Omron VARISPEED L7 Manual page 44

Installing a Moulded-Case Circuit Breaker
If a moulded case circuit breaker is used for the power supply connection (R/L1, S/L2, and T/L3) it must be
suitable for the Inverter.
The MCCB should have a capacity of 1.5 to 2 times of the inverter's rated current.
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For the MCCB's time characteristics selection the inverter's overload protection (one minute at 150% of
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the rated output current) must be considered.
Installing an Earth Leakage Breaker
An earth leakage breaker which is able to detect all kinds of current should be used in order to ensure a safe
earth leakage current detection.
If a special-purpose earth leakage breaker for Inverters is used, it should have an actuating current of at
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least 30 mA per Inverter.
If a standard earth leakage breaker is used, it should have an actuating current of 200 mA or more per
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Inverter and a actuating time of 0.1 s or more.
Installing a Magnetic Contactor at the Input
If the power supply for the main circuit is shut off by a control circuit, a magnetic contactor can be used.
The following things should be considered:
The Inverter can be started and stopped by opening and closing the magnetic contactor on the primary side.
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Frequently opening and closing the magnetic contactor may cause an Inverter fault. Do not exceed one
power up per hour.
When the Inverter is operated using the Digital Operator, automatic operation cannot be performed after
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recovery from a power interruption.
Connecting Input Power Supply to the Terminal Block
The input power supply can be connected in any sequence to the terminals R, S or T on the terminal block; the
input phase sequence is irrelevant to the output phase sequence.
Installing an Input AC Reactor
If the Inverter is connected to a large-capacity power transformer (600 kW or more) or a phase advancing
capacitor is switched nearby, an excessive peak current could flow through the input power circuit, causing an
inverter damage. As a countermeasure an optional AC Reactor the inverter input or a DC reactor at the DC
reactor connection terminals can be installed.
In order to fulfill the EN12015 an AC reactor has to be installed. Refer to
12015 Compatibility for the available reactors. The AC reactor has to be installed between the power supply
and the EMC filter (like shown in
Power AC
Supply Reactor
L1
L2
L3
Installing a Surge Absorber
Always use a surge absorber or diode for inductive loads near the Inverter. Inductive loads include magnetic
contactors, electromagnetic relays, solenoid valves, solenoids, and magnetic brakes.
Fig 2.5)
L7Z
Filter
Inverter
Fig 2.5 AC reactor installation
Chapter 9, AC Reactors for EN
M
2
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