116 Internal cooling circuit
T
air
(°C)
RH = 95%
10
15
20
25
30
35
40
45
50
55
= Not allowed as standard but the coolant temperature must be 0 °C (32 °F) or above.
At an air temperature of 45 °C and relative humidity of 65% the coolant temperature may
Example:
Maximum temperature rise: Depends on heat losses and mass flow. Typically 10 °C (18
°F) with nominal losses and flow.
■
Pressure limits
Base pressure: 100 ... 150 kPa (recommended); 200 kPa (maximum). "Base pressure"
denotes the pressure of the system compared with the atmospheric pressure when the
cooling circuit is filled with coolant.
Air counterpressure in the expansion tank: 40 kPa
Design pressure (PS): 600 kPa
Nominal pressure difference (between main in/out lines): 120 kPa with 25/75% (volume)
coolant solution, 150 kPa with 50/50% (volume) coolant solution. This has to be taken into
account when dimensioning the liquid cooling circuit.
Maximum pressure difference (between main in/out lines): 200 kPa
■
Coolant flow rate limits
The maximum coolant flow rate for all drive equipment is 1.3 × nominal. See the technical
data chapter for nominal values.
■
Cooling circuit materials
Materials used in the internal cooling circuit are listed below. These are also the only materials
that can be used in the external cooling circuit.
•
stainless steel AISI 316L (UNS 31603)
•
heavy gauge aluminum
•
plastic materials such as PA, PEX and PTFE
Note: PVC hoses are not suitable for use with antifreeze.
RH = 80%
9.2
6.7
14.2
11.5
19.2
16.5
24.1
21.4
29.1
26.2
34.1
31.1
39.0
35.9
44.0
40.8
49.0
45.6
53.9
50.4
Min. T
(°C)
coolant
RH = 65%
RH = 50%
3.7
8.4
13.2
17.9
22.7
27.4
32.2
36.8
41.6
46.3
not be below +36.8 °C
RH = 40%
-0.1
-3.0
4.6
1.5
9.4
6.0
13.8
10.5
18.4
15.0
23.0
19.4
27.6
23.8
32.1
28.2
36.7
32.8
42.2
37.1