frako PQC - Troubleshooting; Alarm and Fault Resolution Guide

Troubleshooting | 73
FRAKO | Operating Manual | Power Quality Controller – PQC
9 Troubleshooting
If alarms occur during operation of the PQC, the following table provides assistance
in identifying and remedying the faults.
Alarm
message
Fault Possible cause Remedial action
PQC not working;
no display at front of
instrument
No power – or the wrong
voltage – connected
Check that the correct
instrument power supply
is connected and that
the fuse in the circuit has
not blown.
cosφ cannot
be achieved
PQC gives a cosφ alarm
although the momentary
cosφ is better (nearer to
1) than the target value.
More capacitive than
the control band but still
inductive
See Section 6.3.4.2
“Cosφ Alarm”
for control band alarm
settings.
See Section 6.3.4.2
“Cosφ Alarm”
for control band alarm
settings.
Voltage < set
limit
PQC indicates or states
that voltage is less than
set alarm limit, although
a voltage is shown on
the screen.
The alarm limit has not
been adjusted for the
network nominal voltage.
Default setting is for 400
V networks.
Triggered when the
network voltage is less
than 85 % of the nominal
voltage.
Set the correct alarm
limit for the network
nominal voltage (see
Section 6.3.1 “System
parameters”)
Current < set
limit
No value for current
shown in the display
(0 A)
Break or short-circuit in
the current transformer
cable
Use an ammeter to
check current in current
path (I
min
* 0.015 A).
Danger: see
Section 5.2.7 “Current
measurement”
The current in the current
path is too low.
(I
min
* 0.015 A)
Install a smaller current
transformer.
Defective current
transformer
Check the current
transformer.
Voltage <
set limit +
Current < set
limit
PQC shows no meas-
ured voltage and no
current, although it has
been verified that power
is connected and a
current is flowing.
Multiple zero-voltage
crossings in measured
voltage.
Settings for the Network
nominal parameters
–> Change setting from
Auto to the appropriate
network frequency (50
Hz or 60 Hz).