Toshiba TOSVERT VF-AS3 Instruction Manual page 489

• Install a surge absorber on the exciting coil of a magnetic contactor (MC) and relays.
• When using an auxiliary contacts 2a type magnetic contactor (MC), use the 2a contacts in parallel to
increase the liability of the contacts.
• Selection is for assuming a normal power supply capacity and using a Toshiba 4-pole standard motor
with input power 200 V/400 V-50 Hz.
• For the influence of the leakage current, refer to [2. 4. 3].
10. 2. 2 Installation of a molded-case circuit breaker (MCCB)
and earth leakage circuit breaker (ELCB)
For protection of the wiring system, install a molded-case circuit breaker (MCCB) between the power
supply and the inverter (primary side).
An earth leakage circuit breaker (ELCB) that is equipped with a function to shut off by detecting leakage
current can be also installed. However, be cautious that an ELCB may operate improperly, because the
leakage current becomes large due to the influence of a wiring method, a built-in noise filter, etc.
Because the short-circuit current is different with power supply capacity and wiring system conditions,
select MCCB or ELCB depending on the inverter type and input current in the table [10. 2. 1].
• When complying with UL Standard and CSA Standard, a fuse needs to be installed on the
Memo
primary side of the inverter. For details, refer to [9. 2. 3].
10. 2. 3 Installation of a magnetic contactor (MC)
When installing a magnetic contactor (MC) on the primary or secondary side of the inverter, select fol-
lowing the below.
■ Installation on the primary side
When the power side and the inverter need to be detached in the following cases, install a magnetic
contactor (MC) between the power supply and the inverter (primary side).
Select a magnetic contactor (MC) depending on the inverter type and input current in the table [10.
2. 1].
• Thermal relay on the motor is activated
• Protection detection relay (FL) inside the inverter is activated
• Not to automatically restart at restoration of power after power failure
• When using the braking resistor (option), the thermal relay of the braking resistor is activated
To open the power circuit (primary side) when the protective function detection relay inside the
inverter is activated, the molded-case circuit breaker (MCCB) with a power cutoff device can be
installed instead of magnetic contactors (MC). Make sure the molded-case circuit breaker (MCCB)
trips at the contact of protection detection relay. If earth leakage detector is not installed, earth leak-
age circuit breaker (ELCB) should be installed instead of MCCB.
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10. Selection and installation of peripheral devices
E6582062
3
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