Water Cooling - HEIDENHAIN TNC 410 M Technical Manual

4.5 Water Cooling

4 – 22
Keep the following in mind when mounting and operating water-cooled
HEIDENHAIN inverter components and water-cooled HEIDENHAIN power
modules:
The tightening torque for connecting the hose to the coupling joint on the
HEIDENHAIN components is max. 20 Nm. The hose and the coupling joint
must be steadied from each side by using two wrenches (WAF 22).
The bend radius of the coolant hose is greater than 100 mm.
Use a closed cooling circuit.
The following applies for the temperature of the coolant: 20 °C < coolant/
water < 40 °C.
Warning
The temperature of the coolant must be no more than 5 °K lower than the
ambient temperature of the components to be cooled in order to avoid
condensation in the electronic components.
Maximum coolant pressure = 5 bars. A pressure reducer can be used if
required.
Minimum flow rate of coolant = 3 l/min. HEIDENHAIN recommends a flow
rate of 6 l/min.
If required, filters should be used to prevent the coolant from being
contaminated. The filter fineness must be < 100 μm.
The pH value of the coolant should be approx. 7 to ensure that the service
life of the coolant hoses is not impaired.
If water is used as a coolant, corrosion protection must be used.
HEIDENHAIN recommends using, for example, Waterdos CAN11 with a
ratio of 1 % to 2 % to protect the coolant from corrosion.
The diameter of the hole for leading the hose through the rear wall of the
electrical cabinet must be > 28 mm. Make sure that the coolant hose is not
damaged by the edges of the hole (use plastic ducts if required).
Ensure that the coolant hose does not rest on sharp edges in order to
prevent damage to the hose. A permanently safe operation of the water
cooling system can only be ensured if this is adhered to.
Danger
Check the complete cooling circuit for tightness before putting the
components into service (max. pressure of coolant = 5 bar)!
HEIDENHAIN Technical Manual for Inverter Systems and Motors