Best E5 Series User Manual page 129

E5 User Manual
signal voltage is compared with the protection threshold set by P30.26. If it is higher than
protection threshold, motor overload fault "oL2" could be displayed.
Overload protection
P30.24
detection time of motor 1
When P30.23 is set to "1: judged from motor current", overload protection time is determined
by this parameter on the basis of the running current being 150% of motor rated current. An
alarm of motor overload fault "oL2" shall be displayed once the lasting time exceeds this
parameter value. Protection time when the running current is other value is automatically
calculated according to inverse time lag characteristic curve. See Fig. 5-34.
Fig. 5-34 Motor protection curve for ordinary motor running at 50Hz
Overload protection is performed for variable frequency asynchronous motor or synchronous
motor according to the curve as shown in Fig. 5-34 at either high or low rotation speed. Due to
the fact that fan-based heat dissipation of ordinary motors becomes poor at low speed, the
protection is derated at low speed.
Example: when P30.24 is set to 10.0 minutes, and the motor is running at 10Hz input, motor
overload fault "oL2" shall be displayed when the running current is 150% of the motor rated
current with lasting time 4 minutes.
Fig. 5-35
Motor overload time
10
5
1
0 100% 200%
Motor overload time 电机过载时间
4.0
0 100%
Chapter 5 Specification of Parameters
Range: 0.1min~15.0min
P30.24 = 10 minutes
P30.24 = 5 minutes
P30.24= 1 minutes
Motor current
200%
P30.24 = 10 minutes
(d0-24) =10分钟
150% 200%
- 125 -
Factory default:
5.0min
电机电流
Motor current