LEYBOLD RUVAC RA Series User manual

RUVAC RA
Roots Pumps
RA 3001, 5001, 7001, 9001, 13000
Cat. No.
119 50, 119 53, 119 60, 119 63, Custom
Operating Instructions
GA 03.201/5.02
Vacuum Solutions Application Support Service LEYBOLD VACUUM

Contents
Contents
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Page
1Description . . . . . . . . . . . . . . . . . . . . . . . . .3
1.1 Design and Function . . . . . . . . . . . . . . . . . . . .3
1.2 Supplied Equipment . . . . . . . . . . . . . . . . . . . .5
1.3 Technical Data . . . . . . . . . . . . . . . . . . . . . . . .7
1.4 Accessories . . . . . . . . . . . . . . . . . . . . . . . . . .8
2 Transportation and Storage . . . . . . . . . . . . .9
3Installation and Connection . . . . . . . . . . . .10
3.1 Installation . . . . . . . . . . . . . . . . . . . . . . . . . .10
3.2 Electrical Connections . . . . . . . . . . . . . . . . .10
3.3 Connection of the Flanges . . . . . . . . . . . . . .12
4Operation . . . . . . . . . . . . . . . . . . . . . . . . . .13
4.1 Start-Up . . . . . . . . . . . . . . . . . . . . . . . . . . . .13
4.2 Operation . . . . . . . . . . . . . . . . . . . . . . . . . . .14
4.3 Shutdown and Storage . . . . . . . . . . . . . . . . .15
4.4 Option: RUVAC RA with Barrier Gas Facility .15
5Maintenance . . . . . . . . . . . . . . . . . . . . . . . .16
5.1 Safety Information . . . . . . . . . . . . . . . . . . . .16
5.2 Exchanging the Oil . . . . . . . . . . . . . . . . . . . .16
5.3 Cleaning the Fan Cowl and the Cooling Fins .18
5.4 Cleaning the Pumping Chamber . . . . . . . . . .18
5.5 Exchanging the Shaft Seals . . . . . . . . . . . . .19
5.6 Leybold Service . . . . . . . . . . . . . . . . . . . . . .21
6. Troubleshooting . . . . . . . . . . . . . . . . . . . . .22
Declaration of Conformity . . . . . . . . . . . . .23
Indicates procedures that must be strictly
observed to prevent hazards to persons.
Indicates procedures that must strictly be
observed to prevent damage to, or destruc-
tion of the equipment.
Figures
The references to figures, e.g. (1/2) consist of the Fig.
No.and the Item No.in that order.
Leybold-Service
If a pump is returned to Leybold, indicate whether the
pump free of substances damaging to health or whether
it is contaminated.
If it is contaminated also indicate the nature of the
hazard. Leybold must return any pumps without a
"Declaration of Contamination" to the sender's address.
Disposal of waste oil
Under the amended law relating to waste disposal dated
November 1, 1986 (valid in the Federal Republic of Ger-
many) the disposal of used oil is subject to new provi-
sions.According to legislation relating to waste disposal
the so-called principle of causality is applied. Hence,
anyone in possession of used oil is responsible for its
proper disposal.
Used oils coming from vacuum pumps must not be
mixed with other substances.
Used oils from vacuum pumps (LH-oils on the basis of
mineral oils) having been affected by normal contamina-
tion due to oxygen from the ambient air, increases in
temperature and mechanical wear, must be disposed of
as used oil in accordance with the regulations.
Used oils from vacuum pumps that have been contami-
nated by other substances must be labelled, stored and
disposed of as special waste with reference to the kind
of contamination.
When disposing of used oil please observe the safety
regulations that are valid in your country.
In many countries proof of were the oil has finally been
left is required by Law and often shipping of such conta-
minated waste requires permission by the authorities.
Waste disposal information is available through:
Bundesamt für Gewerbliche Wirtschaft (BAW)
Frankfurter Str.29-31
D-65760 Eschborn/Taunus
Phone: [phone] - Telex: 415603/04
We reserve the right to modify the design and the speci-
fied data.The illustrations are not binding.
2GA 03.201/5.02 - 10/97
Warning
Caution

Description
1Description
1.1 Design and Function
The RUVAC RA 3001 to 9001 are Roots pumps driven
directly by a canned motor.The RUVAC RA 13000 is dri-
ven via a V-belt.
The number in the designation indicates the pumping
speed of the pump in m3· h-1.
Standard RUVAC pumps are not suitable for pumping
oxygen at concentrations which exceed that of the
atmosphere.
1.1.1 Principle of Operation
Roots pumps – also known as Roots blowers – contain
in their pump casing (1/3) two symmetrical impellers
(1/4) rotating in opposite directions.The impellers have
roughly the cross section of a figure "8" and are syn-
chronised by a toothed gearing so that they move past
each other and the casing without contact but with a
small clearance.
The principle of operation is explained in Fig. 2.
In impeller positions I and II, the volume in the intake
flange is increased. When the impellers rotate further to
position III, part of the volume is sealed off from the in-
take side.
In position IV, this volume is opened to the discharge
side, and gas at backing pressure (higher than the inta-
ke pressure) flows in. The inflowing gas compresses the
gas volume pumped from the intake side.As the impel-
lers rotate further, the compressed gas is ejected via the
discharge flange.
This process occurs twice per complete revolution of
each of the two impellers.
Due to the non-contacting rotation in the pumping cham-
ber, Roots pumps can be operated at high speeds (stan-
dard n = 3,600 rpm at a mains frequency of 60 Hz for the
RUVAC RA 3001).Thus a relatively high pumping speed
is attained with small pumps.
The pressure differential and compression ratio between
the intake and discharge sides are limited on Roots
pumps.If the allowable pressure differential is exceeded,
the pump overheats.
3
GA 03.201/5.02 - 10/97
Fig. 2Functional diagram of a Roots pump
(vertical flow)
Fig. 1Schematic cross-section of a Roots pump
(vertical flow)
1
2
3
4
5
Key to Fig. 1
1Intake flange
2Pumping chamber
3Casing
4Impeller
5Discharge flange

Description
In practice, the maximum attainable pressure differential
is significant only in the rough vacuum range (p > 10
mbar), whereas for pressures in the fine vacuum range
(p < 10 mbar) the attainable compression ratio is decisi-
ve.
For these reasons Roots pumps can not pump against
atmospheric pressure without additional means; they are
thus either used in connection with backing pumps or in
closed gas cycles.
The pump's power consumption depends not only on the
volume of the pumping chamber and the rotational
speed of the pump, but also on the pressure differential
between the discharge and intake flanges (see Fig. 6).
4GA 03.201/5.02 - 10/97
Fig. 3 Longitudinal section of a RUVAC RA 3001 (without motor, other models are similar)
Key to Fig. 3
1 Pair of gearwheels
2Intake flange
3 Driven impeller shaft
4 Impeller seals
5Bearing
6Splash disc
7Shaft seals
8Bushing
9 Drive shaft
10 Impellers

Description
1.1.2 Design
RUVAC Roots pumps can pump gas in the vertical or
horizontal direction.The direction required must be sta-
ted when ordering the pump.The direction may be chan-
ged, but this conversion should only be made by Ley-
bold.
Although the pumping chamber of Roots pumps is free
of sealing agents and lubricants, the two gearwheels of
the synchromesh gearing (3/1) and the bearings (3/5) of
the impeller shafts are lubricated with oil. The gear-
wheels and bearings of the RUVAC are located in two
side chambers which also contain the oil supply.
These two side chambers are separated from the pum-
ping chamber by the impeller seals (3/4).During operati-
on of the pump, the side chambers are evacuated via the
impeller seals.
In the bearing chamber on the side of the motor a splash
disk (3/6) and in the front end bearing chamber an oil
guidance arrangement ensure that the bearings and
gearwheels receive sufficient lubricant at all recommen-
ded speeds.
The motor of the RUVAC RA 3001 to 9001 is directly
flanged to the coupling housing. The pump shaft (3/9)
and the motor shaft are linked by means of an elastic
coupling. The shaft of the other impeller (3/3) is driven
via the synchromesh gear.In the case of the RUVAC
13000 the shaft (3/9) is driven via a V-belt.
The feedthrough of the shafts of the impellers between
the evacuated bearing chamber and the atmosphere is
sealed by two shaft seals.The shaft seals are oiled.They
are located in a shaft seal housing having a separate oil
reservoir.The oil level in the shaft seal housing can be
checked at an oiler.
The housing for the shaft sealing ring is air-cooled. The
air flow for cooling of the motor and the pump is produ-
ced by a motor fan.
Incorporated in the stator coils of the motor is one each
PTC resistor which serves the purpose of monitoring the
temperature of the motor.
1.2 Supplied Equipment
The RUVAC RA pumps are supplied as standard for a
vertical pumping direction. If a horizontal pumping direc-
tion is required, this must be stated when ordering the
pump.
The housing for the shaft sealing ring is supplied with an
oil filling. The oil for the bearing spaces is not included
with the delivery.
The pumps are equipped with connection flanges to
DIN 2532, ND 10/16.
A dirt collection sieve should always be
installed on the intake side in order to pro-
tect the pump.Please order this item sepa-
rately (see Section 1.4).
5
GA 03.201/5.02 - 10/97
Caution

Description
6GA 03.201/5.02 - 10/97
SV 630
SV 630
SV 630
SV 630
SV 630
Pumping speed
Pressure
Fig. 5Pumping speed for 50 Hz operation
Fig. 4 Dimensional drawing, on the right RUVAC RA 13 000 (Maßangaben in mm)
Type DN a a1 a2 a3 a4 a5 a6 b b1 b2 Ødk6 Ød1 h h1 h2
DIN
2532
RA 3001 200 980 470 510 290 350 1101 1570 652 538 600 35 23 500 35 250
RA 5001 200 1013 468 545 280 360 1136 1610 800 652 720 42 23 630 50 315
RA 7001 250 1143 533 610 410 490 1266 1740 800 652 720 42 23 630 50 315
RA 9001 300 1467 685 782 655 800 1594 2220 910 810 830 55 27 710 30 355
b
h
1
h
1
b
DN
220
2
h
2
b
d1
DN
2110*
RUVAC RA 13 000
* Breite = 1000
420
782
685 DN 300
DIN 2532
d
a
6
a
5
a
2
a
1
a
3
a4
a
930
Fig. 6 Power consumption of the RUVAC RA

GA 03.201/5.02 - 10/97
Description
7
1.3 Technical Data
50 Hz operation, SI units, "Euro versions"
1) as per DIN 28400 ff..
2) for a ratio of 1:4 max.
3) at an operating pressure < 10-1 mbar, 50 Hz operation
4) as per DIN 2532, ND 10/16
5) please note that not all machines may be operated with 60 Hz supplies.Select a different model, as required
RUVAC RA 3001 5001 7001
Nominal pumping speed1) m3· h-1 3900 5550 7470
Maximum pumping speed
- at pumping speed for the backing pump of m3· h-1
m3· h-1 3300
630 5000 1260 6800 1850
Maximum allowable pressure differential
- in continuous operation2)
- for less than 3 minutes mbar
mbar 53 93 53 93 53 93
Mains voltage at the motor, 50 Hz V380 - 420 / 660 - 725 Y
Nominal speed at 50 Hz min-1 3000 3000 3000
Max. permissible speed5) min-1 3600 3000 3000
Oil filling, approx.
- vertical flow
- horizontal flowl l7,0
3,5 12,0 5,4 12,0 5,4
9001 13000
9720 13000
8800
1850 12000 2600
66
133 53 93
Mains voltage at the motor, 60 Hz5) V440 - 480 ∆
1500 2000
5454
Protection IP 54 54 54
130130
Trigger temperature for the PTC resistors °C130 130 130
3022
Motor power, 50 Hz kW 11 15 18,5
1800 2000
11,0
7,6 11,0 7,6
Noise level3) dB (A) 77 78 79 69 72
Weight, complete, approx. kg 620 770 870 1500 -
Intake flange4)
Discharge flange 4) DN DN 200 200 200 200 250 250 300 300 300 300
Permissible ambient temperatures °C12 - 40
RUVAC RA with motor
coupling and lantern Kat.-Nr.119 50 119 53 119 60 119 63 auf Anfr.

GA 03.201/5.02 - 10/97
1.4 Accessories
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Cat. No.
Diaphragm pressure switch SM 42
0.5 to 6 mbar . . . . . . . . . . . . . . . . . . . . . . . . . .164 05
5 to 50 mbar . . . . . . . . . . . . . . . . . . . . . . . . . . .164 06
40 to 400 mbar . . . . . . . . . . . . . . . . . . . . . . . . .164 07
Accessories for mounting SM 42
Adapter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .168 39
Right-angle bend DN 25 KF . . . . . . . . . . . . . . .184 37
Centering ring DN 20 KF/25 KF, 2x . . . . . . . . . .183 57
Clamping ring DN 20 KF, 2x . . . . . . . . . . . . . . .183 42
Pressure switch PS 114 . . . . . . . . . . . . . . . . .160 01
Pressure switch PS 115 . . . . . . . . . . . . . . . . .160 04
Pressure switch PS 112 Ex . . . . . . . . . . . . . . .160 91
Accessories for mounting PS 114/115/112 Ex
Adapter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .168 40
Right-angle bend DN 16 KF . . . . . . . . . . . . . . .184 36
Centering ring DN 16 KF, 2x . . . . . . . . . . . . . . .183 26
Clamping ring DN 16 KF, 2x . . . . . . . . . . . . . . .183 41
Contact amplifier SV 110, 230 V. . . . . . . . . . .160 78
Oil N 62*, 20 l . . . . . . . . . . . . . . . . . . . . . . . . . .177 03
Oil HE-200*, 5 gal . . . . . . . . . . . . . . . . . . .98-198-008
N 62 is an oil grade of LH Cologne, and HE-200 is an oil grade
of LVP Export. They are interchangeable and comply with ISO
VG 100. For other quantities, see catalogue.
Description
8
RA 3001 RA 7001 RA 9001
RA 13 000
Ref.-No.of the complete collar flanges 200 14 472 200 14 473 200 14 474
for the intake and the pressure sides.
Intake side 200 DIN-250 ISO-K 250 DIN-250 ISO-K 300 DIN-350 ISO-K
Adapter flange 200 13 750 200 13 751 200 13 886
Centering ring 233 93 340 233 93 340 233 93 109
Outer ring 233 93 339 233 93 332 233 93 205
Clamping screws (qty.) 201 98 163 (3) 201 98 163 (3) 201 98 163 (3)
O-ring 239 50 739 239 50 740 239 70 180
O-ring 239 50 740 239 50 740 239 50 743
Dirt sieve 200 13 011 200 13 012 200 13 013
Discharge side 200 DIN-160 ISO-K 250 DIN-250 ISO-K 300 DIN-250 ISO-K
Adapter flange 200 13 749 200 13 751 200 13 752
Centering ring 200 07 328 233 93 340 233 93 340
Outer ring 200 07 330 233 93 332 233 93 332
Clamping screws (qty.) 201 98 163 (2) 201 98 163 (3) 201 98 163 (3)
O-ring 239 50 739 230 50 740 230 70 180
O-ring 239 50 727 239 50 740 239 50 740
Ordering numbers for ISO-K collar flanges for RA pumps

GA 03.201/5.02 - 10/97
Transportation and Storage
9
Roots pumps are heavy machines (> 70 kg) made of
cast iron and thus should only be lifted using suitable lif-
ting equipment.
Before transporting the pump always drain
out the oil from the bearing chambers (see
Section 5.2). Screw the oil-drain plug with
its gasket back in and wipe any oil droplets
off from the casing.
Draining out of the oil contained in the shaft
seal housing (oiler) is not necessary.
The pump should be transported and sto-
red in a horizontal position (5 °max. tilt with
respect to its longitudinal axis). Otherwise
there is the danger that oil from the side
chambers may enter the pump chamber,
even before the pump is filled with oil for the
first time.
The pump must only be transported and
installed horizontally.Otherwise the oil
reservoir in the shaft seal chamber (oiler)
may escape.
When shelving the pump for a longer period
of time, the oil should be drained out. Also
seal off the flanges of the pump with a piece
of foil or the cardboard discs initially sup-
plied with the pump using the collars.Place
a bag with desiccant in the pump chamber,
if required.
The area of the motor (fan and slits at the
flange of the motor) must be protected
against dust and dripping water.
2 Transportation and Storage
Caution

GA 03.201/5.02 - 10/97
10
Installation and Connection
3.1 Installation
Install RUVAC RA pumps on a flat, perfectly horizontal
surface . If the pump is not level, lubricant may enter the
pumping chamber from the gear chambers.
Screw the two feet to the motor side of the pump.Fit the
other two feet with spacers so that in case of a thermal-
ly expanding casing the axial displacement will be as
small as possible (see Fig. 7).
When bolting the feet down, make certain
that there is no stress or twist on the pump
casing. Stress on the pump can change the
close tolerances between the impellers and
the pump casing and may result in damage
to the pump.
Since compensation elements must be
attached to the flanges on the suction and
pressure sides, the screws for attachment
of the feet must always be fitted and tighte-
ned firmly.
Use the following screws:
RA 3001 - 7001: 4 x M 20
RA 9001 - 13000: 4 x M 24
Keep the air intake and exhaust ducts for cooling the
motor unobstructed and clean them from dust and depo-
sits from time to time.
The pump's ambient temperature should be between
12 °C and 40 °C. Lower temperatures hamper run-up;
higher ones shorten the oil change intervals and may
lead to greater wear.
Set up the motor of the RUVAC RA 13000 next to the
pump.Link the shaft on the pump to the shaft on the
motor by means of the 5 V-belts supplied. The V-belts
have been tensioned correctly when they can be inden-
ted at a testing force of 75 N by 1.55 mm per 100 mm
shaft spacing and per V-belt. Check tensioning of the V-
belt after 30 minutes and also after 24 hours. Re-tension
the V-belts as required.
The V-belt protector must always remain in
place during operation of the pump.Never
operate the pump without its V-belt protec-
tor.
3.2 Electrical Connections
Disconnect the mains before doing work on
the wiring.
Electrical connections must be made by a
skilled electrician as defined by VDE 0105
and in accordance with the guidelines of
VDE 0100.
For proper connection, a suitable motor pro-
tection switch must be used. Set the switch
in accordance with the rating on the motor
nameplate.
Connect the pump to the correct mains vol-
tage through the terminals provided in the
junction box (see Fig. 8). Always provide an
uninterrupted connection for the protective
ground conductor connecting it in a pro-
fessional manner.Never leave the protec-
tive ground conductor for the pump
unconnected.
Do not link control circuits to the power cir-
cuit of the motor.Observe the wiring dia-
gram (Fig. 8).
The motor is equipped with PTC resistors (temperature
sensors). For connection of these see Fig. 8.
Notes concerning the PTC resistors
The trigger temperature of the PTC resi-
stors is 130 °C. The applied voltage must
never exceed 2.5 V. To check the resistors
use only a measurement bridge or a resi-
stance meter.If one resistor has failed, you
may short auxiliary terminals A1 and A2 to
bypass the failed resistor (some pumps are
not equipped with auxiliary terminals).
The RA models are only conditionallysui-
ted for operation in connection with fre-
quency converters. For the speeds of all
pump sizes, see Section 1.3 - Technical
Data. Consult us for advice.
After connecting the motor and every time
you alter the wiring, check the direction of
rotation.
Never allow the pump to run in the wrong
direction or with open flanges for a longer
period of time.
3Installation and Connection
Warning
Warning
Warning
Caution
Caution

GA 03.201/5.02 - 10/97 11
Installation and Connection
An arrow (15/13) on the coupling cage shows the correct
direction of rotation of the motor shaft.To check rotation,
switch on the motor briefly and observe the direction of
impeller rotation through the pump's intake, and then
immediately switch off again.
Wear protective goggles for protection
against particles which may be forced out of
the flange opening. Keep your hands away
from the flange opening.
The impellers should move up from the center and drop
down to the side.
If this is not the case, disconnect the pump from the
mains and interchange two mains phases.
Even if the pump has been already firmly connected to
the piping, you may determine the direction of rotation.
For this, evacuate the vacuum system down to a pressu-
re below 20 mbar with the aid of the backing pump.Then
switch on the RUVAC briefly; now the pressure must
drop.If the pressure increases or remains constant, the
RUVAC is turning in the wrong direction.
Then rewire as described above.
The RUVAC can be automatically switched on and off via
a contactor using a pressure switch and the contact
amplifier SV 110 (see Section 1.4).
Warning
high voltage low voltage Connection of the PTC resistors
to circuit breaker
Fig. 8 Electrical connection
Fig. 7 Attachment screw with spacer
Key to Fig. 9
1Pressure switch
2Centering and clamping ring
3Bend
4Centering and clamping ring
5Adapter
Fig. 9 Attachment of the pressure switch

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12
Installation and Connection
The pressure switches SM 42 or PS 114/115 are set to
a fixed threshold in our factory. Please specify the swit-
ching threshold for the pressure switch when ordering.
The contact amplifier is the same for all pressure swit-
ches.
Explosion hazard rated pressure switches and contact
amplifiers are available upon request.
After removal of a sealing screw it is possible to fit the
pressure switch (9/1) together with an adapter (9/5) and
a bend (9/3) to bore (8/6).
When doing so, ensure proper sealing and air-tight
installation.
It is advisable to mount the switch vertically to reduce the
entry of contaminants.
3.3 Connection of the
Flanges
Already small quantities of liquids (from the
vacuum chamber or the piping) can lead to
liquid damages within the pump.These may
lead to a deformation of the impellers and
may entirely destroy the pump.Suitable pro-
tective measures should be provided as
required in the piping on the suction side
(separator, T-piece).
The RUVAC RA pumps have not been desi-
gned to pump ignitable or explosive mixtu-
res without additional protection.
If the pumps are none-the-less to be used
under such conditions, the customer him-
self must ensure that proper measures for
the purpose of protection against explo-
sions (pressure monitor, flame arresters
etc.) are introduced in line with the require-
ments of the applicable laws.
In such cases it is advisable to contact us
for advice.
If not already done, remove the protective cardboard pie-
ces, foil or packing flanges from the flanges (10/1) and
(10/5).
We recommend that you retain the transport flanges of
the pumps in case you want to store the pump at a later
date.
Clean the flanges and check that the sealing surfaces
are in perfect condition.
Flange the pump to the vacuum system.
Don't place any stress on the pump casing
when installing the intake and discharge
lines.Fit compensation elements in order
to avoid such stresses.
If required manually turn the blower after
having tightened the flanges.It must turn
easily.If a resistance is detected check all
connections for mechanical strain once
more and make sure that no such strains
have built-up.
A dirt trap should always be fitted into the intake flange
when there is the possibility of contaminants entering the
pump coming from the vacuum chamber or the piping.
Even with clean vacuum processes, contaminants from
the system may enter upon initial start-up. Depending on
the operating conditions, the dirt trap may reduce the
pumping speed of the pump.
Observe the maintenance information provided in Sec-
tion 5.5.
Caution
Caution
Warning

GA 03.201/5.02 - 10/97 13
Operation
4.1 Start-up
Check the pump motor's direction of rotation (see Sec-
tion 3.2).
Check the oil levels in the bearing chambers and in the
oiler (see Fig. 11 and Section 5.2 on page 16).
If required drain out some oil or top up some oil (see
Section 5.2)
The RUVAC must only be switched on after the backing
pump has evacuated the vacuum vessel to the cut-in
pressure.
For processes in which condensable vapours are pum-
ped, it is advisable to evacuate the vacuum vessel via a
roughing line to the cut-in pressure.Electrically switch on
the Roots pump together with the backing pump and cut
it in upon reaching the cut-in pressure.The initial bypas-
sing of the Roots pump serves to prevent condensation
of vapours in the cold pump.
The permissible cut-in pressure depends on the ratio
between the Roots pump and the backing pump.It can
be calculated according to the following formula:
∆pmax
pE= ———
kth - 1
pE=Cut-in pressure
∆pmax =Maximum permissible pressure differential
(see technical data)
kth =theoretical compression ratio
=nominal pumping speed of Roots pump /
pumping speed of backing pump.
Example:
Pump combination:
RUVAC RA 3001 / SOGEVAC SV 630
3900 m3· h-1
kth = ——————— ∼6.5
600 m3· h-1
53 mbar
pE= ————— = 10 mbar
6.5 - 1
With small vacuum vessels, the maximum permissible
pressure differential may be briefly exceeded (max. 3
min) upon start-up.If a pressure switch has been instal-
led, do not set it to this higher pressure because it will fail
to protect the pump against overload in the event of a
greater gas quantity.
It is advisable to switch the RUVAC on and
off via a pressure switch to ensure that it
runs only in the permissible pressure range.
4Operation
Caution
1
2
3
Key to Fig. 10
1Intake flange
2 Terminal box
3Discharge flange
Fig. 10 Connection components (wide arrows = pumping direction)

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14
Operation
4.2 Operation
Do not operate the pump without having
connected the flanges to a vacuum system.
During operation of the RUVAC, check the oil level from
time to time at three places (11/1, 11/2 and 11/3) and
also the condition of the oil (see also Section 5.2). Nor-
mally, the oil N 62 or HE-200 is light-brown. If it turns
dark, this is a sign of early ageing due to excessively
high temperatures.
The oil level for the shaft seal housing must always be
visible in the oiler. Top up oil as required. For this we
recommend oils N 62 or HE-200.
If it is found necessary to top up oil frequently, it is very
likely that a shaft seal has developed a fault (see Section
5.6).
Run the Roots pump exclusively under the
operating conditions for which it has been
designed. Any modification of the operating
parameters (e.g. intake pressure, intake
temperature, ratio between Roots pump
and backing pump, pumping speed of the
backing pump) for a longer period may
place an inadmissible thermal load on the
pump.Increases in temperature which are
not compensated by taking suitable measu-
res may damage the Roots pump and/or
the backing pump.
During normal operation temperatures
exceeding 80 °C may occur at the oil cham-
bers and at the line on the pressure side.
When touching these there is the danger of
receiving burns.
Note the labels on the pump.
Never open the oil-fill or oil-drain screw (Fig.
13) in the presence of a vacuum or while
the pump is running. There is the danger
that oil may squirt out.
Warning
Caution
Warning
1 2 3
Key to Fig. 11
1Oil level glass of the front bearing chamber
2Oil level glass of the bearing chamber on the side of the motor
3Oiler (Oil level check and oil reservoir for the shaft seals)
Fig. 11 Checking the oil levels

GA 03.201/5.02 - 10/97 15
Operation
4.3 Shutdown and Storage
Close the valve between the Roots pump and the vacu-
um system. First switch off the Roots pump, then the
backing pump.
After working with corrosive gases, the system should be
vented with dry protective gas (e.g. N2) to prevent corro-
sion during standstill.
When shutting down the pump and removing it from the
system, it is advisable to seal the connecting flanges
tightly.
Before removing pump from the vacuum
system, disconnect it from the mains
supply.
Note possible contamination of the pump.
Observe all safety regulations.
For transportation and storing of the pump, observe the
information provided in Section 2.
4.4 Option: RUVAC RA with
Barrier Gas Facility
Upon request the RUVAC RA is supplied equipped with
a barrier gas facility.
Shown in Fig. 12 is a schematic diagram of the barrier
gas facility.The barrier gas is admitted between the
impeller seals (12/2). Thus a gas flow is created which
passes over the impeller seals and flows into the pump
chamber of the pump.This gas flow prevents the entry of
the pumped medium into the bearings and bearing
chambers.Since the barrier gas is admitted between the
impeller seals, the passage of oil from the bearing cham-
bers into the pump chamber is prevented.
The barrier gas flow must be set on the flow controller
(12/7) to such a level that the pressure as measured by
the pressure gauge (12/6) is approximately 10 mbar
greater compared to the pressure at the discharge of the
RUVAC.
The components (12/4) to (12/7) are only supplied upon
request with the barrier gas facility.
Key to Fig. 12
1Shaft
2Impeller seals
3Barrier gas bore
4 Branch leading to the other impeller seals
5 Valve
6Pressure gauge
7Flow controller
Fig. 12 Schematic diagram for the barrier gas facility
Warning

GA 03.201/5.02 - 10/97
16
Maintenance
5Maintenance
5.1 Safety Information
The safety information given in the following applies to all
maintenance work.
Disconnect the electrical power before
disassembling the pump and vent it to
atmospheric pressure.Make absolutely
sure that the pump cannot be accidentally
started.
If the pump has been pumping harmful sub-
stances, determine the nature of hazard
and introduce suitable safety measures.
Always wear safety goggles when drying or
blowing out the pump with pressurised air.
Observe all safety regulations !
If you send a pump to LEYBOLD for repair
please indicate all harmful substances exi-
sting in or around the pump or which might
be present. For this use the "Declaration of
Contamination" form which has been pre-
pared by us and which we will provide upon
request.
Any pump received by us without, or an
incompletely filled in declaration will delay
the repair.
When shipping contaminated pumps which
require approval by the authorities, you
must observe the applicable packaging and
shipping regulations.
All maintenance and cleaning work descri-
bed in this section must be carried out only
by suitably trained personnel.
When disposing of used lubricants please
observe the relevant environmental regula-
tions.
Improper maintenance or repairs may affect
the service life and performance of the
pump, and cause problems when filing war-
ranty claims.
Advanced repair work not described here
should be left to the LEYBOLD Service.
We would like to point out that LEYBOLD offers training
courses on the maintenance, repair, and troubleshooting
of RUVAC pumps.Further details are available on
request.
5.2 Exchanging the Oil
Observe all safety information provided in
Section 5.1.
Very little lubricant is consumed by wear in the bearings
and the gear under clean operating conditions. We
recommend changing the oil after the first 500 hours of
operation to remove any wearing residue.Then, under
normal operating conditions, change the oil after every
3,000 hours of operation.
Change the oil more frequently when pumping corrosive
vapours or large amounts of dust or when cycling fre-
quently from atmospheric to working pressure.
Before removing the oil-drain or oil-fill plug
always switch off the pump first and vent to
atmospheric pressure.
When the pump has become warm during
operation, the casing and the oil temperatu-
re may exceed 80 °C - there is the danger
of receiving burns.
Leave the pump to cool down. Always wear
protective gloves also to protect yourself
against aggressive residues in the oil.
Unscrew the two oil-drain plugs (13/4) and the two oil-fill
plugs (13/1) and drain the oil.
Clean the sealing surfaces and firmly reinstall the plug
(13/4) using a gasket which is in perfect condition.
Fill new oil into the two bearing chambers.
Only oil of viscosity class ISO VG 100 (previously SAE
30) must be used. We strongly recommend the use of
our special oils N 62 or HE-200. When planning to ope-
rate the pump with a different kind of oil or with special
lubricants, contact us first for advice.
Warning
Warning
Caution
Warning

GA 03.201/5.02 - 10/97 17
Maintenance
Check the oil level in both bearing chambers while the
pump is at standstill.
Correct oil level for vertical flow:
-on the side of the motor at the centre of the oil level
glass (14/3),
-on the front side at the upper third of the oil level glass
(14/2).
Correct oil level for horizontal flow:
-on the side of the motor at the upper third of the oil
level glass (14/2),
-on the front side at upper rim of the oil level glass
(14/1).
If the oil level is too low, the bearings and
gearwheels are not lubricated adequately; if
it is too high, oil may enter the pumping
chamber.
Clean the oil-fill port and reinstall the plugs (13/1) using
a gasket which is in perfect condition. Wipe off any oil
residues.
The oil-fill ports must be sealed air-tight. In
the presence of a vacuum, the entry of air
may cause oil-containing gas to enter the
pumping chamber via the impeller seals.
Check the oil level at the shaft seal housing regularly.
The oil level for the shaft seal housing must be visible in
the oiler (13/2). If required top up some oil at the oiler.
Maximum level
- when the pump is warm = 1/2 of the oiler’s height
- when the pump is cold = 1/3 of the oiler’s height.
Wipe off any oil residues from the casing.
Fig. 14 Oil levels
Caution
Caution
12 1
3434
Key to Fig 13
1Oil fill plugs
2Oiler (oil check and oil reservoir for the shaft seals)
3Oil level glasses
4Oil drain plugs
Fig. 13 Oil change

GA 03.201/5.02 - 10/97
18
Maintenance
5.3 Cleaning the Fan Cowl
and the Cooling Fins
Observe all safety information provided in
Section 5.1.
The slits in the fan cowl as well as the fins on the motor
and on the pump may be contaminated depending on
humidity conditions and the degree of contamination in
the ambient air.
In order to ensure a sufficient air flow for the motor and
the pump's casing, the grid of the fan cowl must be cle-
aned with a clean brush when contaminated.
Any coarse dirt must be removed from the fins on the
motor and the pump.
5.4 Cleaning the Pumping
Chamber
Observe all safety information provided in
Section 5.1.
Under dirty operating conditions, contaminants may be
deposited in the pumping chamber or on the impellers.
After removing the two connecting lines, the contami-
nants can be blown out with dry compressed air or flus-
hed out with a suitable solvent.
Contaminants that cannot be blown or flushed out, can
be removed completely from the pumping chamber with
a wire brush, metallic sponge or scraper.
Then change the oil.
During cleaning, the blower must be turned
only by hand.
The loosened deposits must not remain in
the pump.After cleaning, check the pump
by slowly turning the impellers by hand.
They should move freely and without any
resistance.
Generally, the Roots pump does not need to
be disassembled. If necessary, this should
only be done by our after-sales service.
Warning
Caution
Warning
Warning

GA 03.201/5.02 - 10/97 19
Maintenance
5.5 Exchanging the Shaft
Seals
Observe all safety information provided in
Section 5.1.
The shaft feedthrough of the RUVAC RA is sealed with
two shaft seals.In order to reduce wear on the shaft,
these shaft seals run on a bushing.
A dropping oil level in the oiler is a sign for malfunctio-
ning shaft seals.
When the oil level in the oiler drops and when no oil
appears under the shaft seal housing, it is likely that the
inner shaft seal is faulty.In this case the oil flows from the
shaft seal housing into the bearing spaces of the pump
thereby creating in the bearing spaces an unacceptably
high oil level. In such a case the pump must be switched
off immediately and it must be repaired.
When the oil level in the oiler drops and when oil appears
under the shaft seal housing, it is likely that only the
outer shaft seal is malfunctioning. If the oil loss is only
slight, the pump may still be operated for some time, pro-
vided the lost oil is topped up regularly.
Collect the oil which drips out under the
motor.There is the danger that someone
may slip.Have the pump repaired.
Required Special Tools:
Puller for the bushing:
Span 250 mm, span depth 200 mm.
Shaft seal driver according to Fig. 16.
Place an oil trough under the shaft seal housing.
Support the motor so that it can not drop.
Unscrew the nuts and remove the motor with the cou-
pling half (15/12).
Remove the coupling element (15/11).
Unscrew the screws and remove the coupling cage
(15/10).
Unscrew the pin and pull the coupling half (15/9) off on
the side of the pump.
Remove key (15/8).
Unscrew the screws and pull off the shaft seal housing
(15/6).
Remove the securing ring (15/4) from the housing.
Force the shaft seals (15/5) and (15/7) out of the hou-
sing.
Pull the bushing (15/3) off from the shaft.
Remove O-ring (15/2) and spacing ring (15/1).
It is strongly recommended always to exchange the shaft
seals, the bushing and the O-ring against new parts.
Clean all other parts and replace them as required.
Reassemble in the reverse order as during disassembly.
While doing so, ensure that the recess on the bushing is
placed correctly for the key.
Use shaft seal driver to drive the shaft seals down.They
must not be edged in any way.
Apply some oil to the sealing lips of the shaft seals.Be
careful when pushing the sealing ring housing on to the
bushing!
Before starting the pump up, fill in oil at the oiler.
Warning
Warning

GA 03.201/5.02 - 10/97
20
Maintenance
Fig. 16 Shaft seal driver
a a1 a2 Ø d Ø d1
RA 3001 150 3137 75 64.5
RA 5001, 7001, 150 3137 90 79.5
RA 9001, 13000 150 2138 95 85.5
13
Fig. 15 Exchanging the shaft seals
Key to Fig. 15
1Spacing ring
2O-ring
3Bushing
4Securing ring
5Shaft seal
6Shaft seal housing
7Shaft seal
8 Key
9Coupling half on the side of the pump
10 Coupling cage
11 Coupling element
12 Motor with coupling half
13 Arrow indicating the direction of rotation