Installation - Siemens SINAMICS S120 Manual

Cooling circuit and coolant properties
13.1 Cooling circuit requirements
Dimensioning the cooling circuit
Recommendation for dimensioning the cooling circuit:
The differential pressure between the supply and return lines should be selected so that:
ΣdPi < dP
The individual pressure drops Pi represent the pressure drops of components (heat
exchanger, piping, 70 kPa for the SINAMICS devices connected in parallel, valves, dirt traps,
pipe bends, etc.).
Coolant pipes must be routed with extreme care. The pipes must never come into contact
with electrically live components; an insulation clearance of > 13 mm must always be left
between pipes and live parts! The pipes must be securely mounted and checked for leaks.
13.1.4

Installation

A closed stainless-steel cooling circuit, preferably combined with monitoring of the coolant
quality, is strongly recommended to ensure the longest possible service life for the heat sink.
NOTICE
Damage caused by incorrectly routed coolant lines
Leaking coolant can cause a short circuit.
• Route the coolant pipes very carefully.
• Fix the pipes securely and check them for leaks.
• Ensure that the pipes never come into contact with live components.
Materials and connections
Stainless-steel pipes are used to route the coolant through the cooling plates on the liquid-
cooled power units. For power units with cold plate, the coolant is routed by means of
integrated channels in the aluminum cold plate.
To minimize the electrochemical processes taking place in the cooling system, the materials
must be coordinated with one another accordingly. Mixed installations, i.e. a combination of
different materials, such as copper, brass, iron, or halogenated plastic (PVC hoses and
seals), should therefore be avoided or limited to the absolutely essential minimum.
The valves and connections required in the cooling system must be made of stainless steel
(V2A or V4A steel; NIROSTA austenite).
776
< ΣdPi + 30 kPa
Syst
Booksize Power Units
Manual, (GH2), 07/2016, 6SL3097-4AC00-0BP8