Yaskawa SGDH Linear Sigma Series - Manual (Page 197)

7.5 Others
7-33
7
7.5.2 Wiring for Noise Control
(1) Wiring Example
The SERVOPACK uses high-speed switching elements in the main circuit. It may receive “switching noise”
from these high-speed switching elements if the processing of wiring or grounding around the SERVOPACK is
not appropriate. To prevent this, always wire and ground the SERVOPACK correctly.
The SGDH SERVOPACK has a built-in microprocessor (CPU), so protect it from external noise as much as pos-
sible by installing a noise filter in the appropriate place.
The following is an example of wiring for noise control.
(2) Correct Grounding
(a) Grounding the Motor Frame
Always connect the linear servomotor frame terminal FG to the SERVOPACK ground terminal .
Also be sure to ground the ground terminal .
Ground both coil assembly and magnetic way of the linear servomotor.
If the linear servomotor is grounded via the machine, a switching noise current will flow from the SERVO-
PACK power unit through the linear servomotor stray capacitance. The above grounding is required to pre-
vent the adverse effects of switching noise.
(b) Noise on the Reference Input Line
If the reference input line receives noise, ground the 0 V line (SG) of the reference input line. If the main cir-
cuit wiring for the linear servomotor is accommodated in a metal conduit, ground the conduit and its junction
box.
For all grounding, ground at one point only.
For grounding wires connected to the casing, use a thick wire with a thickness of at least 3.5mm 2
(equivalent to a copper braided flat conductor)
: represents twisted-pari wires.
When using a noise filter, follow the precautions in (3) Using Noise Filters.
U
W
V
L2
L1
L3
L2C
L1C
CN2
CN1
SERVOPACK
Linear servomotor
Coil
assembly
(FG)
(Magnetic way)
Operation relay sequence
Signal generation circuit
(provided by customers)
1LF
AVR
(Grounding)
(Casing) (Casing) (Casing)
Wires of 3.5mm 2 min.
(Casing)
(Ground plate)
Ground: Exclusive grounding with
grounding resistance 100W max.
3.5mm 2
min.
200 VAC
Noise filter ∗3
∗3
∗1
∗1
∗2
∗3
∗1
∗2
2 mm 2
3.5mm 2 min.
∗1
2.0 mm 2
min.
3.5mm 2
min.
Linear scale
PG
Properly treat the end of shielded
wire.
Serial
converter
unit