Wilo HC 20.1+EMU FA Instrucciones De Instalación Y Funcionamiento página 38

en-US
9.5.1 Visual inspection of the connec-
tion cable
9.5.2 Visual inspection of accessories
9.5.3 Visual inspection of coatings and
housing for wear
9.5.4 Function test of the monitoring
devices
9.5.4.1 Test the resistor for the internal
electrodes for terminal room/mo-
tor compartment monitoring
9.5.4.2 Checking resistor in the tempera-
ture sensor
38
Maintenance and repair
WARNING
Hand, foot or eye injuries due to a lack of protective equipment!
During work there is a risk of (serious) injury. Wear the following protective equipment:
• Safety gloves that protect against cuts
• Safety shoes
• Closed safety goggles
Before starting the maintenance measures the following requirements must be fulfilled:
▪ Pump cooled to ambient temperature.
▪ Pump thoroughly cleaned and (if necessary) disinfected.
Check the connection cable for:
▪ Bubbles
▪ Cracks
▪ Scratches
▪ Abrasion
▪ Pinch points
If damage is identified on the connection cable, decommission the pump immediately! Have
the connection cable replaced by Wilo customer service. Only start the pump up again once
the damage has been properly remedied!
CAUTION! Due to damaged connection cables, water can penetrate into the pump! Water
ingress causes total breakdown of the pump.
The accessories must be checked for:
▪ Correct attachment
▪ Proper function
▪ Signs of wear, e.g. cracks caused by vibrations
Any detected defects must be repaired immediately or the accessories must be replaced.
The coatings and housing parts must not show any signs of damage. If deficiencies are iden-
tified, the following points must be observed:
▪ If the coating is damaged, the coating must be repaired.
▪ Contact customer service if housing components are worn!
The mixer must be cooled down to ambient temperature to test resistances!
The internal electrodes are switched in parallel. During testing, all the electrodes are thus
measured together.
Measure the resistor of the electrodes with an ohmmeter. The measured value must ap-
proach "infinity". At values ≤ 30 kOhm, there is water in the terminal room or motor com-
partment. Contact customer service!
Measure the resistor of the temperature sensors with an ohmmeter. The following measured
values must be complied with:
▪ PTC sensor (PTC thermistor): Measured value depends on the number of sensors installed. 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) in-
crease.
At an ambient temperature of 20 °C (68 °F), the resistance is 107.7 ohms.
WILO SE 2019-01