Wilo Rexa FIT-S User manual

Pioneering for You
·
Wilo-Rexa FIT-S
6092602 • Ed.01/2022-03
en Installation and operating instructions

Rexa FIT-S
http://qr.wilo.com/414
Rexa FIT
https://qr.wilo.com/771

en
Installation and operating instructions • Wilo-Rexa FIT-S • Ed.01/2022-03 3
Table of contents
1 General information...................................................................4
1.1 About these instructions ..................................................... 4
1.2 Digital instructions................................................................ 4
1.3 Copyright ............................................................................... 4
1.4 Subject to change................................................................. 4
1.5 Exclusion from warranty and liability.................................4
2 Safety...........................................................................................4
2.1 Identification of safety instructions................................... 4
2.2 Personnel qualifications....................................................... 5
2.3 Personal protective equipment........................................... 5
2.4 Electrical work .......................................................................5
2.5 Monitoring devices ............................................................... 6
2.6 Fluids hazardous to health................................................... 6
2.7 Transport................................................................................ 6
2.8 Use of lifting equipment......................................................6
2.9 Installing/dismantling........................................................... 7
2.10 During operation ................................................................... 7
2.11 Clean and disinfect ............................................................... 7
2.12 Maintenance tasks................................................................ 7
2.13 Operating fluid ...................................................................... 7
2.14 Operator responsibilities...................................................... 8
3 Transportation and storage.......................................................8
3.1 Delivery................................................................................... 8
3.2 Transport................................................................................ 8
3.3 Storage ................................................................................... 8
4 Application/use...........................................................................9
4.1 Intended use.......................................................................... 9
4.2 Improper use.......................................................................... 9
5 Product description....................................................................9
5.1 Description............................................................................. 9
5.2 Materials................................................................................. 9
5.3 Technical data .....................................................................10
5.4 Type key...............................................................................10
5.5 Scope of delivery.................................................................10
5.6 Accessories ..........................................................................10
6 Installation and electrical connection....................................10
6.1 Personnel qualifications.....................................................10
6.2 Installation types.................................................................10
6.3 Operator responsibilities....................................................10
6.4 Installation ...........................................................................11
6.5 Electrical connection..........................................................13
7 Commissioning .........................................................................14
7.1 Personnel qualifications.....................................................14
7.2 Operator responsibilities....................................................14
7.3 Direction of rotation check for three-phase AC motor
...............................................................................................14
7.4 Before switching on............................................................15
7.5 Switching on and off ..........................................................15
7.6 During operation .................................................................15
8 Shut-down/dismantling...........................................................16
8.1 Personnel qualifications.....................................................16
8.2 Operator responsibilities....................................................16
8.3 Shut-down............................................................................16
8.4 Removal.................................................................................16
9 Maintenance and repair............................................................17
9.1 Personnel qualifications......................................................17
9.2 Operator responsibilities.....................................................17
9.3 Operating fluid......................................................................17
9.4 Maintenance intervals .........................................................17
9.5 Maintenance measures .......................................................18
9.6 Repairs ...................................................................................19
10 Faults, causes and remedies ....................................................20
11 Spare parts.................................................................................22
12 Disposal......................................................................................22
12.1 Oils and lubricants................................................................22
12.2 Protective clothing ..............................................................22
12.3 Information on the collection of used electrical and elec-
tronic products .....................................................................22
13 Appendix....................................................................................22
13.1 Tightening torques ..............................................................22

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4 Installation and operating instructions • Wilo-Rexa FIT-S • Ed.01/2022-03
1 General information
1.1 About these instructions
These instructions form part of the product. Compliance with the
instructions is essential for correct handling and use:
•Read the instructions carefully before all activities.
•Keep the instructions in an accessible place at all times.
•Observe all product specifications.
•Observe the markings on the product.
The language of the original operating instructions is German. All
other languages of these instructions are translations of the ori-
ginal operating instructions.
1.2 Digital instructions
The digital version of the instructions is available on the following
product page:
https://qr.wilo.com/00414
1.3 Copyright
WILO SE © 2022
The reproduction, distribution and utilization of this document as
well as the communication of its contents to others without ex-
press authorization is prohibited. Offenders will be held liable for
the payment of damages. All rights reserved.
1.4 Subject to change
Wilo shall reserve the right to change the listed data without no-
tice and shall not be liable for technical inaccuracies and/or omis-
sions. The illustrations used may differ from the original and are in-
tended as an example representation of the device.
1.5 Exclusion from warranty and liability
Wilo shall specifically not assume any warranty or liability in the
following cases:
•Inadequate configuration due to inadequate or incorrect in-
structions by the operator or the client
•Non-compliance with these instructions
•Improper use
•Incorrect storage or transport
•Incorrect installation or dismantling
•Insufficient maintenance
•Unauthorised repairs
•Inadequate construction site
•Chemical, electrical or electrochemical influences
•Wear
2 Safety
This section contains basic information about
the individual stages in the life cycle of the
pump. Failure to observe this information leads
to:
•Danger to persons
•Danger to the environment
•Property damage
•Loss of claims for damages
2.1 Identification of safety instructions
These installation and operating instructions set
out safety instructions for preventing personal
injury and damage to property. These safety in-
structions are shown differently:
•Safety instructions relating to personal injury
start with a signal word, are preceded by a
corresponding symbol and are shaded in
grey.
DANGER
Type and source of the danger!
Consequences of the danger and instructions for
avoidance.
•Safety instructions relating to property dam-
age start with a signal word and are displayed
without a symbol.
CAUTION
Type and source of the danger!
Consequences or information.
Signal words
•DANGER!
Failure to observe the safety instructions will
result in serious injuries or death!
•WARNING!
Failure to follow the instructions can lead to
(serious) injuries!
•CAUTION!
Failure to follow the instructions can lead to
property damage and a possible total loss.
•NOTICE!
Useful information on handling the product
Markups
✓Prerequisite
1. Work step/list
⇒Notice/instructions
▶Result
Identifying cross references
The name of the section or table is in inverted
commas [“ ”]. The page number follows in
square brackets [].
Symbols
These instructions use the following symbols:

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Installation and operating instructions • Wilo-Rexa FIT-S • Ed.01/2022-03 5
Danger caused by electric voltage
Danger of bacterial infection
Danger of explosion
General warning symbol
Warning – risk of cutting injuries
Warning – hot surfaces
Warning – high pressure
Working alone is prohibited! A second
person must be present.
Useful information
2.2 Personnel qualifications
•Personnel have been instructed on locally ap-
plicable regulations governing accident pre-
vention.
•Personnel have read and understood the in-
stallation and operating instructions.
•Electrical work: qualified electrician
Person with appropriate technical training,
knowledge and experience who can identify
and prevent electrical hazards.
•Installation/dismantling work: trained sewage
technology professional
Fixation and pipework in wet well and dry well
installation, lifting equipment, basic know-
ledge of wastewater facilities
•Maintenance work: trained sewage techno-
logy professional
Application/disposal of operating fluids used,
basic engineering knowledge (installation/
dismantling)
•Lifting work: trained specialist for the opera-
tion of lifting devices
Lifting equipment, lifting gear, attachment
points
Children and persons with limited abilities
•Persons under the age of 16: Use of this
product is prohibited.
•Persons under the age of 18: Supervise them
during use of the product (supervisor)!
•Persons with limited physical, sensory or
mental capacities: Use of this product is pro-
hibited!
2.3 Personal protective equipment
The protective equipment specified is the min-
imum requirement. Observe the requirements of
the work regulations.
Protective equipment: Transport, installation,
removal and maintenance
•Safety shoes: Protection class S1 (uvex 1
sport S1)
•Protective gloves (EN388): 4X42C (uvex
C500 wet)
•Safety helmet (EN397): Conforms to stand-
ards, protection against lateral deformation
(uvex pheos)
(If lifting equipment is used)
Protective equipment: Cleaning work
•Protective gloves (ENISO374-1): 4X42C +
Type A (uvex protector chemical NK2725B)
•Safety goggles (EN166): (uvex skyguard NT)
–Labelling frame: W 166 34 F CE
–Labelling disc: 0-0.0* W1 FKN CE
* Protection level according to EN170 not
relevant for this work.
•Breathing protection mask (EN149): Half
mask 3M series 6000 with filter 6055 A2
Article recommendations
The branded products in the parentheses con-
stitute non-binding suggestions. Similar
products from other brands can also be used.
Adherence to the standards mentioned is re-
quired.
WILO SE does not assume any liability for the
adherence of the aforementioned products to
the corresponding standards.
2.4 Electrical work
•Electrical work must be carried out by a quali-
fied electrician.
•Disconnect device from the mains and secure
it against being switched on again without
authorisation.
•Observe applicable local regulations when
connecting to the mains power supply.

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6 Installation and operating instructions • Wilo-Rexa FIT-S • Ed.01/2022-03
•Comply with the requirements of the local
energy supply company.
•Train personnel on how to make electrical
connections.
•Train personnel on the options for switching
off the device.
•Observe the technical information in these
installation and operating instructions as well
as on the rating plate.
•Earth the device.
•Observe provisions for connection to the
electrical switching system.
•Comply with the specifications on electro-
magnetic compatibility when using electronic
start-up controllers (e.g. soft starter or fre-
quency converter). If required, take special
measures into account (e.g. shielded cables,
filters, etc.).
•Replace defective connection cables. Contact
customer service.
2.5 Monitoring devices
The following monitoring devices must be
provided on-site:
Circuit breaker
The size and switching characteristics of the
circuit breakers must conform to the rated cur-
rent of the connected product. Observe local
regulations.
Motor protection switch
Make provision for an on-site motor protection
switch for devices without a plug! The minimum
requirement is a thermal relay/motor protection
switch with temperature compensation, differ-
ential triggering and anti-reactivation device in
accordance with the local regulations. In case of
sensitive mains, make provision for the installa-
tion on-site of other protective equipment (e.g.
overvoltage, undervoltage or phase failure relay,
etc.).
Residual-current device (RCD)
•Install a residual-current device (RCD) in ac-
cordance with the regulations of the local en-
ergy supply company.
•If people can come into contact with the
device and conductive fluids, install a resid-
ual-current device (RCD).
2.6 Fluids hazardous to health
Hazardous germs form in sewage or in stagnant
water. There is a danger of bacterial infections!
•Wear protective equipment!
•Clean and disinfect the product thoroughly
after removal!
•Inform all persons about the pumped fluid and
the danger it poses!
2.7 Transport
•Locally applicable laws and regulations on
work safety and accident prevention must be
complied with.
•Always carry the product by the handle!
2.8 Use of lifting equipment
If lifting equipment (lifting device, crane, chain
hoist…) is used, observe the following points:
•Wear a safety helmet according to EN397!
•Comply with local regulations on the use of
lifting equipment.
•The technically correct use of the lifting
equipment is the operator’s responsibility!
•Lifting gear
–Use legally specified and approved lifting
gear.
–Select lifting gear based on the attachment
point.
–Attach lifting gear to the attachment point
according to local regulations.
•Lifting equipment
–Check it functions properly before use!
–Sufficient bearing capacity.
–Ensure stability during use.
•Lifting operation
–Do not jam the product when lifting and
lowering it.
–Do not exceed the max. permissible bearing
capacity!
–If necessary (e.g. blocked view), assign a
second person to coordinate.
–No one should stand under suspended
loads!

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Installation and operating instructions • Wilo-Rexa FIT-S • Ed.01/2022-03 7
–Do not move loads over workplaces where
persons are present!
2.9 Installing/dismantling
•Locally applicable laws and regulations on
work safety and accident prevention must be
complied with.
•Disconnect device from the mains and secure
it against being switched on again without
authorisation.
•All rotating parts must stop.
•Ensure enclosed spaces have sufficient vent-
ilation.
•When working in enclosed spaces, a second
person must be present for safety reasons.
•Toxic or asphyxiating gases may build up in
enclosed spaces or buildings. Observe pro-
tective measures in accordance with work
regulations, e.g. carry a gas detector with you.
•Clean the device thoroughly.
•If the product has been used in fluids that are
hazardous to health, disinfect the product!
2.10 During operation
•Demarcate and cordon off the working area.
•No persons are allowed in the working area
during operation.
•Depending on the process, the product is ac-
tivated and deactivated using separate con-
trols. The product may automatically be ac-
tivated following power cuts.
•If the motor emerges, the motor housing can
heat up to above 40°C (104°F).
•Superior must be informed immediately of
any faults or irregularities.
•The product must be switched off immedi-
ately if faults occur.
•Never reach into the suction port. The rotat-
ing parts can crush and sever limbs.
•Open all gate valves in the inlet and pressure
pipe.
•Ensure minimum water submersion by using
dry-running protection.
•Sound-pressure level depends on several
factors (installation, duty point, etc.). Measure
the current noise level under operating condi-
tions. Wear hearing protection at noise levels
of 85dB(A) and over. Demarcate the working
area!
2.11 Clean and disinfect
•If a disinfectant is used, wear protective
equipment according to the manufacturer’s
instructions!
•Inform all persons about the disinfectant and
how to use it correctly!
2.12 Maintenance tasks
•Disconnect device from the mains and secure
it against being switched on again without
authorisation.
•Clean the device thoroughly.
•If the product has been used in fluids that are
hazardous to health, disinfect the product!
•Carry out maintenance work in a clean, dry
and well-lit place.
•Only carry out maintenance tasks described in
these installation and operating instructions.
•Only original parts of the manufacturer may
be used. The use of any non-original parts re-
leases the manufacturer from any liability.
•Collect any leakage of fluid and operating
fluid immediately and dispose of it according
to the locally applicable guidelines.
2.13 Operating fluid
The following white oils are used:
•ExxonMobile: Marcol52
•ExxonMobile: Marcol82
General remarks
•Absorb leakages immediately.
•If major leakages occur, contact customer
service.
•If the seal is defective, the oil enters the
pumped fluid.
First aid measures
•Skin contact
–Rinse skin areas thoroughly with soap and
water.
–If skin irritation occurs, consult a doctor.
–In case of contact with open skin, consult a
doctor!
•Eye contact
–Remove the contact lenses.

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8 Installation and operating instructions • Wilo-Rexa FIT-S • Ed.01/2022-03
–Rinse eye thoroughly with water.
–If eye irritation occurs, consult a doctor.
•Inhalation
–Remove from the contact area!
–Create air exchange!
–If the respiratory tract becomes irritated or
there is dizziness or nausea, consult a doc-
tor immediately!
•Ingestion
–Consult a doctor immediately!
–Do not induce vomiting!
2.14 Operator responsibilities
•Provide installation and operating instructions
in a language which the personnel can under-
stand.
•Make sure that the personnel have received
the required training for the specified work.
•Provide protective equipment. Ensure that
the protective equipment is worn by person-
nel.
•Ensure that safety and information signs
mounted on the device are always legible.
•Train the personnel on how the system oper-
ates.
•Fit dangerous components within the system
with an on-site guard.
•Demarcate and cordon off the working area.
•Measure the noise level. At noise levels of
85dB(A) and over, wear hearing protection.
Demarcate the working area!
3 Transportation and storage
3.1 Delivery
•After receiving the shipment, check it immediately for defects
(damage, completeness).
•Defects must be noted on the freight documentation.
•Defects must be notified to the transport company or the man-
ufacturer on the day of receipt of shipment.
•Subsequently notified defects can no longer be asserted.
3.2 Transport
CAUTION
Soaked packaging may tear!
The product may fall on the ground if unprotected
and may be damaged. Lift wet packaging carefully
and replace it immediately!
Fig.1: Attachment point
•Wear protective equipment! Observe the work regulations.
–Protective gloves: 4X42C (uvex C500 wet)
–Safety shoes: Protection class S1 (uvex 1 sport S1)
•Carry the pump by the handle!
•Protect the connection cable against water ingress. Do not im-
merse attached plugs in the pumped fluid.
•Only remove the outer packaging at the place of utilisation to
ensure that the pump is not damaged during transport.
•Use tear-proof plastic sacks of sufficient size to package the
used pump for transport in a leak-proof manner.
3.3 Storage
DANGER
Danger due to fluids which are hazardous to
health!
Danger of bacterial infection!
• Disinfect the pump after removal!
• Observe the specifications of the work regula-
tions!
WARNING
Risk of injury from sharp edges on the cut-
ting device!
The macerator has extremely sharp edges. In addi-
tion, sharp edges can form on the suction port.
There is a danger of cuts!
• Wear protective gloves!
• Do not touch the macerator!
CAUTION
Defective macerator due to objects lying
around!
Hard objects can damage the macerator! When set-
ting down, ensure that no objects come into contact
with the macerator.

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Installation and operating instructions • Wilo-Rexa FIT-S • Ed.01/2022-03 9
CAUTION
Total damage due to moisture ingress
The ingress of moisture into the connection cable
damages the cable and the pump! Never immerse
the ends of the connection cable in fluid. Seal them
tightly during storage.
•Place the pump upright (vertical) on a firm bearing surface.
•Secure the pump against falling over and slipping!
•Store the pump for a maximum of one year. Consult the cus-
tomer service before storing the device for more than one year.
•Storage conditions:
–Maximum: -15 to +60°C (5 to 140°F), max. humidity: 90%,
non-condensing.
–Recommended: 5 to 25°C (41 to 77°F), relative humidity: 40
to 50%.
–Protect the pump from direct exposure to sunlight. Extreme
heat can cause damage!
•Do not store the pump in rooms where welding work is carried
out. The resulting gases or radiation can corrode the elastomer
parts and coatings.
•Seal the suction and discharge connection tightly.
•Protect the connection cable against kinking and damage.
Maintain a constant bend radius!
4 Application/use
4.1 Intended use
For pumping in commercial areas of:
•Sewage containing faeces
•Wastewater (with small amounts of sand)
Sewage pumping according to (DIN)EN12050
The pumps meet the requirements of EN12050-1.
4.2 Improper use
DANGER
Explosion due to pumping of explosive fluids!
Pumping of highly flammable and explosive fluids
(gasoline, kerosene, etc.) in pure form is strictly pro-
hibited. There is a risk of fatal injury due to explo-
sion! The pumps are not designed for these fluids.
The submersible pumps must not be used for pumping:
•Untreated sewage
•Drinking water
•Fluids containing hard components (such as stones, wood,
metal, etc.)
•Fluids containing high quantities of abrasive contents (e.g.
sand, gravel).
Intended use also includes compliance with this manual. Any other
use is regarded as non-compliant with intended use.
5 Product description
5.1 Description
Fully submersible grinder pump for stationary and portable wet
well installation in intermittent operation.
1
2
3
4
5
6
7
Fig.2: Overview
1 Handle/attachment point
2 Motor housing
3 Discharge connection
4 Macerator
5 Hydraulics housing
6 Seal housing
7 Connection cable
Rexa FIT-S.../M.../P
Sewage pump with radial macerator with double shear effect. Hori-
zontal discharge port with flange and oval connection. Hydraulics
housing and impeller made of grey cast iron; macerator made of
hardened cutting steel. Surface-cooled 1~ motor with self-
switching thermal motor monitoring. Oil-filled sealing chamber
with two mechanical seals. Stainless steel motor housing. Detach-
able connection cable with capacitor box and plug (CEE 7/7).
Rexa FIT-S.../M.../A
Sewage pump with radial macerator with double shear effect. Hori-
zontal discharge port with flange and oval connection. Hydraulics
housing and impeller made of grey cast iron; macerator made of
hardened cutting steel. Surface-cooled 1~ motor with self-
switching thermal motor monitoring. Oil-filled sealing chamber
with two mechanical seals. Stainless steel motor housing. Detach-
able connection cable with capacitor box, float switch and plug
(CEE 7/7).
Rexa FIT-S.../T.../O
Sewage pump with radial macerator with double shear effect. Hori-
zontal discharge port with flange and oval connection. Hydraulics
housing and impeller made of grey cast iron; macerator made of
hardened cutting steel. Surface-cooled 3~ motor with thermal
motor monitoring. Oil-filled sealing chamber with two mechanical
seals. Stainless steel motor housing. Detachable connection cable
with bare cable ends.
5.2 Materials
•Pump housing: EN-GJL-250 (ASTMA48 Class35/40B)
•Impeller: EN-GJL-250 (ASTMA48 Class35/40B)
•Macerator: 1.4528/59HRC (AISI440B+Co)

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10 Installation and operating instructions • Wilo-Rexa FIT-S • Ed.01/2022-03
•Motor housing: 1.4301 (AISI304)
•Shaft: 1.4401 (AISI 316)
•Seal on the motor side: C/MgSiO4
•Seal on the fluid side: SiC/SiC
•Seal, static: NBR (nitrile)
5.3 Technical data
General
Date of manufacture* [MFY] See rating plate
Mains connection [U/f] See rating plate
Power consumption [P1] See rating plate
Rated power [P2] See rating plate
Max. delivery head [H] See rating plate
Max. volume flow [Q] See rating plate
Activation type [AT] Direct
Fluid temperature [t] 3…40°C (37…104°F)
Fluid temperature, short-term 60°C (140°F) for 3min
Protection class IP68
Insulation class [Cl.] F
Speed [n] See rating plate
Max. switching frequency 60/h
Cable length 10m (33ft)
Permissible immersion depth
with attached connection cable
[8]
7m (23ft)
Immersion depth, max. 20m (66ft)
Operating modes
Immersed S1
Non-immersed S2-15min; S310%
Discharge connection
Flange connection DN32/40, PN10; ANSIB16.1,
Size1.5, Class125
Oval connection 36mm
Extended use
Explosion protection -
Operation on frequency con-
verter
-
*The date of manufacture is stated in accordance with ISO8601:
JJJJWww
•JJJJ = year
•W = abbreviation for week
•ww = calendar week
5.4 Type key
Ex-
ample:
Rexa FIT-S03-123A/21M015-523/P
Rexa Submersible sewage pump
FIT Series
S Macerator
03 Nominal diameter of the discharge connection:
DN32/40
123 Hydraulics type
A Material version: Standard
2 Number of poles
1 IE class
M Mains connection version:
•M = single-phase current (1~)
•T = three-phase current (3~)
15 Value/10 = rated power P2 in kW
- Not Ex-rated
5 Mains frequency: 5 = 50Hz/6 = 60Hz
23 Key for rated voltage
P Additional electrical equipment:
•O = with bare cable end
•P = with plug (CEE7/7)
•A = with float switch and plug (CEE7/7)
5.5 Scope of delivery
•Pump
•Installation and operating instructions
5.6 Accessories
•Connection cable with fixed cable lengths:
–1~ motor: up to max. 30m (98ft).
–3~motor: up to max. 50m (164ft).
•External pencil electrode for monitoring the sealing chamber
•Suspension unit for wet well installation
•Pump support foot for portable installation
•Level control devices
•Fixation sets with anchor bolts
•Fixation accessories and chains
•Switchgear, relays and plugs
6 Installation and electrical connection
6.1 Personnel qualifications
•Electrical work: qualified electrician
Person with appropriate technical training, knowledge and ex-
perience who can identify and prevent electrical hazards.
•Installation/dismantling work: trained sewage technology pro-
fessional
Fixation and pipework in wet well and dry well installation, lift-
ing equipment, basic knowledge of wastewater facilities
6.2 Installation types
•Vertical stationary wet well installation with suspension unit
•Vertical portable wet well installation with pump support foot
6.3 Operator responsibilities
•Observe locally applicable accident prevention and safety regu-
lations.
•Observe all regulations for working with heavy loads and under
suspended loads.
•Provide protective equipment. Ensure that the protective
equipment is worn by personnel.
•Observe local sewage technology regulations for the operation
of sewage systems.
•Avoid pressure surges!
Pressure surges can occur in long pressure pipes with steep ter-
rain. These pressure surges can lead to the destruction of the
pump!
•Ensure the cooling time of the motor depending on the operat-
ing conditions and the size of the pump chamber.

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Installation and operating instructions • Wilo-Rexa FIT-S • Ed.01/2022-03 11
•Structural components and foundations must be of sufficient
stability in order to allow the device to be fixed in a secure and
functional manner. The operator is responsible for the provision
and suitability of the structural component/foundation!
•Check that the available consulting documents (installation
plans, installation location, inflow conditions) are complete and
accurate.
6.4 Installation
DANGER
Risk of fatal injury due to dangerous lone
working practices!
Work in chambers and narrow rooms as well as work
involving risk of falling are dangerous work. Such
work may not be carried out autonomously!
• Only carry out work with another person!
•Wear protective equipment! Observe the work regulations.
–Protective gloves: 4X42C (uvex C500 wet)
–Safety shoes: Protection class S1 (uvex 1 sport S1)
–Safety helmet: EN397 Conforms to standards, protection
against lateral deformation (uvex pheos)
(When using lifting equipment)
•Prepare the installation site:
–Clean, free of coarse solids
–Dry
–Frost-free
–Disinfected
•Toxic or asphyxiating gases may build up during work:
–Observe protective measures in accordance with work regu-
lations (gas measurement, carry a gas detector with you).
–Ensure adequate ventilation.
–If toxic or asphyxiating gases accumulate, leave the work-
place immediately!
•Always carry the pump by the handle!
•Install lifting equipment: even surface, clean, firm base. Ware-
house and installation location must be easily accessible.
•Attach chain or wire rope to handle/attachment point with a
shackle. Only use lifting gear that has been technically ap-
proved.
•All connection cables must be laid properly. The connection
cables must not pose any risk (i.e. tripping, damage during op-
eration). Check whether the cable cross-section and the cable
length are sufficient for the selected installation type.
•Installation of switchgear: Observe information in the manufac-
turer’s instructions (IP class, overflow-proof, potentially explos-
ive atmospheres)!
•Avoid air intake into the fluid. Use baffles or deflector plates at
the inlet. Install the ventilation systems!
•Do not allow the pump to run dry! Avoid air pockets. Do not go
below the minimum water level. Installation of dry-running pro-
tection is recommended!
6.4.1 Indications for double pump operation
If several pumps are used in an operating space, minimum dis-
tances between the pumps and the wall must be complied with.
Here there is a difference in the distances depending on the type
of system: Alternating operation or parallel operation.
d
A2
A1
Fig.3: Minimum distances
d Diameter hydraulics housing
A1Minimum distance from the wall:
- alternating operation: min. 0.3×d
- parallel operation: min. 1×d
A2Distance to pressure pipes
- alternating operation: min. 1.5×d
- parallel operation: min. 2×d
6.4.2 Maintenance tasks
After a storage period of more than 12months, carry out the fol-
lowing maintenance tasks before installation:
•Check the oil in the sealing chamber and replace it if necessary.
See section “Oil change in sealing chamber [}19]”.
6.4.3 Stationary wet well installation
The pump is installed in a pump chamber or basin. A suspension
unit is installed to connect the pump to the pressure pipe. The on-
site pressure pipe is connected to the suspension unit. The pump is
connected to the suspension unit via a coupling connection.
The pressure pipe must meet the following requirements:
•The connected pressure pipe is self-supporting. The pressure
pipe must not be supported by the suspension unit!
•The pressure pipe must not be smaller than the pump’s dis-
charge connection.
•All prescribed valves (gate valves, backflow preventers…) are
present.
•Pressure pipe laid frost-proof.
•Ventilation systems (e.g. air vent valves) installed. Air pockets in
the pump and in the pressure pipe can lead to delivery prob-
lems.

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12 Installation and operating instructions • Wilo-Rexa FIT-S • Ed.01/2022-03
1
5
6
3
4
2
OFF!
S1
S2, S3
Fig.4: Wet well installation, stationary
1 Suspension unit
2 Non-return valve
3 Stop valve
4 Guide pipes (provided by the customer)
5 Lifting equipment
6 Attachment point for lifting equipment
✓Place of use prepared.
✓Suspension unit installed.
✓Coupling connection mounted on the pump.
1. Use a shackle to attach the lifting equipment to the attach-
ment point on the pump.
2. Lift the pump and swing it over the opening of the pump
chamber.
3. Slowly drain the pump and thread the guide pipes into the
coupling connection.
4. Lower the pump until it sets on the suspension unit and is
connected automatically. CAUTION!Hold the connection
cables slightly taut when lowering the pump!
5. Loosen the lifting gear from the lifting equipment and secure
it against falling at the pump chamber outlet.
6. Correctly route the connection cables and lead them out of
the pump chamber. CAUTION!Do not damage the connec-
tion cables!
- No chafing or kinking.
- Do not immerse the cable end in the fluid.
- Observe the bending radii.
▶Pump installed, make the electrical connection.
6.4.4 Portable wet well installation
Attach the pump support foot (available separately as an access-
ory) to the pump. The pump support foot allows the pump to be
positioned anywhere at the place of use. A pressure hose is con-
nected on the discharge side.
•Use a hard surface or underlay at the place of use to prevent
sinking on a soft bearing surface.
•If the pump is used at the same location for a longer period of
time, bolt the pump support foot to the floor. This reduces vi-
brations and enables quiet operation.
1
6
5
3
4
2
OFF!
S1
S2, S3
Fig.5: Portable wet well installation
1 Pump support foot
2 Pipe elbow with hose connection or Storz fixed coupling
3 Storz hose coupling
4 Pressure hose
5 Lifting equipment
6 Attachment point
✓Place of use prepared.
✓Pump support foot mounted.
✓Discharge connection prepared: Hose connection or Storz
coupling fitted.
✓Soft bearing surface: solid surface available.
1. Use a shackle to attach the lifting equipment to the attach-
ment point on the pump.
2. Lift and align the pump at the installation location.
3. Place the pump on a firm bearing surface. Avoid sinking!
4. Secure the pump against moving and falling over: Bolt the
pump support foot to the floor.
5. Lay the pressure hose and fasten it properly at the appropriate
place (e.g. drainage).
6. Correctly route the connection cables. CAUTION!Do not
damage the connection cables!
- No chafing or kinking.
- Do not immerse the cable end in the fluid.
- Observe the bending radii.
▶Pump installed, make the electrical connection.
6.4.5 Level control
The “A” version is equipped with a float switch. The pump is
switched on and off depending on the fill level. The switching level
is determined by the cable length of the float switch.
Observe the following points during installation:
•Float switch must be able to move freely!
•The minimum permissible water level is not fallen short of!
•The maximum switching frequency is not exceeded!
In order to achieve larger switching differences in case of
strongly fluctuating fill levels, provide a level control with two
measuring points.

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Installation and operating instructions • Wilo-Rexa FIT-S • Ed.01/2022-03 13
6.4.6 Dry-running protection
Dry-running protection prevents the pump from being operated
without fluid and air from entering the hydraulics. For this purpose,
the minimum permissible fill level is monitored using an external
control. When the minimum fill level is reached, the pump is
switched off. Furthermore, depending on the control, a visual and
acoustic alarm is triggered.
The dry-running protection can be integrated into existing con-
trols as an additional measuring point. Alternatively, the dry-run-
ning protection can also work as a stand-alone shut-off device.
Depending on the system security, the pump can be restarted au-
tomatically or manually.
Installation of dry-running protection is recommended for op-
timum operational reliability.
6.5 Electrical connection
DANGER
Risk of fatal injury due to electrical current!
Improper conduct when carrying out electrical work
can lead to death due to electric shock!
• Electrical work must be carried out by a qualified
electrician!
• Observe local regulations!
•Mains connection corresponds to the information on the rating
plate.
•Power supply on mains side with clockwise rotating field for
three-phase AC motors (3~ motor).
•Route the connection cables according to the local regulations
and connect them according to the wire assignment.
•Connect all of the monitoring devices and check their function.
•Secure the earthing in accordance with the local regulations.
6.5.1 Fuse on mains side
Circuit breaker
The size and switching characteristics of the circuit breakers must
conform to the rated current of the connected product. Observe
local regulations.
Motor protection switch
Make provision for an on-site motor protection switch for devices
without a plug! The minimum requirement is a thermal relay/motor
protection switch with temperature compensation, differential
triggering and anti-reactivation device in accordance with the local
regulations. In case of sensitive mains, make provision for the in-
stallation on-site of other protective equipment (e.g. overvoltage,
undervoltage or phase failure relay, etc.).
Residual-current device (RCD)
•Install a residual-current device (RCD) in accordance with the
regulations of the local energy supply company.
•If people can come into contact with the device and conductive
fluids, install a residual-current device (RCD).
6.5.2 Maintenance tasks
•Check the insulation resistance of the motor winding.
•Check the resistance of the temperature sensors.
6.5.2.1 Checking the insulation resistance of the motor wind-
ing
✓Insulation tester 1000V
✓Motors with capacitor: Short-circuited windings!
1. Check the insulation resistance.
⇒Measured value at initial commissioning: ≥20MΩ.
⇒Measured value at interval measurement: ≥2MΩ.
▶Insulation resistance checked. If the measured values devi-
ate from the specifications, consult the customer service.
6.5.2.2 Test the resistor of the temperature sensor
✓Ohmmeter available.
1. Measure the resistance.
⇒Measured value Bimetallic strip: 0ohms (passage).
▶Resistance checked. If the measured value deviates from
the specification, consult the customer service.
6.5.3 Connection single-phase AC motor (1~motor)
bn
bu
Cr
Cs
M 1~
gn-ye
U1/Z1
bn
U2
bk
Z2
gy
gn-ye
LNPE
Fig.6: Connection diagram 1~ motor
Wire colour Terminal
Brown (bn) L
Blue (bu) N
Green/yellow (gn-ye) Earth
The pump is equipped with a plug (CEE 7/7). Connection to the
mains is established by inserting the plug into the socket (type E or
type F). The plug is not watertight.
Bimetallic strips are installed in the motor in addition to the capa-
citor box for thermal motor monitoring. The motor monitoring is
self-switching. Separate connection is not possible.
If the pump is directly connected to the switchgear, cut off the
plug. Connect the connection cable according to the connection
diagram in the switchgear.

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14 Installation and operating instructions • Wilo-Rexa FIT-S • Ed.01/2022-03
6.5.4 Connection of the three-phase AC motor (3~ motor)
W
5
1 2
V
4
U
3
M 3~
gn-ye
L3L2 2120L1PE
250 V (AC); 2,5 A
cos φ = 1
Fig.7: Connection diagram 3~ motor
Wire number Name Terminal
1 20 WSK
2 21 WSK
3 U L1
4 V L2
5 W L3
Green/yellow (gn-ye) Earth PE
•Connection cable with bare cable ends.
•Connection in the switchgear according to the connection dia-
gram.
•Mains connection with clockwise-rotating field
•Thermal motor monitoring:
–Sensor: Bimetallic strip
–Number of temperature circuits: 1, temperature limiter
–Connection values: max. 250V(AC), 2.5A, cosphi=1
–Threshold value: is set by sensor.
–Triggering status: If the threshold value is reached, switch
off the pump!
6.5.5 Optional equipment
Information on electrical accessory connection or possible special
configurations. Please refer to the order confirmation or configura-
tion overview for details on the special configuration.
6.5.5.1 Connection external pencil electrode
CAUTION
Trigger status for sealing chamber monitor-
ing
The pencil electrode detects water ingress into the
sealing chamber. The threshold value is reached
when a certain amount of water is present in the oil.
An alarm is triggered or the pump is switched off via
the evaluation relay:
• The pump may be a total loss if only an alarm oc-
curs.
• Recommendation: Always switch off the pump!
The connection must be made via an evaluation relay (e.g.
“NIV101/A”):
•Sensor: Electrode
•Connection values: max. 250V(AC), 2.5A, cosphi=1
•Threshold: 30kOhm
•Triggering status: If the threshold value is reached, trigger the
alarm or switch off the pump!
6.5.6 Motor protection adjustment
6.5.6.1 Direct activation
•Full load
Set the motor protection to the rated current according to the
rating plate.
•Partial load operation
Set the motor protection to 5% above the current measured at
the duty point.
6.5.6.2 Soft starter
•Full load
Set the motor protection to the rated current according to the
rating plate.
•Partial load operation
Set the motor protection to 5% above the current measured at
the duty point.
Please observe the following points:
•Current consumption must always be below the rated current.
•Complete starting and stopping within 30s.
•To avoid power dissipation, bypass the electronic starter (soft
start) once normal operation is reached.
6.5.7 Operation with frequency converter
Operation on the frequency converter is not permitted.
7 Commissioning
NOTICE
Automatic activation after power cut
Depending on the process, the product is switched
on and off using separate controls. The product may
automatically switch on following power cuts.
7.1 Personnel qualifications
•Operation/control: Operating personnel, instructed in the func-
tioning of the complete system
7.2 Operator responsibilities
•Providing installation and operating instructions by the pump or
at a place specially reserved for it.
•Making the installation and operating instructions available in
the language of the personnel.
•Making sure that the installation and operating instructions are
read and understood by all personnel.
•All safety devices and emergency cut-outs on the system-side
must be active and checked to ensure that they work properly.
•The pump is suitable for use under the specified operating con-
ditions.
7.3 Direction of rotation check for three-phase AC motor
The pump has been checked and adjusted to the correct direction
of rotation at the factory. To allow the correct direction of rota-
tion, a clockwise rotating field must be available at the mains con-
nection. The pump is not approved for operation with a counter-
clockwise rotating field!

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Installation and operating instructions • Wilo-Rexa FIT-S • Ed.01/2022-03 15
•Check the direction of rotation.
Check the rotating field at the mains connection with a rotat-
ing-field testing device.
•Correct the direction of rotation.
If the direction of rotation is incorrect, change the connection
as follows:
–Direct starting: swap two phases.
–Star-delta starting: Swap the connections of two windings
(e.g. U1/V1 and U2/V2).
7.4 Before switching on
Check the following prior to activation:
•Has the electrical connection been carried out in accordance
with regulations?
•Has the connection cable been routed safely?
•Can the float switch move freely?
•Accessories attached correctly?
•Temperature of the pumped fluid observed?
•Immersion depth observed?
•Are the pressure pipe and pump sump free of deposits?
•All gate valves in the pressure pipe open?
•Are ventilation systems present in the pressure pipe?
Air pockets in the pump and in the pressure pipe can lead to de-
livery problems.
7.5 Switching on and off
•When the pump starts, the rated current is exceeded for a short
time.
•During operation, do not exceed the rated current any more.
CAUTION!Material damage! If the pump does not start, switch
off the pump immediately. Motor failure! Remove the fault first
before reactivation.
Observe the following points for transportable installation:
•Place the pump on a firm bearing surface. Avoid sinking!
•If the pump has fallen over, place it upright again before activ-
ating it.
•If the pump “moves away”, screw the pump to the ground.
Pump with attached float switch and plug
•Single-phase AC version (1~ motor)
Insert the plug into the socket, the pump is ready for operation.
The pump is controlled via two switches on the capacitor box:
–HAND/AUTO: Set the operating mode.
HAND: Switch the pump on and off manually. AUTO: Switch
the pump on and off automatically depending on the fill
level.
–ON/OFF: Switch the pump on and off in operating mode
“HAND”.
Pump with attached plug
•Single-phase AC version (1~ motor):
Insert the plug into the socket, the pump is ready for operation.
Switch the pump on and off with the ON/OFF switch on the ca-
pacitor switchgear.
Pump with bare cable end
The pump is switched on and off using a separate operating point
(on/off switch, switchgear) provided by the customer.
7.6 During operation
WARNING
Risk of injury from rotating components!
No persons are allowed to be present in the working
area of the pump. There is a risk of injury!
• Demarcate and cordon off the working area.
• If there are no persons in the working area, activ-
ate the pump.
• If persons enter the working area, switch off the
pump immediately.
WARNING
Risk of burns from hot surfaces!
Motor housing can become hot during operation. It
may cause burns.
• Allow the pump to cool down at ambient tem-
perature after switching it off!
CAUTION
Do not allow the pump to dry run!
Dry running of the pump is prohibited. When the
minimum delivery level is reached, switch off the
pump. Dry running may destroy the seal and cause
the pump to be irreparably damaged.
NOTICE
Cleaning cloths and wipes can cause clogging
in the macerator!
To prevent cleaning cloths and wipes in the fluid,
mechanically pre-clean the incoming fluid.
NOTICE
Pumping problems due to water level being
too low
The hydraulics are self-venting. Smaller air cushions
are resorbed during pumping. If the fluid is lowered
too much, separation of the volume flow may occur.
The minimum permissible water level must reach the
upper edge of the hydraulics housing!
Please regularly check the following points:
•Inlet quantity corresponds to the pump delivery rate.
•The level control device and dry-running protection work cor-
rectly.
•Minimum water submersion ensured.
•Connection cable is not damaged.
•Pump free from deposits and encrustations.
•No air intake in the pumped fluid.
•All gate valves open.
•Quiet and low-vibration running.
•Max. switching frequency not exceeded.

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16 Installation and operating instructions • Wilo-Rexa FIT-S • Ed.01/2022-03
•Mains connection tolerances:
–Operating voltage: +/-10%
–Frequency: +/- 2%
–Current consumption between the individual phases: max.
5%
–Voltage difference between the individual phases: max.1%
NOTICE
Emerge the motor during operation
• If the motor is emerged during operation, ob-
serve the “operating mode non-immersed”! See
indication “OTE” on the rating plate!
• Ensure cooling of the motor for continuous duty:
The motor must be completely immersed before
reactivation!
Operating mode S310%: Operating mode S325% is permitted if
the necessary motor cooling is ensured before reactivation! To en-
sure the required cooling, the motor must be completely immersed
for at least 1min!
8 Shut-down/dismantling
8.1 Personnel qualifications
•Operation/control: Operating personnel, instructed in the func-
tioning of the complete system
•Electrical work: qualified electrician
Person with appropriate technical training, knowledge and ex-
perience who can identify and prevent electrical hazards.
•Installation/dismantling work: trained sewage technology pro-
fessional
Fixation and pipework in wet well and dry well installation, lift-
ing equipment, basic knowledge of wastewater facilities
8.2 Operator responsibilities
•Locally applicable accident prevention and safety regulations of
trade associations.
•Observe regulations for working with heavy loads and under
suspended loads.
•Provide the necessary protective equipment and make sure that
the personnel wears it.
•Provide adequate aeration in closed rooms.
•Take immediate countermeasures if there is a build-up of toxic
or suffocating gases!
8.3 Shut-down
The pump is deactivated, but remains installed. This ensures that
the pump is always ready for operation.
✓Completely immerse the pump in the fluid to protect the
pump from frost and ice.
✓Minimum fluid temperature: +3°C (+37°F).
1. Switch off the pump.
2. Secure the operating point against being switched on again by
unauthorised persons (e.g. lock main switch).
▶The pump is decommissioned.
If the pump remains installed after decommissioning, observe the
following points:
•Ensure that the aforementioned requirements are maintained
for the complete period of shutdown. Remove the pump if
meeting these requirements cannot be guaranteed!
•For an extended period of shutdown, carry out a function test at
regular intervals:
–Period: monthly to quarterly
–Running time: 5minutes
–Only run a function test in valid operating conditions!
8.4 Removal
DANGER
Danger due to fluids which are hazardous to
health!
Danger of bacterial infection!
• Disinfect the pump after removal!
• Observe the specifications of the work regula-
tions!
DANGER
Risk of fatal injury due to electrical current!
Improper conduct when carrying out electrical work
can lead to death due to electric shock!
• Electrical work must be carried out by a qualified
electrician!
• Observe local regulations!
DANGER
Risk of fatal injury due to dangerous lone
working practices!
Work in chambers and narrow rooms as well as work
involving risk of falling are dangerous work. Such
work may not be carried out autonomously!
• Only carry out work with another person!
WARNING
Risk of burns from hot surfaces!
Motor housing can become hot during operation. It
may cause burns.
• Allow the pump to cool down at ambient tem-
perature after switching it off!
Wear the following protective equipment while performing the
work:
•Safety shoes: Protection class S1 (uvex 1 sport S1)
•Protective gloves: 4X42C (uvex C500 wet)
•Safety helmet: EN397 Conforms to standards, protection
against lateral deformation (uvex pheos)
(When using lifting equipment)
If contact with hazardous fluid occurs during work, wear the fol-
lowing additional protective equipment:
•Safety goggles: uvex skyguard NT
–Labelling frame: W 166 34 F CE
–Labelling disc: 0-0.0* W1 FKN CE

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Installation and operating instructions • Wilo-Rexa FIT-S • Ed.01/2022-03 17
•Breathing protection: Half mask 3M series 6000 with filter 6055
A2
The protective equipment specified is the minimum requirement.
Observe the specifications of the work regulations!
* Protection level according to EN170 not relevant for this work.
8.4.1 Stationary wet well installation
✓Pump is decommissioned.
✓Gate valves on the inlet and pressure sides are closed.
1. Disconnect the pump from the mains.
2. Attach the lifting equipment to the attachment point.
3. Slowly raise the pump and lift it over the guide pipes out of
the operating space. CAUTION!Do not damage the connec-
tion cable! Hold the connection cables slightly taut when
lifting!
4. Coil up the connection cables and attach them to the motor.
- Do not kink.
- Do not crush.
- Observe the bending radii.
5. Thoroughly clean the pump (see section “Cleaning and disin-
fecting”).
8.4.2 Portable wet well installation
✓Pump has been decommissioned.
1. Disconnect the pump from the mains.
2. Coil up the connection cables and attach them to the motor.
- Do not kink.
- Do not crush.
- Observe the bending radii.
3. Loosen the pressure pipe from the pressure port.
4. Attach the lifting equipment to the attachment point.
5. Lift the pump out of the operating space. CAUTION!Do not
damage the connection cable! Pay attention to the connec-
tion cable when setting down the pump!
6. Thoroughly clean the pump (see section “Cleaning and disin-
fecting”).
8.4.3 Clean and disinfect
•Wear protective equipment! Observe the work regulations.
–Safety shoes: Protection class S1 (uvex 1 sport S1)
–Breathing protection: Half mask 3M series 6000 with filter
6055 A2
–Protective gloves: 4X42C + Type A (uvex protector chemical
NK2725B)
–Safety goggles: uvex skyguard NT
•Use of disinfectants:
–Use strictly according to the manufacturer’s instructions!
–Wear protective equipment according to the manufacturer’s
instructions!
•Dispose of rinsing water in accordance with the local regula-
tions, e.g. feed it into the sewer!
✓Pump removed.
1. Ensure that the plug or bare cable ends are packed and stored
in a watertight manner!
2. Attach the lifting equipment to the attachment point on the
pump.
3. Lift the pump approximately 30cm (10in) above the ground.
4. Spray the pump with clean water from top to bottom.
5. Guide the water jet inwards through the discharge port to
clean the impeller and pump interior.
6. Disinfect the pump.
7. Dispose of dirt residue on the ground, e.g. flush it into the
sewer.
8. Allow the pump to dry out.
9 Maintenance and repair
9.1 Personnel qualifications
•Electrical work: qualified electrician
Person with appropriate technical training, knowledge and ex-
perience who can identify and prevent electrical hazards.
•Maintenance work: trained sewage technology professional
Application/disposal of operating fluids used, basic engineering
knowledge (installation/dismantling)
9.2 Operator responsibilities
•Provide the necessary protective equipment and make sure that
the personnel wears it.
•Collect operating fluids in suitable tanks and dispose of prop-
erly.
•Dispose of protective clothing used in accordance with regula-
tions.
•Use only original parts of the manufacturer. The use of any non-
original parts releases the manufacturer from any liability.
•Collect any leakage of fluid and operating fluid immediately and
dispose of it according to the locally applicable guidelines.
•Provide the tools required.
•If flammable solvents and cleaning agents are used, fire, naked
flames and smoking are prohibited.
•Document maintenance tasks in the system’s inspection list.
9.3 Operating fluid
9.3.1 Oil types
•ExxonMobile: Marcol52
•ExxonMobile: Marcol82
•Total: FinavestanA80B (NSF-H1 certified)
9.3.2 Filling quantities
The filling quantity is 900ml (30US.fl.oz).
9.4 Maintenance intervals
•Regularly carry out maintenance tasks.
•Contractually adjust maintenance intervals depending on the
actual environmental conditions. Contact customer service.
•If strong vibrations occur during operation, check the installa-
tion.
9.4.1 Maintenance intervals for normal conditions
1500operating hours or after 5years
•Visual inspection of the connection cables
•Visual inspection of accessories
•Visual inspection of the coating and housing
•Function test of monitoring devices
•
Sealing chamber oil changeNOTICE!If a sealing chamber mon-
itoring is installed, the oil is changed according to the indic-
ator!
5000operating hours or after 10years
•Complete overhaul

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18 Installation and operating instructions • Wilo-Rexa FIT-S • Ed.01/2022-03
9.4.2 Maintenance intervals for use in sewage lifting units
When the pump is used in sewage lifting units inside buildings or
on plots of land, carry out maintenance intervals and measures in
accordance with DINEN12056‑4!
9.4.3 Maintenance intervals for harsh conditions
Under the following operating conditions, shorten the specified
maintenance intervals in consultation with the customer service:
•Fluids with long-fibre components
•Turbulent inlet (e.g. due to air entry, cavitation)
•Highly corrosive or abrasive fluids
•Strongly gassing fluids
•Operation at an unfavourable duty point
•Pressure surges
If there are harsh operating conditions, it is recommended to con-
clude a maintenance contract.
9.5 Maintenance measures
WARNING
Risk of injury from sharp edges on the cut-
ting device!
The macerator has extremely sharp edges. In addi-
tion, sharp edges can form on the suction port.
There is a danger of cuts!
• Wear protective gloves!
• Do not touch the macerator!
Before starting maintenance work, meet the following require-
ments:
•Wear protective equipment! Observe the work regulations.
–Safety shoes: Protection class S1 (uvex 1 sport S1)
–Protective gloves: 4X42C (uvex C500 wet)
–Safety goggles: uvex skyguard NT
For detailed marking of frame and disc, see the section on “Per-
sonal protective equipment [}5]”.
•The pump has been thoroughly cleaned and disinfected.
•Motor must have cooled down to the ambient temperature.
•Workplace:
–Clean, good lighting and ventilation.
–Firm and stable work surface.
–Secured against falling over and slipping.
NOTICE!Only perform the maintenance work described in these
installation and operating instructions.
9.5.1 Recommended maintenance measures
Regular inspection of power consumption and the operating
voltage in all three phases is recommended for smooth operation.
In normal operation, these values remain constant. Slight fluctu-
ations depend on the characteristics of the fluid. Power consump-
tion can provide an early indication of damage or malfunctions in
the impeller, bearings or motor, which can be rectified. Larger
voltage fluctuations strain the motor winding and can cause the
pump to break down. Regular inspections can therefore largely
prevent major secondary damage and reduce the risk of total
breakdown. In this regard, it is recommended to use remote monit-
oring for regular inspections.
9.5.2 Visual inspection of the connection cable
Check connection cable for:
•Bubbles
•Cracks
•Scratches
•Abrasion
•Pinch points
If the connection cable is damaged:
•Decommission the pump immediately!
•Have the connection cable replaced by the customer service!
CAUTION!Material damage! Damaged connection cables cause
water to enter the motor. Water in the motor leads to total
damage of the pump.
9.5.3 Visual inspection of accessories
Accessories must be checked for:
•Correct fixation
•Smooth function
•Signs of wear, e.g. cracks caused by frequencies
Any defects detected must be repaired immediately or the ac-
cessories must be replaced.
9.5.4 Visual inspection of the coatings and housings
Coatings and housings must not show any damage. If there are de-
fects, observe the following:
•Repair damaged coating. Order repair kits from the customer
service.
•If housings are worn out, consult the customer service!
9.5.5 Function test of the monitoring device
To test resistances, the pump must be cooled down to the ambient
temperature!
9.5.5.1 Test the resistor of the temperature sensor
✓Ohmmeter available.
1. Measure the resistance.
⇒Measured value Bimetallic strip: 0ohms (passage).
▶Resistance checked. If the measured value deviates from
the specification, consult the customer service.
9.5.5.2 Testing the resistor of the external electrode for seal-
ing chamber control
✓Ohmmeter available.
1. Measure the resistance.
⇒Measured values “infinite (∞)”: Monitoring device OK.
⇒Measured value ≤30kOhm: Water in oil. Change oil.
▶Resistance checked. If the measured value still deviates
after the oil change, consult customer service.

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Installation and operating instructions • Wilo-Rexa FIT-S • Ed.01/2022-03 19
9.5.6 Oil change in sealing chamber
WARNING
Operating fluid under pressure!
High pressure can build up in the motor! This pres-
sure is released when the screw plugs are opened.
• If screw plugs are opened without due caution,
they can be ejected at high speed!
• Hot operating fluid may spray out!
– Wear protective equipment!
– Allow the motor to cool down to ambient
temperature before carrying out any work!
– Adhere to the prescribed sequence of work
steps!
– Unscrew the screw plugs slowly.
– As soon as the pressure escapes (audible
whistling or hissing of air), stop turning the
screw plug any further!
– Only when the pressure has been completely
released, fully unscrew the screw plug.
+/-
Fig.8: Sealing chamber: Oil change
+/- Sealing chamber screw plug
✓Protective equipment used!
✓Pump has been removed, cleaned and disinfected.
1. Place the pump on a firm work surface in a horizontal position.
The screw plug should face upwards.
2. Secure the pump against falling over and slipping!
3. Unscrew the screw plug slowly.
4. When the pressure has been released, completely unscrew the
screw plug.
5. Position a suitable tank to collect the operating fluid.
6. Drain the operating fluid: Rotate the pump until the opening
points downwards.
7. Check the operating fluid:
⇒Operating fluid clear: Operating fluid can be reused.
⇒Operating fluid contaminated (black): fill with new operat-
ing fluid.
⇒Operating fluid milky/cloudy: Water in oil. Minor leakage
through the mechanical seal is normal. If the ratio of oil to
water is less than 2:1, the mechanical seal may be dam-
aged. Change the oil and check again four weeks later. If
water is again present in the oil during the second check,
contact customer service!
⇒Metal chips in the operating fluid: Contact the customer
service!
8. Pour in operating fluid: Rotate the pump until the opening
points upwards. Pour the operating fluid into the opening.
⇒Comply with the specifications for the operating fluid type
and quantity!
9. Clean the screw plug, replace the seal ring and screw it back
in. Max. tightening torque: 8Nm (5.9ft·lb)!
9.5.7 General overhaul
During the general overhaul, the motor bearings, shaft sealings, O-
rings and connection cables are checked for wear and damage.
Damaged components are replaced with original parts. This en-
sures correct operation.
The general overhaul is performed by the manufacturer or an au-
thorised service centre.
9.6 Repairs
WARNING
Risk of injury from sharp edges on the cut-
ting device!
The macerator has extremely sharp edges. In addi-
tion, sharp edges can form on the suction port.
There is a danger of cuts!
• Wear protective gloves!
• Do not touch the macerator!
The following preconditions must be met prior to starting repair
work:
•Wear protective equipment! Observe the work regulations.
–Safety shoes: Protection class S1 (uvex 1 sport S1)
–Protective gloves: 4X42C (uvex C500 wet)
–Safety goggles: uvex skyguard NT
For detailed marking of frame and disc, see the section on “Per-
sonal protective equipment [}5]”.
•The pump has been thoroughly cleaned and disinfected.
•Motor must have cooled down to the ambient temperature.
•Workplace:
–Clean, good lighting and ventilation.
–Firm and stable work surface.
–Secured against falling over and slipping.
NOTICE!Only carry out the repair work described in these in-
stallation and operating instructions.
For repair work, the following applies:
•Wipe up spillage quantities of fluid and operating fluid immedi-
ately!
•Always replace O-rings, gaskets and screw locking devices!
•Observe the tightening torques in the appendix!
•The use of force is strictly prohibited!
9.6.1 Instructions on using screw locking devices
A screw locking device can be used on the screws. Screw locking is
done at the factory using two different methods:
•Thread-locking fluid

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20 Installation and operating instructions • Wilo-Rexa FIT-S • Ed.01/2022-03
•Mechanical screw locking device
Always re-apply the screw locking device!
Thread-locking fluid
Medium-strength thread-locking fluid (e.g. Loctite243) is used for
the liquid screw locking compound. This threadlocker can be
loosened with increased force. If the thread-locking fluid cannot
be loosened, then the compound must be heated to approx. 300°C
(572°F). Clean the components thoroughly after dismantling.
Mechanical screw locking device
The mechanical screw locking device consists of two Nord-Lock
wedge lock washers. The screw connection is secured by the
clamping force. The Nord-Lock screw locking device must only be
used on bolts with strength class 10.9 which have been coated
with Geomet. The use of stainless screws is prohibited!
9.6.2 Replace macerator
A
B
1
2
3
4
4
45
Fig.9: Replacing the macerator
A Overview: View from below
B Detail view: Macerator with fixation
1 Macerator
2 Cutting plate
3 Cutting head
4 Cutting plate fixation M6
5 Cutting head fixation M8
✓Wear protective glove!
✓Pump cleaned and disinfected if necessary.
✓Hexagon socket with T-handle, sizes 5 and 6.
✓Torque wrench.
✓Wedge (width: approx. 10...15mm) made of hardwood or
plastic to secure the cutting head.
CAUTION!Do not use a metal wedge! A metal wedge can
damage the blades.
✓Liquid thread-locking fluid, medium strength (e.g. Loctite
243).
1. Secure the cutting head: Insert wedge between cutting head
and cutting plate.
2. Loosen and remove fastening screw on cutting head.
3. Remove wedge.
4. Pull off cutting head. WARNING!Cut injury! Do not touch
cutting head on cutting blade!
5. Fit new cutting head.
6. Wet fastening screw with thread-locking fluid and screw it
into cutting head. Tighten the fastening screw hand-tight.
7. Secure the cutting head: Insert wedge between cutting head
and cutting plate.
CAUTION!Tighten fastening screw hand-tight before in-
serting wedge! The wedge can displace the cutting head.
8. Tighten fastening screw on cutting head to 18.5Nm (13.5 ft
lb).
9. Remove wedge.
10. Loosen and unscrew cutting plate fastening screws.
11. Carefully lever out cutting plate with wedge.
12. Remove cutting plate. WARNING!Cut injury! Do not touch
cutting plate on blade!
13. Insert new cutting plate.
14. Wet cutting plate fastening screws with thread-locking fluid
and screw in.
15. Tighten cutting plate fastening screws crosswise to 7.5Nm
(5.5 ft lb).
▶Macerator changed.
NOTICE!Observe drying time! Allow the thread-locking fluid to
dry before using the pump.
10 Faults, causes and remedies
WARNING
Risk of injury from rotating components!
No persons are allowed to be present in the working
area of the pump. There is a risk of injury!
• Demarcate and cordon off the working area.
• If there are no persons in the working area, activ-
ate the pump.
• If persons enter the working area, switch off the
pump immediately.
Fault: Pump does not start
1. Electricity supply interrupted or short-circuit/earth fault in the
cable or motor winding.
⇒Have the connection and motor checked by a qualified
electrician and replace if necessary.
2. Tripping of fuses, of the motor protection switch or the mon-
itoring device
⇒Have the connection and the monitoring device checked by
a qualified electrician and change it if necessary.
⇒Have the motor protection switches and fuses installed and
adjusted according to the technical specifications by a
qualified electrician and reset monitoring device.
⇒Check the impeller to make sure that it runs smoothly,
clean the hydraulics if necessary.