ABB 615 Series ANSI, Техническое руководство, Страница: 225 / 713

Section 4
1MAC050144-MB C
Protection functions
218 615 series ANSI
Technical Manual
The physical and dielectric insulations of the system deteriorate with age and the
deterioration is accelerated by the temperature increase. Insulation life is related to the
time interval during which the insulation is maintained at a given temperature.
An induction motor stalls when the load torque value exceeds the breakdown torque value,
causing the speed to decrease to zero or to some stable operating point well below the rated
speed. This occurs, for example, when the applied shaft load is suddenly increased and is
greater than the producing motor torque due to the bearing failures. This condition
develops a motor current almost equal to the value of the locked-rotor current.
51LR is designed to protect the motor in stall or mechanical jam situations during the
running state. To provide a good and reliable protection for motors in a stall situation, the
temperature effects on the motor have to be kept within the allowed limits.
4.1.12.6 Signals
Table 211: 51LR Input signals
Table 212: 51LR Output signals
4.1.12.7 Settings
Table 213: 51LR Non group settings
4.1.12.8 Monitored data
Table 214: 51LR Monitored data
Name Type Default Description
I_A SIGNAL 0 Phase A current
I_B SIGNAL 0 Phase B current
I_C SIGNAL 0 Phase C current
BLOCK BOOLEAN 0=False Block signal for activating the blocking mode
Name Type Description
TRIP BOOLEAN Trip
Parameter Values (Range) Unit Step Default Description
Operation 1=Enable
5=Disable
1=Enable Operation Disable / Enable
Pickup value 0.10...10.00 xln 0,01 2.50 Pickup value
Trip delay time 100...120000 ms 10 2000 Trip delay time
Reset delay time 0...60000 ms 1 100 Reset delay time
Name Type Values (Range) Unit Description
PICKUP BOOLEA
N
0=False
1=True
Pickup
PICKUP_DUR FLOAT32 0.00...100.00 % Ratio of pickup time / trip time
51LR Enum 1=enabled
2=blocked
3=test
4=test/blocked
5=disabled
Status