Process And Instrumentation - Danfoss VACON NX Commissioning And Maintenance Manual

1 4 VACON
4.2

PROCESS AND INSTRUMENTATION

The HX-
transports the heat load from the AC drive to the plate heat exchanger. The secondary circuit liquid
flowing through the plate heat exchanger then collects the heat load and transports it to an external
condenser. This external condenser (which does not appear on the
diagram) is part of the customer and/or end-
system. Another way to dispose of the heat load is to use existing natur al
resources e.g. a lake or river. The use and choice of a system for
responsibility.
•
Primary circuit, HXL120-PS01 (green colour in the Figure 4.2-1)
•
Secondary circuit, HXL120-PS02 (red colour in the Figure 4.2-1)
The FTSA11 flow switch, which monitors the flow in the primary circuit,
also includes a temperature sensor. This temperature sensor controls
the primary circuit temperature. This sensor sends out an analogue
signal to the HX control unit. The control unit application adjusts the
secondary circuit flow through the plate heat exchanger (HX11) by
adjusting the 3-way valve actuator (FV11) to match the temperature setup
value for the primary circuit. This temperature setup value is project
specific and is adjusted at commissioning. The temperature setup value is
dependent on the ambient temperature in the drive cubicle and on the
maximum temperature of the customer inlet liquid. The calculation of
this value is explained in chapter
Figure 4.2-2 Piping and instrumentation diagram (P&ID)
A larger P&ID is found in the Commissioning and Maintenance folder that is supplied with the unit.
The HX-unit is equipped with flow, temperature, pressure and leak supervision. The HX control unit
application monitors these quantities. The application generates alarms or shut-offs from the
interface panel allows the user to access these settings. The settings are found as editable
parameters in the HX control unit application. Apart from the leak sensor, LS11, which is placed on
the HX-unit floor, all instruments are placed in the primary circuit. Therefore the temperature and
flow monitoring in the secondary circuit is the responsibility of the customer and/or end-user.
4
-to-liquid transfer of heat. The primary circuit
5.3.6, Temperature set
epending on the parameter settings. The HX control unit
Local contacts: http:/ / dr ives.danfoss.com/ danfoss- dr ives/ local - contacts/
-
points.
I NTRODUCTI ON
Figure 4.2-1