YASKAWA A1000 Technical Manual page 597


L1-01 Motor Overload Protection Selection
The drive has an electronic overload protection function (oL1) based on time, output current, and output frequency,
which protects the motor from overheating. The electronic thermal overload function is UL-recognized, so it does not
require an external thermal relay for single motor operation.
This parameter selects the motor overload curve used according to the type of motor applied.
Setting
0 Disabled
1 Standard fan cooled motor (default)
2 Drive duty motor with a speed range of 1:10
3 Vector motor with a speed range of 1:100
4 Permanent Magnet motor with variable torque
5 Permanent Magnet motor with constant torque
6 Standard fan cooled motor (50 Hz)
When connecting the drive to more than one motor for simultaneous operation, disable the electronic overload protection
(L1-01 = 0) and wire each motor with its own motor thermal overload relay.
Enable the motor overload protection (L1-01 = 1 to 6) when connecting the drive to a single motor, unless another motor
overload preventing device is installed. The drive electronic thermal overload function causes an oL1 fault, which shuts
off the output of the drive and prevents additional overheating of the motor. The motor temperature is continually
calculated as long as the drive is powered up.

L1-02 Motor Overload Protection Time
Setting Range: 0.1 to 5.0 min
Factory Default: 1.0 min
Parameter L1-02 determines how long the motor is allowed to operate before the oL1 fault occurs when the drive is
running at 50 Hz and at 150% of the full load amp rating (E2-01) of the motor. Adjusting the value of L1-02 can shift the
set of oL1 curves up the y axis of the diagram below, but will not change the shape of the curves.
Figure D.9
YASKAWA ELECTRIC SIEP C710616 27G YASKAWA AC Drive A1000 Technical Manual
Table D.12 Overload Protection Settings
Disabled the drive's internal motor overload protection.
Selects protection characteristics for a standard self cooled motor with limited cooling capabilities when running below
the rated speed. The motor overload detection level (oL1) is automatically reduces when running below the motor rated
speed.
Selects protection characteristics for a motor with self-cooling capability within a speed range of 10:1. The motor
overload detection level (oL1) is automatically reduced when running below 1/10 of the motor rated speed.
Selects protection characteristics for a motor capable of cooling itself at any speed — including zero speed (externally
cooled motor). The motor overload detection level (oL1) is constant over the entire speed range.
Selects protection characteristics for a variable torque PM motor. The motor overload detection level (oL1) is
automatically reduces when running below the motor rated speed.
Selects protection characteristics for a constant torque PM motor. The motor overload detection level (oL1) is constant
over the whole speed range.
Selects protection characteristics for a standard self cooled motor with limited cooling capabilities when running below
the rated speed. The motor overload detection level (oL1) is automatically reduces when running below the motor rated
speed.
Operation time (minutes)
10
7
3
1
0.4
0.1
0 100
Figure D.9 Motor Overload Protection Time
Description
Cold start
Hot start
Motor current (%)
150 200
E2-01 = 100% motor current
D.3 UL Standards
D
597