
4-113
08-05
Motor overload protection (OL1) Default: 0001b
Range
【
xxx0b
】
: Motor overload is disabled
【
xxx1b
】
: Motor overload is enabled
【
xx0xb
】
: Cold start of motor overload
【
xx1xb
】
: Hot start of motor overload
【
x0xxb
】
: Standard motor
【
x1xxb
】
: Special motor
【
0xxxb
】
: Reserved
【
1xxxb
】
: Reserved
The motor overload protection function estimates the motor overload level based on the output current, output
frequency, motor characteristics and time. The motor overload trip time depends on the motor rated current when the
output frequency is greater than 60Hz. The electronic thermal overload function is UL-recognized, so an external
thermal overload relay is not required for single motor operation.
On AC Drive power-up the motor overload protection internal thermal accumulation register is automatically reset.
To use the built-in motor overload protection function, parameter 02-01 (motor rated current) has to match the motor
rated current on the motor nameplate.
Turn off the motor overload protection when using two or more motors connected to the AC Drive
(set
08-05 = xxx0b
), and provide external overload protection for each motor (e.g. thermal overload switch).
With cold start enabled (
08-05 = xx0xb
), motor overload protection occurs in 5.5 minutes when operating the motor
at 150% of the motor rated current at an output frequency greater than 60Hz.
With hot start enabled (
08-05 = xx1xb
), motor overload protection occurs in 3.5 minutes when operating the motor at
150% of the motor rated current at an output frequency greater than 60Hz. Use hot start when the power supply is
turned on and off frequently because the thermal values are reset each time power is turned off.
Refer to the following figure for an example of motor overload protection curve.
Low Speed
Hot Start
100%
150%
200%
Motor Load Current (%)
(02-01 = 100%)
Overload Protect Time (min)
1.5
2.9
7.9
Low Speed
Cold Start
100%
150%
200%
Motor Load Current (%)
(02-01 = 100%)
Overload Protect Time (min)
2.4
4.5
12.4
High Speed
(60Hz)
Hot Start
106%
150%
200%
Motor Load Current (%)
(02-01 = 100%)
Overload Protect Time (min)
1.7
3.9
28.8
start activated point
High Speed
(60Hz)
Cold Start
106%
150%
200%
Motor Load Current (%)
(02-01 = 100%)
Overload Protect Time (min)
2.7
6.1
45.2
start activated point