Siemens 6RA70 Series Instructions Manual page 105

Microprocessor-based converters from 15a to 1680a for variable speed dc drives
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  • Faq (4 pages)
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Fault
No.
Cause as a function of fault value
(r047.001, r949.001 or r949.009 with acknowledged error)
The drive has reached the positive torque limit even though the applied field current setpoint is still ≥ 50% of P102
12
(I F,motor )
Possible cause:
Armature current is very "unsteady", e.g. due to high speed controller P gain setting in P225 (on drive with high integral-
action time). In this case, setting a lower actual speed filtering value in P200 and execution of another speed controller
optimization run (P051=26) may help.
Check torque limits
The drive has reached the positive armature current limit even through the applied field current setpoint is still ≥ 50% of
13
P102 (I F,motor )
Possible cause:
Armature current is very "unsteady", e.g. due to high speed controller P gain setting in P225 (on drive with high integral-
action time). In this case, setting a lower actual speed filtering value in P200 and execution of another speed controller
optimization run (P051=26) may help
Check armature current limits
14
The speed has changed by more than 12.5% at a constant speed setpoint even through the applied field current setpoint is
still ≥ 50% of P102 (I F,motor )
Possible cause: as for fault value 12
15
The EMF setpoint is too small to plot a field characteristic
EMF set = U A – I A,motor * R A = P101 – P100 * P110 < 10% of 1.35 * P078.i001
(e.g. P078.i001 = 400 V . . . minimum EMF set = 54 V)
16
Field weakening operation is not allowed in operation without a tachometer (P083=3)
17
The field current controller cannot be optimized because the field circuit time constant cannot be determined (actual field
current does not decay after switch-off to below 0.95*initial value within approximately 1s or to below 0.8 * 0.95*initial
values within approximately 2 s)
Possible cause:
Setting in P103 is too high
Field circuit inductance is too high
Fault in actual field current sensing circuit (gating board or A7001 electronics board defective)
Ratio r073.02 / P102 is too high (change P076.02 if necessary)
18
Field weakening range is too wide, i.e. during power-up (at full field) to a speed setpoint of +10% n max , the |EMK| is > 77%
of setpoint EMF (P101 – P100 * P110)
Possible cause:
Maximum speed setting is incorrect
Pulse encoder parameters are incorrect (P140 to P143)
Parameters for tachometer adaptation are incorrect (P741)
Setpoint EMF is not correct (P101, P100, P110)
An excessively high load torque (in positive or negative direction, e.g. a suspended load) causes the drive to rotate, one
of the armature current or torque limits may be parameterized too low
19
A steady-state actual speed of +10%, +20%, +30% . . . or +100% of the maximum speed cannot be reached within 3
minutes (or maximum value of the three set acceleration times) in speed-controlled operation (the speed setpoint/actual
value difference averaged over 90 firing cycles must equal <0.1% n max for a specific time period)
Possible cause:
Acceleration time is set too low (P303, P307, P311)
Drive is blocked
An excessively high load torque (in positive or negative direction, e.g. a suspended load) causes the drive to rotate, one
of the armature current or torque limits may be parameterized too low
Poor speed controller setting (P225, P226, P228) or speed controller is parameterized as pure P controller or with
droop
A band elimination filter (P201, P202 or P203, P204) is active
Command "Ramp-function generator enable" =0 or "Ramp-function generator STOP" =1 is applied
9-16
Description
Further information (r047.002 to r047.016)
SIMOREG DC Master Base Drive Panel Operating Instructions
Siemens Energy & Automation

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