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Incorrect phase sequence
protection I
>> (47)
2
Stall protection I
> (48)
st
Recorded values of the latest eight faults
Detailed information is available on the eight latest faults: Time
stamp, unbalance current, elapsed delay and setting group.
Table 3.11 – Recorded values of the current unbalance stage (8 latest faults) I
Parameter
Value
yyyy-mm-dd
hh:mm:ss.ms
Flt
EDly
SetGrp
1
2
The phase sequence stage prevents the motor from running in the
wrong direction, thus protecting the load.
When the ratio between negative and positive sequence current
exceeds 80%, the phase sequence stage starts and trips after 100 ms.
Table 3.12 – Parameters of the Incorrect Phase Sequence Stage: I
Parameter
Measured
I2/I1
value
Recorded
SCntr
values
TCntr
Flt
EDly
The stall protection unit I
component of the phase currents.
Stage I
> can be configured for definite time or inverse time
st
operation characteristic.
The stall protection stage protects the motor against prolonged starts
caused by e.g. a stalled rotor. While the current has been less than
I
for at least 500 ms and then within 200 milliseconds exceeds
STOP
I
the stall protection stage starts to count the operation time T
StartMin
according to Equation 3.2. The equation is also drawn in Figure 3.12.
When current drops below 120 % x I
releases. Stall protection is active only during the start of the motor.
Protection Functions
Unit
Description
Time stamp of the recording, date
Time stamp, time of day
%Imot
Maximum unbalance current
%
Elapsed time of the operating time setting.
100% = trip
Active setting group during the fault
Value/unit
%
Neg. phase seq. current/pos. phase
seq. current
Start counter (Start) reading
Trip counter (Trip) reading
%
Max. value of fault current
%
Elapsed time as compared to the set
operate time, 100% = tripping
> measures the fundamental frequency
st
the stall protection stage
mot
3-19
> (46)
2
>> (47)
2
Description
857-UM001A-EN-P – July 2009
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