Doc. No.

VQ4000V-OMV0001

Solenoid Valve
PRODUCT NAME

VQ4000/5000
(Pilot Valve V100)
MODEL/ Series
Contents

Safety Instructions ---------------------------------------------------------------------------- 2,3

Precautions on Design ---------------------------------------------------------------------- 4,5,6

Selection ---------------------------------------------------------------------------------------- 4,5,6

Mounting ---------------------------------------------------------------------------------------- 6

Piping -------------------------------------------------------------------------------------------- 6

Wiring -------------------------------------------------------------------------------------------- 6

Lubrication -------------------------------------------------------------------------------------- 7

Air Supply --------------------------------------------------------------------------------------- 7

Operating Environment ---------------------------------------------------------------------- 7

Maintenance ------------------------------------------------------------------------------------ 7,8

Specific Product Precautions --------------------------------------------------------------- 9 ~11

Construction and optional parts ------------------------------------------------------------ 12~15

Trouble shooting ------------------------------------------------------------------------------- 16,17

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S

VQ4000V-OMV0001
 Safety Instructions
These safety instructions are intended to prevent hazardous situations and/or equipment damage.
These instructions indicate the level of potential hazard with the labels of “Caution,” “Warning” or “Danger.”
They are all important notes for safety and must be followed in addition to International Standards
(ISO/IEC)*1), and other safety regulations.
*1) ISO 4414: Pneumatic fluid power -- General rules relating to systems
ISO 4413: Hydraulic fluid power -- General rules relating to systems
IEC 60204-1: Safety of machinery -- Electrical equipment of machines (Part 1: General requirements)
ISO 10218-1992: Manipulating industrial robots -- Safety

Caution Caution indicates a hazard with a low level of risk which, if not avoided,
could result in minor or moderate injury.

Warning Warning indicates a hazard with a medium

avoided, could result in death or serious injury.
level of risk which, if not

Danger Danger indicates a hazard with a high level of risk which, if not avoided, will
result in death or serious injuty.

Warning
1. The compatibility of the product is the responsibility of the person who designs the equipment or
decides its specifications.
Since the product specified here is used under various operating conditions, its compatibility with specific
equipment must be decided by the person who designs the equipment or decides its specifications based on
necessary analysis and test results.
The expected performance and safety assurance of the equipment will be the responsibility of the person who
has determined its compatibility with the product.
This person should also continuously review all specifications of the product referring to its latest catalog
information, with a view to giving due consideration to any possibility of equipment failure when configuring the
equipment.
2. Only personnel with appropriate training should operate machinery and equipment.
The product specified here may become unsafe if handled incorrectly.
The assembly, operation and maintenance of machines or equipment including our products must be
performed by an operator who is appropriately trained and experienced.
3. Do not service or attempt to remove product and machinery/equipment until safety is confirmed.
1.The inspection and maintenance of machinery/equipment should only be performed after measures to
prevent falling or runaway of the driven objects have been confirmed.
2.When the product is to be removed, confirm that the safety measures as mentioned above are implemented
and the power from any appropriate source is cut, and read and understand the specific product precautions
of all relevant products carefully.
3.Before machinery/equipment is restarted, take measures to prevent unexpected operation and malfunction.
4. Contact SMC beforehand and take special consideration of safety measures if the product is to
be used in any of the following conditions.
1.Conditions and environments outside of the given specifications, or use outdoors or in a place exposed to
direct sunlight.
2.Installation on equipment in conjunction with atomic energy, railways, air navigation, space, shipping,
vehicles, military, medical treatment, combustion and recreation, or equipment in contact with food and
beverages, emergency stop circuits, clutch and brake circuits in press applications, safety equipment or
other applications unsuitable for the standard specifications described in the product catalog.
3.An application which could have negative effects on people, property, or animals requiring special safety
analysis.
4.Use in an interlock circuit, which requires the provision of double interlock for possible failure by using a
mechanical protective function, and periodical checks to confirm proper operation.

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VQ4000V-OMV0001
 Safety Instructions
Caution
The product is provided for use in manufacturing industries.
The product herein described is basically provided for peaceful use in manufacturing industries.
If considering using the product in other industries, consult SMC beforehand and exchange specifications
or a contract if necessary.
If anything is unclear, contact your nearest sales branch.

Limited warranty and Disclaimer/Compliance Requirements

The product used is subject to the following “Limited warranty and Disclaimer” and “Compliance
Requirements”.
Read and accept them before using the product.

Limited warranty and Disclaimer

1.The warranty period of the product is 1 year in service or 1.5 years after the product is
delivered.∗2)
Also, the product may have specified durability, running distance or replacement parts. Please
consult your nearest sales branch.

2.For any failure or damage reported within the warranty period which is clearly our responsibility, a
replacement product or necessary parts will be provided.
This limited warranty applies only to our product independently, and not to any other damage
incurred due to the failure of the product.

3.Prior to using SMC products, please read and understand the warranty terms and disclaimers
noted in the specified catalog for the particular products.

∗2) Vacuum pads are excluded from this 1 year warranty.

A vacuum pad is a consumable part, so it is warranted for a year after it is delivered.
Also, even within the warranty period, the wear of a product due to the use of the vacuum pad or
failure due to the deterioration of rubber material are not covered by the limited warranty.

Compliance Requirements
1.The use of SMC products with production equipment for the manufacture of weapons of mass
destruction (WMD) or any other weapon is strictly prohibited.
2.The exports of SMC products or technology from one country to another are govemed by the
relevant security laws and regulation of the countries involved in the transaction. Prior to the
shipment of a SMC product to another country, assure that all local rules goveming that export
are known and followed.

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VQ4000V-OMV0001
 VQ4000/5000 Series
5-Port Solenoid Valves Precautions 1
Be sure to read this before handling products.

Design/Selection 11. 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
1. Confirm the specifications. inside of the confined area and to release the heat generated by
Products represented in this catalog are designed only for use in the valve.
compressed air systems (including vacuum).
12. Extended periods of continuous energization
Do not operate at pressures, temperatures, etc., beyond the
range of specifications, as this can cause damage or ・If a valve will be continuously energized for an extended period
malfunction.(Refer to the specifications.)Please contact SMC of time, the temperature of the valve will increase due to the
when using a fluid other than compressed air (including heat generated by the coil assembly. This will likely adversely
vacuum).We do not guarantee against any damage if the affect the performance of the valve and any nearby peripheral
product is used outside of the specification range. equipment. Therefore, when it is continuously energized or the
energized period per day is longer than the de-energized period
2. Actuator drive use the valve with a power saving circuit. As a valve not
When an actuator, such as a cylinder, is to be driven using a mentioned above can also be used depending on the operating
valve, take appropriate measures (such as the installation of a conditions (in particular, DC specification valves) , please
cover or the restricting of access to the product) to prevent contact SMC for further information.
potential danger caused by actuator operation. ・For applications such as mounting a valve on a control panel,
3. Intermediate stops incorporate measure to limit the heat radiation so that the
For the 3-position closed center or double check valve types, it
temperature will be high when a 3 station manifold.
is difficult to make the piston stop at the required position
accurately due to the compressibility of air.
Furthermore, since valves and cylinders are not guaranteed for 13. Do not disassemble the product or make any
zero air leakage, it may not be possible to hold a stopped modifications, including additional machining.
position for an extended period of time. Doing so may cause human injury and/or an accident.
Please contact SMC if it is necessary to hold a stopped position 14. Pilot exhaust
for an extended period of time. Mount the silencer to both D and U side of the pilot exhaust port
4. Effects of back pressure when using a manifold
(PE) or exhaust the air to the atmosphere. If the pilot exhaust is
Use caution when valves are used on a manifold because
actuators may malfunction due to back pressure. common with the main exhaust, the main valve may malfunction
For the 3-position exhaust center valve or single acting cylinder, due to back pressure.
take appropriate measures to prevent malfunction by using it
with an individual EXH spacer assembly, a back pressure check
valve, or an individual exhaust manifold.
5. Holding pressure (including vacuum)
Since valves are subject to air leakage, they cannot be used 1. Precautions for 2-position double solenoid valves
for applications such as holding pressure (including vacuum)
If a double solenoid valve is operated with momentary
in a pressure vessel.
6. Not suitable for use as an emergency shutoff valve, energization, it should be energized for at least 0.1 seconds.
etc. However, depending on the piping conditions, the cylinder may
The valves listed in this catalog are not designed for safety malfunction even when the double solenoid valve is energized
applications such as an emergency shutoff valve. If the valves
for 0.1 seconds or longer. In this case, energize the double
are used in such applications, additional safety measures
should be adopted. solenoid valve until the cylinder is exhausted completely.
7. Release of residual pressure
For maintenance and inspection purposes install a system for 2. Leakage voltage
releasing residual pressure. Especially in the case of the Take note that the leakage voltage will increase when a
3-position closed center valve or double check valve types, resistor is used in parallel with a switching element or when a
C-R circuit (surge voltage suppressor) is used for protecting a
ensure that the residual pressure between the valve and the
switching device because of the leakage voltage passing
cylinder is released. through the C-R circuit. The suppressor residual leakage
8. Operation in a vacuum condition voltage should be as follows.
When a valve is used for switching a vacuum, take measures to
install a suction filter or similar to prevent external dust or other
foreign matter from entering inside the valve.
In addition, at the time of vacuum adsorption, be sure to supply
a constant supply of vacuum. Failure to do so may result in
foreign matter sticking to the adsorption pad or air leakage,
causing the workpiece to drop.
9. Regarding vacuum switch valves and vacuum
release valves
If a non-vacuum valve is installed in the middle of a piping
system that contains a vacuum, the vacuum condition will not be DC coil：3% or less of the rated voltage
maintained. Use a valve designed for use under vacuum AC coil：8% or less of the rated voltage
conditions.
10. Double solenoid type
When using the double solenoid type for the first time, actuators
may travel in an unexpected direction depending on the
switching position of the valve. Implement measures to prevent
any danger from occurring when operating the actuator.

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VQ4000V-OMV0001
 VQ4000/5000 Series
5-Port Solenoid Valves Precautions 2
Be sure to read this before handling products.

Design/Selection

3. Solenoid valve drive for AC with a solid state output 5. Surge voltage intrusion
(SSR, TRIAC output, etc.) With non-polar type solenoid valves, at times of sudden
1) Current leakage interruption of the loading power supply, such as emergency
When using a snubber circuit (C-R element) for surge protection shutdown, surge voltage intrusion may be generated from
of the output, a very small amount of electrical current will loading equipment with a large capacity (power consumption),
continue to flow even during the OFF state. and a solenoid valve in a de-energized state may switch over
This results in the valve not returning. In a situation where the (see Figure 1).
tolerance is exceeded, as in the above case, take measures to When installing a breaker circuit for the loading power supply,
install a bleeder resistor. consider using a solenoid valve with polarity (with polarity
2) Minimum allowable load amount (Min. load current) protection diode), or install a surge absorption diode between the
When the consumption current of a valve is less than the loading equipment COM line and the output equipment COM line
output’s minimum allowable load volume or the margin is small, (see Figure 2).
the output may not switch normally. Please contact SMC.
3) Solenoid valve with full wave rectifier circuit
When the solenoid valve built-in full wave rectifier circuit with AC
specifications is used, a return failure of the solenoid valve may
occur depending on the kind of triac output circuit. Carefully
check this point when selecting a SSR or sequencer.
For details, contact the SSR or sequencer manufacturer.
4. Surge voltage suppressor
1) The surge voltage suppressor built into the valve is intended
to protect the output contacts so that the surge generated inside
valve does not adversely affect the output contacts. Therefore, if
an overvoltage or overcurrent is received from an external
peripheral device, the surge voltage protection element inside
the valve is overloaded, causing the element to break. In the
worst case, the breakage causes the electric circuit to enter
short-circuit status. If energizing continues while in this state, a
large current flows. This may cause secondary damage to the
output circuit, external peripheral device, or valve, and may also
cause a fire. So, take appropriate protective measures, such as
the installation of an overcurrent protection circuit in the power
supply or a drive circuit to maintain a sufficient level of safety.
2) 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.

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VQ4000V-OMV0001
 VQ4000/5000 Series
5-Port Solenoid Valves Precautions 3
Be sure to read this before handling products.

2. Preparation before piping

Design/Selection Before piping is connected, it should be thoroughly blown out
with air (flushing) or washed to remove chips, cutting oil, and
other debris from inside the pipe
3. Winding of sealant tape
6. Operation in low temperature conditions When screwing piping or fittings
It is possible to operate a valve in extreme temperatures, as low into ports, ensure that chips from
as –10°C. Take appropriate measures to avoid the freezing of
drainage, moisture, etc., in low temperatures. the pipe threads or sealing material
7. Operation for air blowing do not enter the piping. Also,
When using a solenoid valve for air blowing, use an external if sealant tape is used, leave
pilot type. Use caution because the pressure drop caused by the 1 thread ridge exposed
air blowing can have an effect on the internal pilot type valve
when internal pilot type valves and external pilot type valves are at the end of the threads.
used on the same manifold. 4. Closed center and double check valve types
Additionally, when compressed air within the pressure range of For the closed center or double check valve types, check the
the established specifications is supplied to the external pilot
type valve’s port, and a double solenoid valve is used for air piping to prevent air leakage from the piping between the
blowing, the solenoids should be energized when air is being valve and the cylinder.
blown. 5. Connection of piping and fittings
8. Mounting orientation When screwing piping or fittings into the valve, tighten them as
Rubber seal: The mounting orientation is universal.
Metal seal: The mounting orientation of a single solenoid is follows.
universal. No specific orientation is necessary. When installing 1) For a fitting with sealant R or NPT, first, tighten it by hand,
a double solenoid or a 3-position configuration, mount the valve then use a suitable wrench to tighten the hexagonal portion of
so that the spool valve is horizontal.
the body an additional two or three turns. For the tightening
Mounting torque, refer to the table below.
Connection thread size (R, NPT) Proper tightening torque (N·m)
1/8 3 to 5
1/4 8 to12
3/8 15 to 20
1. Operation manual 1/2 20 to 25
Install the products and operate them only after reading the 2) If the fitting is tightened with excessive torque, a large amount
operation manual carefully and understanding its contents. Also, of sealant will seep out. Remove the excess sealant.
keep the manual where it can be referred to as necessary. 3) Insufficient tightening may cause seal failure or loosen the
2. Ensure sufficient space for maintenance activities. threads.
When installing the products, allow access for maintenance and 4) For reuse
inspection. (1) Normally, fittings with a sealant can be reused up to 2 to 3
3. Tighten threads with the proper tightening torque. times.
When installing the products, follow the listed torque (2) To prevent air leakage through the sealant, remove any
specifications. loose sealant stuck to the fitting by blowing air over the
4. If air leakage increases or equipment does not threaded portion.
operate properly, stop operation. (3) If the sealant no longer provides effective sealing, wind
Check mounting conditions when air and power supplies are sealing tape over the sealant before reusing. Do not use any
connected. Initial function and leakage tests should be form of sealant other than the tape type of sealant.
performed after installation. (4) Once the fitting has been tightened, backing it out to its
5. Painting and coating original position often causes the sealant to become
Warnings or specifications printed on or affixed to the product defective. Air leakage will occur.
should not be erased, removed, or covered up.Please consult 6. Piping to products
with SMC before applying paint to resinous parts, as this may When piping to a product, refer to the operation manual to avoid
have an adverse effect due to the solvent in the paint. mistakes regarding the supply port, etc
Wiring
Piping

1. The solenoid valve is an electrical product. For safety,

install an appropriate fuse and circuit breaker before
1. Refer to the Fittings and Tubing Precautions for use.
handling One-touch fittings.

1. Polarity
There is no polarity.

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VQ4000V-OMV0001
 VQ4000/5000 Series
5-Port Solenoid Valves Precautions 4
Be sure to read this before handling products.

water separator should be installed upstream from filters.

Wiring

3. Drain flushing
If condensation in the drain bowl is not emptied on a regular
2. Applied voltage basis, the bowl will overflow. This may cause the malfunction of
When electric power is connected to a solenoid valve, be careful pneumatic equipment. If the drain bowl is difficult to check and
to apply the proper voltage. Improper voltage may cause remove, the installation of a drain bowl with an auto drain option
malfunction or coil damage. is recommended.
3. Check the connections. For compressed air quality, refer to the SMC Best Pneumatics No. 6
Check if the connections are correct after completing all wiring. catalog.
4. External force applied to the lead wire 4. Use clean air.
If an excessive force is applied to the lead wire, this may cause Do not use compressed air that contains chemicals, synthetic
faulty wiring. Take appropriate measures so that a force of 30 N oils that include organic solvents, salt, corrosive gases, etc., as
or more is not applied to the lead wire. it can cause damage or malfunction.
Lubrication

1. When extremely dry air is used as the fluid,

1. Lubrication degradation of the lubrication properties inside the
[Rubber seal] equipment may occur, resulting in reduced reliability
1)The valve has been lubricated for life by the factory and does (or reduced service life) of the equipment. Please
not require any further. consult with SMC.
2) If a lubricant is used in the system, use class 1 turbine oil (no 2. Install an air filter.
additives), ISO VG32. For details about lubricant manufacturers’ Install an air filter upstream near the valve. Select an air filter
brands, refer to the SMC website. Additionally, please contact with a filtration size of 5 μm or smaller.
SMC for details about class 2 turbine oil (with additives) ISO 3. Take measures to ensure air quality, such as by
VG32.Once lubricant is utilized within the system, since the installing an aftercooler, air dryer, or water separator.
original lubricant applied within the product during Compressed air that contains a large amount of drainage can
manufacturing will be washed away, please continue to supply cause the malfunction of pneumatic equipment, such as valves.
lubrication to the system. Without continued lubrication, Therefore, take appropriate measures to ensure air quality, such
malfunctions could occur.If turbine oil is used, refer to the as by providing an aftercooler, air dryer, or water separator.
Safety Data Sheet (MSDS) of the oil. 4. If an excessive amount of carbon powder is present,
[Metal seal] install a mist separator on the upstream side of the
1) These valves can be used without lubrication. valve.
2) If a lubricant is used in the system, use class 1 turbine oil (no If excessive carbon dust is generated by the compressor, it may
additives), ISO VG32. For details about lubricant manufacturers’ adhere to the inside of a valve and cause it to malfunction.
brands, refer to the SMC website. Additionally, please contact For compressed air quality, refer to the SMC Best Pneumatics No. 6
SMC for details about class 2 turbine oil (with additives) ISO catalog.
VG32.
2. Lubrication amount Operating Environment
If the lubrication amount is excessive, the oil may accumulate
inside the pilot valve, causing malfunction or response delay.
So, do not apply a large amount of oil. When a large amount of 1. Do not use in an atmosphere containing corrosive
oil needs to be applied, use an external pilot type to put the gases, chemicals, sea water, water, water steam, or
supply air on the pilot valve side in the non-lube state. This where there is direct contact with any of these.
prevents the accumulation of oil inside the pilot valve. 2. Products with IP65 and IP67 enclosures (based on
Air Supply IEC60529) are protected against dust and water.
However, these products cannot be used in water.
3. Products compliant with IP65 and IP67 satisfy the
1. Type of fluids
product specifications when mounted properly. Be
Please consult with SMC when using the product in applications
sure to read the precautions for each product.
other than compressed air.
2. When there is a large amount of drainage 4. Do not use in an environment where flammable gas
Compressed air containing a large amount of drainage can or explosive gas exists. Usage may cause a fire or
cause the malfunction of pneumatic equipment. An air dryer or explosion. The products do not have an explosion
proof construction.

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VQ4000V-OMV0001
 VQ4000/5000 Series
5-Port Solenoid Valves Precautions 5
Be sure to read this before handling products.

3. Low-frequency operation
Operating Environment Valves should be operated at least once every 30 days to
prevent malfunction. (Use caution regarding the air supply.)
4. Manual override
When a manual override is operated, connected equipment
will be actuated.
5. Do not use in a place subject to heavy vibration
Operate only after safety is confirmed.
and/or shock.
5. If the volume of air leakage increases or the valve
6. The valve should not be exposed to prolonged
does not operate normally, do not use the valve.
sunlight. Use a protective cover. Note that the valve
Perform periodic maintenance on the valve to
is not for outdoor use. confirm the operating condition and check for any
7. Remove any sources of excessive heat. air leakage.
8. If it is used in an environment where there is
possible contact with oil, weld spatter, etc., exercise
preventive measures.
9. When the solenoid valve is mounted in a control 1. Drain flushing
panel or it’s energized for a long period of time, make Remove drainage from the air filters regularly.
sure the ambient temperature is within the 2. Lubrication
specifications of the valve. In the case of rubber seals, once lubrication has been started,
it must be continued.
Use class 1 turbine oil (with no additives), VG32. If other
lubricant oil is used, it may cause a malfunction. Please
1. Temperature of ambient environment contact SMC for information on the suggested class 2 turbine
Use the valve within the range of the ambient temperature oil (with additives), VG32.
specification of each valve. In addition, pay attention when using
the valve in environments where the temperature changes 3. Manual override operation
drastically. When switching a double solenoid valve via the manual override
2. Humidity of ambient environment operation, Instantaneous operation may cause the malfunction of
• When using the valve in environments with low humidity, take the cylinder. It is recommended that the manual override be held
measures to prevent static.
until the cylinder reaches the stroke end position.
• If the humidity rises, take measures to prevent the adhesion of
water droplets on the valve.

Maintenance

1. Perform maintenance and inspection according to

the procedures indicated in the operation manual.
If handled improperly, human injury and/or malfunction or
damage of machinery and equipment may occur.
2. Removal of equipment, and supply/exhaust of
compressed air
Before components are removed, first confirm that measures
are in place to prevent workpieces from dropping, run-away
equipment, etc. Then, cut off the supply air and electric power,
and exhaust all air pressure from the system using the
residual pressure release function.
For the 3-position closed center or double check valve types,
exhaust the residual pressure between the valve and the
cylinder.
When the equipment is operated after remounting or replacement,
first confirm that measures are in place to prevent the lurching of
actuators, etc. Then, confirm that the equipment is operating
normally.
In particular, when a 2-position double solenoid valve is used,
releasing residual pressure rapidly may cause the spool valve
to malfunction, depending on the piping conditions, or the
connected actuator to operate.

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VQ4000V-OMV0001
 VQ4000/5000 series
Specific Product Precautions 1
Be sure to read this before handling the products.
Continuous Duty Valve Mounting

After confirming that the gasket is installed correctly,

When the product is continuously energized for a long
securely tighten the mounting screws according to
period of time (10 minutes or longer), select the low the tightening torque shown below.
wattage type (DC specification). The AC type cannot be
continuously energized for 10 minutes or longer. If
anything is unclear, please contact SMC.

Manual Override

Since connected equipment will operate when the

manual override is activated, confirm that conditions
are safe prior to activation.

Replacement of One-touch Fittings/VQ4000

Cylinder port fittings are available in cassette type and

can be replaced easily. Fittings are secured
with a retaining clip that is
inserted from the top side
of the valve. After removing
the valve, remove the clip
with a flat head screwdriver
to replace the fittings.
To mount a fitting, insert the
fitting assembly until it stops
and reinsert the retaining clip
to its designated position.

Lead Wire Connection

Plug-in sub-plate (With terminal block)

●If the junction cover ① of the sub-plate is removed, you can see
the plug-in type terminal block② mounted inside the sub-plate.

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VQ4000V-OMV0001
 VQ4000/5000 series
Specific Product Precautions 2
Be sure to read this before handling the products.

Lead Wire Connection ●Installation

Place the cover straight over the pilot assembly so that
the pilot valve is not touched,and push it until the cover
hook locks without twisting the protective O-ring. (When
●The terminal block is marked as follows. Connect wiring to pushed in, the hook opens and locks automatically.)
each of the power supply terminals.

Note 1) There is no polarity. It can also be used as –COM.

Note 2) The sub-plate is double wired even for the VQ(4,5)10(0,1)

●Applicable terminal:1.25-3s,1.25Y-3,1.25Y-3N,1.25Y-3.5
Installation and Removal of Light Cover
Lead Wire Connection

Installation/Removal of light cover (VQ5000)

●Removal
Plug lead: Grommet type To remove the pilot cover pull it straight off. If it is pulled off
Make connections to each corresponding wire. at an angle, the pilot valve may be damaged or the
protective O-ring may be scratched.
● Installation
Place the cover straight over the pilot assembly so that the
pilot valve is not touched, and push it until the cover hook
locks without twisting the protective O-ring. (When pushed
in, the hook opens and locks automatically.)

Replacement of Pilot Valve

● Removal
Remove the mounting screw that holds the pilot valve
using a small screwdriver.
● Installation
After confirming the gasket is correctly placed under the
Installation and Removal of Light Cover valve, securely tighten the bolts with the proper torque
shown in the table below.
Proper tightening torque [N·m]
0.1 to 0.13
Installation/Removal of light cover (VQ4000) Note) The light circuit boards: A side is orange and the B
●Removal side is green. It must be mounted on the pilot valve in
Open the cover by inserting a small flat head accordance with the mounting indicators.
screwdriver into the slot on the side of the pilot assembly
(see drawing below), lift the cover out about 1 mm and
then pull off. If it is pulled off at an angle, the pilot valve
may be damaged or the protective O-ring may be
scratched.

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VQ4000V-OMV0001
 VQ4000/5000 series
Specific Product Precautions 3
Be sure to read this before handling the products.
Plug Lead Type
Attaching and detaching connectors
● To attach a connector, hold the lever and connector unit Internal Wiring Specifications
between your fingers and insert straight onto the pins of
the solenoid valve so that the lever’s pawl is pushed into
the groove and locks.
● To detach a connector, remove the pawl from the groove
by pushing the lever downward with your thumb, and
pull the connector straight out.

Note) Do not pull on the lead wires with excessive force.

This can cause faulty and/or broken contacts.

Note) For DC, coil surge voltage generated when OFF is

about –60 V. Please contact SMC separately for further
suppression of the coil surge voltage.

Enclosure IP65

Wires, cables, connectors, etc. used for models

conforming to IP65 should also have enclosures
equivalent to or stricter rating than IP65.

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VQ4000V-OMV0001
VQ4000 Series
Construction

Plug-in Unit

Component Parts
Number Description Material Note Component Parts
1 Body Aluminum Number Description Material Note
die-casted 1 Body Aluminum die-casted
2 Spool/Sleeve Stainless steel 2 Spool/Sleeve Aluminum, HNBR
3 Piston Resin 3 Piston Resin

Replacement Parts Replacement Parts

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VQ4000V-OMV0001
VQ4000 Series
Construction

Plug Lead Unit

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VQ4000V-OMV0001
VQ5000 Series
Construction

Plug-in Unit

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VQ4000V-OMV0001
VQ5000 Series
Construction

Plug Lead Unit

- 15 -
VQ4000V-OMV0001
 For valve failure, take following countermeasure
Problem Possible causes Countermeasures
referring to Problem.
1) Sliding failure or sticking of the • Replace the valve.
The valve operate when main valve Foreign matter • Purify the air source.
the manual override coming from the air source is
NO
caught in the main valve, causing
button is pushed? sliding failure or sticking.
2) Decreased pressure • Adjust the pressure within the
Air source pressure is reduced specification range for the valve.
and minimum operating pressure
YES
of the valve was not reached.
1) Non-conformance of electric
system
Indicator LED turns • Incorrect wiring
on when the valve is • Fuse blown out, breakage of lead Check all possible causes and make
wire sure the wiring is correct. Replace the
energized? NO • Incorrect contact at the contact part, if necessary.
and connection
Operation • Sequencer non-conformance
failure • Supply voltage insufficient
1) Drop of supply voltage • Check the supply voltage. Take corrective
Air is not Even if the indicator LED turns on, action if voltage drop is confirmed.
switched. YES the valve may not operate due to
voltage drop.
2) Leakage current Check the residual voltage.
The valve does not switch due to Keep the residual voltage.
the residual voltage when OFF.
DC coil：3% or less of the rated voltage.
AC coil：8% or less of the rated voltage.
3) Failure of the installed pilot
valve
• Pilot valve coil breakage • Replace the pilot valve assembly.
• Foreign matter is caught in the
pilot valve armature. • Clean the air supply
• Swelling of the pilot valve poppet
• Pilot valve coil burnt • Check the voltage, and replace the pilot
(High voltage, difference of the coil valve assembly.
specifications, entry of water) • Protect the valve, especially the coil to
prevent being exposed to water.
1) Leakage current Check the residual voltage.
Response delayed due to the Keep the residual voltage.
Response residual voltage when the valve is DC coil：3% or less of the rated voltage.
failure off. AC coil：8% or less of the rated voltage.
2) Sliding failure or sticking of the • Replace the valve.
Slow main valve. • Clean the air supply
response Foreign matter coming from the air
source is caught in the main valve,
causing sliding failure or sticking.
1-1) Valve mounting screw is loose Make sure that the gasket of the valve
Check the air leakage point mounting surface is not displaced or
deformed before tightening.
Appropriate tightening torque
Air leakage １． Leakage between the valve and base
• VQ4000 : 0.8 to 1.2N・m
• VQ5000 : 1.0 to 1.8N・m
If gasket is scratched, replace the gasket.
1-2) Gasket is caught Replace the gasket.

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VQ4000V-OMV0001
 For valve failure, take following countermeasure
Problem Possible causes Countermeasures
referring to Problem.
2． Air leaks from the One-touch fitting. 2-1) Tube is not inserted all the
way into the fitting. Check all possible causes and make sure
2-2) Tube has a gouge the piping is correct. Replace the part, if
2-3) The cut surface of the tube is necessary.
slanted.
2-4) One-touch fitting seal is
Replace One-touch fitting assembly
damaged
3. Air leakage from the exhaust (R) port. 3-1) Internal leakage increased
Air leakage Note) Metal seal type has approximately 250cc of because foreign matter coming • Replace the valve.
leakage per valve set. This is within specification from the air source is caught in
value. (Supply pressure: 0.5 MPa) • Purify the air source.
the main valve.

4. Air leaks from the manifold 4-1) Loose DIN rail clamp screw Hold manifolds tightly for tightening so that
there is no gap between the valves.
Appropriate tightening torque
• VQ4000 : 0.8 to 1.2N・m
• VQ5000 : 1.0 to 1.8N・m

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VQ4000V-OMV0001
 Revision history

1st Printing :Wo

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Note: Specifications are subject to change without prior notice and any obligation on the part of the manufacturer.
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VQ4000V-OMV0001