Maintenance And Inspection - Mitsubishi Electric FR-K-400-U Instruction Manual

(5) Do not add a capacitor nor surge absorber t o the output circuit of the inverter. This may activate
the overcurrent protection.
(6)
I f you are using a motor with mechanical brakes, the brake exciting circuit should not be con-
nected t o the inverter output, and make certain theat brake action can be affected after turning
off the inverter's power supply.
(7) I f using motors o f different capacity or special-purpose motors, or i f more than one motor is being
used simultaneously, add a thermal overload relay t o the inverter output circuit t o protect the
motor from being burned up. I n this case turn the electronic thermal relay setting dial (TH) on
the operation panel as far as it will go i n the clockwise direction.
(8) Th= FR-K-400 can also be used with a single phase power supply, but when doing so be sure t o
connect the power supply t o terminals R and S.
(9)
Since the built-in brake resistor will cause temperature increases, mount it on noninflammable
materials such as metal or concrete.
6. MAINTENANCE AND INSPECTION
The FREQROL-K is the static type, so almost no daily maintenance is required. The following maintenance
practices should, however, be observed.
(1) Since the capacitor i n the inverter remains charged at high voltage for a while after the inverter is turned
off, perform inspections only after charge indication lamp "CHARGE" goes out. Also, the cooling fan
will continue t o run for some time after the power has been turned off, so be careful t o keep hands away
from this area.
(2) From time t o time, inspect the inverter for dust and dirt accumulated inside, and clean it i f there is a
buildup.
(3) Check the tightness of terminal block screws and mounting screws. I f they come any loose, tighten
them securely. Make certain there are no defects i n the wiring parts or components. Replace defective
wiring part i f found, or contact your service representative.
(4) Megger test
a)
When performing a megger test on the external equipment, remove all inverter terminals so that the
test voltage will not be applied t o the inverter.
b)
Perform megger tests only for the main circuit of the inverter as shown i n Fig.
2.
Do not apply the
test voltage t o the control circuit.
c)
TO check the FFiEQROL-K control circuit, use a multimeter (set t o high resistance range position).
Do not use a megger or buzzer.
Fig. 2 Megger Test
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Earth terminal