Yokogawa Button Operated MV2000 - Manual (Page 21)

Connecting Input Cables
Wiring to the Signal Input Terminals
WARNING
• To prevent electric shock, make sure that the power source is turned OFF.
CAUTION
• Exposing the input and output signal cables connected to the MV to high tension
may damage the cables and the MV terminals. Do not stretch the cables to their
limit, and make sure that the terminals are not being pulled on.
• To prevent fire, only use signal cables with a temperature rating of 70°C or above.
• Do not run a current through any of the input terminals that exceeds the voltages
below. Doing so may damage the MV.
• Maximum input voltage: ±60 VDC
• Maximum common mode voltage: ±60 VDC (under measurement category II
conditions)
• The MV is an installation category II product.
Wiring Precautions
Take the following precautions when wiring the input signal cables:
When using a screw terminal, we recommend that you use a crimp-on lug with an
insulation sleeve (designed for 4-mm screws).
Crimp-on lug (designed for 4 mm screws) with an insulation sleeve
When using a clamp terminal, we recommend that you use the following kind of cable:
• Conductive cross-sectional area: 0.08 mm
2 to 1.5 mm 2 (AWG28 to 16)
• Stripped section: Approx. 7 mm
Take measures to prevent noise from entering the measurement circuit.
• Move the measurement circuit away from the power cable (power circuit) and ground
circuit.
• Ideally, the object being measured should not generate noise. However, if this is
unavoidable, isolate the measurement circuit from the object. Also, ground the object
being measured.
• Shielded wires minimize the noise caused by electrostatic induction. Connect a shield
to the ground terminal of the MV as necessary (make sure you are not grounding at
two points).
• To minimize noise caused by electromagnetic induction, twist the measurement circuit
wires at short, equal intervals.
• Make sure to ground the protective ground terminal through minimum resistance (less
than 100 Ω).
When using internal reference junction compensation on a thermocouple input,
take measures to stabilize the temperature at the input terminal.
• Always use the terminal cover.
• Do not use thick wires which may cause large heat dissipation (we recommend a
cross-sectional area of 0.5 mm 2 or less).
• Make sure that the ambient temperature remains reasonably stable. Large
temperature fluctuations can occur if a nearby fan turns ON or OFF.
22 M-4661