Synchronous Motor; Single Phase Motor; Permissible Maximum Frequency Of General-Purpose Motor; Inverter-Driven 400V Motor - Mitsubishi Electric FR-A700 Technical Manual

3.3.10 Synchronous motor

Synchronous motor is not available in general.
Synchronous motor may not synchronize to inverter output
frequency, and may not start. And even if the motor is

3.3.11 Single phase motor

It is not recommended to use a single-phase motor with an
inverter. The small capacity of the single-phase motor is
often rated at 100V and does not match the inverter. The
SC, SL, SCL and other motors with capacitors cause an
excessive current to flow in the capacitor, resulting in
capacitor breakage.

3.3.12 Permissible maximum frequency of general-purpose motor

(1) Standard models
Drip-proof protection motor: SB-JR(F, V)
Totally-enclosed fan-cooled motor:
SF-JR(F, V)
Number
of poles
2
Frame
Number
63
71
120Hz (*2)
80
(7200 r/min)
90
100
112 90Hz
132 (5400 r/min)
75Hz
160
(4500 r/min)
65Hz
180
(3900 r/min)
200 60Hz
225 (3600 r/min)
*1 The value in the parentheses indicates synchronous
speed.
*2 When a two-pole motor of frame number 90 or 100 is run
at 120Hz, noise will exceed 90dB (A).

3.3.13 Inverter-driven 400V motor

In the PWM type inverter, a surge voltage attributable to
wiring constants is generated at the motor terminals.
Especially for a 400V class motor, the surge voltage may
deteriorate the insulation. When the 400V class motor is
driven by the inverter, consider the following measures:
Countermeasure
It is recommended to take either of the following measures:
(1) Reinforcing the motor insulation and
limiting the PWM
according to the wiring length
For a 400V class motor, use an insulation-enhanced
motor. Specifically:
1) Specify the "400V class inverter-driven, insulation-
enhanced motor".
2) As a dedicated motor such as a constant-torque
motor or low-vibration motor, use a "motor
dedicated to inverter operation".
4 6
120Hz
(3600 r/min)
120Hz
(2400 r/min)
100Hz
(3000 r/min)
65Hz 65Hz
(1950 r/min) (1300 r/min)
carrier frequency
started, depending on a load, difference in synchronization
may occur.
A split-phase-start or repulsion-start motor cannot be used
because this will cause the centrifugal switch to be
deactivated. (The starting winding will be burned out in a
short time.)
(2) Other models
Number of
Models/
Frame Number
With TB brake
63 to 132
Outdoor
type
Waterproof
type
3) Set [Pr. 72 PWM frequency selection] as indicated
below according to the wiring length.
50m or less
[Pr. 72 PWM
15(14.5kHz)
frequency
selection]
(2) How to suppress surge voltage on the
inverter side
Connect the surge voltage suppression filter (FR-
ASF-H or FR-BMF-H) to the 55K or less and the sine
wave filter (MT-BSL/BSC) to the 75K or more on the
inverter output side.
504
SELECTION
poles
2 4
65Hz
Not (except
available vertical
type)
120Hz
160 65Hz 100Hz
180
200 65Hz
60Hz
225
Wiring Length
50m to 100m
A700 F700
9(9kHz) or less 4(4kHz) or less
or less
E700 D700
8(8kHz) or less 2(2kHz) or less
6
90Hz
(except
vertical
type)
120Hz
90Hz
65Hz
More than
100m
A700 F700
E700 D700