User`s manual

19
Wiring Chapter 2-2
Wiring on the Input Side of the Main Circuit
Installing a Molded-case
Circuit Breaker
Always connect the power input terminals (R/L1, S/L2, and T/L3) and power
supply via a molded case circuit breaker (MCCB) suitable to the Inverter.
• Install one MCCB for every Inverter used.
• Choose an appropriate MCCB capacity according to the Circuit breaker
capacity column in the table on the previous page.
• For the MCCB’s time characteristics, be sure to consider the Inverter’s
overload protection (one minute at 150% of the rated output current).
• If the MCCB is to be used in common among multiple Inverters, or other
devices, set up a sequence such that the power supply will be turned off
by a fault output, as shown in the following diagram.
Installing a Ground
Fault Interrupter
Inverter outputs use high-speed switching, so high-frequency leakage current
is generated.
In general, a leakage current of approximately 100 mA will occur for each
Inverter (when the power cable is 1 m) and approximately 5 mA for each
additional meter of power cable.
Therefore, at the power supply input area, use a special-purpose breaker for
Inverters, which detects only the leakage current in the frequency range that
is hazardous to humans and excludes high-frequencyleakage current.
• For the special-purpose breaker for Inverters, choose a ground fault
interrupter with a sensitivity amperage of at least 10 mA per Inverter.
• When using a general leakage breaker, choose a ground fault interrupter
with a sensitivity amperage of 200 mA or more per Inverter and with an
operating time of 0.1 s or more.
Installing a
Magnetic Contactor
If the power supply of the main circuit is to be shut off because of the
sequence, a magnetic contactor can be used instead of a molded-case circuit
breaker.
When a magnetic contactor is installed on the primary side of the main circuit
to stop a load forcibly, however, the regenerative braking does not work and
the load coasts to a stop.
• A load can be started and stopped by opening and closing the magnetic
contactor on the primary side. Frequently opening and closing the
magnetic contactor, however, may cause the Inverter to break down. In
order not to shorten the service life of the Inverter’s internal relays and
electrolytic capacitors, it is recommended that the magnetic contactor is
used in this way no more than once every 30 minutes.
• When the Inverter is operated with the Digital Operator, automatic
operation cannot be performed after recovery from a power interruption.
Power
supply
3-phase/Single-phase
200 V AC
3-phase 400 V AC
Inverter
Fault output
(NC)
MCCB
OFF ON
R/L1
S/L2
T/L3
MB
MC