Danfoss VACON NX Commissioning And Maintenance Manual page 53

TROUBLESHOOTING
If the high temper atur e shutoff is active (same panel layout as high temperature alarm) the HX-unit
indicator lights on the electrical box door are active. The reasons for this shutoff are the same as for
the high temperature alarm.
If the l ow temper atur e al ar m is active (acc. to panel below) the HX-unit is still online and the
electrical box door are also active. Check the following issues to solve why the alarm has been
activated:
RUN READY ALARM
F1.
I/ O ter m
86 LowTemp
A T1 T16
Mal function
The regulating valve
V130 (refer to the
P&ID) is
malfunctioning
The FTSA11 (refer to
the P&ID) flow
sensor with the
analogical
temperature outlet
is malfunctioning.
Table 7.1-3, Low temperature fault detection
Local contacts: http:/ / dr ives.danfoss.com/ danfoss- dr ives/ local - contacts/
 Figure 7.1-3, Low temperature alarm on the NXP panel
Reasons for mal function
The 3-way valve V130 is
malfunctioning
therefore directing too
much flow through the
plate heat exchanger.
The inlet temperature on
the secondary circuit is
decreasing too fast,
and the 3-way valve is
not able to adjust the
flow in the secondary
circuit fast enough
The FTSA11 flow sensor
with the analogical
temperature outlet is
broken.
Cor r ection measur es
Run the actuator calibration according to the
and instructions found in the HX-unit manual
that is supplied with the unit, i.e. set the
actuator Dip-
actuator is
procedure it is broken and has to be
replaced.
Wait for two minutes and see if the alarm is
reset automatically. If the alarm is active
longer than two minutes, check the 3-way
valve actuator is malfunctioning it must be
replaced. If the temperature in the primary
circuit is too low it will
condensation in the main drive section. No
condensation is allowed.
The temperature in the secondary circuit
should not be allowed to decrease or
increase too fast. A change of 1°C / minute
should not be exceeded.
Check the temperature by comparing the
FTSA11 temperature with the secondary
circuit temperature indicator TI21. The
temperature of FTSA11 should be higher
than the TI21 temperature. Replace the
FTSA11 if necessary.
If a TI21 is not installed then check the primary
circuit temperature (using a portable
measuring device) and compare it to
FTSA11. To get an accurate value the
portable temperature gauge must be
connected close to the FTSA11. Replace
the FTSA11 if necessary.
VACON
not moving during
-way valve or the
result
5 3
this
in
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