39 SM01P
NOTE
If this parameter is changed while the drive is running, the new value will not take
effect until the drive is stopped.
P25 CURRENT LIMIT
P25 sets the maximum allowable output current of the drive. The maximum setting is
either 180% or 150%, depending on whether LINE VOLTAGE SELECTION (Parameter
01) is set to HIGH or LOW.
If the load demands more current than the CURRENT LIMIT setting, the drive will reduce
the output frequency in an attempt to reduce the output current. When the overcurrent
condition passes, the drive will accelerate the motor back up to the speed setpoint.
P26 MOTOR OVERLOAD
The SCL/SCM Series is UL approved for solid state motor overload protection, and
therefore does not require a separate thermal overload relay for single motor applications.
This circuit allows the drive to deliver up to 150% current for one minute. If the overload
circuit “times out”, the drive will trip into an OVERLOAD fault (displayed as "PF"). MOTOR
OVERLOAD should be set to the ratio (in percent) of the motor current rating to the drive's
output current rating to properly protect the motor.
Example: A 3 HP, 480 Vac drive with a 4.8 Amp rating is operating a 2 HP motor with a
current rating of 3.4 Amps. Dividing the motor current rating by the drive's output current
rating yields 71% (3.4 / 4.8 = 0.71 = 71%), so this parameter should be set to 71%.
P27 BASE FREQUENCY
The BASE FREQUENCY determines the V/Hz ratio by setting the output frequency at
which the drive will output full voltage to the motor. In most cases, the BASE FREQUENCY
should be set to match the motor’s rated frequency.
Example: A 230 Vac, 60 Hz motor requires a V/Hz ratio of 3.83 (230 V / 60 Hz = 3.83
V/Hz) to produce full torque. Setting the BASE FREQUENCY to 60 Hz causes the drive
to output full voltage (230 Vac) at 60 Hz, which yields the required 3.83 V/Hz. Output
voltage is proportional to output frequency, so the 3.83 V/Hz ratio is maintained from 0
- 60 Hz, allowing the motor to produce full torque from about 2 Hz (below 2 Hz there is
less torque due to slip) up to 60 Hz.
NOTE
If this parameter is changed while the drive is running, the new value will not take
effect until the drive is stopped.
To Next Page
Loading...
Need help?
General
