Goodrive270 series VFD for fan and pump Basic operation guidelines
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5.5.19 Motor reducing
Output
frequency
t
Run
status
RO2
Motor
connected
to RO1
1
2
3
ǏP94.26ǐ
ǏP94.28ǐ
ǏP94.25ǐ
ǏP94.20ǐ
Figure 5±9 Motor reducing timing diagram
During VFD running, if the output frequency is equal to or lower than P94.25 (Running frequency for
motor reducing), PID1 feedback is less than the difference between PID1 reference and P94.24
(Pressure tolerance for motor reducing), and this condition lasts a period of time longer than P94.26
(Motor reducing delay), the motor reducing function is triggered.
If P94.27 (Variable-frequency motor action for motor reducing) is set to 1, the VFD not only
disconnects the relay but also increases the output frequency to P94.20 (Running frequency for motor
adding) within the time specified by P94.28 (ACC time for motor reducing).
When the ACC is completed or P94.27 is set to 0, the VFD disconnects the relay corresponding to the
power-frequency motor.
5.5.19.1 Automatic polling
The automatic polling function can achieve two goals: First, to keep the run time of each pump/fan the
same to balance the loss; Second, to prevent any pump/fan from stopping for too long, which could
lead to blocking.
When the initial motor running time exceeds P94.34 (Variable-frequency motor polling cycle) and the
present frequency is higher than P94.35 (Polling running frequency threshold), the VFD starts
automatic polling in the way of adding a motor first and then reducing a motor. Then the second-run
motor becomes the first-run motor, and the polling time is calculated again. During normal use, the
polling time is also recalculated for motor reducing.
5.5.19.2 Automatic sleep
Function code P94.01 specifies the sleep method. When the condition specified by P94.02 or P94.03
and the condition lasts the time specified by P94.04, the PID increases by P94.05 (PID boost value
for sleep) with a duration specified by P94.06 (PID boost time), and the VFD enters the sleep state.
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