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Section 12 Troubleshooting
Fault
At target cos phi=1 and inductive load,
switch-off or connection of capacitor in
the corrected line
Supply / Drawing mismatched
Wrong line cos phi is displayed
Display:"UNDER CURRENT"
Display: "OVERCURRENT"
Alarm relay: after 1 min.
Display: "UNDERCOMPENSATED"
Alarm relay: after 1 min.
Display: "OVERCOMPENSATED"
Alarm relay: after 1 min.
Display: "MEASUREMENT VOLTAGE ???"
Alarm relay: after 1 min.
Display: "OVERTEMPERATURE"
Alarm relay: after 1 min.
Stages are disconnected for an inductive
line or connected for a capacitive line
The controller does not connect all
stages, or cos phi does not change at the
last stages
In automatic operation, individual stages
are not connected or disconnected
In strongly asymmetrically loaded lines,
differences may occur between control
r e s p o n s e
a n d
measurement, as the power factor is
measured in single phase.
No operating voltage
Check / Solution
Check terminals of the measuring voltage and
current (l and k)!
Check phase position
See above
Current in measuring range?
Line interruption?
Wrong current-converter factor?
Current transformer short-circuited?
Check current-converter ratio
Go through measuring current range
Check connection and phase position!
All stages connected - target cos phi not
reached: compensation network sufficiently
dimensioned?
Check connection and phase position!
Capacitive grid, although all stages
disconnected
No measurement voltage!
Cabinet temperature too high: Outputs are
switched off in stages irrespective of power-line
conditions
If a target cos phi is set which deviates from 1
despite an inductive line load, the display <
(disconnect stages) may light up. The arrows
indicate the control direction and not the line
conditions.
Check END STOPP !
Check whether individual stages are
programmed as fixed stages or OFF in the
"Manual operation / Fixed stages" menu!
Line measurements allow the most favorable
phase for measuring the power factor to be
p o w e r - f a c t o r
determined. The current converter is set
accordingly for the measuring current.
Note: No display, alarm relay is activated
(open)
- 16 -
Prophi
6T
®
17
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