Thermal Overload Protection - YASKAWA V7 Technical Manual

5.25 THERMAL OVERLOAD PROTECTION

n036 : Motor Rated Current
This parameter should be set, in increments of 0.1 A, to the rated current (FLA) value shown on the motor
nameplate; this value MUST BE between 10% and 150% of the drive rated current. If the motor FLA does not
fall within this range, a different Model No. drive must be used.
NOTE: Setting n036 to " 0.0 " disables the motor overload protection
function, regardless of the setting of n037 or n038.
n037 : Electronic Thermal Motor Protection
Setting
0
1
2
n038 : Electronic Thermal Overload Protection
Time Constant
This parameter sets the electronic thermal overload relay protection time when when 150% of overload is
applied after the motor is operated continuously at rated current.
The Drive protects against motor overload with a UL-recognized, built-in electronic thermal overload relay.
The electronic thermal overload function monitors motor temperature, based on drive output current and time,
to protect the motor from overheating. When the electronic thermal overload trips, an
" oL1 " error occurs, shutting OFF the drive output and preventing excessive overheating of the motor.
When operating with one drive connected to only one motor, an external thermal relay is not needed. When
operating several motors with one drive, install a thermal overload relay on each motor.
Cooling Effect
Effective when
operated at 60Hz
from a commercial
power supply
Effective when
operated at low
speed (approx. 6Hz)
Electronic Thermal Characteristics
Short term rating
Standard rating
Electronic thermal overload protection disabled
Current Characteristics
180
155
140
100
TORQUE
(%)
80
55
Base Frequency
38
60Hz
(V/f for 60Hz,
230V Input Voltage)
180
150
100
TORQUE
(%)
Base Frequency
55
60Hz
38
(V/f for 60Hz,
230V Input Voltage)
5-38
Factory setting: See Table A3-1
Range: see description
Factory setting: 0
Range: 0 to 2
Factory setting: 8
Range: 1 to 60 min.
60 SEC
SHORT TERM
CONTINUOUS
RATING
0
3 20 60 120
OPERATION FREQUENCY (Hz)
60 SEC
SHORT TERM
CONTINUOUS
RATING
0
6 60 120
OPERATION FREQUENCY (Hz)
Electronic Thermal
Overload
" " error (motor
oL 1
overload protection)
occurs when
continuously operated
at less than 60Hz at
100% load.
Electronic thermal
overload protection not
activated even when
continuously operated
at less than 60Hz at
100% load.