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APPENDIX
A.2.4 Wiring of the power supply and motor
For wiring the input (R/L1, S/L2, T/L3) and output (U, V, W) terminals of the inverter, use the UL-listed copper wires (rated
at 75°C) and round crimping terminals. Crimp the crimping terminals with the crimping tool recommended by the terminal
maker.
A.2.5 Short circuit ratings
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01160 or less
Suitable for use in a circuit capable of delivering not more than 100kA rms symmetrical amperes, 528V maximum.
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01800 or more
Suitable for use in a circuit capable of delivering not more than 100kA rms symmetrical amperes, 550V maximum.
A.2.6 Motor overload protection
This inverter is certified as a motor overload protection device by UL.
When using the electronic thermal relay function as motor overload protection, set the rated motor current to Pr. 9
Elec-
tronic thermal O/L relay.
Electronic thermal relay function operation characteristic
This function detects the overload (overheat) of the
motor, stops the operation of the inverter's output tran-
sistor, and stops the output.
When using the Mitsubishi constant-torque motor set
"1" in Pr. 71. This provides a 100 % continuous torque
characteristic in the low-speed range. Set the rated
current of the motor in Pr. 9.
*1
When 50% of the inverter rated output current (current
value) is set in Pr. 9.
*2
The % value denotes the percentage to the inverter rated
output current. It is not the percentage to the motor rated
current.
*3
When you set the electronic thermal relay function
dedicated to the Mitsubishi constant-torque motor, this
characteristic curve applies to operation at 6 Hz or higher.
CAUTION
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Protective function by electronic thermal relay function is reset by inverter power reset and reset signal input. Avoid
unnecessary reset and power-OFF.
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When using multiple motors with one inverter, or using a multi-pole motor or a specialized motor, provide an external
thermal relay (OCR) between the inverter and motor. And for the setting of the thermal relay, add the line-to line leakage
current to the current value on the motor rating plate. For low-speed operation where the cooling capability of the motor
reduces, it is recommended to use a thermal protector or thermistor-incorporated motor.
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When the difference between the inverter and motor capacities is large and the setting is small, the protective
characteristics of the electronic thermal relay function will be deteriorated. In this case, use an external thermal relay.
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Operation region
Region on the right of
characteristic curve
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Non-operation region
Region on the left of
characteristic curve
Characteristic when electronic
thermal relay function for
motor protection is turned OFF
(Pr. 9 = 0 (A))
Electronic thermal relay
function for transistor
protection
Inverter output current (%)
(% to the rated inverter current)
Pr. 9 = 100 % setting of
inverter rating
*2
Pr. 9 = 50 % setting of
inverter rating
*1, 2
or more
*3
Operation time [s
]
O
peration time [min]
[s
] unit
dis
p
lay in t
h
is region
[min] unit d
isplay
in t
h
is
region
or more
*3
