Maintenance Work - Wilo -Rexa PRO series Einbau- Und Betriebsanleitung

US English
15000 operating hours or after 10 years at the
latest
• General overhaul
8.2.2. Intervals for harsh operating conditions
Under harsh operating conditions, the specified
maintenance intervals must be shortened accord-
ingly. In this case, please contact Wilo customer ser-
vice. If using the pump under harsh conditions, we
also recommend signing a maintenance contract.
Harsh operating conditions include:
• A large proportion of fibrous material or sand in the
fluid
• Turbulent intake (e.g. due to air entry, cavitation)
• Strongly corrosive fluids
• Strongly gassing fluids
• Unfavorable duty points
• Operating states subject to water hammer
8.2.3. Recommended maintenance measures to ensure
smooth operation
We recommend regular inspections of the cur-
rent consumption and the operating voltage in all
3 phases. In normal operation, these values remain
constant. Slight fluctuations may occur depending
on the characteristics of the fluid. The current con-
sumption can provide an early indication of damage
and/or malfunctions in the impeller, bearings, and/
or motor, which can be rectified. Large 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. We rec-
ommend the use of remote monitoring for regular
inspections. Please contact Wilo customer service.

8.3. Maintenance work

Before carrying out maintenance work:
• Disconnect the pump from the power supply and
secure it against being switched on inadvertently.
• Allow the pump to cool down and clean it thor-
oughly.
• Make sure that all the operationally relevant parts
are in good condition.
8.3.1. Visual inspection of the power supply cable
The power supply cables must be checked for
blisters, cracks, scratches, abrasion and/or crushing.
If any damage is detected, the pump must be de-
commissioned immediately and the damaged power
supply cable must be replaced.
The cables may only be replaced by Wilo custom-
er service or an authorized or certified service
workshop. The pump may only be started up again
once the damage has been properly remedied.
8.3.2. Visual inspection of accessories
Accessories must be checked to ensure they are
properly fitted and function correctly. Loose and/
26
MAINTENANCE AND REPAIR
or faulty accessories must be repaired or replaced
immediately.
8.3.3. Visual inspection of coating and housing for wear
The coatings and housing parts must not show any
signs of damage. If there is visible damage to the
coatings, repair the coating accordingly. If there
is visible damage to housing parts, contact Wilo
customer service.
8.3.4. Functional inspection of safety and monitoring
devices
Monitoring devices include the temperature sensors
in the motor, humidity electrodes, overload relay,
overvoltage relay, etc.
• Motor protection and overvoltage relays and other
triggers can usually be triggered manually for test
purposes.
• To check the pencil electrode or the temperature
sensor, the pump has to be cooled to the ambient
temperature and the electrical connection for the
monitoring equipment has to be disconnected in
the switchgear. The monitoring equipment can then
be checked with an ohmmeter. The values mea-
sured should be as follows:
• Bimetallic strip: Value = "0" passage
• PTC thermistor sensor: A PTC thermistor sensor
has a cold resistance of between 20 and 100 Ω.
If there are 3 sensors in series, this results in a
value of 60 to 300 Ω.
If there are 4 sensors in series, this results in a
value of 80 to 400 Ω.
• Pencil electrode: This value must approach infini-
ty. If the value is low, there is water in the oil. Also
observe the instructions of the optional evalua-
tion relay.
If there are relatively large deviations, consult the
manufacturer.
8.3.5. Inspection of the switchgear/relays used
See the relevant installation and operating instruc-
tions for a description of the individual work steps
for inspecting the switchgear/relays. Faulty devices
must be replaced immediately as they provide no
protection to the pump.
8.3.6. Oil change in sealing chamber
The sealing chamber has a hole for draining and
filling the chamber.
WARNING: risk of injury from hot and/or pres-
surized oil!
After the pump is switched off, the oil is still hot
and pressurized. This can cause the screw plug
to be ejected and hot oil to escape. There is a
risk of injury or burns! First allow the oil to cool
down to ambient temperature.
WILO SE 2014-11 V05 Letter