Installing A Magnetic Contactor At The Power Supply Side; Connecting An Ac Or Dc Reactor - YASKAWA E1000 Technical Manual

8.5 Installing Peripheral Devices
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Installing a Leakage Breaker
Drive outputs generate high-frequency leakage current as a result of high-speed switching. Install an Earth Leakage
Circuit Breaker (ELCB) on the input side of the drive to switch off potentially harmful leakage current.
Because each drive generates about 100 mA of leakage current across a 1 m cable and another 5 mA for each additional
meter, each drive should have a leakage breaker with a sensitivity amperage of at least 30 mA per drive. This will
eliminate harmonic leakage current and suppress any potentially harmful frequencies.
Leakage current can cause unprotected components to operate ncorrectly. If this is a problem, lower the carrier
frequency, replace the components in question with parts protected against harmonic current, or increase the sensitivity
amperage of the leakage breaker to at least 200 mA per drive.
Factors in determining leakage current:
• Size of the AC drive
• AC drive carrier frequency
• Motor cable type and length
• EMI/RFI filter
In order to safely protect the drive system, select a breaker that senses all types of current (AC and DC) and high
frequency currents.

◆ Installing a Magnetic Contactor at the Power Supply Side

Install a magnetic contactor to the drive input for the purposes explained below.
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Disconnecting the Power Supply
The drive should be shut off with a magnetic contactor (MC) when a fault occurs in any external equipment such as
braking resistors.
NOTICE: Do not connect electromagnetic switches or magnetic contactors to the output motor circuits without proper sequencing.
Improper sequencing of output motor circuits could result in damage to the drive.
NOTICE: Install a MC on the input side of the drive when the drive should not automatically restart after power loss. To get the full
performance life out of the electrolytic capacitors and circuit relays, refrain from switching the drive power supply off and on more than
once every 30 minutes. Frequent use can damage the drive. Use the drive to stop and start the motor.
NOTICE: Use a magnetic contactor (MC) to ensure that power to the drive can be completely shut off when necessary. The MC should
be wired so that it opens when a fault output terminal is triggered.
Note: 1. To keep the drive from restarting automatically when power is restored after momentary power loss, install a magnetic contactor to
the drive input.
2. To have the drive continue operating through momentary power loss, set up a delay for the magnetic contactor so that it does not open
prematurely.

◆ Connecting an AC or DC Reactor

AC and DC reactors suppress surges in current and improve the power factor on the input side of the drive.
Use a DC reactor or AC reactor or both:
• To suppress harmonic current or improve the power factor of the power supply.
• When using a phase advancing capacitor switch.
• With a large capacity power supply transformer (over 600 kVA).
Note: Use an AC or DC reactor when also connecting a thyristor converter (such as a DC drive) to the same power supply system,
regardless of the conditions of the power supply.
342 YASKAWA ELECTRIC SIEP C710616 35D YASKAWA AC Drive E1000 Technical Manual