default) and allowing
for 40 second (default) positioning time).
Action:
Check that unit has been set for the correct system flow rate (or DP), check for system blockages, check inverter drive for faults, check
non-return valves on Pumps are not sticking open (Pump rotating slowly backwards). Reduce flow setting (or DP).
A27 Primary Fluid Low Flow 2 —
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Detail:
Will only activate when valve demand is at 100%,‘A33 - Secondary Fluid High Temp alarm is active and Primary fluid temperature is within
specified limits (default 5 min. delay applies).
Action:
Check the wiring connections to the actuator. Try to set the actuator position manually using the Auto Overrides function. Check the
voltage out and return signals (Page 1 of Diagnostics screen).
A28 Primary Fluid No Flow 2 —
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Detail:
Will only activate when Valve Demand is at 100%, A33 - Secondary Water High Temp and A31 - Primary High Temp alarms are active
(default 5 minute delay applies).
Action:
Check operation of cooling valve. Check primary fluid supply flow rate. Ensure system heat load does not exceed the CDU 600 capacity—
check that primary flow is sufficient for heat load. Refer to CoolChip CDU 600 Application and Planning Guide.
A29* Primary Filter Dirty 2
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Detail:
Differential pressure across primary filter (if fitted) is greater than 0.6 bar (9 psi), indicating that the filter should be cleaned (default 60
second delay applies).
Action: Clean filter screen as described in Maintenance on page67 .
A30 Primary Fluid Low Temperature 3
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Detail:
Primary fluid temperature has dropped below the default 4°C (40°F) threshold. Alarm will cancel when temperature rises to 5°C (42°F) or
more (default 2 minute. delay applies).
Action: Check primary fluid supply.
A31 Primary Fluid High Temperature 2
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Detail:
Primary fluid temperature has risen above the default 11°C (52°F) threshold. Alarm will cancel when temperature falls to 10°C (50°F) or less
(default 2 minute delay applies).
Action: Check primary fluid supply..
A32
Secondary Fluid Low
Temperature
2
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Detail:
Secondary fluid temperature has dropped by more than 2°C (4°F) below set point (default). Alarm will cancel when temperature rises to 1°C
(2°F) below set point or higher. If Dew Point Offset is active, then this alarm will only activate when at or below dew point for a period of 3
minutes or more (default 2 minute delay applies).
Action: Check operation of control valve..
A33
Secondary Fluid High
Temperature
2
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Detail:
Secondary fluid temperature has risen by more than 2°C (4°F) above set point (default). Alarm will cancel when temperature falls to 1°C
(2°F) above setpoint or lower. If Dew Point Offset is active, then this alarm will activate at a pre-set default value of 20°C (70°F) . See
Parameters screen 3-12 (default 2 minute delay applies).
Table 4.41 Alarm Identification and Severity Level (continued)
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Vertiv™ CoolChip CDU 600 Operation and Maintenance Guide