2-30
Driver
Leakage current (direct)
(including high-frequency cur-
rent)
Leakage current (resistor-capaci-
tor, in commercial power supply
frequency range)
R88D-UP02H(A) to -UP08H(A)
80 mA
3 mA
R88D-UP12H(A)
60 mA
4 mA
R88D-UP20H(A)
110 mA
5 mA
Note
1. Leakage current values shown above are for motor power lines of 10 m or less. The values will change
depending on the length of power cables and the insulation.
Note
2. Leakage current values shown above are for normal temperatures and humidity. The values will
change depending on the temperature and humidity.
Note
3. Leakage current for 100-VAC-input Servomotors is approximately half that of the values shown above.
H
Improving Encoder Cable Noise Resistance
Signals from the encoder are either A, B, or S phase. The frequency for A- or B-phase signals is 154 kHz
max., while the transmission speed for S-phase signals is 616 kbps. Follow the wiring methods outlined
below to improve encoder noise resistance.
•
Be sure to use dedicated encoder cables.
•
If lines are interrupted in the middle, be sure to connect them with connectors, making sure that the
cable insulation is not peeled off for more than 50 mm. In addition, be sure to use shielded wire.
•
Do not coil cables. If cables are long and are coiled, mutual induction and inductance will increase and
will cause malfunctions. Be sure to use cables fully extended.
•
When installing noise filters for encoder cables, use ferrite cores. The following table shows the rec-
ommended ferrite core models.
Maker
Name
Model
Tokin
EMI core
ESD-QR-25-1
TDK
Clamp filter
ZCAT2032-0930
ZCAT3035-1330
ZCAT2035-0930A
•
Do not wire the encoder cable in the same duct as power cables and control cables for brakes, sole-
noids, clutches, and valves.
H
Improving Control I/O Signal Noise Resistance
Position can be affected if control I/O signals are influenced by noise. Follow the methods outlined be-
low for the power supply and wiring.
•
Use completely separate power supplies for the control power supply (especially 24 VDC) and the
external operation power supply. In particular, be careful not to connect two power supply ground
wires. Install a noise filter on the primary side of the control power supply.
•
Use separate power supplies for control power and for power for the pulse command and deviation
counter reset input lines. Do not connect the ground wires for these two power supplies to the same
ground.
•
We recommend line drivers for the pulse command and deviation counter reset outputs.
•
For the pulse command and deviation counter reset input lines, be sure to use twisted-pair shielded
cable, and connect both ends of the shield wire to ground.
System Design and Installation
Chapter 2
