Unit installation

CDU Installation Guide Page 20
Cooling Distribution Unit
COMMISSIONING (continued)
5.7 System Filling
Refer to Section 3.4 for system fluid capacities
Operation – for secondary circuit filling
It will not be possible to start the unit with the ‘Unit Start/Stop’ pushbutton until the system has
been manually filled with deionized water (i.e. system start is inhibited by reservoir low level
and low pressure interlocks).
Position container of pre-treated deionized water in front of
the cabinet.
Remove the filling wand from its storage location on the right
hand side of the cabinet and connect to the fill hose (white
quick release coupling), then insert to the bottom of the water
container (see Fig. 5) and press the ‘Fill Pump Enable’
pushbutton.
The fill pumps will then start pumping the contents of the
container into the system at the rate of approx. 2l/m
(0.5USgpm). The pumps may be noisy to start with as they self
prime. See page 21 for how to monitor system pressure
during filling process.
Stop the pumps by pressing the ‘Fill Pump Enable’
pushbutton again before the level drops below the wand
intake, to avoid air being drawn into the system.
If more than one container of treated deionized water is
required (see capacities in Section 3.4), repeat the
procedure above until the fill pumps automatically stop.
Pumps will stop when inlet pressure ‘PS1’ reaches 0.5Bar
(8PSI). Leave the filling wand in the container - more water
will be required during the initial stages of operation as air is
expelled from the system and the main pump inlet pressure
(PS1) drops.
Check for leaks.
Once the unit is commissioned – the filling wand may be
disconnected at the white quick release coupling and the fill
hose then connected to the blue flexible make-up container.
Excess treated water may be used to fill this make-up
container - approx. capacity 2L (0.53USgalls), which will allow
the unit to self-fill while unattended in the event of minor
water loss or when any remaining trapped air is purged out of
the system. The container should be regularly inspected
during service visits and refilled if required, however any fill
pump activity after commissioning is logged as a Check
Water Make-up Level warning, as a reminder for
investigation.
Before connecting the blue flexible make-up container, the
air in the container hose should be removed. Fill the
container with water, screw on the fill cap and then squeeze the bag while depressing the
valve on the end of the quick release coupling (see Fig. 6) until air is expelled and hose is full
of water.
NOTE: If there is already pressure in system and air is introduced into the fill pump suction line, then the
fill pumps may not be able to purge this air through the system and may cease to pump. To rectify, switch
unit off and relieve secondary circuit pressure at drain valves(s), then refill system again as above.
Alternatively, leave the unit running while opening a drain valve to relieve pressure, until fill pumps start to
pump.
Fig. 5 - Filling wand
Fig. 6 - Make-up container
Quick release coupling