Unit installation

CDU Installation Guide Page 22
Cooling Distribution Unit
COMMISSIONING (continued)
Reading from left to right the digital outputs are:
- Pump P1 contactor (inverter drive)
- Pump P2 contactor (inverter drive)
- Pump P1 contactor (DOL)
- Pump P2 contactor (DOL)
- Inverter drive enable signal
- Inverter drive fault reset
- Level 1 fault alarm
- Level 2 fault alarm
- Fill pump P3
- (not used)
Using the arrow keys, set ‘Pump 1 contactor (inverter drive)’ and ‘Inverter drive enable signal’ to ‘ON’.
Press to accept, then to return to previous screen and scroll to ‘AO1 – Inverter’ (screen ref. 4-
3-3). The pump speed can be set here as a percentage – a 30% speed is recommended for an initial
setting. When the key is pressed, Pump 1 will ramp up to the set speed.
5.11 Pump Rotation
Once the unit is running, the direction of pump rotation should be checked, the pump should rotate in
an anti-clockwise direction when viewed from above. This can be determined by watching the motor
fan slowing down when the unit is switched OFF. If the direction is clockwise then invert 2 – phases on
the electrical supply connection.
Pump rotation should be checked in all four pump operating modes, i.e. Pump 1 + inverter, Pump 2 +
inverter, Pump 1 DOL & Pump 2 DOL.
DANGER: This should only be carried out by a qualified electrician
5.12 Primary Flow Setup
For best performance the primary water flow rate should be set to an optimum flow. For this purpose, the
number of RDHx’s connected needs to be considered along with the temperature of the incoming water
and level of added glycol. If the water flow is below the necessary requirement, there will be insufficient
cooling and the room temperature will start to rise. If there is too much flow, then the temperature control
could become unstable.
Refer to the graph in Section 3.7 for information on the required flow rate based on incoming water
temperature, the percentage of added glycol and the number of RDHx’s attached to the CDU cabinet.
Example: If 5 x RDHx’s are
connected to the CDU
cabinet and the temperature
of the incoming primary water
is 7.5°C (45.5°F) with 30%
glycol, then the ‘minimum’
required flow rate would be
155L/M (41USgpm).
OK
digital outputs
use arrow keys
1000100000
0 = digital output OFF
1 = digital output ON
(e.g. display above shows Pump P1
selected with inverter drive enabled)
ESC
OK
39 41 43 45 47 49 51
0
5
10
15
20
25
30
35
40
45
50
55
60
65
70
75
80
0
20
40
60
80
100
120
140
160
180
200
220
240
260
280
300
320
4 5 6 7 8 9 10 11
Temperature ( F)
Flow (Usgpm)
Flow (L/M)
Temperature ( C)
Primary Flow/Temperature Graph for 120kW CDUs
1 RDHx (water)
1 RDHx (30% glycol)
2 RDHx (water)
2 RDHx (30% glycol)
3 RDHx (water)
3 RDHx (30% glycol)
4 RDHX (water)
4 RDHx (30% glycol)
5 RDHx (water)
5 RDHx (30% glycol)
6 RDHx (water)
6 RDHx (30% glycol)