Burkert 8745 MFC Ethernet, Руководство по эксплуатации

Страница: 64 / 70

64
Troubleshooting
Type 8745 Ethernet, 8745 Analogue
12.3.8 Unstable measured value (MFM)
You have not connected the functional earth (FE) properly.
→
To connect the functional earth, use a green-and-yellow cable
that is as short as possible. And the cable cross-section must
be at least equal to the cross section of the power supply
cable. Refer to chpt. 8.7.
12.3.9 Unstable measured value (MFC)
Identify the cause to solve the problem:
1. You have not connected the functional earth (FE) properly.
→ To connect the functional earth, use a green-and-yellow cable
that is as short as possible. And the cable cross-section must
be at least equal to the cross section of the power supply
cable. Refer to chpt. 8.7.
2. The residual ripple on the voltage supply is too high.
→ Use a supply voltage that conforms to the technical data
given in chpt. 6.9 Electrical data .
3. The product must compensate for irregularities in an unstable
pressure supply caused, for example, by pumps.
→ Install a suitable pressure regulator in front of the product.
→
Install a buffer tank to absorb the pressure fluctuations.
12.3.10 Set-point value at 0 %, but operating
fluid still flows (MFC)
The operating pressure is above the tight sealing pressure of the
control valve.
→ Reduce the operating pressure.
→ To eliminate the defect, return the product to the
manufacturer.
12.3.11 Set-point value at 0 %, control valve is
closed, no mass flow, but a non-zero
mass flow rate is measured (MFC)
Identify the cause to solve the problem:
1. The installation position of the product is incorrect.
→
Install the product in the position indicated on the calibration
plate or in the calibration protocol.
→ Run the Autotune function to adapt to the operating
conditions.
2. The operating fluid is different from the fluid specified during
the calibration.
→
Use the specified operating fluid or send the product to the
manufacturer for calibration with the new operating fluid.
English