Fig.16 - Fill Pump Manual Activation - Lenovo Neptune DWC RM100 Operation & Maintenance Manual

- The operator will need to press the 'Fill Required' icon, which will then display the message
shown in Fig.16 to ensure that the filling hose (with container of fluid) or the flexible make-up
container is connected before the fill pump is activated by pressing the ON button.
- Once the unit is running, a low system pressure below the default 0.8Bar (12PSI) at PS1 will not
stop the main pump from running but will initialise a 'Fill Required' (after a default 10 second
delay) to request the PS1 pressure is raised to the default of 1.0Bar (15PSI).
- If fill pump has been running for more than 5 seconds, an 'A30 - Check Water Make-up Level'
alarm will also be generated. This is a latched alarm and will need to be manually cleared but
will not stop the unit from running.
- If the fill pump runs for more than 1 minute (default) and PS1 pressure has still not reached
1.0Bar (15PSI), then the fill pump will stop and an 'A15 - Water Make-up Empty' alarm will be
generated. This is a latched alarm and will need to be manually cleared but will not stop the
unit from running.
- If inlet pressure drops to 0.2Bar (3PSI) (set, non-adjustable) below fill pump activation threshold
(i.e. to 0.6Bar (9PSI), if default value) for more than 1 minute (set, non-adjustable), a 'A31
System Low Pressure' event will be generated. This is a latched alarm and will need to be
manually cleared but will not stop the unit from running.
Secondary Circuit Fluid Level
- While the unit is running, if the fluid level sensor is open circuit for more than 1 second, an
'A34 – Level Sensor-No Water Detected' alarm will be generated. Provided the flow or DP is
still greater than 50% of setpoint, the unit will continue to run.
- If flow or DP is below 50% of set point, then the unit will stop and an 'A16 – Insufficient
Water' alarm will be generated. This is a latched alarm and will need to be manually cleared
but will not stop the unit from running.
The following flow charts show the unit pressure/level monitoring and fill pump control during initial
start-up of the unit after commissioning (from a unit off-line condition) and also during normal running
(unit on-line):
CDU Operating & Maintenance Guide
Neptune DWC RM100 in-rack Coolant Distribution Unit
Fig.16 – Fill Pump Manual Activation
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Press to start the fill
pump