Specifications

Series CU
Auto Switch Precautions 3
Be sure to read before handling.
Warning
Warning
Operating Environment
1. Never use in the presence of explosive gases.
The construction of our auto switches does not make them
explosionproof. Never use them in the presence of an explosive
gas, as this may cause a serious explosion
2. Do not use in an area where a magnetic field
is generated.
Auto switches will malfunction or magnets inside cylinders will
become demagnetized if used in such an environment.
(Consult with SMC regarding the availability of magnetic field
resistant auto switches.)
3. Do not use in an environment where the auto
switch will be continually exposed to water.
Switches satisfy IEC standard IP67 construction (JIS C0920:
watertight construction). Nevertheless, they should not be used
in applications where they are continually exposed to water
splash or spray. This may cause deterioration of the insulation
or swelling of the potting resin inside switches and may lead to
a malfunction.
4. Do not use in an environment laden with oil
or chemicals.
Consult with SMC if auto switches will be used in an
environment laden with coolants, cleaning solvents, various oils
or chemicals. If auto switches are used under these conditions
for even a short time, they may be adversely affected by a
deterioration of the insulation, a malfunction due to swelling of
the potting resin, or hardening of the lead wires.
5. Do not use in an environment with temperature
cycles.
Consult with SMC if switches are to be used where there are
temperature cycles other than normal temperature changes, as
they may be adversely affected internally.
6. Do not use in an environment where there is
excessive impact shock.
<Reed switches>
When excessive impact (300m/s² or more) is applied to a reed
switch during operation, the contact point may malfunction and
generate or cut off a signal momentarily (1ms or less). Consult
with SMC regarding the need to use a solid state switch
depending on the environment.
7. Do not use in an area where surges are
generated.
<Solid state switch>
When there are units (such as solenoid type lifters, high
frequency induction furnaces, motors) that generate a large
amount of surge in the area around cylinders with solid state
auto switches, their proximity or pressure may cause
deterioration or damage to the internal circuit elements of the
switches. Avoid and protect against sources of surge
generation and crossed lines.
8. Avoid close contact with accumulated iron
waste or magnetic substances.
When a large accumulated amount of ferrous waste such as
machining chips or welding spatter, or a magnetic substance
(something attracted by a magnet) is brought into close
proximity to an cylinder with auto switches, this may cause the
auto switches to malfunction due to a loss of the magnetic force
inside the cylinder.
Maintenance
1. Perform the following maintenance inspec-
tion and services periodically in order to pre-
vent possible danger due to unexpected auto
switch malfunction.
1) Securely tighten switch mounting screws.
If screws become loose or the mounting position is
dislocated, retighten screws securely after readjusting the
mounting position.
2) Confirm that there is no damage to lead wires.
To prevent faulty insulation, replace switches or repair lead
wires if damage is discovered.
3) Confirm that the green light on the 2-color indicator type
switch lights up.
Confirm that the Green LED is ON when stopped at the set
position. If the Red LED is ON when stopped at the set
position, the mounting position is not appropriate. Readjust
the mounting position until the Green LED lights up.
Other
Warning
1. Consult with SMC concerning water resist-
ance, elasticity of lead wires, and usage at
welding sites.
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