schmalenberger ZHT User manual

27224 - E.1
Circulating pumps
Model ZHT / ZHB / ZHS / TH / THK / DUO
Operator’s manual / installation instructions
GB
Translation of the original
Circulating pumps
Model ZHT / ZHB / ZHS / TH / THK / DUO

Schmalenberger GmbH + Co. KG
D-72072 Tübingen / Germany
2Pump Typ ZH- / TH- / DUO
Version: 27224 - E
EU Declaration of Conformity
Manufacturer:
Schmalenberger GmbH + Co. KG
Strömungstechnologie
Im Schelmen 9-11
D-72072 Tübingen / Germany
The manufacturer hereby declares that the product:
Centrifugal pump type:
ZHT, ZHB, ZHS, TH, THK, DUO, ZHR, DMG (identification numbers: all)
Serial number range: 2018000001 - 2023999999
has been manufactured in accordance with the following directives:
Directive 2006/42/EC "Machinery"
Harmonised standards that were used:
EN 809+A1+AC, EN ISO 12100, EN 60034-1, EN 60034-5/A1, EN 60034-30-1
Authorised representative for the compilation of the technical documentation:
Robin Krauß
Quality assurance
Schmalenberger GmbH + Co. KG
D-72072 Tübingen / Germany
Phone [phone]
The EU Declaration of Conformity has been issued:
Tübingen, 06 July 2020
----------------------------------------------------
Thomas Merkle
Head of Development & Design
Schmalenberger GmbH + Co. KG

Schmalenberger GmbH + Co. KG
D-72072 Tübingen / Germany
Pump Typ ZH- / TH- / DUO
Version: 27224 - E 3
EU Declaration of Incorporation
Manufacturer:
Schmalenberger GmbH + Co. KG
Strömungstechnologie
Im Schelmen 9-11
D-72072 Tübingen / Germany
The manufacturer hereby declares that the product:
Centrifugal pump if delivered without drive, type:
ZH-L, TH-L (identification numbers: all)
Serial number range: 2018000001 - 2023999999
an incomplete machine in accordance with Regulation 2006/42/EC Article 2g and provided exclusively for
assembly with another machine
which meets the following basic requirements of Regulation 2006/42/EC:
Appendix I, Article 1.1.1, 1.1.2, 1.1.3, 1.1.5.
Harmonised standards that were used: EN 809+A1+AC, EN ISO 12100
The incomplete machine must not be placed in operation until it has been determined that the machine to be
installed in the incomplete machine is in compliance with the requirements of the Machinery Directive (2006/
42/EC).
Authorised representative for the compilation of the technical documentation:
Robin Krauß
Quality assurance
Schmalenberger GmbH + Co. KG
D-72072 Tübingen / Germany
Phone [phone]
The EU Declaration of Incorporation has been issued:
Tübingen, 06 July 2020
----------------------------------------------------
Thomas Merkle
Head of Development & Design
Schmalenberger GmbH + Co. KG

Schmalenberger GmbH + Co. KG
D-72072 Tübingen / Germany
4Pump Typ ZH- / TH- / DUO
Version: 27224 - E
Contents
1 General Details ................................................................................ 5
1.1 User Information ................................................................................................... 5
1.2 Usage Instructions ................................................................................................ 5
1.3 Relevant Documentation ...................................................................................... 5
1.4 Technical Data / Specifications ............................................................................ 5
2 Safety Instructions .......................................................................... 6
2.1 General ................................................................................................................. 6
2.2 Temperature ......................................................................................................... 6
2.3 Safety Instructions for Maintenance and Repairs ................................................. 6
3 Description of the types of pump .................................................. 7
3.1 General Description .............................................................................................. 7
4 Transport, Storage, Installation ..................................................... 8
4.1 Transport and Storage .......................................................................................... 8
4.2 Unpacking, Cleaning and Assembling .................................................................. 9
4.3 Installing and connecting ...................................................................................... 9
5 Pump operation ............................................................................. 12
5.1 Initial start-up ...................................................................................................... 12
5.2 Operating ............................................................................................................ 13
5.3 Indications of faulty operation ............................................................................. 14
5.4 Shutdown ............................................................................................................ 14
5.5 Fault elimination ................................................................................................. 15
6 Maintenance / Repair .................................................................... 17
6.1 Maintenance / Service ........................................................................................ 17
6.2 Repair ................................................................................................................. 18
6.3 Spare parts list / Drawing ................................................................................... 21
7 Appendix ........................................................................................ 21
7.1 Shutdown / Storage / Conservation .................................................................... 21
7.2 Disposal .............................................................................................................. 22
7.3 Supporting documents for pump operation ........................................................ 22
7.4 Data sheet .......................................................................................................... 23
7.5 Important Instructions ......................................................................................... 23
8 Spare parts list and drawings ...................................................... 23
8.1 Drawings ............................................................................................................. 24
8.2 Spare parts list .................................................................................................... 33

Schmalenberger GmbH + Co. KG
D-72072 Tübingen / Germany
Pump Typ ZH- / TH- / DUO
Version: 27224 - E 5
1 General Details
1.1 User Information
This operator’s manual makes it easier to get to
know the centrifugal pump and to make full use
of its facilities.
The operator’s manual contains important in-
structions how to use the centrifugal pump safe-
ly, properly and economically. Your careful
attention to these instructions will help to avoid
danger, to reduce repair costs and breakdowns
and to increase the reliability and useful life of
the centrifugal pump.
The operator’s manual does not take account of
local regulations. The user is responsible for en-
suring that they are complied with.
The label specifies the machine series, the frame
size, the most important operating data and the
serial number. We request that you always quote
it in case of queries, when placing subsequent
orders and especially when ordering spare parts.
1.2 Usage Instructions
The centrifugal pump must only be used in ac-
cordance with the original pump specifications
and the operator´s manual. Any other usage or
operation where these figures are exceeded is
not permitted. The manufacturer is not liable for
damage resulting from such improper use.
The pump must only be operated in applications
that are described in the relevant documents.
• The pump must only be operated if it is in
flawless technical condition.
• The pump must not be operated if it is only
partially mounted.
• The pump may only be used to convey the
media described in the data sheet or in the
documentation for the relevant design.
• Never operate the pump without a pumping
medium.
• Pay careful attention to the information in the
data sheet or documentation regarding min-
imum delivery volume (to prevent damage
from overheating, damage to the bearings,
etc.).
• Pay careful attention to the information in the
data sheet or documentation regarding max-
imum delivery volume (to prevent overheat-
ing, damage to the mechanical seal,
cavitation damage, damage to the bearings,
etc.).
• Do not throttle the pump on the suction end
(to prevent cavitation damage).
• Coordinate other types of operation with the
manufacturer if they are not cited in the doc-
umentation or data sheet.
Preventing foreseeable misuse
• Never open the pressure-end shut-off ele-
ments beyond the permissible range
- Exceeding the maximum delivery volume
cited in the data sheet or documentation is
not permitted (possible cavitation damage)
• Never exceed the permissible operating lim-
its cited in the data sheet or documentation
in terms of pressure and temperature, etc.
• Comply with all safety instructions and direc-
tions in this operator's manual.
1.3 Relevant Documentation
Various documents are associated with every
centrifugal pump that comprise the technical
documentation of the pump. These are as fol-
lows:
• Operator’s manual
• Drive operator’s manual
• Manual for accessories listed in the specifi-
cations manual
• Acceptance report from the TÜV (Technical
Certification Authority) etc.
• Pilot run report
• Performance run report
• Installation drawing (dimensions sheet)
• Declaration of conformity with supplement
BA for ATEX pumps
• Declaration of conformity / Declaration of In-
corporation
• Specification with all data
Not all the above documentation has been pro-
duced and supplied in every case. For this
please check the details in the specification.
1.4 Technical Data / Specifications
The specifications of the centrifugal pump is the
most important document in every operator’s
manual. Contained therein are all the relevant
and technical data relating to the centrifugal
pump. It is the birth certificate of the centrifugal
pump and should be treated accordingly.

Schmalenberger GmbH + Co. KG
D-72072 Tübingen / Germany
6Pump Typ ZH- / TH- / DUO
Version: 27224 - E
As a substitute the order confirmation together
with the delivery schedule may also be a source
of technical data.
2 Safety Instructions
2.1 General
It is essential that the relevant safety regulations
and laws that apply in the operating company
and / or country where the pumps are to be used
are observed .
In this operating manual the following symbols
are used to draw your attention to sources of
danger. The symbols are intended to attract your
attention to these instructions!
Symbol Meaning:
Notices attached directly to the pump, e.g. ar-
rows indicating direction of rotation and the
marking for fluid connections, must always be
observed and maintained in a clearly legible con-
dition.
- Use the pump only if it is in perfect technical
condition, in accordance with the regulations,
observing safety requirements and danger
conditions and strictly adhering to all the in-
structions in the operator’s manual!
- Promptly remedy any faults that could influen-
ce safety.
-Prior to starting up, make sure that the ope-
rators have read and understood the opera-
tor’s manual. Not the operator but the owner
is responsible for safety!
- The centrifugal pump is designed to be built
into a total machine or plant. The centrifugal
pump is delivered without any protection
against accidental contact. If necessary, the
system supplier must fit appropriate protective
covers in integrating the centrifugal pump into
the plant (e.g. if hot liquids with a temperature
over 60° C are delivered).
- Leaks of hazardous delivery media, (e.g. ex-
plosive, poisonous, hot) must be controlled so
that no danger occurs to persons or the env-
ironment. Comply with legal requirements.
- Danger from electric shocks must be comple-
tely excluded (for details see the country spe-
cific regulations and / or those of the local
power supply company).
- Electrical equipment must be installed and
maintained exclusively by qualified electricians
in accordance with regulations VDE or IEC.
- Before switching on or starting up the centrifu-
gal pump, make sure that no-one will be en-
dangered by the start-up of the pump!
2.2 Temperature
2.3 Safety Instructions for
Maintenance and Repairs
- Regardless of what nature they may be, re-
pairs must only be carried out by qualified per-
sons and the centrifugal pump must be
emptied first.
- The attached pipework must be depressuri-
zed.
- Allow the pump to cool off.
- Prior to carrying out repairs to the pump it must
be isolated from the electrical supply and pro-
tected from unintentional switching on.
Attention! Danger of injury!
This sign warns you of the danger
of mechanical effects.
Warning! Mortal danger!
This sign warns you of the danger
from electric shocks.
Information:
It also instructs you in the economic
use of the pump.
Important:
The centrifugal pump must be im-
mediately stopped if abnormal
electrical voltages, temperatures,
noises, vibrations, leakages or oth-
er faults should arise.
Warning! / Danger of burns!
The centrifugal pump housing gets
hot during operation. If the temper-
ature rises to over +50°C, the cen-
trifugal pump must be protected
from direct contact by the operator.

Schmalenberger GmbH + Co. KG
D-72072 Tübingen / Germany
Pump Typ ZH- / TH- / DUO
Version: 27224 - E 7
3 Description of the types of
pump
3.1 General Description
Depending on their field of usage, different
pumps are offered. In the following overview, the
types within the range are described.
Type ZHT
- Multi-stage submersible pump with block motor
- Vertical container installation due to support plate
- Shaft seal as mechanical seal
- Axial suction connection
Type ZHS
- Multi-stage submersible pump with block motor
- Vertical installation with suction stand
- Shaft seal as mechanical seal
- Radial suction connection
Type ZHB
- Multi-stage centrifugal pump with block motor
- Horizontal installation
- Shaft seal as mechanical seal
- Axial suction connection
- Special model with dry-run-protection / catchment
chamber
Type TH / THK
- Multi-stage submersible pump with block motor
- Vertical container installation to DIN EN 12157
- Shaft seal as mechanical seal
- Axial suction connection
- THK = Plastic model
Type DUO
- Two multi-stage submersible pumps with block motor
in series
- Vertical container installation due to support plate
- Shaft seal as mechanical seal
- Axial suction connection
Type ZH (T,S) -L
- Multi-stage submersible pump with bearing pedestal
- Vertical installation like ZHT and ZHS but with cou-
pling and Norm-motor

Schmalenberger GmbH + Co. KG
D-72072 Tübingen / Germany
8Pump Typ ZH- / TH- / DUO
Version: 27224 - E
4 Transport, Storage,
Installation
4.1 Transport and Storage
4.1.1 Transport
Centrifugal pumps must be transported lying
down! The eyebolts on the motor are designed to
carry only the weight of the motor. To lift the com-
bined motor and pump aggregate suitable at-
tachments must be made so that both units are
catered for!
If necessary the centre of mass is indicated on
the pump aggregate itself and on the packing
material and places for applying hooks are
marked.
Proper lifting example ZHS
Proper lifting example ZHB
Proper lifting example ZHT
Proper lifting example TH / THK
4.1.2 Storage
- Interim storage
Even for short periods of interim storage, store
on a wooden base in a dry, well ventilated and vi-
bration free environment at constant tempera-
ture.
- Unsuitable storage
If unsuitable storage conditions prevail (e.g. high
humidity) or if the pump is to be stored for longer
than 6 weeks, then the pump housing should be
filled with oil (see 4.1.3).
- Long periods of storage
After a storage period of more than 2 years the
motor roller bearings and bearing supports need
to be re-greased or replaced entirely.
4.1.3 Conservation
The centrifugal pumps that we deliver are treated
with a conservation material corresponding to
the storage time quoted us by the purchaser.
This conservation must be removed before start-
up. See chapter 4.2.2 "Cleaning". If the pump is
to be taken out of service for a longer period of
time or if the originally envisaged storage time is
going to be considerably exceeded, then conser-
vation must be undertaken as protection against
corrosion.
For a detailed description of how to proceed un-
der these circumstances, see chapter 7.1 "Shut-
down / Storage / Conservation".
Warning! Risk of injury!
Use only suitable and technically
perfect lifting and load-bearing
equipment with sufficient carrying
power!
Never stand or work underneath
swinging loads.

Schmalenberger GmbH + Co. KG
D-72072 Tübingen / Germany
Pump Typ ZH- / TH- / DUO
Version: 27224 - E 9
4.2 Unpacking, Cleaning and
Assembling
4.2.1 Unpacking
For transportation purposes the pump is fas-
tened to a palette by bands. For transportation
over long distances it is packed in crates or box-
es . After removing the retaining bands extract
the pump out of its packing with the help of suit-
able lifting equipment. Be sure to observe the in-
structions under 4.1.1.
4.2.2 Cleaning
A number of measures are taken for protection
against transportation damage and corrosion.
Check your pump for which measures have been
taken.
1. Covering lid on the nozzles
2. Shaft protection for deliveries without the
motor
3. Protective paint on exposed parts
These protective measures must be removed
before the pump is set up or installed.
Under no circumstances must impurities be left
inside the pump .
The cleaning agents that can be used include
spirit, Ritzol 155 or a strongly alkaline soap solu-
tion, for example. If a steam jet cleaner is to be
used, then let the solvent work itself in for a time
first.
Please do not use a steam jet cleaner. If this is
unavoidable, then please take care not to dam-
age the electric motor and bearings.
4.2.3 Assembly
In general the pump is delivered fully assembled
and can be installed directly.
In special cases the pump is delivered without
the drive motor. Prior to installing it in the plant,
fit the drive to the pump.
Other external accessories such as a blast tank
or similar equipment that has not been pre-as-
sembled with the pump at the factory, should be
fitted to the pump after it has been installed in the
system or on the pump base.
4.3 Installing and connecting
4.3.1 Safety requirements
Important:
Depending on the delivery medium
to be used, the interior of the pump
should be cleaned of residual trac-
es of oil. Use a cleaning agent that
will not be harmful to the mechani-
cal seal and the pump materials.
Make sure that the pump is careful-
ly dried after cleaning.
Important:
Before installation check that the
pump runs freely and easily.
Explosion proof / 
safety instructions
Electrical appliances that are oper-
ated in areas where there is a dan-
ger of explosion, must comply with
the explosion proof requirements.
This is stated on the factory plate of
the motor. For installations in areas
where there is a danger of explo-
sion, the local explosion regula-
tions and those on the test
certificate supplied with the deliv-
ery, and which was issued by the
responsible inspection authority,
must be observed. The test certifi-
cate supplied must be kept at the
installation location (e.g. the mas-
ter’s office).
Important:
For areas where there is a
danger of explosion
inaccordance with directive
2014 / 34 EU, please observe the
supplementary operating
instructions.

Schmalenberger GmbH + Co. KG
D-72072 Tübingen / Germany
10 Pump Typ ZH- / TH- / DUO
Version: 27224 - E
4.3.2 Check before you start
installing
• Have the machine, the system and the con-
tainer nozzles been properly prepared in ac-
cordance with the figures on the dimensions
sheet or installation plan?
• Has the concrete base got adequate
strength in accordance with DIN 1045?
• Is the concrete base hydrated?
• Is the surface level and even?
4.3.3 Pump installation and removal
Centrifugal pumps type "ZHB" may only be in-
stalled horizontally, those of type "ZHS" may
only be installed vertically.
Apart from certain special models, the pumps
are always equipped with a pump or motor foot
(ZHB) or with a pump stand (ZHS) and must be
placed on a base plate and fastened down with
screws.
When installed on a foundation the pump must
be set up with the aid of a spirit level.
Centrifugal pumps type "ZHT, TH, DUO" may
only be installed in a vertical position.
Apart from certain special models, these pumps
are always placed on the cover plate or the
flange and fastened down with screws.
4.3.4 Connecting the pipework
The pipes must be supported as close as possi-
ble to the centrifugal pump and connected to it
free of all tension. Their weight must not be sup-
ported by the pump.
The positioning must be undertaken with the
greatest care as this is the prerequisite for trou-
ble-free operation of the plant.
If these instructions are not observed, then any
claims under guarantee will be void.
In the case of short pipes the nominal bore
should be at least the same as the centrifugal
pump connections. For long pipes the most eco-
nomic nominal bore should be determined on a
case by case basis.
Connection pieces to larger nominal bores
should be carried out with approx. 8° expansion
angle to avoid significant loss of pressure.
In order to prevent the formation of air pockets,
the suction pipe to the centrifugal pump must be
installed to rise continuously, on the pressure
side it must fall continuously. Depending on the
type of system and centrifugal pump being used,
it is recommended that backflow prevention and
shut-off devices are installed.
Expansion of the pipes due to temperature must
be remedied by suitable measures.
We recommend the installation of compensators
in the pipes.
Warning! Static stability,
Risk of injury!
Pumps with large drives that are
mounted vertically are top heavy.
These pumps must be safeguarded
against tipping up during installa-
tion or removal e.g. with the help of
ropes.
Caution!
Never install the pump with the 
„motor below“.
Warning!
Under no circumstances must
the pump be used as anchor
point for the pipework.
No forces or moments (e.g. due to
twisting or heat expansion) from
the pipework must act on the pump.
Warning!
In the case of hot, caustic or
poisonous delivery media!
If the pipe strength is exceeded
leaks can occur in the pump or in
the flange connections, for exam-
ple, that could result in vast
amounts of medium being ex-
pelled.

Schmalenberger GmbH + Co. KG
D-72072 Tübingen / Germany
Pump Typ ZH- / TH- / DUO
Version: 27224 - E 11
The resulting pressure surges can greatly ex-
ceed the maximum permitted housing pressure
of the pump!
To prevent too strong pressure surges dampers
or blast tanks should be installed.
Often welding beads, scales and other impurities
do not get dislodged for some period of time. The
should be kept clear of the pump by inserting a
sieve in the suction pipe.
The free cross-section of the sieve must be 3
times the cross-section of the pipe so that there
is not too large a resistance built up due to for-
eign bodies that flow in.
Hat-shaped sieves containing a mesh wire net
having a mesh size of 2.0 mm and 0.5 mm wire
diameter made of corrosion resistant material
have proved useful in practice.
4.3.5 Electrical connections
The electrical connections to the pump must be
carried out by a specialised company in the elec-
trical engineering branch approved by the local
energy provider, taking into account the techni-
cal connection requirements.
The connections must be carried out by a quali-
fied electrician. (see 4.3.1)
The relevant DIN VDE (Association of
German Engineers) regulations must be
observed.
Compare the available mains voltage with the
details on the motor’s factory plate and select the
appropriate switching.
We recommend the use of a motor protection fa-
cility.
In compliance with VDE 0530-8, three-phase
motors are always wired for clockwise rotation
(looking at the motor shaft stub).
The direction of rotation of the pump is anti-
clockwise as standard (viewed from the suction
flange).
Always note the arrow on the pump
indicating the direction of rotation.
Connect the motor according to the circuit dia-
gram in fig. 1 or fig. 2.
Delta connection lower voltage)
Fig. 1 Connection diagram for 3-phase motors, 
Circuit arrangement 
Star connection Y (high voltage)
Fig. 2 Connection diagram for 3-phase motors, 
Circuit arrangement Y
Important
Pipe compensators must not be
used to make up for inaccuracies in
the pipelines, for example with a
centre offset of the flange.
Warning! Mortal danger!
Taps that close very suddenly
(abruptly) must be avoided in the
pipework.
At the end of installation, before
starting up the system the contain-
ers, pipes and connections must be
thoroughly cleaned, rinsed and
blown through.
Risk of explosion!
Where there is a risk of explosion a
motor protection device must be fit-
ted!
W2 U2 V2
U1 V1 W1
L2 L1 L3
W2 U2
U1 V1 W1
L2 L1 L3
V2

Schmalenberger GmbH + Co. KG
D-72072 Tübingen / Germany
12 Pump Typ ZH- / TH- / DUO
Version: 27224 - E
Motor with PTC thermistors as thermal
winding protection
Connect the PTC thermistor (PTC sensor) to the
downstream trigger unit if required. The PTC
thermistors are designed according to
DIN 44081 and DIN 44082.
Time relay setting
For three-phase motors with star-delta connec-
tion it must be ensured that the switching points
between star and delta follow each other very
rapidly. Long switching times can result in dam-
age to the motor. Setting of the time relay for
star-delta connection: 3 to 5 seconds depending
on the motor performance.
Direction of rotation check
The direction of rotation of the motor must match
the direction indicated by the direction of rotation
arrow on the hood of the pump. Check by rapidly
switching on and off.
If the direction of rotation is wrong, change any
two phases L1, L2 or L3 of the power supply in
the motor terminal box over.
Additional motor equipment
If particular control devices are to be used e.g. in
connection with the installation of the pump in a
process engineering facility, the instructions of
the manufacturer of the control device must be
strictly observed.
5 Pump operation
5.1 Initial start-up
Motor performance  30kW3 3sec ±30%
Motor performance > 30kW 5sec ±30%
Prior to initially starting up the cen-
trifugal pump please make sure
that the following prerequisites
have been met:
1. The centrifugal pump has been
connected properly electrically
and with all requisite safety fea-
tures.
2. The pump is completely filled
with delivery medium or that
the minimum level of fluid is
present in the tank / pool (the
pump is covered) and that fur-
ther supply is available.
Please observe: Dry running
leads to increased wear and
damage to the pump!
3. On the suction side all shut-off
devices are open and the suc-
tion pipe is vented.
4. The rotating parts of the pump
have been covered by a pro-
tective shield. (In accordance
with UVV (Accident Prevention
Regulations) the centrifugal
pump may only be operated if a
safety shield has been fitted).
5. It has been checked that the
pump shaft rotates easily (ob-
serve the instructions under
4.2.3 )
6. The direction of rotation has
been checked.
7. There is a minimum distance
between the suction inlet and
the tank wall of 150 mm.

Schmalenberger GmbH + Co. KG
D-72072 Tübingen / Germany
Pump Typ ZH- / TH- / DUO
Version: 27224 - E 13
5.1.1 Starting the pump
Only switch the pump on when the shut-off de-
vice on the pressure side is closed! Once the
maximum rotation speed has been reached,
slowly open it up and adjust to full operational
level.
• An automatic backflow prevention device
must constantly open once the operational
value has been reached without the produc-
tion of abnormal noises, vibrations or in-
creased current consumption in the plant.
• Once the operating point has been reached,
the power input to the motor and the bearing
temperature must be monitored! When first
started up the ultimate bearing temperature
is attained only after about 48 hours, de-
pending on ambient conditions.
5.2 Operating
5.2.1 Operation monitoring
In most cases the centrifugal pump is controlled
from the central point of the overall facility. A pre-
requisite for a perfectly functioning centrifugal
pump is adherence to the data provided for its in-
stallation and use. See the chapter on specifica-
tions.
1. Temperature of the delivery fluid
Never operate the pump at temperatures in ex-
cess of those stated in the original specification.
2. Noise emission
The acoustic power or sound pressure level is
determined by the motor as well as the pump,
and especially by the installation situation. Spe-
cial protective measures must be taken to re-
duce transmission of structure-borne or air-
borne sound.
3. Switching frequency
In order to avoid a large temperature increase in
the motor and excessive strain on the pump, mo-
tor and bearings the switching frequency must
not exceed the following guideline figures.
4. Minimum amount
If the sort of facility includes the possibility of a
run against closed shut-off device on the pres-
sure-end, a minimum delivery rate at t -30 to
+70°C 15% of Qopt. must be supplied during this
time. Over +70 to +110°C it must be 25% of
Qopt.
5. Density of the delivery fluid
The power input of the pump changes in propor-
tion to the density of the delivery fluid. To prevent
the motor being overloaded, the density must
correspond to the data in the specifications.
6. Mechanical seal
The sealing unit has been fitted and set at the
factory. The gasket is maintenance free but
should be checked for leaks from time to time.
During initial start up there may be increased
leakage for a brief time. If increased leakage per-
sists then the plant should be switched off at
once and the cause determined. The cause
could be dirty medium or a prior period of dry run-
ning through incomplete venting of the pump, for
example.
5.2.2 Miscellaneous
Installed reserve pumps must be run briefly once
a week to ensure that they are always ready for
operation. They should be run each time for ap-
prox. 10 minutes. This also applies to any pump
that is not in use but must remain ready for oper-
ation.
Pay particular attention to the fol-
lowing points for the manual opera-
tion of the centrifugal pump:
Motor power: Max. no. switches / h
up to 3 kW 20
from 4 to 11 kW 15
from 11 to 45 kW 10

Schmalenberger GmbH + Co. KG
D-72072 Tübingen / Germany
14 Pump Typ ZH- / TH- / DUO
Version: 27224 - E
5.3 Indications of faulty operation
5.3.1 General
When operated via a central control facility faulty
operation can be largely ruled out.
In the case of manual operation, but also within
a control complex, please make sure that:
1. The pump always runs quietly and vibration
free.
2. The pump does not run dry.
3. A longer period of operation with closed
shut-off device is avoided to prevent heating
up the delivery medium. For the requisite
minimum delivery quantity see chapter 5.2.1.
4. The maximum permitted room temperature
of +40°C is not exceeded.
5. The ball bearing temperature does not ex-
ceed the room temperature by more than +
50ºC and in any event does not exceed +
90ºC overall (measured at the exterior of the
motor housing).
6. During centrifugal pump operation the shut-
off device in the supply line is not closed.
5.3.2 Faults
In case of faults in the operation of the centrifugal
pump, that were not caused by the control facility
or other foreign devices, proceed as follows:
1. Locate the site of the fault or defect.
2. Determine the cause.
3. Remedy the fault.
In chapter 5.5 "Fault elimination" there is a table
listing the most frequent faults, their cause and
the recommended way to eliminate them.
5.4 Shutdown
1. Close shut-off device in the pressure and
suction pipes. If backflow prevention is fitted
to the pressure pipe the shut-off device can
remain open, provided that there is back
pressure.
2. Switch motor off. Allow it to come to rest. De-
pending on the sort of facility, the pump
should be allowed sufficient idle run time –
with the heat source, if any, switched off to
allow the delivery fluid temperature to reduce
– to prevent an accumulation of heat within
the pump.
3. Close the shut-off device in the suction pipe.
Warning! 
Risk of damage!
If there is a danger that the pump
may freeze and / or for occasions
where it is to be at a standstill for
longer periods of time, the pump
must be emptied or protected
against freezing up (by auxiliary
heating).

Schmalenberger GmbH + Co. KG
D-72072 Tübingen / Germany
Pump Typ ZH- / TH- / DUO
Version: 27224 - E 15
5.5 Fault elimination
Pump stationary Pump delivery rate too low Motor overload Pump does not deliver, no pump pressure Increased motor / bearing temperature Pump leaks Pump runs noisily, operating noises Pump temperature too high
Cause of the fault Elimination of the fault
xx xCounter-pressure too high, pump
working against too much pressure,
plant resistance too high, performance
too low
Reset operating point, clean the plant
out, increase the rpm, install a new
impeller, clean the pipes, enlarge the
pipes, use a larger pump
xx x Pump / pipework not completely
vented, air being sucked in due to too
little covering, gas production, air pock-
ets in the pipes, high level of air con-
tent in the medium, supply or impeller
blocked
Increase fluid level, correct level con-
trol, install the pump lower down, vent
the plant, clean the pipework, change
the pipework, de-gas the medium,
decrease the resistance in the supply
pipe, fully open valves in the suction
pipe, clean sieves and suction connec-
tions, install a venting valve directly
before the non-return valve
xxx Wrong direction of rotation, incorrect
electrical connection, too low rpm
Swap over two of the power supply
phases in the terminal box, increase
the rpm (*) (if necessary, get a new
motor)
xxxWorn internal parts (e.g. the impeller) Remove foreign bodies out of the
pump housing, replace worn parts
xxx Pump back-pressure is less than
stated in the specifications, incorrect
electrical connection
Set operating point precisely, increase
counter-pressure by throttling the
pump on the pressure side for exam-
ple, turn off impeller if required (*), use
larger motor (*), compare electrical
supply with that on the motor rating
plate; study the circuit diagram, see
chapter 4.3.5
xx Higher density or higher viscosity of
the delivery medium than specified
Re-adjust the pump (*)
xCavitation Throttle the pump on the pressure
side, correct the suction conditions,
use larger pump (*)

Schmalenberger GmbH + Co. KG
D-72072 Tübingen / Germany
16 Pump Typ ZH- / TH- / DUO
Version: 27224 - E
(*) Please consult the manufacturer.
xDefective gaskets, pump badly
adjusted, connecting screws loose
Replace gaskets, adjust the pump
properly, check pipework connections,
tighten connecting screws
xShaft seal worn Replace shaft seal, check catchment
liquid, check coolant supply lines,
check bypass for clear cross-section
xForeign body in the pump, motor bear-
ings defective, circuit breaker tripped
due to motor overload, circuit breaker
too small, winding defective
Remove foreign body from pump hous-
ing, clean or replace pump housing,
replace motor bearings, check electri-
cal connection and compare with
motor rating plate, if the motor is over-
loaded: Throttle the pump, smaller
impeller (*), larger motor (*)
xx Impeller out-of-balance, bearing defec-
tive, too little or too much or the wrong
lubricant
Clean the impeller, balance the impel-
ler (*), replace bearings, add or reduce
or completely replace the lubricant
xxx Pump wrongly adjusted, pump dis-
torted or resonance vibrations in the
pipework, several pumps on one con-
sole
Adjust pump precisely, check pipework
connections / pump holder, individual
installation, connect pipework via com-
pensators, install vibration damper
under the pump, make tank more rigid,
clean pressure-relief holes in the
impeller
xxxDelivery rate too low, pipework
blocked, closed valve on the pressure
side
Re-adjust the pump, for low volumes
provide a bypass, clean the pressure
pipe, switch pump on only when
required, open valve on pressure side;
use a smaller pump (*)
Pump stationary Pump delivery rate too low Motor overload Pump does not deliver, no pump pressure Increased motor / bearing temperature Pump leaks Pump runs noisily, operating noises Pump temperature too high
Cause of the fault Elimination of the fault

Schmalenberger GmbH + Co. KG
D-72072 Tübingen / Germany
Pump Typ ZH- / TH- / DUO
Version: 27224 - E 17
6 Maintenance / Repair
General Instructions
The operator must ensure that all maintenance,
service and repair work on the pump is carried
out exclusively by authorised and specially
trained persons. It must be established beyond
doubt that the person has studied the operator’s
manual in detail.
We recommend the creation and adherence to of
a maintenance schedule. That will enable you to
avoid expensive repairs and have a reliable and
trouble-free pump operation.
Only original spare parts must be used for re-
pairs. This is particularly important for the me-
chanical seal (GLRD ).
If work has to be carried out on the motor the in-
structions in the manual from the relevant motor
manufacturer must be observed.
6.1 Maintenance / Service
Use the following information to create a mainte-
nance schedule. These are recommendations of
minimum requirements that must be adjusted to
local conditions of use of the pump and may
need amending accordingly.
6.1.1 Checks
Continuous checks:
• Centrifugal pump delivery data (pressure,
amount)
• Power take-up
Daily checks:
• Pump running is quiet and vibration free
• Bearing temperature
• Leakage at the mechanical seal (GLRD )
• SKS (catchment chamber system) – check
fluid level
More frequent monitoring must be planned for
liquids with properties that differ greatly from
those of water (which tend to stick or form accu-
mulations, for example, or have a high gas con-
tent).
Smooth operation of the shaft may be impaired
for example by accumulations on the mechanical
seal or if the mechanical seal sticks. If this hap-
pens, smooth operation must be restored before
starting up. See section 7.1.3 "Restarting after
Periods of storage".
Check / replace every 3 months:
• Screws are tight
• In case of SKS change the catchment medi-
um (if not otherwise instructed)
6.1.2 Lubrication and changing
lubricant
Pumps of the types "ZH- / TH- / DUO" in the
standard models only run on bearings in the
drive motors.
The bearings in small motors are designed to
last the useful life of the motor and are filled with
a grease that cannot be replenished. Defective
bearings must be replaced. In this case there are
no lubrication nipples on the bearing supports.
Bearings in larger motors must be regularly re-lu-
bricated. For more details please see the “Oper-
ating instructions for pump drives” in chapter 6.2
Motor bearings.
The model with IEC Norm motor and bearing
pedestal the bearings in the pedestal are provid-
ed with a grease that need not be replenished. It
is designed to last the useful life of the motor and
cannot be re-greased. Defective bearings must
be replaced.
Warning! Mortal danger!
In order to prevent electric shocks,
work on the terminal box and the
machine controller must never be
carried out before the electrical
connections have been isolated or
disconnected.
Warning! Mortal danger!
The pump must be safeguarded
against unintentional switching on
(be disconnected) if checking or
maintenance work is to be under-
taken.

Schmalenberger GmbH + Co. KG
D-72072 Tübingen / Germany
18 Pump Typ ZH- / TH- / DUO
Version: 27224 - E
6.2 Repair
General
Always carry out repair work on the removed
centrifugal pump in an appropriate workshop. Be
sure to observe the general instructions at the
beginning of the chapter!
The following instructions will enable you to dis-
mantle the pump and to re-assemble it properly
with the requisite spare parts in place.
When a new mechanical seal is fitted special in-
structions must be observed.
The work can be undertaken with the usual work-
shop tools. No special tools are needed.
After dismantling thoroughly clean all the individ-
ual parts of the centrifugal pump.
Check the individual parts for wear and damage.
Parts that are not perfect must be reworked or
replaced.
6.2.1 Dismantling Preparations
Prior to starting to dismantle it the pump must be
safeguarded against accidental switching on (it
must be disconnected).
When used in a facility, inform the shift leader or
manager.
6.2.2 Dismantling / 
Removal of the pump
The pump must be allowed to reach room tem-
perature.
• Disconnect the power supply.
• Close valves (on the suction and pressure
sides).
• Empty the pump via the drainage screws
912, 913
• If there is a catchment chamber / pressure
chamber empty it via the drainage screws
912. Dispose of the catchment medium in
the proper manner.
• Disconnect motor.
• Remove existing additional connections.
• Release pressure and suction nozzles.
• Release pump from its base plate.
• Lift the pump off completely (out of the tank
etc.)
When emptying the centrifugal pump please ob-
serve the following instructions!
Note:
Please also observe the drawing in
the chapter “Spare parts / drawing”
at the end of this operator’s manu-
al!
Warning! Mortal danger!
Fasten a warning on the switching
cabinet.
Important:
For the following work, please be
sure to observe local regulations
and conditions.
Warning!
1. If the pump was used to deliver
liquids that are hazardous to
health, then great care must be
taken in emptying the pump
that neither persons nor the en-
vironment are placed at risk
through the process.
2. If necessary, wear protective
clothing and protective mask!
3. The rinsing liquid used and any
residual fluid out of the pump
must be caught and disposed
of properly and without placing
persons or the environment in
any danger.
4. Pumps that deliver liquids that
are hazardous to health must
be decontaminated. In draining
the delivery medium off care
must be taken that neither per-
sons nor the environment are
placed in any danger.
5. Legal requirements must be
adhered to!

Schmalenberger GmbH + Co. KG
D-72072 Tübingen / Germany
Pump Typ ZH- / TH- / DUO
Version: 27224 - E 19
6.2.3 Dismantling / 
Dismantling the pump
Before you begin
Begin the work only once you have checked that:
• The required spare parts are available and
that they will fit this pump or your particular
model thereof. Or that the suspected dam-
aged parts can be obtained promptly. Make
sure that the pump serial number is stated in
your spare parts order.
• You have all the required tools and accesso-
ries for the work.
Observing these instructions is a prerequisite for
trouble-free operation of the pump and for the
acceptance of potential claims under guarantee.
6.2.4 Dismantling the pump 
(from the suction side)
Place the pump on its blower cover and secure
against tipping over.
1st step:
Variant 1 = ZHT, ZHB, TH, DUO
Loosen the nuts 920.01 on the connecting
screws 905 on the clamping ring 531 (ZH3208) /
suction cover 106/162 (ZH3213). Carefully re-
move the suction cover.
Variant 2 = ZHS
Loosen the nuts 920.01 on the connecting
screws 905 on the suction stand 106/187. Care-
fully remove the suction stand.
2nd step:
Loosen the impeller nut 922 and screw it off the
motor shaft 819.
Pull the first impeller 233/233.02 off the motor
shaft 819 (with removal device).
Dismantle the stage casing together with the
pressed-in distributor147 or 109+171.
Remove the key 940 out of its seat.
Further steps (impeller, distributor, stage casing,
distance washer 525, keys) pull off as described
above.
The last distributor 171 (ZH 3208) – seen in the
direction of flow – is pressed into the housing
and prevented from twisting in the housing itself
by a locking pin 561.
3rd step: Dismantling the mechanical seal
(GLRD )
The mechanical seals used in the centrifugal
pumps are not free of wear. When dismantling
the pump check the mechanical seals for dam-
age. Damaged mechanical seals must be com-
pletely replaced. Please observe the following
instructions for this.
There are two types of GLRD built into the
pumps. Please observe the pump specifications.
a) GLRD not relieved – up to max. 13 bar
After loosening the locking ring 932 of the GLRD
pull the sliding ring packet 433 off the shaft 819.
GLRD not relieved
b) GLRD relieved – up to max. 25 bar
Carefully pull the relieving bush 487 with the me-
chanical seal packet 433 and O-Ring 412 off the
shaft Welle 819.
GLRD relieved
Note:
Use only original spare parts for the
repairs!
All the gaskets must be replaced
when the pump is re-installed.
Customer service:
Schmalenberger provides a 24
hour service for the delivery of
spare parts!

Schmalenberger GmbH + Co. KG
D-72072 Tübingen / Germany
20 Pump Typ ZH- / TH- / DUO
Version: 27224 - E
4th step:
Loosen lock nut 924, if existing.
Carefully pull off the housing 107/102 (106.02-
DUO 3213) together with the pressed-in GLRD
counter-ring, without damaging the shaft.
Now the counter-ring can be removed from its
seat in the now loose housing 107/102.
5th step:
If existing, pull off lubrication ring / gamma ring
423 (ZH3208).
Remove intermediate piece 132.
6.2.5 Bearing pedestal
If your pump is equipped with an IEC Norm mo-
tor as drive, then there is a bearing pedestal for
supporting the pump shaft and the coupling be-
tween the cover plate and the motor.
The bearings are enclosed and provided with
grease that cannot be replenished.
The coupling is designed to last for the service
life of the motor under normal operating condi-
tions.
To replace the coupling or one of the bearings,
proceed as follows:
• Loosen the drive from the bearing pedestal.
Remove the motor with the upper half of the
coupling. 
Now you can replace the inner coupling part.
• To replace the ball bearings the pump must
be removed and dismantled as described in
chapter 1.2.4 .
• Then remove the bearing pedestal together
with the shaft from the cover plate.
• Remove the locking rings from the shaft and
out of the bearing pedestal. Take out the ball
bearings.
6.2.6 Intermediate piece / elongated
immersion depth of the pump
Loosen the screws 914 holding the drive motor
from the intermediate piece 132.
Dismantle the drive 802, if necessary loosen the
cover plate 167 from the intermediate piece 132.
Replace the clamp gasket 400 8if existing).
6.2.7 Pump re-installation
In principle the re-installation is in the reverse or-
der of dismantling.
Please observe by way of preparation:
• Thoroughly clean all the individual parts of all
dirt.
• Check all parts for wear. Damaged parts
must be replaced by new ones.
• Clamp gaskets and O-rings must always be
replaced by new ones. Grease O-rings prior
to installation.
Exception: Do not grease O-rings on the GLRD.
See the special instructions for installing the
GLRD.
• When fitting the screw connections always
tighten alternately cross-wise. 
Use a torque wrench for this.
The following table shows the torque to be ap-
plied for standard DIN 13 thread.
The figures apply to new, ungreased screws.
The table values do not apply if deviating values
are specified on the general diagrams or due to
other instructions.
6.2.8 GLRD installation
Preparation:
Increased cleanliness must be observed in the
immediate area where the GLRD installation is to
take place.
Accessories:
- Propyl alcohol and cellulose cloth (no cleaning
rags!)
- O-ring lifter
- Water and detergent
Work steps:
• Unpack the GLRD and check for any dam-
age.
Thread:
Torque [Nm] for screws:
to plastic
parts
to cast parts to bright
steel parts
M8 710 - 15 20
M10 825 - 35 40
M12 10 30 - 40 70
M16 -- 60 - 90 160
M20 -- 80 - 110 --