Mitsubishi Electric FR-D720-008 Installation Manuallines page 12

(2) 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.
100V, 200V class
Pr. 72 PWM frequency selection setting
(carrier frequency)
1 (1kHz) or less
2 to15
(2kHz to 14.5kHz)
400V class
Pr. 72 PWM frequency selection setting
(carrier frequency)
1 (1kHz) or less
2 to15
(2kHz to 14.5kHz)
Total wiring length (FR-D720-070 or higher, FR-D720S-070 or higher, FR-D740-080 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. Take the following measures 1) or 2) in this case.
1) Use a "400V class inverter-driven insulation-enhanced motor" and set frequency in Pr. 72 PWM frequency selection
according to wiring length.
Carrier frequency
2) Connect thhe surge voltage suppression filter (FR-ASF-H/FR-BMF-H) on the inverter output side.
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. (
operation selection in Chapter 4 of the Instruction Manual)
Refer to Chapter 4 of the Instruction Manual for details of Pr. 72 PWM frequency selection. Refer to the manual of the option
for details of surge voltage suppression filter (FR-ASF-H/FR-BMF-H).
When using the automatic restart after instantaneous power failure function with wiring length exceeding below,
select without frequency search (Pr. 162 = "1, 11"). (
Motor capacity
(kW(HP))
Wiring length
008
200m
(656.19 feet)
30m
(98.42 feet)
012
200m
(656.19 feet)
30m
(98.42 feet)
500m
(1640.42feet)
or less
50m(164.04feet) or 50m(164.04feet) to
less 100m(328.08feet)
14.5kHz or less
0.1K(1/8)
20m(65.61feet)
014 025
200m 300m
(656.19 feet) (984.25 feet) (1640.42 feet)
100m 200m
(328.08 feet) (656.19 feet)
022 036
200m 300m
(656.19 feet) (984.25 feet) (1640.42 feet)
100m 200m
(328.08 feet) (656.19 feet)
300m
(984.25feet)
300m(984.25feet) + 300m(984.25feet)
= 600m(1968.50feet)
Wiring Length
Exceeding
100m(323.08feet)
8kHz or less 2kHz or less
Refer to Pr. 22 Stall prevention operation level and Pr. 156 Stall prevention
Refer to Chapter 4 of the Instruction Manual)
0.2K(1/4)
50m(164.04feet)
WIRING
070
042
or Higher
500m 500m
(1640.42 feet)
300m 500m
(984.25 feet) (1640.42 feet)
080
050
or Higher
500m 500m
(1640.42 feet)
300m 500m
(984.25 feet) (1640.42 feet)
300m
(984.25feet)
0.4K(1/2)
100m(323.08feet)
9