LEESON Micro Series Compact Inverters - Manual (Page 56)

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NOTE 1: 240/120 Vac units have the same limits as 240/200 Vac units .
NOTE 2: The parameter value can be set below the minimum value shown, but the value shown is the
operational limit of the drive. For example, if DECEL is set for 0.1 seconds on a 10 HP drive without
dynamic braking, the actual deceleration time would be 0.3 seconds.
If an attempt is made to decelerate a high-inertia load too quickly, the motor will regenerate voltage back
into the drive . This will cause the DC bus voltage to rise, which can result in a HI VOLTS fault . In order
to prevent faulting, the drive will enter DECEL FREEZE, which halts the deceleration until the DC bus
voltage returns to a normal level . The drive will then begin to decelerate again, and if necessary, will enter
DECEL FREEZE repeatedly to avoid faulting . If a very short deceleration time is programmed, DECEL
FREEZE may not be able to compensate fast enough, resulting in a HI VOLTS fault .
In applications where very short deceleration times are required on high-inertia loads, dynamic braking may
be required. Consult the factory for more information on the Dynamic Braking option.
10 MIN FRQ (MINIMUM FREQUENCY)
This parameter defines the lower limit of the drive’s speed range. MIN FRQ is used in conjunction with
MAX FRQ (Parameter 11 below) to define the operating range of the drive.
If MIN FRQ is set to a value above 0.0 Hz, the drive will ramp up from 0.0 Hz when given a start
command . Once running, however, the drive will not operate below the MIN FRQ setting unless the
rotation is changed, or a stop command is issued and the drive is programmed to ramp to a stop .
If the MINIMUM FREQUENCY is set to 0.0 Hz, the drive may be operated in ZERO SPEED mode
(drive is in RUN state, but there is no output to the motor). ZERO SPEED operation can be used in
applications requiring the ability to start and stop the drive using only the selected speed reference. The drive
will start when the speed reference is raised above 0 VDC or 4 mA, and it will stop when the reference is
lowered to 0 VDC or 4 mA . Note that the drive must be initially started using one of the normal start commands
(keypad or terminal strip).
DECELERATION LIMITS
HORSEPOWER/VOLTAGE RATING DECEL RANGE
240/200 Vac
480/400 Vac 590/480 Vac WITHOUT DB
MODELS
MODELS MODELS (NOTE 2)
WITH DB
(NOTE 1)
0 .25 - 7 .5 HP 1 - 7 .5 HP N/A 0 .3 - 3600 SEC 0 .1 - 3600 SEC
10 - 15 HP 10 - 20 HP 1 - 7 .5 HP 0 .5 - 3600 SEC 0 .1 - 3600 SEC
20 - 30 HP 25 - 60 HP 10 - 20 HP 1 .0 - 3600 SEC 0 .2 - 3600 SEC
N/A N/A 25 - 60 HP 2 .0 - 3600 SEC 0 .2 - 3600 SEC
N/A 75 HP N/A 3 .0 - 3600 SEC 0 .8 - 3600 SEC
N/A 100 - 150 HP N/A 7 .0 - 3600 SEC 1 .8 - 3600 SEC