LEYBOLD DRYVAC B Series User manual

2
DRYVAC225/50/100BManual
GA 01.415/2.02 - 7/97
Contents Page
Safety Information .................................................... 3
1Description.......................................................... 4
1.1 Design and Function....................................... 4
1.2 Standard Equipment....................................... 6
1.3 Ordering Data................................................. 6
1.4 Technical Data ............................................... 7
2Installation .......................................................... 8
2.1 Setting up the Pump....................................... 8
2.2 Electrical Connections.................................... 8
2.2.1 Connecting the Switches....................... 8
2.2.2 AC Power Source................................ 10
2.3 Connecting the Cooling Water...................... 11
2.4 Checking the Direction of Rotation ............... 11
2.5 Connecting the Intake Line........................... 12
2.6 Connecting the Exhaust Line........................ 12
3Operation .......................................................... 13
3.1 Start-up and Operation................................. 13
3.2 Shutdown ..................................................... 13
3.3 Storing and Shipping .................................... 13
4Maintenance...................................................... 15
4.1 Routine Maintenance.................................... 15
5Troubleshooting............................................... 16
Note:
References to illustrations consist of (figure number/item
number). For example, (1/2) refers to Figure 1, Item 2.

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DRYVAC225/50/100BManual
GA 01.415/2.02 - 7/97
Safety Information
Hazard analyses per European standard EN 1012 were
conducted for the DRYVAC2® 25, 50 and 100 B pumps.
Every person involved with connecting, operating or main-
taining these pumps shall have read and understood this
DRYVAC2operating instruction manual in order to avoid
hazards and operating malfunctions.
DRYVAC2B pumps are designed to pump down vacuum
chambers to pressure values in the rough and fine
vacuum ranges, and are intended for industrial use.
Precautionary notes in these instructions:
Warning – This indicates procedures and operations
which must be strictly observed to prevent hazards to
persons.
Caution – This indicates procedures and operations
which must be strictly observed to prevent damage or
destruction of the pump.
Media compatibility
The DRYVAC2B models are authorized for clean particle-
free applications.
Warning The DRYVAC2B models do not have a
purge system to dilute process
gases; thus, they are not suitable for
pumping hazardous gases or vapors
including the following:
•ignitable and explosive gases or
vapors,
•oxidants, or
•pyrophoric gases.
Electrical Safety
Warning Disconnect the pump from the main
power supply before beginning any
assembly or disassembly work. Take
measures to ensure that the pump
cannot be started. The electrical con-
nections shall be made only by a
qualified and licensed electrician, in
accordance with local codes.
DRYVAC2is a registered trademark of Leybold.
Mechanical Safety
Warning Do not expose any parts of the body to
the vacuum. In particular do not oper-
ate the pump with flanges open, or
loosen any flange, oil filling or drain
screws when a vacuum is present,
even if the pump is switched off.
Remove the cover panels only when the pump is
switched off.
Do not remove the pump or perform any maintenance
work before it has been vented and has come to a com-
plete stop.
Returning Equipment
Complete the form at the back of this manual before re-
turning equipment to Leybold for service. This form noti-
fies us of any toxic or other harmful products (as defined
by the applicable regulations such as the Common Mar-
ket Guideline L360, 1976/1979 or VBG 16) that may ex-
ist in or near the equipment. Attach the form to the pump
or enclose it with the pump. This statement detailing the
contamination is required to satisfy legal requirement
and to protect our employees.

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DRYVAC225/50/100BManual
GA 01.415/2.02 - 7/97
Section 1 — Description
1Description
1.1 Design and Function
The DRYVAC2B models are dry-compression vacuum
pumps for pumping clean gases. They are not suitable
for pumping gases containing dust or aggressive or cor-
rosive media. Refer to Section 1.4 for technical data.
Pumpoperatingprinciple
DRYVAC2s are four-stage hook-and-claw vacuum pumps.
Figure 1 illustrates the DRYVAC2's operating principle.
The two rotors (1/1) turn in opposite directions inside the
pumping chamber. As they rotate, they open and close
the intake (1/5) and outlet (1/4) slots with each cycle.
The pumping chamber is divided by the rotors. Gas is
drawn in on the one side of the rotors and compressed
on the other side.
The top sketch shows the beginning of the suction and
compression cycle. As the rotors rotate, the sealed
space above the rotors (1/2) is reduced in size and the
gas is compressed. At the same time, the right rotor be-
gins opening the inlet slot and gas is drawn into the
pumping chamber below the rotors.
In the center sketch, the left rotor is starting to open the
outlet slot, and compressed gas is being discharged
from the pumping chamber.
In the bottom sketch, the cycle has been completed and
the inlet and outlet slots are closed. Once the rotors
have passed through the neutral position, the cycle
starts again.
Design
There are four pumping stages (2/2) located one above
the other. The stages are pinned together.
The gas enters the pump through the intake port, is
pumped through four pump stages, flows through an ex-
haust silencer (2/1) into the exhaust.
The rotors are driven by two vertical shafts connected to
the motor (2/3) and synchronized by gears.
The pumping chamber is free of sealants and lubricants;
however, PFPE (perfluoropolyether) is used to lubricate
the gearing and the lower bearings. The upper bearings
are PFPE-grease lubricated.
Piston rings are used to seal each shaft where it passes
through the stages. The gear box is isolated from the
pumping chamber by piston rings and radial shaft seals.
The upper bearings are isolated by shaft seals.
The bearings and seals are mounted in the water-cooled
upper and lower end plates. The supply of cooling water
is limited by an orifice in the water-in port. The pump
stages are air cooled.
The pump is fully enclosed by panels, which can easily
be removed for maintenance purposes. An air outlet for
cabinet ventilation is on the top of the DRYVAC2.
Key to Figure 1
1Rotors
2Compression chamber
3Intake chamber
4Outlet slot
5Intake slot
Figure 1 Pump operating principle

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DRYVAC225/50/100BManual
GA 01.415/2.02 - 7/97
Section 1 — Description
Key to Figure 2
1Exhaust silencer
2Pump stages
3Electric motor
Figure 2 Sectional drawing of a DRYVAC2100B (the 25/50 B models are similar)
Figure 3 Simplified schematic of the DRYVAC2B

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DRYVAC225/50/100BManual
GA 01.415/2.02 - 7/97
Section 1 — Description
Dimensionsinmm
a b b1b2h h1h2I I1I2I3
25B 295 370 178 149 557 573 173 563 278 50 145
50B 295 370 178 149 587 603 173 563 278 50 145
100B 292 394 135 152 598 614 272 652 275 50 145
Dimensions in inches
a b b1b2h h1h2I I1I2I3
25B 115/8149/16 7 57/82115/16 29/16 613/16 23/16 11 2 523/32
50B 115/8149/16 7 57/8231/8233/4613/16 23/16 11 2 523/32
100B 111/2151/255/16 6239/16 243/16 1023/32 2511/16 1013/16 2 523/32
h: upper edge of intake port
Figure 4 Dimensional drawing
1.3 Ordering Data
Catalog No.
DRYVAC225B ....................................................13800
DRYVAC250B ....................................................13830
DRYVAC2100B with3-phasemotor
200–208-240/400-480 V*, 60 Hz, 3 phase ... 138 62
200/400 V*, 50 Hz, 3 phase ......................... 138 60
Repairkit:
DRYVAC225/50B ........................................ 899551
DRYVAC2100B ........................................... 899554
Exhaust silencer SD 25-501............................... 137 50
Dry canister for shipping and storage........ . 200 78 563
*All voltage ±10% from value listed.
ElectricalEquipment
The electrical equipment of the DRYVAC2B includes an
oil-pressure switch, and three thermal switches. These
devices are normally connected to the plant's control
equipment for the purpose of controlling the pump.
The DRYVAC2B is equipped with two thermal switches
that monitor pump temperature. The first switch warns of
an abnormally high temperature, while the second
switch signals that the temperature is too high for contin-
ued pump operation.
A third thermal switch monitors the pump's motor tem-
perature, and opens if the motor temperature exceeds
160 °C (320 °F).
A switch in the gear box monitors the oil pressure. The
signal from this switch can be processed in your plant
control to indicate whether or not the pump is running.
The oil-pressure switch opens when the oil pressure in
the gear box is <1.5 bar (7 psig).
The switch connections are brought together on sub-D
connector X18 on the back of the housing. Sub-D con-
nector X19 is not wired.
1.2 Standard Equipment
The DRYVAC2B is delivered ready for operation with its
gear box filled with PFPE (perfluoropolyether) lubricant.
A sealing disk with dirt trap and a union flange are at-
tached to the intake port.
The intake and exhaust ports, and the water inlet and
outlet fittings are sealed for shipping.
The pump is shipped with the following:
•A 2-meter (6.5-foot) main power cable with plug.
•An Allen key for removing or installing the exhaust
silencer.

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DRYVAC225/50/100BManual
GA 01.415/2.02 - 7/97
Section 1 — Description
1.4 Technical Data
DRYVAC225B 50B 100B
PumpingSpeed
50 Hz operation ..................... 25 m3 · h-1 (14.7 cfm) 45 m3 · h-1 (26.5 cfm) 100 m3 · h-1 (59 cfm)
60 Hz operation ..................... 30 m3 · h-1 (17.7 cfm) 55 m3 · h-1 (32.4 cfm) 100 m3 · h-1 (59 cfm)
Ultimate pressure*
50 Hz operation .............. 6·10-2 mbar (4.5x10-2 Torr) 4·10-2 mbar (3x10-2 Torr) 1·10-2 mbar (0.8x10-2 Torr)
60 Hz operation .............. 3·10-2 mbar (2.3x10-2 Torr) 2·10-2 mbar (1.5x10-2 Torr) 1·10-2 mbar (0.8x10-2 Torr)
Maximum intake pressure
incontinuousoperation .....................1000mbar(750Torr) 300mbar(25Torr) 150mbar(112Torr)
Motorpower ...............................................2.8 kW (4 hp) 2.8 kW (4 hp) 4.0kW(5.4 hp)
Rotationalspeedofpump
50 Hz operation ........................................3000 rpm 3000 rpm 3000 rpm
60 Hz operation ....................................... 3600 rpm 3600 rpm 3000 rpm
Noise level with the exhaust
line connected ..................................................60 dB(A) 64 dB(A) 68 dB(A)
Cooling water requirements (approx.) at 5 bar
(60 psig) water pressure and 15ºC (59ºF)
water temperature..................... 70 l · hr -1 (18.5 gal/hr) 180 l · hr -1 (48 gal/hr) 180 l · hr -1 (48 gal/hr)
Maximum cooling water temp..................... 25 ºC (77 ºF) 25 ºC (77 ºF) 25 ºC (77 ºF)
Cooling water pressure* .......... 2 – 10 bar (14 – 130 psig) 2 – 10 bar (14 – 130 psig) 2 – 10 bar (14 – 130 psig)
Cooling water connection, female threads ........... NPT ½" NPT ½" NPT ½"
Lubricant quantity in gear box..................... 0.75 l (0.8 qt) 0.75 l (0.8 qt) 0.8 l (0.85 qt)
Maximum ambient temperature.................40 ºC (104 ºF) 40 ºC (104 ºF) 40 ºC (104 ºF)
Weight .................................................160 kg (353 lbs) 170 kg (375 lbs) 200 kg (441 lbs)
Intake port ................................................ DN 63 ISO-K DN 63 ISO-K DN 63 ISO-K
Exhaust port ................................................... DN 25 KF DN 25 KF DN 40 KF
*All pressures given in bar or mbar are absolute values.
Figure 5 Pumping speed curves

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DRYVAC225/50/100BManual
GA 01.415/2.02 - 7/97
Section 2 — Installation
2Installation
2.1 Setting up the Pump
Eyebolts are provided for lifting and moving the pump. Do
not tip or turn the pump during movement. Do not stand
beneath the suspended pump during movement.
Set the pump on a flat even surface in a dry location. Lock
the casters after the pump is in place.
The pump is of safety class IP 20. Protect the pump
against dripping and splashed water.
The ambient temperature must not exceed 40ºC
(104ºF). Do not obstruct the ventilation grids. If installing
the pump in an enclosed cabinet or system, ensure that
sufficient ventilation is available.
2.2 Electrical Connections
Warning Electrical connections should be
made only by a qualified and
licensed electrician, in accordance
with local codes. Disconnect the
pump from all voltages before begin-
ning any assembly or disassembly
work. Take measures to ensure that
the pump cannot be started.
2.2.1 Connecting the Switches
The DRYVAC2B has four switches; the switch connec-
tions are brought together in a sub-D connector (X18) at
the back housing panel. The contacts open in response
to excessive temperature or insufficient oil pressure.
Connect the switches to the plant control as shown in
Figure 6.
The voltage source for the control circuits must be pro-
vided from the secondary windings of an isolation trans-
former or from some other isolated source. In addition,
ensure that the control voltage applied to X18 does not
exceed 24 V (AC or DC), and that the contact load of
each switch does not exceed 24 V AC/DC, 250 mA.
The DRYVAC2’s input and output signals must be posi-
tively isolated from potentially hazardous voltages in down-
line processing. This isolation shall be effective even if
there is a defect in the electrical system.
Caution Do not connect equipment to termi-
nals other the ones listed in the fol-
lowing instructions.
Failure to connect the switches as
described may result in major dam-
age to the pump, and lead to a loss of
warranty.
Connect the switches to the plant control equipment as
described below.
Connect a control voltage of 24 V (max.) AC or DC to
connector X18, pin 6. This control voltage is applied to
the contacts of all switches for the purpose of indicating
whether a switch is opened or closed.
Connect the oil-pressure switch so that the pump will
switch off when its contact opens (connector X18, pin 8).
The switch opens when the oil pressure is <1.5 bar
(7 psig), indicating that the pump isn't operating or that
the oil level is very low. Note that it is also open for
3 seconds during start-up, until the oil pressure in-
creases. Bridge this switch for 3 seconds to allow the oil
pressure to build during start-up.
Caution Don't bridge the oil-pressure switch
for more than 3 seconds. If this
switch is bridged for >3 seconds and
the rotation direction is wrong dur-
ing start-up, the pump will be dam-
aged from insufficient lubrication.
Connect the “Warning” thermal switch so that it acti-
vates a warning annunciator (such as a light, horn, bell,
or buzzer) when its contact opens (connector X18,
pin 9). The switch opens to alert you that the pump is
approaching a critical state. You can, however, continue
to operate the pump after the “warning” thermal switch
opens.
Connect the “Alarm” thermal switch so that the pump
shuts down when its contact opens (connector X18,
pin 7). Failure to shutdown the pump when this switch
opens results in major damage to the pump.
Connect the motor overtemperature switch so that the
pump shuts down when its contact opens (connector
X18, pin 4). Failure to shutdown the pump when this
switch opens results in major damage to the motor.

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DRYVAC225/50/100BManual
GA 01.415/2.02 - 7/97
Section 2 — Installation
Figure 6 DRYVAC225/50/100 B Switch Connections

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DRYVAC225/50/100BManual
GA 01.415/2.02 - 7/97
Section 2 — Installation
Figure 7 Fastening screws for the cover Figure 8 AC power source connections
2.2.2 AC Power Source
The DRYVAC2is supplied with a 2-meter (6.5 ft) power
cable (3-phase + ground).
The following are the standard pump voltages and fre-
quencies. Note that all standard DRYVAC2s are wired for
low voltage, unless the customer specifies high voltage
on the sales order.
Catalog No. Voltage, Frequency
25 B: 138 00 ..............200-208-240/400-480 V*, 60 Hz
.................................. 200/400 V*, 50 Hz
50 B: 138 30 ..............200-208-240/400-480 V*, 60 Hz
.................................. 200/400 V*, 50 Hz
100 B:138 62 ..............200-208-240/400-480 V*, 60 Hz
138 60 .................................. 200/400 V*, 50 Hz
If necessary, change the pump's terminal connections in
the motor junction box to match the applied AC line volt-
age as follows:
1. Access the motor junction box by first removing the
four screws (Figure 7) on the base of the pump, and
then removing the front panel.
2. Change the connections on the terminals (Figure 8) to
match the applied AC line voltage and frequency.
3. Replace the front panel.
Connect the pump's AC line cord to its rated AC voltage
and frequency through a suitable circuit breaker (see the
DRYVAC2nameplate). Don't turn ON the breaker until all
electrical and vacuum connections have been made.
DRYVAC2Main power Full load
current
25 B 3 Ph AC 200 V*, 50 Hz 11 A
3 Ph AC 200-208-240 V*, 60 Hz 11 A
3 Ph AC 400 V*, 50 Hz 5.5 A
3 Ph AC 400-480 V*, 60 Hz 5.5 A
50 B 3 Ph AC 200 V*, 50 Hz 11 A
3 Ph AC 200-208-240 V*, 60 Hz 11 A
3 Ph AC 400 V*, 50 Hz 5.5 A
3 Ph AC 400-480 V*, 60 Hz 5.5 A
100 B 3 Ph AC 200 V*, 50 Hz 15 A
3 Ph AC 200-208-240 V*, 60 Hz 15 A
3 Ph AC 400 V*, 50 Hz 7.5 A
3 Ph AC 400-480 V*, 60 Hz 7.5 A
*All voltage ±10% from value listed.
Note: All standard DRYVAC2s are wired for low voltage
unless the customer specifies high voltage on
the sales order.
2

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DRYVAC225/50/100BManual
GA 01.415/2.02 - 7/97
Section 2 — Installation
Figure 9 Connection side Figure 10 Shipping Seals
2.3 Connecting the
Cooling Water
The cooling water should have the following properties:
pH.............................................................7.0 to 8.5
Chloride (Cl –)....................... ≤75 mg/l = 2.1 mmol/l
Sulfate (SO4 –2)...................... ≤70 mg/l =0.7 mmol/l
Calcium ions.......................> 1.0 mmol/l = 100 ppm
≤2.7 mmol/l = 268 ppm
Hydrogencarbonate hardness............ 125 – 179 ppm
Significant deviations from the recommended values
may result in premature corrosion or deposits.
Connect the cooling water lines. Ensure that your water
supply line is connected to the DRYVAC2water inlet and
your drain line is connected to the DRYVAC2water outlet
(see Figure 9).
Caution Operation without cooling water will
damage the pump.
Note: Special modifications may be required when using
deionized (DI) water. Consult your Leybold sales or ser-
vice representative for information.
Note: If you will be using a closed-loop cooling system,
flush out the DRYVAC2's cooling water to remove any re-
sidual rust before connecting the pump to your cooling
system; also add a rust inhibitor to the cooling water.
2.4 Checking the Direction
of Rotation
Caution Don’t remove the shipping seals un-
til you are ready to install the pump.
The pump’s interior must be pro-
tected against humidity for as long
as possible.
Check the direction of rotation as follows:
1. Remove the shipping seals from the intake port (see
Figure 10) and ensure that the pump's intake and ex-
haust ports are open. Save the shipping seals for fu-
ture use.
Key to Figure 10
1Shipping cap
2Drying canister
3Gasket
4Sealing disc

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DRYVAC225/50/100BManual
GA 01.415/2.02 - 7/97
Section 2 — Installation
2. Loosen the four ¼-turn retaining clips, and remove the
front top half of the housing.
3. Briefly switch ON the pump and check the direction of
rotation of the motor fan; then, immediately turn OFF
the pump. The motor fan should rotate counterclock-
wise.
If the pump rotated in the wrong direction, first en-
sure that the incoming power to the pump is OFF, and
then interchange two of the input leads at the power
source.
4. Reinstall the cover.
Warning All housing panels and covers must
be reinstalled to protect the opera-
tors against contact with the hot
pump.
If the oil-pressure switch is connected correctly as de-
scribed in Section 2.2.1, the pump will switch off after
3 seconds if its rotation direction is wrong. The pump will
be damaged if it rotates in the wrong direction for longer
than 3 seconds.
2.5 Connecting the
Intake Line
The intake line should have the same or larger diameter
than the DRYVAC2intake flange. The line must be clean
and oil-free.
We recommend installing a valve between the pump
and the vacuum chamber.
A RUVAC WS 151 or WS 251 roots pump can be con-
nected directly to the intake port of a DRYVAC225B. A
RUVAC WS 251 or WS 501 can be connected directly to
the intake port of a DRYVAC250B or 100B.
Connect the intake line to the intake port; use bellows to
eliminate tension in the line.
Always install the supplied dirt trap in the intake flange to
prevent dirt from entering the pump from the vacuum
chamber or from the piping.
2.6 Connecting the
Exhaust Line
Connect the exhaust line; use bellows to eliminate ten-
sion in the line.
The exhaust line should have the same or larger diam-
eter than the DRYVAC2exhaust flange.
Avoid connecting the DRYVAC2together with oil-sealed
pumps to one central exhaust system. Using a common
exhaust line could result in condensate backstreaming
into the DRYVAC2or in dust adhering in the exhaust line.
Special modifications may be necessary to eliminate
noise and vibration when connecting several exhaust
lines to a single plenum. Consult your Leybold sales or
service representative.
The outlet for the ventilation air is on the top of the
DRYVAC2; if necessary, you can place an exhaust hood
over the pump for certain clean-room applications.

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DRYVAC225/50/100BManual
GA 01.415/2.02 - 7/97
Section 3 — Operation
3 Operation
3.1 Start-up and Operation
Open the cooling water supply.
Switch ON the pump.
If the motor’s circuit breaker trips when evacuating a large
vacuum chamber, preevacuate the chamber with a small-
diameter line (soft pump line).
3.2 Shutdown
We recommend that you operate the DRYVAC2continu-
ously. Allow it to continue operating overnight with its in-
let closed to avoid corrosion during idle periods.
To shutdown, close the valve to the vacuum chamber
and allow the pump to run for an additional 15 minutes.
Then switch OFF the pump and close the water supply.
Warning During operation, the pump's tem-
perature can exceed 100ºC (212ºF).
Always allow the pump to cool down
before removing it from the system
or before opening its housing.
If the DRYVAC2will be shutdown for an extended period,
seal its intake and exhaust ports, and purge it with inert
gas at a pressure of 1,000 mbar (760 Torr).
Refer Section 3.3 if the DRYVAC2will be disconnected
from the system.
3.3 Storing and Shipping
Shutdown the pump as described in Section 3.2.
Warning During operation, the pump's tem-
perature can exceed 100ºC (212ºF).
Always allow the pump to cool down
before removing it from the system
or before opening its housing.
Place drying canisters onto the pump’s inlet to protect
the pump’s interior from moisture. Then, seal the
DRYVAC2’s intake and exhaust ports. You can reuse the
shipping seals that were originally on the pump (see Fig-
ure 10); but you must use new drying canisters (P/N 200-
78-563).
Caution Always drain the cooling water be-
fore storing or shipping the pump.
Failure to drain the water can result
in the water freezing and bursting the
pump housing.
DrainingWaterFromtheDRYVAC2100B
1. Turn off the water supply.
2. Disconnect the cooling water hoses and drain the water.
3. Blow compressed air through the DRYVAC2’s water out
port to remove as much of the residual water as pos-
sible.
Draining Water From the DRYVAC225B and 50B

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DRYVAC225/50/100BManual
GA 01.415/2.02 - 7/97
Figure 11 DRYVAC225/50B Water Drain Plug
1. Turn off the water supply.
2. Open all necessary ¼-turn retaining clips and take off
the rear panel and the top covers.
3. Unscrew the hex socket screws at the bottom of the
left-side panel and remove the panel.
4. Disconnect the cooling water hoses; remove the
M12x1.5 plug screw (see Figure 11); and let the water
drain out. Blow compressed air through the DRYVAC2’s
water out port to remove as much of the residual water
as possible.
5. Reinstall the plug screw, the side panel, the top covers,
and the rear panel.
Service by Leybold
If you ship a pump to Leybold, be sure to indicate whether
the pump is free of substances that could be hazardous to
health or if it is contaminated. If it is contaminated, indi-
cate the nature of the hazard.
You must complete the form at the back of this manual
before sending any equipment to Leybold. Attach the
form to the pump or enclose it with the pump. This state-
ment detailing the contamination is required to satisfy
legal requirement and to protect our employees.
Leybold will return to the sender any pumps that are not
accompanied by a contamination statement.
Pack the pump so that it cannot be damaged during
shipping. The pump must also be shipped either in a gas
tight container or sealed in plastic so that no contami-
nants can escape from the packaging.
Section 3 — Operation

15
DRYVAC225/50/100BManual
GA 01.415/2.02 - 7/97
Section 4 — Maintenance
4Maintenance
4.1 Routine Maintenance
The DRYVAC2may require rebuilding periodically depend-
ing on your application and your production cycle. In some
installations, the rebuild interval may vary from 12 to 24
months. If you seldom need to clean the inlet and exhaust
lines, then the rebuild interval could be longer. Contact
your Leybold service center for recommendations on
rebuild intervals for your particular installation. Also
ask about the service options available in your region.
All work must be done by suitably trained personnel. Main-
tenance or repair done by inexperienced personnel may
affect the life and performance of the pump and may void
the warranty.
Warning During operation, the pump’s tem-
perature can exceed 100°C (212°F).
Always allow the pump to cool down
before removing it from the system
or before opening its housing.
Before doing any maintenance or repair, shutdown the
pump as described in Section 3.2 and disconnect it from
the system.
Caution Always drain the cooling water be-
fore storing or shipping the pump.
Failure to drain the water can result
in the water freezing and bursting the
pump housing.
If the pump will be returned to Leybold, it must be ac-
companied by a listing of all hazardous substances
which might be present in or around it. Complete the
form at the back of this manual before sending any
equipment to Leybold. Refer to Section 3.3 to prepare
the pump for shipping.

16
DRYVAC225/50/100BManual
GA 01.415/2.02 - 7/97
1.1 Pump does not
start.
1.2 Pump runs up
briefly and then
shuts down.
2. Pump tempera-
ture is too high.
The “Warning”
thermal switch
opens to alert the
operator that the
pump tempera-
ture is above
normal. When
the “Alarm”
thermal switch
opens, the pump
must be shut
down.
Check setting of motor breaker. Turn ON the
breaker.
Check wiring and repair. Check the voltage at your
AC power source.
See notes on malfunction 2, 3, or 4.
Repair the pump.
Repair or replace the motor.
Disconnect the pump from your AC power source.
Interchange two of three input leads.
Modify the system.
Modify the process.
Change site or supply cooler air.
Clean the ventilation grids and cooling air chan-
nels. Increase the distance between the vent grids
and the walls.
Repair the pump.
Open the cooling water supply.
Ensure sufficient supply of cooling water.
Repair the pump.
Dismantle the pump and clean the cooling water
channels.
Connect the cooling water lines correctly.
Replace malfunctioning part.
2.2.2
2.2.2
---
Service
Service
2.4
1.4
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Service
3.1
1.4
Service
Service
2.3
Service
Possible cause Recommended corrective actionSymptom Refer-
ences*
* This column refers to the section in the Operating instructions that contains the applicable repair information.
Section 5 — Troubleshooting
Motor circuit breaker is off.
Error in power connection.
See Symptom 2, 3, or 4 below.
Pump has seized causing the motor
circuit breaker to open at start-up.
Motor malfunction.
Direction of rotation is wrong. If the
oil pressure switch is connected as
described in Section 2.2.1, the pump
will shutdown after running in the
wrong direction for 3 seconds.
Intake pressure is too high in
continuous operation.
Process gas is too hot.
Ambient temperature is too high.
Cooling air is restricted.
Too much friction inside the pump.
Cooling water inlet is not open.
Cooling water pressure is too low.
Lime deposits in cooling water
channels inside the pump. [During
normal operation, the cooling water
temperature will be below 50ºC
(120ºF). At these temperatures,
deposits form very slowly. Early
clogging is an indication of some
operational difficulty.]
Dirt deposits in the pump’s cooling
water channels.
Cooling water lines connected
incorrectly.
Switch, plug, or cord malfunction.
5 Troubleshooting

17
DRYVAC225/50/100BManual
GA 01.415/2.02 - 7/97
Pump rotation direction in incorrect;
see malfunction 1.2.
Too little lubricant in the gearbox.
Oil pump malfunction.
Switch, plug, or cord malfunction.
Intake pressure is too high in
continuous operation.
Exhaust pressure is too high.
Ambient temperature is too high.
Cooling air is restricted.
Incorrect AC power connection.
Pump contaminated by deposits.
Switch, plug, or cord malfunction.
Intake line is too long or too narrow.
Dirt trap at intake port is clogged.
Intake line is leaking or dirty.
Unsuitable measurement procedure
or measuring instrument.
Pump has external leak.
Evaporating liquids in pump.
Vacuum vessel is leaking or dirty.
Intake line is leaking or dirty.
Motor bearing failure.
Liquid “knocking" in pump. (Too
much liquid in pump.)
3. Oil pressure is
too low. Switch
has opened.
4. Motor tempera-
ture is too high.
Switch has
opened.
5. Evacuation
period is too
long. (Pumping
speed is to low.)
6. Pump does not
reach ultimate
pressure.
7. Pump is ex-
tremely loud.
Refer-
ences*
Symptom Possible cause Recommended corrective action
Disconnect the pump from the power supply.
Interchange two phases at your AC power source.
Measure the lubricant level via the fill plug. The target
value is 6 to 9 mm (1/4to 3/8inch) for the 100B and
12 to 15 mm (1/2to 5/8inch) for the 25/50B.
Repair the oil pump.
Replace malfunctioning part.
Modify the system.
Clean or modify the exhaust line.
Change site or supply cooler air.
Clean the ventilation grids and cooling air chan-
nels. Increase the distance between the vent grids
and the walls.
Change the connections in the motor junction box
to match the AC power source.
Rebuild the pump.
Replace malfunctioning part.
Install a shorter or wider diameter intake line.
Clean dirt trap.
Seal or clean the intake line.
Use correct measurement procedure with proper
measuring instrument. Check pressure directly at
pump intake port.
Find leak and repair pump.
Measure the partial pressure of non-condensable
gases. To do so, insert a cryo trap between the
gauge and the intake port. If the ultimate pressure
is reached using this measurement, there are
liquids evaporating in the pump. A possible remedy
is to allow the pump to run for half an hour without
process load.
Seal or clean vacuum vessel.
Seal or clean the intake line.
Replace or repair the motor.
Install the exhaust line with a downward slope
away from the pump, or install a condensate trap.
Section 5 — Troubleshooting
* This column refers to the section in the Operating instructions that contains the applicable repair information.
2.4
Service
Service
Service
1.4
2.6
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2.2.2
Service
Service
2.5
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Service
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Service
2.6