9.5.5.2
Testing the resistor of the ex-
ternal electrode for sealing cham-
ber control
9.5.6
Visual inspection of accessories
9.5.7
Oil change
9.5.7.1
Oil change in seal housing
(TR 20-1/28-1, TRE 20)
Fig. 13: Oil change
Installation and operating instructions Wilo-Flumen OPTI-TR 20-1, 28-1, 30-1, 40-1 Wilo-Flumen EXCEL-TRE 20, 30, 40
Maintenance and repair
▪ 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.
+/-
Drain/fill seal housing oil
‡
Mixer is not installed.
‡
Mixer is not connected to the mains.
‡
Protective equipment must be put on!
1. Place the mixer horizontally on a firm surface.
WARNING! Risk of hands being crushed. Ensure that the mixer cannot fall over
or slip away!
CAUTION! Do not set the mixer down on the propeller! Use an appropriate plat-
form for the propeller diameter.
2. Position a suitable tank to collect the operating fluid.
+/-
3. Unscrew the screw plug (+/-).
4. Tip the mixer and allow the operating fluid to drain out.
5. Check the operating fluid: Notify customer service if the operating fluid contains
metal swarf!
6. Dispose of operating fluid in accordance with local regulations!
en
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