Endress+Hauser Liquiphant FTL31 - Diagnostics and Troubleshooting; 8.1 LED Display Diagnostics; Maintenance

Liquiphant FTL31 Diagnostics and troubleshooting
Endress+Hauser 33
8 Diagnostics and troubleshooting
8.1 Diagnostic information via LED display
LED display on housing cover
Malfunction Possible cause Corrective action
Green LED
Not lit
No power supply
Check connector, cable and power supply
Red LED
Flashing
Overload or short-circuit in
load circuit
• Rectify short-circuit
• Reduce maximum load current to below 250 mA
Red LED
Lit
Internal sensor failure or sensor
corroded
Replace device
Connection: 2-wire AC/DC to 20 to 253 V DC
Malfunction Possible cause Corrective action
Unexpected behavior
of yellow LED
Incorrect connector assignment or
incorrect cable wiring
Pay attention to the polarity of the power supply!
Correct connection:
Valve plug: L+ to PIN1, L- to PIN 3
Cable: L+ BK (black), L- BN (brown)
Result (for MIN operating mode)
• Tuning fork covered: yellow LED lit.
• Tuning fork not covered: yellow LED not lit.
Result (for MAX operating mode)
• Tuning fork covered: yellow LED not lit.
• Tuning fork not covered: yellow LED lit.
9 Maintenance
No special maintenance work is required.
9.1 Cleaning
The sensor must be cleaned if necessary. It can also be cleaned while installed (e.g. CIP
Cleaning in Place / SIP Sterilization in Place). Care must be taken to ensure that no damage
occurs to the sensor in the process.