Possible faults, their probable cause and solutions are presented in Table 2.8.
Fault | Probable cause | Solution |
1 When the coriolis controller is powered there is no indication on display nor any signal on the coriolis mass flowmeter’s outputs | Incorrect connection of the power wires to the coriolis mass flow controller. | Check the power cable connection according to the wiring diagram in Appendix . |
Power wires broken or loose.. | Check the power wires and replace them if needed. | |
Power supply voltage does not meet the requirements . | Check the power supply voltage and set its value in accordance with the requirements of this manual. | |
2 When the coriolis flow controller is powered the measured parameters are displayed correctly but there are no signals on the coriolis mass flow meter’s outputs | Wrong connection of the output wires to the coriolis gas flow meter or secondary devices. | Check the output wires connection according to the wiring diagrams in Appendix . |
Check the computer’s port used to connect the flowmeter to the computer through digital interface. Make sure that the same port number is set in the “TFM-Integrator” settings. | ||
3 When there is a known flow the coriolis mass flowmeter shows zero flow rate on the outputs | The actual flow rate is less than the lower limit of the measuring range for this size of the coriolis flow meter. | Fully open the valves to set the flow rate within the measuring flow range. |
The actual flow rate is less than the low flow cutoff value set in the menu. | Decrease the low flow cutoff value to be less than the actual flow rate. |
Fault | Probable reason | Repairing way |
4 When there is no flow the coriolis flow meter indicates a certain flow | Deviation of the zero point caused by temperature and pressure deviation from temperature and pressure values on previous zero point calibration. | Perform zero calibration in accordance with the paragraph |
2.5.4 “Zero point adjustment”. | ||
5 In the menu it we can not enter the “Calibration” and “System Para” sections | At least one of the switches of the protection switch block is set to the ON position. | Set all the switches to OFF positions (see Figure 2.15) only for for the time needed to perform changes in those sections. Put back in the protection mode when done. |
A special LED indicator is provided for indication of some faults of the coriolis mass flow controller. LED is located above the display and its color and blink period indicates the coriolis controller’s fault shown in Table 2.9.
Table 2.9 – LED diagnostics
Lighting period | Fault |
Lights continuously right after power-up | Self-diagnostics test failed |
Lights continuously some time later after power-up | Incorrect zero calibration |
Flashing. The color is red | Malfunction of the coriolis controller |
Flashing. Lights within 3/4 of the period, dark within 1/4 of the period | Flow rate is less than the lower limit of the flow range for this size of the coriolis flow controller |
To determine a fault in the sensor part of the coriolis gas flow meter it is necessary to check the resistance of the coils first. Resistance value should be in the ranges specified in Table 2.10.
Table 2.10 – Coils diagnostics
Circuit element | Wire color | Contact number | Resistance, Ohms |
Left coil | Brown, red | 1, 2 | 60 – 75 |
Right coil | Orange, yellow | 3, 4 | 60 – 75 |
Drive coil | Blue, green | 5, 6 | 6 – 30 |
Temperature sensor | Gray, white | 7, 8 | 75 – 175 |
Temperature sensor | Gray, black | 7, 9 | 75 – 175 |