4 System Design
4-46
G5 Series AC Servo Drives With Built-in EtherCAT Communications, Linear Motor Type
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Install surge suppressors for loads that have induction coils, such as relays, solenoids, brakes,
clutches, etc.
The following table shows the types of surge suppressors and recommended products.
Additional Information
Thyristors and varistors are made by the following manufacturers. Refer to manufacturer's
documentation for details on these components.
•
Thyristors: Ishizuka Electronics Co.
•
Varistor: Ishizuka Electronics Co., Panasonic Corporation
•
Select contactors based on the circuit's inrush current and the maximum momentary phase current.
•
The drive inrush current is covered in the preceding explanation of no-fuse breaker selection.
And the maximum momentary phase current is approx. twice the rated current.
Surge Suppressors
Type
Feature
Recommended product
Diodes
Diodes are used for relatively small loads such as
relays when the reset time is not a critical issue.
At power shutoff the surge voltage is the lowest,
but the reset time takes longer.
Used for 24/48-VDC systems.
Use a fast-recovery diode with a short
reverse recovery time.
(e.g. RU2 of Sanken Electric Co., Ltd.).
Thyristors and
varistors
Thyristors and varistors are used for loads when
induction coils are large, as in electromagnetic
brakes, solenoids, etc., and when reset time is
critical.
The surge voltage at power shutoff is approx. 1.5
times the varistor voltage.
Select the varistor voltage as follows.
•
24-VDC systems: varistor voltage 39 V
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100-VDC systems: varistor voltage 200 V
•
100-VAC systems: varistor voltage 270 V
•
200-VAC systems: varistor voltage 470 V
Capacitor
resistor
The capacitor plus resistor combination is used to
absorb vibration in the surge at power supply
shutoff.
The reset time can be shortened by selecting the
appropriate capacitance and resistance.
Okaya Electric Industries Co., Ltd.
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XEB12002 0.2
F-120
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XEB12003 0.3
F-120
Contactors
100
10
1
0.1
0.01
0.001
0.0001
1
10
100
1,000
10,000
100,000
Impedance (Ω)
Frequency (kHz)
T400-61D