Lenze SCL series Installation And Operaion Manual page 43

NOTE
If ths parameter s changed whle the drve s runnng, the new value wll not take
effect untl the drve s stopped .
P25 CURRENT LIMIT
P25 sets the maxmum allowable output current of the drve . The maxmum settng s
ether 180% or 150%, dependng on whether LINE VOLTAGE SELECTION (Parameter
01) s set to HIGH or LOW .
If the load demands more current than the CURRENT LIMIT settng, the drve wll reduce
the output frequency n an attempt to reduce the output current . When the overcurrent
condton passes, the drve wll accelerate the motor back up to the speed setpont .
P26 MOTOR OVERLOAD
The SCL/SCM Seres s UL approved for sold state motor overload protecton, and
therefore does not requre a separate thermal overload relay for sngle motor applcatons .
Ths crcut allows the drve to delver up to 150% current for one mnute . If the overload
crcut "tmes out", the drve wll trp nto an OVERLOAD fault (dsplayed as "PF") . MOTOR
OVERLOAD should be set to the rato (n percent) of the motor current ratng to the drve's
output current ratng to properly protect the motor .
Example: A 3 HP, 480 Vac drve wth a 4 .8 Amp ratng s operatng a 2 HP motor wth a
current ratng of 3 .4 Amps . Dvdng the motor current ratng by the drve's output current
ratng yelds 71% (3 .4 / 4 .8 = 0 .71 = 71%), so ths parameter should be set to 71% .
P27 BASE FREQUENCY
The BASE FREQUENCY determnes the V/Hz rato by settng the output frequency at
whch the drve wll 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 requres a V/Hz rato of 3 .83 (230 V / 60 Hz = 3 .83
V/Hz) to produce full torque . Settng the BASE FREQUENCY to 60 Hz causes the drve
to output full voltage (230 Vac) at 60 Hz, whch yelds the requred 3 .83 V/Hz . Output
voltage s proportonal to output frequency, so the 3 .83 V/Hz rato s mantaned from 0
- 60 Hz, allowng the motor to produce full torque from about 2 Hz (below 2 Hz there s
less torque due to slp) up to 60 Hz .
NOTE
If ths parameter s changed whle the drve s runnng, the new value wll not take
effect untl the drve s stopped .
39 SM01M