Warning
Design / Selection
1. Confirm the specifications.
Products represented in this manual are designed only for
use in compressed air systems.
Do not operate at pressures, temperatures, etc., beyond the
range of specifications, as this can cause damage or malfunction.
Please contact SMC when using a fluid other than compressed
air.
We do not guarantee against any damage if the product is
used outside of the specification range.
2. Actuator drive
When an actuator, such as a cylinder, is to be driven using a
valve, take appropriate measures (such as the installation of
a cover or the restricting of access to the product) to prevent
potential danger caused by actuator operation.
3. Intermediate stops
It is difficult for products like cylinders to make a piston stop
at the required intermediate position accurately and precisely
due to the compressibility of air.
Furthermore, since valves and cylinders are not guaranteed
for zero air leakage, it may not be possible to hold a stopped
position for an extended period of time.
Please contact SMC if it is necessary to hold a stopped
position for an extended period of time.
4. Holding pressure
Since valves are subject to air leakage, they cannot be used
for applications such as holding pressure in a pressure vessel.
5. Not suitable for use as an emergency shutoff valve,
etc.
The valves presented in this catalog are not designed for safety
applications (e.g. emergency shutoff valve). If the valves are
used in such applications, additional safety measures should
be adopted.
6. Release of residual pressure
For maintenance and inspection purposes install a system for
releasing residual pressure.
7. Ventilation
Provide ventilation when using a valve in a confined area,
such as in a closed control panel. For example, install a
ventilation opening, etc., in order to prevent pressure from
increasing inside of the confined area and to release the heat
generated by the valve.
8. Extended periods of continuous energization
If a valve is continuously energized for an extended period of
time, heat generated by the coil assembly may result in
reduced performance and shorter service life, or have
adverse effects on peripheral equipment. If the total energizing
time per day is expected to be longer than the total
de-energizing time per day, use a valve which has DC type,
power saving type or long loading time type.
Depending on the operating conditions, it may be possible to
use valves which are not mentioned above. Please contact us.
When the valve is mounted onto a control panel, take
measures against radiation in order to keep the valve
temperature within the specified range.
9. Do not disassemble the product or make any
modifications, including additional machining.
Doing so may cause human injury and/or an accident.
1. Leakage voltage
Take note that the leakage voltage will increase when a resistor
is used in parallel with a switching element or when a C-R
circuit (surge voltage suppressor) is used for protecting a
switching device because of the leakage voltage passing
through the C-R circuit. The suppressor residual leakage
voltage should be as follows.
DC coil
3% or less of the rated voltage
AC coil
20% or less of the rated voltage
2. Solenoid valve drive for AC with a solid state output
(SSR, TRIAC output, etc.)
1) Current leakage
When using a snubber circuit (C-R element) for surge
protection of the output, a very small amount of electrical
current will continue to flow even during the OFF state.
This results in the valve not returning. In a situation
where the tolerance is exceeded, as in the above case,
take measures to install a bleeder resistor.
2) Minimum allowable load amount (Min. load current)
When the consumption current of a valve is less than the
output’s minimum allowable load volume or the margin is
small, the output may not switch normally. Please contact
SMC.
3. Surge voltage suppressor
If a surge protection circuit contains nonstandard diodes,
such as Zener diodes or varistor, a residual voltage that is in
proportion to the protective circuit and the rated voltage will
remain. Therefore, take into consideration the surge voltage
protection of the controller.
In the case of diodes, the residual voltage is approximately 1 V.
4. Operation in low temperature conditions
It is possible to operate a valve in extreme temperatures, as low
as 0°C. Take appropriate measures to avoid the freezing of
drainage, moisture, etc., in low temperatures.
5. Mounting orientation
Mounting orientation is not specified.
Caution
VEX5 Series
3 Port Solenoid Valves / Precautions 1
Be sure to read before handling
- 4 -
No.VEX
∗∗∗∗
-OMA0019-C
