Daily And Periodic Inspections - Hitachi SJ700-2 Instruction Manual

Chapter 6 Maintenance and Inspection

6.2 Daily and Periodic Inspections

Part to
Inspection item
inspect
General Environment Check the ambient temperature,
humidity, and dust.
Whole inverter Check for abnormal vibrations and
noise.
Power supply Check that the main circuit voltage
voltage is normal.
Main General check (1) Check the ground resistance
circuit between the main circuit and
ground terminals with a megger.
(2) Check screws and bolts for
loosening.
(3) Check each part for any trace of
overheating.
Connecting (1) Check the conductors for
conductors and distortion.
cables
(2) Check the cable insulations for
damage.
Terminal block Check the terminal blocks for
damage.
Inverter circuit Check the resistance between
and converter terminals.
circuit (including
resistors)
Smoothing (1) Check for liquid leak.
capacitor
(2) Check that the relief valve does
not protrude or swell.
Relay (1) Check that no fluttering sound is
generated during the relay
operation.
(2) Check the contacts for damage.
Control
Operation (1) While performing a unit
and
operation of the inverter, check
protective
the balance output voltage
circuits
among the individual phases.
(2) Carry out a sequential
protection operation test, and
check the protective and display
circuits for any abnormality.
Cooling Cooling fan (1) Check for abnormal vibrations
system and noise
(2) Check the joints for loosening.
Heat sink Check for clogging.
Display Monitor (1) Check that all LEDs light up
normally.
(2) Clean the monitor.
Meter Check that meter readings are
normal.
Motor General (1) Check for abnormal vibrations
and noise.
(2) Check for unusual smells.
Insulation Check the ground resistance
resistance between all motor terminals and the
ground terminal with a megger.
*1 The operating life of the smoothing capacitor is under the influence of the ambient temperature. Refer to Section 6.6, "Smoothing-Capacitor Life Curve," as a standard for the
operating life until replacement.
*2 The operating life of the cooling fan varies depending on environmental conditions, including the ambient temperature and dust. Check the status of the cooling-fan operation
during daily inspections.
*3 The standard operating life (number of years or operation cycles) and the data described in Section 6.6, "Smoothing-Capacitor Life Curve," are based on the expected design
life, but they do not indicate the guaranteed life of any parts.
Inspection cycle
Detail of inspection
Periodic
Daily
Annual Biennial
Inspection method
See Section 2.1, "Installation."
Check visually and by listening.
Measure the voltage between the
main circuit terminals R, S, and T.
Disconnect all input and output cables
from the inverter's main circuit terminal
block, detach the control circuit terminal
block from the inverter, and remove the
jumper for switching the inverter's
internal filter function. Subsequently,
measure the insulation resistance
between the ground terminal and the
jumper connecting all the following
terminals:
R, S, T, U, V, W, P, PD, N, RB, R0, and
T0
Retighten loose screws and bolts.
Check visually.
Check visually
Check visually
Remove all cables from the
inverter's main circuit terminal block.
Use a tester (in 1Ω range mode) to
measure the following:
- Resistance between terminals R,
S, and T and terminals P and N
- Resistance between terminals U,
V, and W and terminals P and N
Check visually.
Check by listening.
Check visually.
Measure the voltage between the
cables connected to the main circuit
terminals U, V, and W.
Short-circuit or open the protective
circuit outputs as a simulation.
Turn the fan manually during the
inverter power-off status.
Check visually.
Check visually.
Check visually.
Clean the monitor with a rag.
Check the meter readings on the
panel.
Check vibrations and noise visually,
by listening, and with physical
senses.
Check for any unusual smells
caused by overheating or damage.
Remove the cables from the
inverter's main circuit terminals U, V,
and W, connect the motor wires (for
three phases) with one another, and
measure the ground resistance
between the motor wires and the
ground terminal.
6 - 2
Criterion Test equipment
The ambient temperature must Thermometer,
be within -10°C to +50°C without hygrometer,
congelation. The ambient recorder
humidity must be 90% RH or less
without condensation.
There must be no abnormality
found.
The measured voltage must be Tester, digital
within the allowable tolerance for multimeter
AC power voltage.
500 VDC class
megger
The measured ground resistance
must be 5MΩ or more.
There must be no abnormality
found.
There must be no abnormality
found.
There must be no abnormality
found.
There must be no abnormality
found.
Analog tester
See Section 6.5, "Method of
Checking the Inverter and
Converter Circuits." Standard
operating life of inverter circuit
until replacement: 106 cycles of
starting and stopping (*3)
There must be no abnormality Capacitance
found. meter
Target operating life until
replacement: 10 years
(*1) (*3)
There must be no abnormality
found.
There must be no abnormality
found.
The inter-phase voltage balance Digital
must be as follows: multimeter,
200 V class models: 4 V or less rectifier
400 V class models: 8 V or less instrument, and
voltmeter
An error must be detected
according to the sequence.
The fan must rotate smoothly.
There must be no abnormality
found.
Standard operating life until
replacement: 10 years
(*2) (*3)
The heat sink must not be
clogged.
The LEDs must light up normally.
The readings must meet the Voltmeter and
standard and control values. ammeter
There must be no abnormality
found.
There must be no abnormality
found.
500 VDC class
megger
The measured ground resistance
must be 5MΩ or more.