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OPERATION
Control Options
80
Performance Control Features
Acceleration/Deceleration Control
Standard Rates
The VFD accelerates and decelerates a motor in VFD control mode (PID is off) at a controlled rate based on
the following parameters:
Accel Time [SET–11]:
Time in seconds for the drive to accelerate from 0 Hz to maximum frequency.
Decel Time [SET–12]:
When
Stop Mode [SET–16]
is set to Decelerate, time in seconds to slow down from maxi
-
mum frequency to 0 Hz.
The defaults for these parameters are determined by the
Application Sel [SET–00]
setting, but can be adjusted
as required.
IMPORTANT:
Setting acceleration or deceleration times that are too short may trigger over-current or over-
voltage faults. Use of a suitable dynamic breaking unit/resistor can help with short deceleration times.
NOTE:
When PID is enabled, the VFD will ramp up to PID Low Freq Limit at
[SET-11]
rate and then it will follow
the rate calculated by PID control. During deceleration, the VFD will follow PID deceleration rate down to
PID Low Freq Limit and then will follow
[SET-12]
rate.
Change by Frequency
Acceleration and deceleration rates can be changed when the VFD
reaches a target frequency. For example: It may be desirable to start a
motor quickly, as with a submersible pump, and then slow the
response at higher speeds.
The VFD starts at the Standard rate and switches to
Second ACC [SET–54]
and
Second DEC [SET–55]
when it reaches
ACC Change Freq [SET–53].
When the
VFD decreases frequency below
[SET–53]-[SET–56]
it will switch back to
the Standard rates.
ACC Change Freq [SET–53]:
Frequency to switch from Standard
acceleration/deceleration rate to second acceleration/deceleration rate.
Second ACC [SET–54]:
Time in seconds for drive to accelerate from 0 Hz to maximum frequency. This rate
takes effect when frequency is above
[SET–53]
. Default = 60 sec.
Second DEC [SET–55]:
When
Stop Mode [SET–16]
is set to Decelerate, time in seconds to slow down from max
-
imum frequency to 0 Hz. This rate takes effect when frequency is above
[SET–53]
. Default = 60 sec.
ACC/DEC Hyster [SET–56]:
Hysteresis sets the difference between 2nd ACC/DEC rates activation and
deactivation frequencies. This setting is subtracted from
[SET–53]
to delay the switch back to the
[SET–12]
rate.
Default = 1.0 Hz.
Hopping Carrier [VFD-45]:
When enabled, VFD will automat
-
ically change carrier frequency from 2 to 5kHz (Depends on
the drive frame size) in predetermined offset pattern to mini
-
mize audible noise from the motor.
H-Carrier Pitch [VFD-58]
: Determines the running duration
for each carrier frequency value.
Hz
Hi Hz Limit
[SET-23]
Lo Hz Limit
[SET-22]
ACC Change Freq
[SET–53]
ACC/DEC Hyster
[SET–56]
Time
2nd Accel/Decel
1st Accel/Decel
Hopping Carrier Frequency
|->
Next Cycle
5 kHz
4.5 kHZ
4 kHz
3.5 kHz
3 kHz
2.5 kHz
2 kHz
0.1s
0.1s
0.1s
0.1s
0.1s
0.1s
0.1s
0.1s
0.1s
Time
Summary of Contents for CERUS X-DRIVE CXD-003A-4V
Page 2: ......
Page 3: ...CERUS X DRIVE INSTALLATION AND OPERATION MANUAL Firmware Version 1 2 Franklin Electric Co Inc ...
Page 96: ...OPERATION Protection Features 96 ...
Page 112: ...ADVANCED APPLICATION OPTIONS Multi Drive Configurations 112 ...
Page 124: ...COMMUNICATIONS BACnet Communication 124 ...
Page 128: ...ACCESSORIES Optional Extension Cards 128 Frame D Frame E Frame F ...
Page 129: ...ACCESSORIES Optional Extension Cards 129 Frame G Frame H ...
Page 132: ...ACCESSORIES Optional Extension Cards 132 ...
Page 234: ...PARAMETER REFERENCE TABLES Parameter Descriptions Motor Menu 234 ...
Page 250: ...GLOSSARY 250 ...