Mitsubishi Electric FR-D720 K Series Instruction Manual page 30

(3) Total wiring length
The overall wiring length for connection of a single motor or multiple motors should be within the value in the table below.
Cable Pr. 72 Setting
Type (carrier frequency)
1 (1kHz) or lower
Unshielded
cable
2 (2kHz) or higher
1 (1kHz) or lower
Shielded
cable
2 (2kHz) or higher
Total wiring length when using a general-purpose motor (FR-D720-1.5K or higher, FR-D720S- or
higher, FR-D740- or higher)
When driving a 400V class motor by the inverter, surge voltages attributable to the wiring constants may occur at the motor
terminals, deteriorating the insulation of the motor. If that is the case, use a "400V class inverter-driven insulation-enhanced
motor" and set a frequency in Pr. 72 PWM frequency selection according to the total wiring length shown in the following table.
(Refer to page 49 to drive a 400V class motor with an inverter.)
Pr. 72 PWM frequency selection
(Carrier frequency)
NOTE
 Especially for long-distance wiring, the inverter may be affected by a charging current caused by the stray
capacitances of the wiring, leading to a malfunction of the overcurrent protective function, fast response current limit
function, or stall prevention function or a malfunction or fault of the equipment connected on the inverter output side.
If malfunction of fast-response current limit function occurs, disable this function. If malfunction of stall prevention
function occurs, increase the stall level. (Refer to page 82 for Pr. 22 Stall prevention operation level and Pr. 156 Stall prevention
operation selection.)
 When using the automatic restart after instantaneous power failure function with wiring length exceeding below,
select without frequency search (Pr. 162 = "1, 11"). (Refer to page 139.)
Motor capacity
Wiring length
Parameters referred to
Pr. 72 PWM frequency selection
Voltage Class 0.1K
100V/200V 200m
400V -
100V/200V 30m
400V -
100V/200V 50m
400V -
100V/200V 10m
400V -
500m or less
50m or less
15 (14.5kHz) or less
0.1kW
20m
Refer to page 151.
Main circuit terminal specifications
0.2K 0.4K 0.75K
200m 300m 500m
- 200m 200m
100m 200m 300m
- 30m 100m
50m 75m 100m
- 50m 50m
25m 50m 75m
- 10m 25m
300m
300m
300m+300m=600m
Wiring Length
50m to 100m
8 (8kHz) or less
0.2kW 0.4kW or higher
50m
3.7K
1.5K 2.2K
or Higher
500m 500m 500m
300m 500m 500m
500m 500m 500m
200m 300m 500m
100m 100m 100m
75m 100m 100m
100m 100m 100m
50m 75m 100m
Exceeding 100m
2 (2kHz) or less
100m
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