Mitsubishi Electric 800 Series, Инструкция по установке

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71
APPENDIX
A.2.6 Short circuit ratings
l
200V class
Suitable for use in a circuit capable of delivering not more than 100kA rms symmetrical amperes, 240V maximum.
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400V class
Suitable for use in a circuit capable of delivering not more than 100kA rms symmetrical amperes, 480 Y / 277 V
maximum.
A.2.7 Motor overload protection
The following explains the details of the motor overload protection.
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" .
This function detects the overload (overheat) of the
motor and shut off the inverter output by stopping the
operation of the transistor at the inverter output side.
(The operation characteristic is shown on the left.)
When using the Mitsubishi Electric constant-torque
motor set one of "10", "13" to "16", "50", "53", "70",
"73", "1800" or , "1803" in Pr. 71. (This enables a 100%
constant-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 the electronic thermal relay function dedicated to the
Mitsubishi Electric constant-torque motor is set, this
characteristic curve applies to operation at 6 Hz or higher.
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The internal accumulated heat value of the electronic thermal O/L relay is reset to the initial value by the inverter's power
reset or reset signal input. Avoid unnecessary reset and power-OFF.
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Install an external thermal relay (OCR) between the inverter and motors to operate several motors, a multi-pole motor or
a dedicated motor with one inverter.
When configuring an external thermal relay, note that the current indicated on the motor rating plate is affected by the
line-to-line leakage current. (Refer to the Instruction Manual (Function).) The cooling effect of the motor drops during
low-speed operation. Use a motor with built-in thermal protector. When the difference between the inverter and motor
capacities is large and the set value is small, the protective characteristics of the electronic thermal relay function will be
deteriorated. Use an external thermal relay in such cases.
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A dedicated motor cannot be protected by the electronic thermal relay. Use an external thermal relay.
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Motor over temperature sensing is not provided by the drive.
52.5%
105%
50
100
150
60
120
180
240
50
60
70
6Hz
0.5Hz
20Hz
10Hz
6Hz
0.5Hz
30Hz
30Hz
20Hz
10Hz
230
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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))
Region for
transistor
protection
Inverter output current [%]
(% to the inverter rated current)
Pr. 9 = 100 % setting of
inverter rating
*1, *2
Pr. 9 = 50 % setting of
inverter rating
*1, *2
or more
*3
Op
er
at
io
n t
im
e [s]
O
pe
ra
tion
tim
e
[m
in]
Seco
nd
un
it disp
la
y in
this
re
gi
on
Min
u
te
disp
la
y
in
t
his
re
gi
on
or more
*3