Adjusting The System Flow And Setting The Switch Point Of The Ftsa11 - Danfoss VACON NX Commissioning And Maintenance Manual

COMMISSIONING
11. The LED-display on the FTSA11 should register that there is flow in the system. If not, stop
the pump and re-check that all valves are open, e.g. in the drive section, in the HX-unit and if
there is piping/valves made by customer in the primary circuit then check them also. The
flow switch is set to 50% as default and has a 5 second delay (the 5 second delay is
programmed into the HX control unit application). What this means is that the flow has to get
over the 50% limit within 5 seconds of starting the pump, or the HX control unit will shut
down the pump.
12. If the pump is shut down and the HX control unit display is registering a flow fault, reset the
fault from the VACON
does not stay online after three (3) attempts, de-airing has not been done correctly or some
of the valves mentioned in step 1 and 2 are still closed. De-air the system again; refer to
Chapter 5.1.7 Adding liquid and
13.
online after a new de-airing, try to temporarily lower the flow switching point for the FTSA11
to 10% (50% as default). Information on how to modify the FTSA11 switching point is found in
chapter 5.3.5, FTSA11 flow switch
14. If the pump stays online, run it for 15 minutes and then change the flow switch point back to
the project-specific setup value. The flow switch point can be changed during operation.
During the first days of operation, the pre-pressure decreases because some air might be left in the
system after de-airing.
To adjust the pressure:
1. Connect a filling hose to valve V161. De-air the filling hose before adding liquid to avoid air
getting into the primary circuit.
2. Add liquid to increase the pressure back to 1.5 bar on the PI11 pressure gauge.
3. Close valve V161 and remove the hose.

5.4.2 Adjusting the system flow and setting the switch point of the FTSA11

The pump flow should be adjusted according to the required flow of the connected drives. Before
adjusting the flow, the primary circuit has to be correctly filled and de-aired. The target flow can be
calculated by adding up the nominal flow for the main drives connected to the HX-unit. For
information on how to calculate the optimum system flow see the example below.
To adjust the system flow:
1. Start up the pump and run it at 50 Hz, which is the default value in the HX control unit
application.
2. Check the actual flow speed in percent from the flow switch FTSA11 and convert it into l/min
by using the flow speed diagram 5.4-1 5.4-4 (depending on the amount of glycol) or by using
the converting formula.
3. Adjust the frequency of the pump to match the required total nominal flow + 10% (see
example).
Exampl e: If you are using 3 x Ch74 drive, the nominal flow according to the NX Liquid drive manual
Local contacts: http:/ / dr ives.danfoss.com/ danfoss- dr ives/ local - contacts/
®
de-airing.
function.
VACON 4 1
nel). If the pump
5