Danfoss VACON NX Commissioning And Maintenance Manual page 26

2 6 VACON
WARNING
8. Repeat this procedure until every AC drive/inverter is de-aired, that is, open the valve V312
and V313 next and so on.
9. After all the main drive hoses have been de-aired and closed, open valve V140 and then open
the filling valve V161. After no more rattling can be heard due to air in the system, close valve
V162, the manual de-airing valve.
10. When valve V162 is closed the pressure (see at the PI11, pressure indicator) will start to rise
in the primary system. When the pressure in the primary system has raised to two (2) bar
close the V161 filling-valve. If you are using an external pump for adding the water it can now
be turned off.
11. Keep the two (2) bar pressur e for about 10 minutes, letting the air bubbles in the system rise
up to the HX11 heat exchanger. Then open the manual de-airing valve V162 to let the
pressure back down to 1.5 bar. Close valve V162.
12. Now the system is almost completely de-aired. After this the pumps must be run for short
periods to get the rest of the air out from the HX-unit. Refer to
pump for more the rest of the de-airing instructions.
The pre-pressure in the primary circuit should be set to 1.5 bar. During operation the pre-pressure
should be between 1.0 to 1.5 bar. If the pre-pressure is reduced to below 1.0 bar during operation
is below 0.5 bar.
5
If the external water system used for the filling can produce more than 6 bars
there is a risk of the safety valve (V120) opening. This might cause unnecessary
problems if some particles are left on the sealing surface of the safety valve and
therefore causing a leak. If this happens the safety valve must be cleaned.
Local contacts: http:/ / dr ives.danfoss.com/ danfoss- dr ives/ local - contacts/
COMMI SSI ONI NG
chapter 5.4.1 Starting the
- -pressure