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4. CONNECTIONS
4.2
Cautions on Connections
Observe the following cautions during connections for securing safety and reliability.
1
Power supply
Use a single-phase power supply having a stable
voltage without any waveform distortion for the
purpose of preventing wrong operations.
Prepare a switch and an overcurrent
protective device (3 A) to the power
supply for preventing an accidental
electric shock during connection work.
This instrument is not provided with any
replaceable overcurrent protective device.
Make sure to turn off the power supply
before connecting the power and the
input/output terminals to prevent an
electric shock.
2
Keep the input/output connections
away from high voltage power
circuits
Don’t place the input/output cables close to or in
parallel with any strong power circuits including
power lines. Place the cables 50cm or more away
from high voltage power circuits when they are
placed close to or in parallel to other circuits.
3
Keep the thermocouple input away
from a heat source
For thermocouple inputs, keep the input terminals
away from a heat source (a heating body) to
reduce a reference junction compensation error.
Don’t expose the input terminals to direct sunlight,
etc.
4
Keep the input/output connections
away from noise source
Keep all connection cables away from noise
source as far as possible, otherwise a malfunction
may occur. Provide a solution if the cables cannot
be separated from a noise source due to
unavoidable circumstances.
Major noise sources
Remedial measures
Electromagnetic switch,
etc. Power line having
waveform distortion,
Inverter, Thyristor regulator
Insert noise filters
between power
terminals and
input/output terminals.
A CR filter is often used.
5
Use crimp style terminals
(1) Mount crimp style terminals for connection
cable terminations to prevent any looseness
or disconnection of terminals or a short-circuit
failure between terminals.
(2) Use the crimp style terminals with an
insulation sleeve to prevent an electric
shocks.
6
Unused terminals
Don’t use any unused terminals for relaying,
otherwise the electric circuits may be damaged.
Secure the connected cables so as not to
allow them to be hooked by a person or a
substance, otherwise the connections may
be cut and disrupted, and may cause an
electric shock or other accidents.
Terminal block
Screw
diameter
Tightening
torque
Termination (unit: mm)
Power and
protective
conductor
terminals
M4
1.2N • m
Terminals other
than described
above
M3.5
0.8N • m
*Use Type O chip (on the left) whenever possible.
A switch and an overcurrent
protective device
Turn off the power supply
before starting connections.
Kinds of terminals and termination
Reference
Warning
Warning
Secure the connected
cables properly.
Warning
8.5 or less
8 or less 3.7 or more
3.7 or more
8 or less
4.3 or more
(with an insulation sleeve)
t : 0.8, with an insulation sleeve
t : 0.8, with an insulation sleeve