Emheater EM12 Series, User Manual

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5.Description of Function Codes EM12 User's Manual
72
This parameter is used to display the delivered model and cannot be modified.
0: Applicable to variable torque load (fan and pump) with rated parameters specified.
1: Applicable to constant torque general load with rated parameters specified.
bb-01
Motor overload protection selection Default 1
Setting
Range
0 Disabled
1 Enabled
bb-02
Motor overload protection gain
Default
1.00
Setting Range
0.20~10.00

bb-01 =0
The motor overload protective function is disabled. The motor is exposed to potential damage due to overheating. A
thermal relay is suggested to be installed between the frequency inverter and the motor.

bb-01 = 1
The frequency inverter judges whether the motor is overloaded according to the inverse time-lag curve of the
motoroverload protection.
The inverse time-lag curve of the motor overload protection is:
220% × (bb-02) × rated motor current
(if the load remains at this value for one minute,the frequency inverter reports motor overload fault), or
150% × (bb-02) ×rated motor current
(if the load remains at this value for 60 minutes,the frequency inverter reports motor overload fault).
Set bb-02 properly based on the actual overload capacity. If the value of bb-02 is set too large, may result in damaging
to the motor because the motor overheats but the frequency inverter does not report the alarm.
bb-03
Motor overload pre-warning coefficient
Default
80%
Setting Range 50%~100%
This function is used to give a warning signal to the control system via DO before motor overload protection. This
parameter is used to determine the percentage, at which pre- warning is performed before motor overload. The larger
the value is, the less advance the pre-warning will be.
When the output current of the frequency inverter is greater than the value of the overload inverse time-lag curve
multiplied by bb-03, the DO terminal of the frequency inverter set with motor overload pre-warning becomes ON.
bb-04
Overvoltage stall gain Default 0
Setting Range
0~100
bb-05
Overvoltage stall protective voltage Default 130%
Setting Range
120%~150%
When the DC bus voltage exceeds the value of bb-05 (Overvoltage stall protective voltage) during deceleration of the
frequency inverter, the frequency inverter stops deceleration and keeps the present running frequency. After the bus
voltage declines, the frequency inverter continues to decelerate.
bb-04 (Overvoltage stall gain) is used to adjust the overvoltage suppression capacity of the frequency inverter. The
larger the value is, the greater the overvoltage suppression capacity will be.In the prerequisite of no overvoltage
occurrence, set bb-04 to a small value.
For small-inertia load, the value should be small. Otherwise, the system dynamic response will be slow. For
large-inertia load, the value should be large. Otherwise, the suppression result will be poor and an overvoltage fault