Siemens SINAMICS S120 Equipment Manual page 178

Cooling circuit and coolant properties
8.1 Cooling circuits
Note
When arranging the units in the cooling circuit, please note that the Basic Line Modules,
Active Line Modules and Motor Modules must always be positioned upstream of the motors.
Dirt traps (strainers), at least one pressure measuring point and a service inspection window
are important.
Table 8-2 Components of a closed cooling circuit
Component
1. Pressure-relief valve
2. Pressure compensator
(pressurizer)
3. Pressure-relief dP valve
4. Pump
5. Connecting pipes
6. Inspection window
7. Dirt traps (strainers)
8. Pressure measuring point
9. Connection hose
10. Heat exchanger
11. Bypass valve
12. Coolant
8-4
Explanation
Required in cooling circuits with aluminum owing to the hydroxide reaction with H
reaction product.
Closed pressurizer if possible, normal type used for heating systems suitable only for
closed cooling circuits, with inhibitors and Antifrogen N.
Required for systems with very powerful pumps and to dissipate H
Delivery area made of stainless steel, avoid use of grey cast iron wherever possible.
Stainless steel, ABS, also common steel in closed circuits with inhibitors in the coolant.
Recommended for diagnosing turbidity and discoloration of the coolant which can indicate
ageing or corrosion problems.
Dissolved substances (reaction products) must be trapped before they cause blockages
in the heatsink!
Required for servicing.
EPDM hose
Ideally stainless steel, but a copper heat exchanger can be used as an alternative in
closed circuits.
May be necessary to protect against condensation.
See Section 8.2
SINAMICS S120 Equipment Manual, Edition 12/2007, 6SL3097-2AM00-0BP4
as the
2
.
2
Chassis Power Units Liquid Cooled