Wilo T 12 Notice De Montage Et De Mise En Service page 104

en
9.6.4.5 Testing the resistor of the ex-
ternal electrode for sealing cham-
ber control
9.6.5 Oil change in sealing chamber
T 12
+/-
Fig. 14: Sealing chamber: Oil change
104
Maintenance and repair
▪ PTC sensor (PTC thermistor): Measured value depends on the number of sensors in-
stalled. A PTC sensor has a cold resistance range of 20 to 100 ohms.
– With three sensors in series, the measured value range is from 60 to 300 ohms.
– With four sensors in series, the measured value range is from 80 to 400 ohms.
▪ Pt100 sensor: Pt100 sensors have a resistance value of 100 ohms at 0 °C (32 °F).
Between 0 °C (32 °F) and 100 °C (212 °F), the resistance increases by 0.385 ohms per
1 °C (1.8 °F) increase.
At an ambient temperature of 20 °C (68 °F), the resistance is 107.7 ohms.
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.
Motor T 12, T 13, T 17, T 17.2
T 13
+/-
+/- 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!
T 17
+/-
T 17.2
+/-
WILO SE 2019-01