YASKAWA CIMR-LE2A0018DAC Manual De Instrucciones página 6

1 Selecting an L1000E AC Drive for Elevator Applications

Low Speed Operation
Table 1 and Table 2 pertain to motor operation above 6.0 Hz. Elevators applications make use of the L1000E's S-curve
function to limit the rate of change of acceleration ('jerk') to provide an comfortable ride. Acceleration current increases
linearly over the S-curve interval (about 0.5 seconds) while speed and frequency increase simultaneously. A typical 50/60
Hz geared elevator motor will be near or above 6.0 Hz before full acceleration current is required. The 5.0 second
overload capacities in Table 2
Some elevator applications require the drive to spend a significant portion of the acceleration time below 6.0 Hz. L1000E
current capacity must be de-rated below 6.0 Hz to maximize the life of its IGBTs. Consequently the L1000E current
capacity is decreased from 100% at 6.0 Hz and above, to 50% at 0.0 Hz (DC). The de-rating is linear as depicted in the
graph below.
The operating frequency at which the motor reaches full acceleration torque should be used as the basis for low-frequency
de-rating.
Figure 1

Using Torque Boost

Function Description
Automatic Torque Boost [L8-38] is useful in elevators that experience occasional high starting current due to overload.
Enable the Automatic Torque Boost Function [L8-38=3] to boost motor torque during heavy load conditions. The
L1000E automatically reduces the carrier frequency to 3.0 kHz to make increased current available when the starting
current is about to exceed the current level as indicated in
as the heavy load condition subsides.
Note: Audible motor noise will increase when the Automatic Torque Boost function is operates.
Parameter Name
L8-38 (Automatic Torque Boost Selection)
L8-39 (Reduced Carrier Frequency)
6
assume the drive is operating near or above 6.0 Hz before it achieves full acceleration.
100%
50%
Output Frequency/Motor Speed
Figure 1 Low Speed Operation De-rating
Automatic Torque Boost Function Parameters
6 Hz/180 RPM (4 pole motor)
Table 2. The carrier frequency will return to the [C6-03] value
Setting
0: Disabled (Default) 3: Enabled
3.0 kHz (Default) (Range: 1.0 to 15.0 kHz)
YASKAWA AN.L1E.02 L1000E AC Drive Selection Application Note