Troubleshooting; Alarms And Shutoffs; Chapter 5.3.2, Application Parameter; Flowfault - Danfoss VACON NX Commissioning And Maintenance Manual

TROUBLESHOOTING

7. TROUBLESHOOTING
7.1 Al ar ms and shutoffs
This chapter provides help in case the HX-control unit activates an alarm or fault. An alarm or fault
is activated, because the HX-unit is working outside the parameter settings in the HX-control unit.
The pre-set parameters for the HX-unit are shown in
7.1.1 Flow fault
If the fl ow faul t shutoff is active (acc. to panel below) the HX-unit pump has stopped and the
box door is also active. Check the following issues to solve why the alarm has been activated:
STOP
F1.
I/ O ter m

87 FlowFault

F F1 F11
Figure 7.1-1, Flow fault on the NXP panel
Mal function
The pre-pressure is
too low in the
primary circuit, i.e.
below 0.5 bar.
delivering enough
pressure i.e. the
flow is too low.
The FTSA11 is set
incorrectly (this is a
fault that is most
likely to appear
during maintenance
or at the
commissioning
stage).
Table 7.1-1, Flow fault detection
Local contacts: http:/ / dr ives.danfoss.com/ danfoss- dr ives/ local - contacts/
FAULT

Reasons for mal function
•
The pre-pressure in the
expansion vessel EV11
has been reduced.
•
There is a leak in the
primary circuit.
A valve in the primary
circuit is closed.
The pump is broken.
•
The flow requirement
has changed after the
commissioning stage.
•
The FTSA11 setup
values have been poorly
adjusted during
commissioning.

chapter 5.3.2, Application parameter

Cor r ection measur es
Check the EV11 pre-pressure and add
pressure if necessary.
Add pre-pressure to the primary circuit by
adding liquid through valve V161.
Check the primary circuit for leaks. If a leak
is found the unit must be drained and
the leak fixed before the unit is
restarted.
Check if any of the following valves in the
primary circuit is closed (refer to the
P&ID):
•
V140
•
V310...3xx
•
Any valves in the primary
circuit added by the
customer
Replace the broken pump.
Check the current flow requirements, they
might have changed if e.g. an AC drive is
taken offline (and its valves closed)
because of maintenance.
Check the required flow values for the AC
drives and readjust the alarm set point
on the FTSA11 (refer to
Adjusting the system flow and setting
the switch point of the
VACON 5 1
list.
chapter 5.4.2
FTSA11).
7