Lenze MC1000 Series - Manual (Page 55)

13435742_EDBM101_v24 51
18 BASE (BASE FREQUENCY)
The BASE FREQUENCY determines the V/Hz ratio by setting the frequency at
which the drive will output full voltage to the motor. For most applications the base
frequency should be set to match the motor’s rated frequency.
For example, if the drive is rated for 460 Vac output, and the BASE FREQUENCY is
set to 60 Hz, the drive will maintain a constant ratio of 7.66 V/Hz (except when AC
BOOST or FX BOOST are active, refer to Parameters 19 and 20) from 0 Hz to 60 Hz.
This range is the region of constant torque. If the motor speed is increased past 60
Hz, the output voltage remains constant while the frequency increases, resulting in a
reduced V/Hz ratio. This range, from 60 Hz to about 90 Hz, is the region of constant
horsepower. Above 90 Hz, horsepower begins to decrease as frequency increases.
Refer to Section 6.1 - DESCRIPTION OF AC MOTOR OPERATION.
19
FX BOOST (FIXED BOOST)
This parameter is used in applications which require high starting torque. FX BOOST
increases the output voltage at lower output frequencies (below 30 Hz for 60 Hz
base frequency), in order to boost the torque capability of the motor. Refer to the
diagram below. The factory default for FX BOOST depends on the horsepower
rating. Refer to the table below:
FX BOOST FACTORY DEFAULT SETTINGS
HP
FACTORY DEFAULT
(ALL VOLTAGES)
HP
FACTORY DEFAULT
(240 / 200 VAC)
FACTORY DEFAULT
(400+ VAC)
0.25 - 1 HP 5.30 % 40 HP 2.30 % 1.20 %
1.5 - 2 HP 4.40 % 50 HP --- 0.80 %
3 HP 3.60 % 60 HP 2.10 % 0.80 %
5 HP 3.00 % 75 HP --- 2.00 %
7.5 HP 2.70 % 100 HP --- 1.90 %
10 HP 2.40 % 125 HP --- 1.90 %
15 HP 2.20 % 150 HP --- 1.80 %
20 HP 2.00 %
25 HP 1.80 %
30 HP 1.60 %