19
6.7 - Variable flow evaporator
Variable evaporator flow can be used. The controlled flow
rate must be higher than the minimum flow given in the
table of permissible flow rates and must not vary by more
than 10% per minute.
If the flow rate changes more rapidly, the system should
contain a minimum of 6.5 litres of water per kW instead of
3.25 l/kW.
It is possible to use a dedicated terminal to connect the
pump drive (0/10V signal) .
Please refer to 30XB/30XA/XAS/XW/XWZE Touch Pilot
control manual.
6.8 - System minimum water volume
Whichever the system, the water loop minimum volume is
given by the formula: Volume = Cap (kW) x N litres
Application
N
Normal air conditioning
3.25
Process type cooling
6.5
Where Cap is the nominal system cooling capacity (kW) at
the nominal operating conditions of the installation.
This volume is necessary for stable operation.
It is often necessary to add a buffer water tank to the circuit
in order to achieve the required volume. The tank must
itself be internally baffled in order to ensure proper mixing
of the liquid (water or brine). Refer to the examples below.
Connection to a buffer tank
6.5 - Standard and optional number of water passes
Standard-efficiency units 30XW--
Size
254
304
354
402
452
552
602
652
702
802
852
1002 1052 1154 1252 1352 1452 1552 1652 1702
Evaporator
Standard
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
Option 100C
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
Condenser
Standard
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
Option 102C
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
High-efficiency units 30XW-P
Size
512
562
712
812
862
1012
1162
1314
1464
1612
1762
Evaporator
Standard
2
2
2
2
2
2
2
2
2
2
2
Option 100C
1
1
1
1
1
1
1
1
1
1
1
Condenser
Standard
2
2
2
2
2
2
2
2
2
2
2
Option 102C
1
1
1
1
1
1
1
1
1
1
1
6.6 - Evaporator and condenser water flow rates
These below values are given for standard units. For options 100C and 102C, please refer to the unit selection program.
Standard-efficiency units 30XW--
Size
254 304 354 402 452 552 602 652 702 802 852 1002 1052 1154 1252 1352 1452 1552 1652 1702
Evaporator water flow rate, l/s
Minimum
6
6
6
7
7
7
7
9
9
9
9
13
13
15
18
18
18
18
22
22
Maximum
39
39
39
39
43
43
43
57
57
57
61
67
67
78
84
84
84
84
116 116
Condenser water flow rate, l/s
Minimum
4
4
4
4
4
4
4
6
6
6
8
8
8
9
12
12
12
12
14
14
Maximum
29
29
29
29
47
47
47
55
55
55
82
82
82
109 119 119 119 119 134 134
High-efficiency units 30XW-P
Size
512
562
712
812
862
1012
1162
1314
1464
1612
1762
Evaporator water flow rate, l/s
Minimum
10
10
13
13
13
18
18
22
22
28
28
Maximum
57
57
76
76
76
84
84
116
116
121
121
Condenser water flow rate, l/s
Minimum
6
6
8
8
8
12
12
18
18
22
22
Maximum
55
55
74
74
74
119
119
130
130
149
149
Notes
- Minimum evaporator flow rate based on a water velocity of 0,5 m/s.
- Minimum condenser flow rate based on a water velocity of 0,3 m/s.
- Maximum flow rate based on a pressure drop of 120 kPa (units with two evaporator passes and two condenser passes).
Bad
Bad
Good
Good
