OPERATION
Protection Features
75
Protection Features
High Load Detection
High Load Detection (HLD) protects the VFD and equipment against damage from an over-torque condi
-
tion. Two options are available:
•
HLD by Current:
The VFD trips when current is above
HLD Level [SET-48]
with frequency equal to or
greater than
HLD Freq [SET-49]
for a duration of
HLD Delay [SET-50]
.
•
HLD by Torque:
The VFD calculates a High Load Torque Limit
curve across the full frequency range based on motor
parameters, VFD Base Frequency, and HLD settings. The VFD
then trips when torque rises above this curve with frequency
equal to or greater than
HLD Freq [SET-49]
for a duration of
HLD
Delay [SET-50]
. This feature is primarily used for centrifugal
loads such as centrifugal pumps or fans. It is not recom
-
mended for progressive cavity pumps or constant torque
loads.
To enable High Load Detection, adjust the following parameters:
HLD Select [SET–47]:
Disable, By Current, or By Torque.
HLD Min Torque [PROT–58]:
Only if using HLD by Torque, set
minimum torque level percentage at 0 Hz. Default = 10%.
HLD Level [SET–48]:
For HLD by Current, set as a percentage of motor FLA (SFA) (default = 110%). For HLD
by Torque, set as a percentage of nominal torque at base frequency. If all conditions are met, VFD will trip
above this level.
HLD Frequency [SET–49]:
Set minimum frequency for HLD by Current or Torque detection.
HLD Delay [SET–50]:
Delay range from 0 to 360 seconds. When timer expires, if current or torque is still
above limits and frequency is still above [Set–49], VFD will trip based on [Set–47].
HLD Recovery Time [SET–51]:
0 to 720 min (default = 0 min). If timer is set to value greater than 0 minutes,
VFD will restart after timer expires. If set to 0 and the VFD trips, manual or remote reset is required (no auto
retries).
If the VFD trips the first time on high load, it will restart after the Recovery timer expires. If VFD trips
again, the timer value will be doubled. The VFD will continue restart attempts, doubling the timer value
until it reaches 720 minutes (12 hours). Then every restart will be in 720 min.
HLD Recover Cnt [SET–
52]
displays the countdown before the next restart attempt.
When the VFD finally runs without tripping for 180 sec, the recovery timer will be reset to original set
-
ting and at next high load trip VFD will wait for original [Set–51] time value.
If the run command is removed, or HOA is set to OFF, the high load feature is canceled and the [Set–51]
timer is reset to its original setting.
Fine Tune Settings for HLD by Torque
1.
Verify accuracy of Motor FLA (SFA) [Set–03], Motor Voltage [Set–05], and VFD Base Freq [VFD–02].
These values determine nominal torque.
2. Adjust HLD Frequency [Set–49] to be equal to minimum operational frequency [Set–13] or [Set–22].
3. Run motor at minimum frequency and verify water movement for pump or air movement for fans.
Nominal Torque
Percent
High Load Torque
Limit
Nominal Torque Load
Base Freq VFD-02
HLD Freq SET-49
HLD Level SET-48
HLD Min PROT-58
Nominal Torque 100%
Summary of Contents for Cerus X-Drive
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Page 3: ...CERUS X DRIVE INSTALLATION AND OPERATION MANUAL Firmware Version 1 1 Franklin Electric Co Inc ...
Page 94: ...COMMUNICATIONS BACnet Communication 94 ...
Page 98: ...ACCESSORIES Optional Extension Cards 98 Frame D Frame E Frame F ...
Page 99: ...ACCESSORIES Optional Extension Cards 99 Frame G Frame H ...
