Wilo -EMU TR 50-2 Serie Notice De Montage Et De Mise En Service page 320

en
9.5.3 Visual inspection of cable brack-
ets and cable tensioning
9.5.4 Visual inspection for wear of the
mixer
9.5.5 Function test of the monitoring
device
9.5.5.1 Test the resistor of the temper-
ature sensor
9.5.5.2 Check the resistance of the ex-
ternal electrode for pre-chamber
monitoring
9.5.6 Visual inspection of accessories
9.5.7 Oil change
320
Maintenance and repair
CAUTION! Water can enter into the mixer if the connection cable is damaged! Water
ingress leads to the mixer being written off.
Check cable brackets and anchoring of the connection cable (lifting equipment or sep-
arate nylon rope) for material fatigue or shrinkage. If there are signs of wear, replace the
faulty components immediately.
Inspect individual components (propeller, hub, etc.) for damage and wear. If there are
defects, observe the following:
▪ If the coating is damaged, restore it.
▪ If components have worn, contact customer service and replace the components in
question!
The mixer must be cooled down to ambient temperature to test resistances!
Measure the resistor of the temperature sensors with an ohmmeter. The following
measured values must be complied with:
▪ Bimetallic strip: Measured value = 0 Ohm (passage).
▪ PTC sensor (PTC thermistor): Measured value depends on the number of sensors in-
stalled. At PTC sensor has a cold resistance of between 20 and 100 Ohm.
– With three sensors in series, the measured value is between 60 und 300 Ohm.
– With four sensors in series, the measured value is between 80 und 400 Ohm.
Measure the resistor of the electrode with an ohmmeter. The measured value must ap-
proach "infinity". For values ≤ 30 kOhm, if there is water in the oil – change the oil!
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 accessories must be re-
placed.
WARNING
Operating fluid under high pressure!
A pressure of several bar can build up in the motor! This pressure escapes when the
screw plugs are opened. If screw plugs are opened without due caution, they can be
ejected at high speed! To avoid injuries, observe the following instructions:
• Adhere to the prescribed sequence of work steps.
• Unscrew the screw plugs slowly, but never unscrew them completely. As soon
as the pressure escapes (audible whistling or hissing of air), stop turning the
screw plug any further!
• When the pressure has completely dissipated, fully unscrew the screw plugs.
• Wear closed safety goggles.
WARNING
Scalding from hot operating fluids!
Hot operating fluids can also spray out when pressure is released. This can result in
scalding! To avoid injuries, the following instructions must be observed:
• Allow the motor to cool down to the ambient temperature before opening the
screw plugs.
• Wear closed safety goggles or face protection and gloves.
WILO SE 2019-01