Справочник Пользователя для Mitsubishi Electronics FR-A700

Special operation and frequency control

⋅ When the regenerative status is serious, the DC bus voltage rises and an overvoltage fault (E. OV ) may occur.

When this bus voltage rise is detected and the bus voltage level reaches or exceeds Pr. 883, increasing the
frequency avoids the regenerative status.

⋅ For regeneration avoidance operation, you can select whether it is always activated or activated only at a constant

speed.

⋅ Setting Pr. 882 to "1, 2" validates the regeneration avoidance function.

This function detects a regenerative status and increases the frequency to avoid the regenerative status.

Possible to avoid regeneration by automatically increasing the frequency and continue operation if the fan
happens to rotate faster than the set speed due to the effect of another fan in the same duct.

0

0

Regeneration avoidance function invalid

1

Regeneration avoidance function is always valid

2

Regeneration avoidance function is valid only during a constant 
speed operation

380VDC/

760VDC *

300 to 800V

Set the bus voltage level at which regeneration avoidance operates. 
When the bus voltage level is set to low, overvoltage error will be 
less apt to occur. However, the actual deceleration time increases. 
The set value must be higher than the power supply voltage 

×  .

* The initial value differs according to the voltage level. (200V / 400V)

0

0

Regeneration avoidance by bus voltage change ratio is invalid 

1 to 5

Set sensitivity to detect the bus voltage change ratio
Setting

1

5

Detection sensitivity low

high

6Hz

 0 to 10Hz

Set the limit value of frequency which rises at activation of 
regeneration avoidance function.

9999

Frequency limit invalid

100%

 0 to 200%

Adjust responsiveness at activation of regeneration avoidance. A 
larger setting will improve responsiveness to the bus voltage 
change. However, the output frequency could become unstable.  
When vibration is not suppressed by decreasing the Pr. 886 
setting, set a smaller value in Pr. 665.

100%

 0 to 200%

⋅ The inclination of the frequency increased or decreased by the regeneration avoidance function changes depending on the

regenerative status.

⋅ The DC bus voltage of the inverter is normally about 

 times greater than the input voltage.

When the input voltage is 220VAC (440VAC), the bus voltage is about 311VDC (622VDC).

However, it varies with the input power supply waveform.

⋅ The  Pr. 883 setting should be kept higher than the DC bus voltage level. Otherwise, the regeneration avoidance function is

always ON even in the non-regeneration status and the frequency increases.

⋅ While overvoltage stall (

) is activated only during deceleration and stops the decrease in output frequency, the regeneration

avoidance function is always ON (Pr. 882 = 1) or activated only during a constant speed (Pr. 882 = 2) and increases the
frequency according to the regeneration amount.

2

Time

Time

Regeneration avoidance operation 
example for acceleration

Bus voltage 

(VDC)

Output 

frequency(Hz)

During regeneration 
avoidance function operation

Time

Time

Regeneration avoidance operation 
example for constant speed

Bus voltage 

(VDC)

Output 

frequency(Hz)

During regeneration 
avoidance function operation

Time

Time

Bus voltage 

(VDC)

Output 

frequency(Hz)

During regeneration 
avoidance function operation

Regeneration avoidance operation 
example for deceleration

2