Ulvac DOP-120SX User manual

No．28111-2-01-3
Original instructions
User Manual
Rocking piston type dry vacuum pump
DOP-120SX
DOP-120SY
Request
In order to safely and efficiently use this product, please
read the instruction manual before use.
Keep the user manual in a safe place.
The dimensions and specifications stated in this manual
are subject to change without notice in order to improve
performance.
ULVAC KIKO, Inc.

We,
Company:ULVAC KIKO,Inc.
of
Address:291-7 Chausubaru Saito-city,Miyazaki (ZIP Cord:881-0037) Japan.
This declaration is issued under the sole responsibility of the manufacturer.
In accordance with the following Directive:
2006/42/EC
Machinery Directive
2011/65/EU+(EU)2015/863
RoHS Directive
declare under our sole responsibility that the product,
Type of Product
:
Oscillating Piston Type Dry Vacuum Pump
Model Name
:
DOP-120SX
DOP-120SY
to which this declaration related is in conformity with the following standards:
EN 1012-2:1996+A1:2009
Compressors and vacuum pumps – Safety requirements, Part2. Vacuum pumps
IEC EN 61010-1:2010+A1:2019
Safety requirement for electrical equipment for measurement, control and laboratory use
Part1.General requirement
following the provisions of
The person stated below will keep the following technical documentation:
operating and maintenance instructions
technical drawings
description of measures designed to ensure conformity
other technical documentation, e.g. quality assurance measures for design and production
Person authorized to compile the technical file:
( Name and address) Chris Goebel
ULVAC GmbH
Klausnerring 4 85551 Kirchheim b. München, Germany
31.Mar, 2023
Makoto Uchimura
Miyazaki , Japan
Development manager
(date & place)
(name, function, signature)
Declaration of Conformity

We,
Company:ULVAC KIKO,Inc.
of
Address:291-7 Chausubaru Saito-city,Miyazaki (ZIP Cord:881-0037) Japan.
This declaration is issued under the sole responsibility of the manufacturer.
In accordance with the following Directive:
Supply of Machinery (Safety) Regulations 2008
(S.I. 2008 No. 1597, as amended by S.I. 2019 No. 696)
The Restriction of the Use of Certain Hazardous Substances in Electrical and
Electronic Equipment Regulations 2012 (S.I. 2012 No. 3032)
declare under our sole responsibility that the product,
Type of Product
:
Oscillating Piston Type Dry Vacuum Pump
Model Name
:
DOP-120SX
DOP-120SY
to which this declaration related is in conformity with the following standards:
BS EN 1012-2:1996+A1:2009
Compressors and vacuum pumps – Safety requirements, Part2. Vacuum pumps
BS IEC EN 61010-1:2010+A1:2019
Safety requirement for electrical equipment for measurement, control and laboratory use
Part1.General requirement
following the provisions of
The person stated below will keep the following technical documentation:
operating and maintenance instructions
technical drawings
description of measures designed to ensure conformity
other technical documentation, e.g. quality assurance measures for design and production
Person authorized to compile the technical file:
( Name and address) Chris Goebel
ULVAC GmbH
Klausnerring 4 85551 Kirchheim b. München, Germany
31.Mar, 2023
Makoto Uchimura
Miyazaki , Japan
Development manager
(date & place)
(name, function, signature)
Declaration of Conformity

Table of Contents
indicates a page with safety-related content.
0. Before using................................................................................................................P.01
0-1. Check when opening the package......................................................................P.02
0-2. For safe use of this product ................................................................................P.03
･Safety symbols ...................................................................................................P.03
･Cautions about safety while using ......................................................................P.04
1. Product Outline .............................................................................................................P.1
1-1. Purpose of Use and Prohibited Items...................................................................P.1
1-2. Product Specification............................................................................................P.1
1-3. Protective equipment (Thermal protector) ............................................................P.2
2. External drawings..........................................................................................................P.2
3. Installation and storage.................................................................................................P.4
3-1. Safety cautions for installation and storage ..........................................................P.4
3-2. Ambient conditions during installation, storage and operation..............................P.4
3-3. Installation location...............................................................................................P.5
3-4. Operation check when installing...........................................................................P.5
3-5. Wiring ...................................................................................................................P.5
3-6. Fluctuations in the power supply voltage and frequency ......................................P.6
3-7. Piping....................................................................................................................P.6
3-8. Storage.................................................................................................................P.6
4. Safety cautions..............................................................................................................P.7
4-1. Safety cautions.....................................................................................................P.7
4-2. When the thermal protector trips...........................................................................P.7
4-3. Precautions when starting ....................................................................................P.7
5. Pump performance........................................................................................................P.8
5-1. Ultimate pressure..................................................................................................P.8
5-2. Exhaust velocity....................................................................................................P.8
5-3. Required power ....................................................................................................P.8
6. Maintenance, inspection and repair ..............................................................................P.9
6-1. Cautions for maintenance, inspection and repair..................................................P.9
6-2. Maintenance.........................................................................................................P.9
6-3. Periodic inspection..............................................................................................P.10
6-4. Replacement and cleaning of consumables.......................................................P.11
6-5. Disposal..............................................................................................................P.12
6-6. Trouble checklist.................................................................................................P.13

7. Final notes...................................................................................................................P.14
･Warranty...................................................................................................................P.14
･Usage Status Check Sheet
(Used when requesting disassembly and repair)
･Product information, service bases, and contact information
Tables and figures
Fig. 2-1. DOP-120SX external drawing............................................................................P.2
Fig. 2-2. DOP-120SY external drawing............................................................................P.3
Fig. 3-1. Ground cable wiring position..............................................................................P.5
Fig. 3-2. Power supply installation example .....................................................................P.5
Fig. 3-3. Fluctuations in the power supply voltage and frequency....................................P.6
Fig. 3-4. Piping example for evacuating container ...........................................................P.6
Fig. 6-1. Disassembly drawings .....................................................................................P.12
Table 1-1.DOP-120SX/Y product specifications.................................................................P.1
Table 1-2.Thermal protector characteristics.......................................................................P.2
Table 4-1.Thermal protector characteristics.......................................................................P.7
Table 6-1.List of consumable parts ..................................................................................P.10
Table 6-2.Maintenance and Inspection Locations............................................................P.10
Table 6-3.Trouble checklist..............................................................................................P.13
Attached document: Wiring method..................................................................................P.15

01
0. Before using
Thank you for purchasing this product.
This pump is only for evacuating vacuums. If it is not handled correctly, it may lead to damage
or accidents. Use after reading the instruction manual and pay attention to inspections,
maintenance and safety, etc.
Users
This product is only to be handled by people who have read the instruction manual, and
sufficiently understood the items related to the safety cautions, pump specifications and
operation method.
Reading and Understanding the Manual
Read the manual thoroughly before use, and ensure that the equipment is used correctly.
It is particularly important to read the section entitled “For safe use of this product.”
Storing the User Manual
Keep the user manual in a safe place.
After reading the manual, store it in a safe place where it is readily available to users.
Copying of the Instruction Manual Prohibited
Copying of any part of this manual for use by a third party is prohibited without permission
of ULVAC.
Legal Compliance
Ensure that the pump is disposed of in accordance with national legislation, and as
required by your local authority.
Safety During Repairs
To ensure the safety of repair personnel, please note the usage conditions, particularly the
presence of any dangerous substances, when making a repair request to the
manufacturer.
The repair request may be refused if the usage conditions are unclear.

02
0-1. Check when opening the package
Check the following after opening the packaging.
(1) Check that the product is as ordered.
(2) Check that all the accessories are there.
<Standard Accessories>
- User Manual ............................................... 1
- Intake/exhaust plug (attached to pump) ............................................... 2
- Rubber feet (attached to pump) ............................................... 4
- Nylon clip (attached to pump) ............................................... 1
(3) Check that there is no damage.
(4) Check that the screws on the outside are not loose or missing.
Contact your dealer or ULVAC sales department if a problem has occurred.
1. When taking the pump out of the packaging box, don’t hold the pipe on the top of the
pump and press or bend it. Doing so may lead to damage to the pipe and reduced
pump performance.
2. Remove the intake/exhaust plug before using the pump.
3. If there is a possibility of foreign matter or dust entering the pump, attach an intake
filter.
4. In order to lower the pump ambient temperature, open ventilation holes into the
device and attach a cooling fan. Do not block the cooling fan ventilation holes.
Ensure there is at least 100 mm space from the pump.
5. Attach a silencer to reduce the operation noise.
DOP-120SX/Y
Pipe
Attention

03
0-2. For safe use of this product
Read the section “For safe use of this product” thoroughly before using the equipment.
This manual and the pump warnings include safety icons to assist in understanding points to
be followed.
The safety symbols noted here are provided to ensure that the product is used safely, and to
avoid danger and injury to users and other personnel. Ensure that these precautions are
always followed.
- Safety symbols
The meanings of these symbols are as described below.
Incorrect use poses an imminent threat and can result in a fatality or a serious injury
for the users.
There is a danger of death or serious injury to the operator if the equipment is used
incorrectly.
Incorrect use poses a risk and can result in light or moderate injury to users, or
physical damage.
Incorrect use poses a possibility of damage to the equipment, or problems with
operation.
Parts of the pump surface may reach temperatures in excess of 60ºC while the
pump is operating.
Don’t touch the pump while it is operating. It may result in burns.
Turn OFF the main power supply when performing work involving electricity such as
wiring.
Failure to do so may lead to electric shocks.
Pump Intake pipe
Pump exhaust pipe
Danger
Warning
Caution
Attention
Caution –high temperatures
Caution –electric shock

04
- Cautions about safety while using
<Purposes>
(1) This pump does not have an explosion-proof structure. Don’t use it to evacuate explosive
gasses.
(2) The gas sucked in by the pump may leek out from places other than the exhaust. Don’t
use it for anything other than clean, room-temperature air or N2.
<Maintenance and repair>
(3) When requesting ULVAC’s service division for disassembly or repair, always note the
gases used, and complete the check list at the end of this manual. If the pump has been
used to exhaust toxic gases, the pump itself will also be toxic. Use with some gases may
render disassembly and repair impossible. Pay sufficient attention.
<Installation>
(1) Do not use the pump in an explosive atmosphere. Use under such conditions may result
in injuries or a fire.
(2) Ensure that the vicinity of the pump is completely free of inflammable material such as
flammable solvents, etc.
Failure to follow this requirement may result in fire.
(3) Ensure that the vicinity of the motor is free of obstacles which may obstruct ventilation.
Obstructed ventilation may result in burns or a fire.
(4) In order to avoid the possibility of fires and explosions, protect the pump with a
nonflammable cover.
<Power supply>
(5) When inspecting and repairing the pump, turn OFF the main power supply of the device
and check the pump has stopped before starting it.
(6) Ensure that all wiring work is performed in accordance with electrical equipment
standards and internal wiring regulations. Incorrect wiring work may result in fire.
(7) When performing electrical wiring, turn OFF the main power supply of the device before
starting it. Never perform the work while the electricity is still flowing. Working under such
conditions may lead to electric shock.
(8) Ensure that the equipment is earthed correctly. Failure to earth the equipment correctly
may result in electric shock in the event of a malfunction or earth leakage.
(9) Use the motor only at the rated voltage. Use at a different voltage may result in the
overload protection not operating correctly, motor burnout, or fire.
(10) Do not damage the pump-side power supply lead or modify it, pull it, or put anything on
top of it. It may result in earth leakages or electric shocks or fires.
[Continued on the next page]
Danger
Warning

05
(11) When attaching the electric cord to the pump, attach it firmly to the terminal block in an
appropriate manner.
Failure to do so may lead to electric shocks. Ensure that wiring and installing work is done
in accordance with local regulations and safety requirements. Connect the earth to the
bottom of the pump terminal block.
(Refer to 3-4 and 3-5.) (Attached document: wiring method)
(12) When removing the attached power cord, remove it from the terminal block after turning
OFF the main power supply of the device. Failure to do so may lead to electric shock.
(13) Do not touch the electric cord with wet hands. Doing so may lead to electric shocks.
(14) If the electric cord is connected to the terminal block, do not touch the electrical wiring.
Doing so may result in electric shocks.
<Operation>
(15) This pump does not have an explosion-proof structure. Do not use the pump near
inflammable material such as flammable solvents, etc. or in an explosive atmosphere.
Use under such conditions may result in injuries or a fire.
(16) Do not put your fingers or anything else in the motor openings. Failure to follow this
requirement may result in electric shocks, injuries, or fire.
(17) There is a danger of bursting. Do not operate the pump with the exhaust blocked, or with
the passage of gas on the exhaust side obstructed. Under these conditions, the pump
pressure increases, and this may cause it to burst, or the motor to become overloaded.
This pump does not have a pressure-resistant structure.
The internal pressure limit of this pump is 0.03 MPa (gauge pressure).
<Maintenance and repair>
(18) Ensure that this pump is dismantled and repaired only by a repair technician.
Repair technician: Somebody who has received technical education from us.
(19) Wear a dust mask and gloves when replacing the cup packing, intake valve, exhaust
valve or gasket, etc. Fine wear particles disperse into the air and can enter your body
through inhalation.
Photo: attachment example

06
<Installation>
(1) Wear debris from the cup packing is discharged from the exhaust and contaminates the
room. If necessary, attach a pipe, etc. and discharge it outside.
(2) This pump is designed with very precise clearances, and the following conditions must
therefore be satisfied during storage, mounting, and operation.
1. Ambient temperature during operation: within the ambient temperature in the product
specifications (refer to Table 1-1).
2. Ambient humidity during operation: 85% RH (relative humidity) or less
3. Other (during storage and operation)
a) A level location with sufficient floor strength.
b) No condensation.
c) No dust.
d) Inside a room with good ventilation.
e) No corrosive or explosive gas.
f) Not in direct sunlight.
g) No danger of ignition.
h) When assembling the pump, temperature around the pump not to exceed the
ambient temperature upper limit in the product specifications (refer to Table 1-1).
i) There is sufficient space around the pump and the pump cooling fan is not blocked.
(3) In order to lower the pump ambient temperature, open ventilation holes into the device
and attach a cooling fan.
Do not block the cooling fan ventilation holes.
Ensure there is at least 100 mm space from the pump.
<Operation>
(4) Do not touch the rotating parts such as the motor and cooling fan, etc. while the pump is
operating.
Doing so may result in injury.
(5) The entire pump becomes very hot when the thermal protector trips. Do not touch it. It
may lead to burns. Turn OFF the main power supply of the device.
(6) The pump becomes very hot during operation, and the motor should therefore not be
touched, either during operation or immediately after it has stopped. Contact with the hot
pump may result in burns.
(7) Do not put your fingers or any objects in, or look into, the intake or exhaust while the
pump is operating.
Doing so may lead to injuries or malfunctions. [Continued on the next page]
Caution

07
<Maintenance and repair>
(8) If the pump does not operate, or a fault occurs, switch OFF the main power supply of the
pump immediately and unplug the power cord to prevent from any accidents, and contact
your dealer or ULVAC, for inspection or repair.
(9) Leave the pump for at least 30 minutes after it stops and check that it has cooled down
before starting work. The inside of the pump is hot immediately after the pump stops, and
touching it may lead burns.
<Installation>
(1) Do not subject the pump to impacts or lay it on its side. Doing so may lead to
malfunctions.
(2) Do not hold the pipe on the top of the pump and press or bend it. Doing so may lead to
damage to the pipe and reduced pump performance.
(3) If there is a possibility of foreign matter or dust entering the pump, attach an intake filter.
<Purposes>
(4) This pump does not have corrosion-resistant specifications. Do not use it for anything
other than clean, room-temperature air or a gas with the same characteristics.
(5) This pump is only for evacuating vacuums. Do not operate it close to atmospheric
pressure for long periods.
Doing so may lead to malfunctions.
<Operation>
(6) Use at an ambient temperature within the ambient temperature in the product
specifications (refer to Table 1-1).
If operated at higher temperatures, the life of the pump is extremely shortened.
(7) Do not apply back pressure to the pump exhaust side when starting the pump. It will apply
a load on the motor and may prevent the pump from starting.
<Maintenance and repair>
(8) This pump is designed with precise clearances. As it requires special skills to assemble
the pump, please ask our service department to replace the consumable parts if a repair
technician is not available.
Caution
Attention

1
1. Product Outline
1-1. Purpose of Use and Prohibited Items
This is a piston type dry vacuum pump that evacuates vacuums by moving a special resin (cup
packing) in a reciprocating motion. It is designed to be built-in, so do not use it as a stand-alone
pump.
Observe the prohibited items below to ensure that the product is used correctly.
<Prohibited>
1) This pump is only for evacuating vacuums. Do not use it for pressurizing.
2) Do not perform any operation, repairs or modifications that are not approved by us.
3) This pump does not have corrosion-resistant specifications. Do not use it for anything
other than clean, room-temperature air or a gas with the same characteristics.
4) Do not use the pump with any gases that contain any dirt, dust, moisture or corrosive
gases, etc.
5) Do not operate it close to atmospheric pressure for long periods. Doing so may lead to
malfunctions.
1-2. Product Specification
Table 1-1. DOP-120SX/Y product specifications
Model
DOP-120SX/Y
Exhaust
velocity
(L/min)
120/140
Ultimate
pressure
(kPa)
8
Motor
3-phase, 120 W, 4 pole
With built-in automatic-recovery type thermal protector
Frequency
(Hz)
50/60
Voltage
(V)
200
220
Rated current
(A)
1.4/1.4
1.6/1.4
Noise level
dB(A)
60 or less (at ultimate pressure and 1m)
Intake
Exhaust
Rc1/4
Mass
(kg)
6.4
Ambient
temperature
(°C)
7 ~ 40
External
dimensions
(W × L × H)
(mm)
(139.5) × (255) × (167)
Overvoltage category
II
Pollution degree
2
Electric shock
protection class
Class 1
Warning
Attention

2
1-3. Protective equipment (Thermal protector)
1) An automatic-recovery type thermal protector is built-in to this pump as an overload protection
device.
This automatically breaks the circuit of the motor power supply and prevents the motor from
being burnt out if the pump stops rotating during operation or if the motor temperature
increases due to an overload.
2) Attach protection devices other than the overload protection device (earth leakage breaker,
motor breaker).
Table 1-2. Thermal protector characteristics
Operating
temperature
115 ± 5°C
Recovery
temperature
75 ± 15°C
Warning
Refer to Warning (9) on page 4.
Caution
Refer to Caution (5) on page 6.
2. External drawings
Fig. 2-1. DOP-120SX external drawing

3
Fig. 2-2. DOP-120SY external drawing

4
3. Installation and storage
3-1. Safety cautions for installation and storage
Warning
Refer to Warnings (1), (2), (3), (4), (6), (7),
(8) and (9) on page 4, and
(10), (11), (12), (13) and (14) on page 5.
Caution
Refer to Cautions (1), (2) and (3) on page 6.
Attention
Refer to Attentions (1), (2) and (3) on page 7.
3-2. Ambient conditions during installation, storage and operation
This pump is designed with very tight tolerances, and the following conditions must therefore be
satisfied during storage, mounting, and operation.
(1) Operation altitude: 1,000 m or lower
(2) Temperature during operation: within the ambient temperature in the product specifications
(refer to Table 1-1).
(3) Ambient humidity during operation: 85% RH (relative humidity) or less
(4) Other (during storage and operation)
a. A level location with sufficient floor strength.
b. No condensation.
c. No dust.
d. Inside a room with good ventilation.
e. No corrosive or explosive gas.
f. Not in direct sunlight.
g. No danger of ignition.
h. When assembling the pump, temperature around the pump not to exceed the ambient
temperature upper limit in the product specifications (refer to Table 1-1).
i. There is sufficient space around the pump and the pump cooling fan is not blocked.

5
3-3. Installation location
Select a location with as little dust and humidity as possible for the installation, and ensure that the
pump is installed level. Select a location that will enable installation, removal, inspection, and
cleaning operations. Pay particular attention to the ambient temperature and ensure that the
cooling fan air is not blocked, when installing the pump inside another device.
Place the pump on anti-vibration rubber, etc. to ensure that vibrations do not reach the pump.
If the pump is directly fixed, the pump may be damaged due to the vibrations.
Refer to “3-2. Ambient conditions during installation, storage and operation” for details of the
ambient conditions.
3-4. Operation check when installing
1) Remove the rubbers plugs attached to the intake and exhaust.
2) Attach the U, V and W power supply leads in accordance with the plate on the top of the pump
terminal block. (Attached document: Wiring method)
3) Attach the ground cable to the pump body, fix the power supply leads with nylon clips.
When fixing the cords, pay attention to the minimum bending radius and do not apply a load to
the power supply cords. (Figs. 3-1 and 3-2)
Fig. 3-1. Ground cable wiring position Fig. 3-2. Power supply installation example
4) Turn ON the main power supply of the device, and check the rotational direction and fan
cooling air. (Refer to Fig. 2-1or2-2.)
5) After you have finished checking, turn OFF the device main power supply and check that it has
stopped.
Note: Recommended power supply cord
4-core power supply cord: lead size min. 0.75 mm2, min. 300 V, min. 5 A, 1 is ground cable
Cable diameter: 7.5 –8 mm (prepare silicon clips for other sizes)
Caution
Use a power supply cord with a temperature resistance
of 80ºC or higher.
Do not bend the power supply cord more than its
minimum bending radius. Doing so may result in the wire
breaking or fires.
3-5. Wiring
1) Attach protection devices other than the overload protection device (earth leakage breaker,
motor breaker).
2) Ensure that a ground cable is attached to the pump.
3) When using an extension cable, select one with an appropriate type, electrical ratings and
maximum length, etc.
4) Ensure that wiring and earth work follows the local regulations and safety requirements.
5) After the wiring is completed, check that the pump rotation direction is correct.
(Refer to Fig. 2-1or2-2.)
Ground mark
Ground cable
connection position
(M4 tap)

6
Fig. 3-3. Fluctuations in the
power supply voltage and
frequency
3-6. Fluctuations in the power supply voltage and
frequency
Standard: Rotating electric machine general rules IEC
60034-1:2004.
There is no problem to main parts when operated continuously
under the voltage and frequency fluctuations in area A, and no
problem to main parts when operated under the voltage and
frequency fluctuations in area B.
Here, “no problem” means that the pump can be operated safely
and without the life of the parts being shortened, and does not
refer to the pump characteristics or the rated conditions such as a
rise in temperature.
The ratings are the rated torque (N.m).
3-7. Piping
1) Perform the piping so that there are no leaks, and attach a
filter in front of the intake.
(Intake/exhaust screw pitch: Rc ¼, tightening torque: 6 N.m)
2) Use rubber hoses, etc. to ensure that pump vibrations do not
reach between the pump and piping, otherwise the pump or
piping may be damaged.
3) Use piping with an inner diameter of 10 mm or more for the
intake.
4) Perform the piping so that there is no back pressure on the exhaust. If there is any back
pressure, ensure it is 0.03 MPa (gauge pressure) or less.
5) If the pump is used to evacuate a container, perform the piping as shown in Fig. 3-3 with a
shut-off valve to maintain the vacuum between the pump intake pipe and container.
6) When starting the pump, it may not start if the intake-side pressure is lower than the
atmospheric pressure.
Attach an atmospheric release leak valve between the pump intake pipe and container, and
set the intake-side pressure to atmospheric pressure when starting the pump.
3-8. Storage
Turn OFF the main power supply of the device, check that the pump has stopped, remove the
power supply cable connected to the pump, attach rubber plugs to the intake/exhaust, and store
it in a place with lower humidity.
Warning
Refer to Warnings (7) and (8) on page 4,
and (10), (12), (13) and (14) on page 5.
Fig. 3-4. Piping example for evacuating container
Vacuum pump
Filter
Leak valve
Shut-off valve
Container

7
4. Safety cautions
4-1. Safety cautions
Danger
Refer to Dangers (1) and (2) on page
4.
Warning
Refer to Warning (9) on page 4, and
(13), (14), (15), (16) and (17) on page
5.
Caution
Refer to Cautions (3), (4), (5), (6) and
(7) on page 6, and (8) on page 7.
Attention
Refer to Attentions (3), (4), (5), (6)
and (7) on page 7.
4-2. When the thermal protector trips
If the thermal protector has activated, turn OFF the main power supply and contact ULVAC.
The motor is extremely hot at this time. Do not touch it .
When the cause of malfunction is solved, check that the motor has cooled down, turn ON the
main power supply of the device, and check that the pump is operating correctly.
Caution
Refer to Cautions (5) and (6) on page 6 and (9) on page 7.
If the thermal protector has activated, turn OFF the main
power supply and contact ULVAC.
Table 4-1. Thermal protector characteristics
Operating
temperature
115 ± 5°C
Recovery
temperature
75 ± 15°C
4-3. Precautions when starting
1) Starting when it is cold
When it is cold, the bearing grease and cup packing, etc. may become hard making it difficult to
start the pump. Follow the following procedure when it is difficult to start the pump.
a) Open the intake to the atmosphere and turn ON/OFF the main power supply of the
device 2 or 3 times until the pump starts operating. If the pump still does not start, raise
the ambient temperature to 7ºC or higher.
b) Operate the pump for a few minutes with the intake open to the atmosphere to warm the
pump up. After the pump has warmed up, use it normally.
2) Precautions regarding the intake-side pressure
Set the intake-side pressure to atmospheric pressure when starting the pump.
If the pressure is lower than atmospheric pressure, it will apply a load on the motor and may
prevent the pump from starting.
If it is necessary to maintain a vacuum, attach a cut-off valve or three-way valve between the
pump and container.
Refer to fig. 3-4 for a piping example using a cut-off valve.

8
5. Pump performance
5-1. Ultimate pressure
The “ultimate pressure” referred to in catalogs and this instruction manual means “the lowest
pressure attainable when the pump is operated without any gas being introduced through the
intake (no-load operation)”.
Be aware that the displayed pressure may differ depending on the type of vacuum gauge.
Also, in actual vacuum devices, the ultimate pressure may be higher than the values stated in
catalogs.
This is for the following reasons.
The vacuum gauge is installed far from the pump, and also water vapor produced by the drops of
water and rust that are on the inside walls of the device and on the piping, etc. increase the
ultimate pressure.
Vacuum leaks in the vacuum path that lead to gas being introduced increase the ultimate pressure.
5-2. Exhaust velocity
The exhaust velocity of a pump varies depending on the type gas being introduced and the
pressure. Generally, the exhaust speed is highest when introducing atmospheric air and reduces
together with the pressure.
Also, the smaller the piping diameter and longer the pipe, the higher the pipe resistance and the
more the exhaust velocity decreases.
The nominal exhaust velocity of this pump is the maximum value when introducing dry air to the
pump.
5-3. Required power
The power required to drive the pump is the total of that for the rotation friction (mechanical work)
and that for compressing the air (compression work), and reaches a maximum at approximately an
intake pressure of 4×104to 6×104Pa.
At lower pressures, there is little compression work, and the power is consumed by mechanical
work.