Yokogawa Standalone MW100 - Manual (Page 99)

2-11 IM MW100-01E
Installation and W
iring
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App
Index
2.4 Connecting Signal Wires
• Do not apply a voltage exceeding the value indicated below to the input
terminals of the 10-CH, High-Speed Digital Input Module and the output
terminals of the 10-CH, Medium-Speed Digital Output Module. Doing so can
damage the modules.
• Maximum input voltage
10-CH, High-Speed Digital Input Module: ± 10 VDC (-D05), ± 50 VDC (-D24)
10-CH, Medium-Speed Digital Output Module: ± 250 VAC or 250 VDC
• Maximum common mode voltage
Input/output terminal to ground: 250 VACrms (50/60 Hz)
• Do not apply a voltage exceeding the value indicated below to the input
terminals of the analog output modules or the PWM output modules. Doing so
can damage the modules.
• Maximum common mode voltage
Output terminal to ground: 250 VACrms (50/60 Hz)
• This is a measurement category II (IEC61010-1) and overvoltage category II
(CSA1N.61010-1) instrument.
Consider the points indicated below to prevent noise from entering the
measurement circuit. For information about measures against noise, see
section 2.9, “Measures against Noise on the MW100 Data Acquisition Unit.”
• Keep the measurement circuit away from the power supply cable (power supply
circuit) and ground circuit.
• It is desirable that the object under measurement is not a noise source. However, if
this is not avoidable, insulate the object under measurement and the measurement
circuit. In addition, ground the object under measurement.
• Shielded wires are effective against noise caused by electrostatic induction. As
necessary, connect the shield to the ground terminal of the MW100 (make sure this
does not lead to grounding at two points).
• Twisting the measurement circuit wires at short intervals is relatively effective against
noise caused by electromagnetic induction.
• The protective earth ground must be connected to low ground resistance (100 Ω or less).
When using the reference junction compensation of the MW100 through
thermocouple input, take measures to stabilize the temperature at the
terminal section.
• Always close and secure the terminal cover.
• Do not use thick wires with high heat radiation effect (cross-sectional area of 0.5 mm
2
or smaller recommended).
• Keep the ambient temperature consistent. Large temperature fluctuation occurs such
as when a fan nearby is turned ON/OFF.
Connecting the input wires in parallel with other instruments may mutually
affect the measured values. If you need to make a parallel connection:
• Turn OFF burnout.
• Ground each instrument at a single common point.
• Do not turn ON/OFF the instrument while measurement is in progress. It may cause
adverse affects on the other instrument.
Note that RTDs and resistors cannot be connected in parallel.