Wilo Rexa CUT, Installation And Operating Instructions Manual, Page: 52 / 384

52 WILO SE 11-2014 V05 DIN A4
English MAINTENANCE AND REPAIR
8.3.2. Visual inspection of accessories
Accessories must be checked to ensure they are
properly fitted and function correctly. Loose and/
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 sen-
sors in the motor, humidity electrodes, overload
relay, overvoltage relay, etc.
• Motor protection, overvoltage relay and other
triggers can generally 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 follow -
ing values should be measured:
• Bimetallic strip: Value = “0” passage
• Pencil electrode: This value must approach
infinity. If the value is low, there is water in the
oil. Also observe the instructions of the option-
al evaluation relay.
If there are larger deviations, consult the man-
ufacturer.
8.3.5. Inspection of the switchgear/relays used
See the relevant installation and operating in-
structions for a description of the individual work
steps for inspecting the switchgear/relay. 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.
RISK of injury from hot and/or pressurised oil!
After the pump is switched off, the oil is still
hot and pressurised. 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.
Fig. 7.: Screw plugs
1 Screw plug
1. Position the pump horizontally on a firm surface
with the screw plug facing upward.
Make sure that the pump cannot fall over and/
or slip!
2. Carefully and slowly unscrew the screw plug.
Attention: the oil may be pressurised! This can
cause the screw to be ejected at speed.
3. Empty out oil by rotating the pump until the hole
points downwards. Collect the oil in a suitable
container and dispose of it in accordance with the
requirements in the "Disposal" chapter.
4. Rotate the pump back until the hole is pointing
upwards again.
5. Pour the new oil in through the hole for the screw
plug. The oil should reach up to about 1 cm below
the hole. Note the recommended oils and filling
quantities.
6. Clean the screw plug, replace the joint ring and
screw it back in.
8.3.7. General overhaul (motor version "P" only)
In a general overhaul, the normal maintenance
work is carried out and in addition the motor
bearings, shaft seals, O-rings and power supply
cables are checked and replaced, if necessary.
This work may be performed only by the manu -
facturer or an authorised service workshop.
8.4. Repairs
Before carrying out repairs:
• Disconnect pump from power supply (disconnect
from mains network).
• Allow the pump to cool down and clean it thor-
oughly.
• Place the pump on a firm surface and secure it
against slipping.
• Always replace O-rings, seals and screw locking
devices (spring lock washers, Nord-Lock wash -
ers).
• Note and comply with the specified tightening
torques in the appendix and in the individual work
steps.
• Never use force when carrying out this work!
8.4.1. Readjusting the macerator
BEWARE of the macerator!
The pump is equipped with a macerator. When
coming into contact with the blade, limbs
may be crushed or be amputated! Never reach
directly into the macerator. Wear the correct
protective gloves when working on the unit!
Internal macerator (CUT GI)
Normally, the gap between the cutting plate and
rotating blade is 0.1 mm. If the gap is larger, the
cutting performance may decline and clogging
may increase. In this case, the gap needs to be
readjusted.
Fig. 8.: Overview of macerator
1...4 Grub screw 7 Rotating blade
5 Cylinder head screw 8 Pressure connection
6 Cutting plate