Application - ABB RED615 Technical Manual

Section 4
Protection functions
4.4.3.5
4.4.3.6
4.4.3.7
Table 373: PREVPTOC Group settings
Parameter
Start value
Operate delay time
458
the fault disappears before the module operates, the reset timer is activated. If the
reset timer reaches the value of 200 ms, the operation timer resets and the START
output is deactivated.
The timer calculates the start duration value START_DUR, which indicates the
percentage ratio of the start situation and the set operation time. The value is
available in the monitored data view.

Application

The rotation of a motor in the reverse direction is not a desirable operating
condition. When the motor drives fans and pumps, for example, and the rotation
direction is reversed due to a wrong phase sequence, the driven process can be
disturbed and the flow of the cooling air of the motor can become reversed too.
With a motor designed only for a particular rotation direction, the reversed rotation
direction can lead to an inefficient cooling of the motor due to the fan design.
In a motor, the value of the negative-sequence component of the phase currents is
very negligible when compared to the positive-sequence component of the current
during a healthy operating condition of the motor. But when the motor is started
with the phase connections in the reverse order, the magnitude of I
So whenever the value of I
rotation direction and provides an operating signal that disconnects the motor from
the supply.
Signals
Table 371: PREVPTOC Input signals
Name
I
2
BLOCK
Table 372: PREVPTOC Output signals
Name
OPERATE
START
Settings
Values (Range) Unit
0.05...1.00 xIn
100...60000 ms
exceeds the start value, the function detects the reverse
2
Type Default Description
SIGNAL 0 Negative sequence current
BOOLEAN 0=False Block signal for activating the blocking mode
Type Description
BOOLEAN Operate
BOOLEAN Start
Step Default
0.01 0.75
10 100
1YHT530004D05 D
is very high.
2
Description
Start value
Operate delay time
Technical Manual
615 series