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11. OPTIONS AND AUXILIARY EQUIPMENT
11.16 Surge absorbers (recommended)
A surge absorber is required for the electromagnetic brake. Use the following surge absorber or equivalent.
When using the surge absorber, perform insul ation beforehand to prevent short-circuit.
Maximum rating
Permissible circuit
voltage
Surge
immunity
Energy
immunity
Rated
power
Maximum
limit voltage
Static capacity
(reference
value)
Varistor voltage
rating (range) V1mA
AC[Vma] DC[V] [A] [J] [W] [A] [V] [pF] [V]
140 180
(Note)
500/time 5 0.4 25 360 300 220
(198 to 242)
Note. 1 time 8 20 s
13.5
16.5
4.7 1.0
0.8
3.0 or less
30.0 or more
[Unit: mm]
(Example) ERZV10D221 (Matsushita Electric Industry)
TNR-10V221K (Nippon chemi-con)
Outline drawing [mm] (ERZ-C10DK221)
11.17 Noise reduction techniques
Noises are classified into external noises which enter the servo amplifier to cause it to malfunction and those
radiated by the servo amplifier to cause perip heral devices to malfunction. Since the servo amplifier is an
electronic device which handles small signa ls, the following general noise reduction techniques are required.
Also, the servo amplifier can be a source of noise as its outputs are chopped by high carrier frequencies. If
peripheral devices malfunction due to noises produced by the servo amplifier, noise suppression measures
must be taken. The measures will vary slight ly with the routes of noise transmission.
(1) Noise reduction techniques
(a) General reduction techniques
Avoid laying power lines (input and output cables) and signal cables side by side or do not bundle
them together. Separate power lines from s ignal cables.
Use shielded, twisted pair cables for connecti on with the encoder and for control signal transm ission,
and connect the shield to the SD terminal.
Ground the servo amplifier, servo motor, etc. together at one point (refer to section 3.12).
(b) Reduction techniques for external noises that cause the servo amplifier to malfunctio n
If there are noise sources (such as a magnetic contactor, an el ectromagnetic brake, and many relays
which make a large amount of noise) near t he servo amplifier and the servo amplifier may m alfunction,
the following countermeasures are required.
Provide surge absorbers on the noise sources to suppress noises.
Attach data line filters to the signal cables.
Ground the shields of the encoder connecting c able and the control signal cables with cable clamp
fittings.
Although a surge absorber is built into the servo amplifier, to protect the servo amplifier and other
equipment against large exogenous noise and lightn ing surge, attaching a varistor to the power input
section of the equipment is recommended.