Trips and Fault Finding
7-9
590+ Series DC Digital Converter
Trip Message and Meaning
Possible Reason for Trip
SPEED FEEDBACK
The difference between speed feedback
and armature voltage feedback is
greater than the SPDFBK ALM LEVEL
parameter value
If FLD WEAK ENABLE parameter is
enabled, speed feedback is less than
10% when in the field weakening region
Analog tacho feedback polarity incorrect (terminals
G3 and G4)
The ENCODER SIGN parameter’s polarity is incorrect
Disconnection of wiring, including fibre optics
Tachogenerator failure
Tachogenerator coupling failure
Alarm time delay : 0.4 seconds
ENCODER FAILED
No speed feedback signal
The SPEED FBK SELECT parameter is set to ENCODER
but an optional Encoder board is not fitted
Where applicable, check fibre optic cable for
damage, bend radius, operating length - refer to
Microtach handbook.
Check cable and connections on wire-ended encoder
FIELD FAIL
Field current is less than 6% of rated
current when in Current Control mode
Field current is less than 50mA when in
Voltage Control mode (with default
current burden of 15K)
Open circuit motor field - check connection and
measure field resistance
Faulty operation of field controller
Where an ac supply feeds the onboard field
regulator, check connections FL1 & FL2 for line-to-line
voltage (rather than line-to-neutral) - L1 into FL1, L2
into FL2. Note that the 3-phase supply must be
present for mains synchronisation purposes.
For loads where no field supply is required, e.g. a
permanent magnet motor, set the FIELD ENABLE
parameter to disable to suspend this alarm.
Alarm time delay : 0.75 seconds
3-PHASE FAILED
3-phase supply failure
Total failure of supply, or missing phase of 3-phase
supply (detected under most circumstances) - check
supply to the controller, check high-speed thyristor
stack protection fuses, check power chassis coding
fuses.
Check the mains voltage of the Converter (refer to
Product Code). This alarm may not operate properly
with controller if the voltage is incorrect, i.e. wrong
unit or controller.
PHASE LOCK
Supply frequency is outside the
frequency band limits 45 - 65Hz
Check supply frequency
Synchronisation errors caused by distorted supply
5703 RCV ERROR
Invalid data received via P3 port from
another Converter
(Alarm only operates when MODE parameter is set to
5703 SLAVE)
STALL TRIP
With motor stationary (AT ZERO SPEED
parameter shows TRUE), current has
exceeded the STALL THRESHOLD
parameter value for longer than the
STALL TRIP DELAY parameter value
(Alarm only operates when the STALL TRIP parameter
is enabled).