Wilo Rexa PRO Instrucciones De Instalación Y Funcionamiento página 172

en
9.5.5.1 Test the resistor of the internal
electrodes for motor compart-
ment monitoring
9.5.5.2 Test the resistor of the temper-
ature sensor
9.5.5.3 Testing the resistor of the ex-
ternal electrode for sealing cham-
ber control
9.5.6 Oil change in sealing chamber
Fig. 15: Sealing chamber: Oil change
172
Maintenance and repair
Measure the resistor of the electrode with an ohmmeter. The measured value must ap-
proach "infinity". For values ≤ 30 kOhm, there is water in the motor compartment. Con-
tact customer service!
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!
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.
+/- Fill/drain the oil in the sealing chamber
‡
Protective equipment has been put on!
‡
Pump has been dismantled and cleaned (decontaminated if required).
1. Position the pump horizontally on a firm surface. The screw plug points upwards.
WARNING! Risk of hands being crushed. Ensure that the pump cannot fall over
+/-
or slip away!
2. Unscrew the screw plug slowly, but do not unscrew it completely. WARN-
ING! Overpressure in the motor! Stop turning the screw plug further if hissing
or whistling is audible! Wait until the pressure has completely dissipated.
3. After the pressure has dissipated, fully unscrew the screw plug.
4. Place a suitable tank to collect the operating fluid.
5. Drain the operating fluid: Rotate the pump until the opening points downwards.
6. Check the operating fluid: Notify customer service if an operating fluid contains
metal chips!
7. Pour in operating fluid: Rotate the pump until the opening points upwards. Fill-in
the operating fluid into the opening.
⇒ Comply with the specifications for operating fluid locations and quantity!
WILO SE 2019-02