VARISTAR LHX 20
Maintenance and Repair
Cooling module 60714-050
www.schroff.biz
25
R2.1, May 10, 2012
7.3.3 Flushing the cooling module with antifreeze
Work steps: flushing the module:
1 Remove cooling module from cabinet.
2 Close condensate drain.
3 Connect a pressure pump (hand pump) to the inlet.
4 Connect a hose (approx. 3 m) to the return.
5 Open the control valve actuator by hand. (See procedure in the section
'Bleeding air from the cooling module')
6 Lie the module on its left side (bleeder valve and condensate drain upward)
7 Place the inlet hose of the pump and the return hose of the cooling module
in a container with capacity of approx. 15 litres.
8 Pour about 3.5 litres of antifreeze into the container. (This will provide frost
protection down to about -20 °C)
9 Start the pump and allow the module to be flushed with antifreeze for
between 5 and 15 minutes, until the antifreeze is fully mixed with the cooling
water of the heat exchanger.
10 Switch off pump and open bleeder valve on the heat exchanger. (If the pump
is fitted with a non-return valve, it should be replaced with a hose.)
11 If required, further residual water can be forced out of the heat exchanger by
means of pressurised air. To do this, connect a compressor (max. pressure
6 bar!) to the inlet. Open the air pressure valve slowly to avoid an overflow of
water/antifreeze mixture in the collecting vessel.
12 After evacuation, seal inlet and return with suitable plugs.
13 The module should be clearly labelled with the following text:
"Beware: contains residual coolant. Open only with a receptacle placed
beneath module."
14 Coolant should be disposed of in accordance with environmental regula-
tions.
Attention!
If the cooling module is to be left on its side, all water connections must first be
sealed to prevent any leakage of water that could damage the control
electronics.
The cooling module may be flushed with a conventional glycol-based anti-
freeze, e.g. Glysantin produced by BASF.
Care should however be taken to ensure the compatibility of the antifreeze with
the external pipework.
Summary of Contents for 60714-050
Page 51: ......
