ABB FEX300, Operating Instruction

Page: 130 / 176

Extended diagnostic functions
130 FEX300, FEX500 OI/FEX300/FEX500-EN
8.1.3 Detection of deposits on measuring electrodes
1)
This function provides the opportunity to detect deposits on the measuring electrodes by using
an adjustable maximum limit value.
When the set limit value is exceeded, an alarm is tripped via the programmable digital output,
depending on the configuration.
Conditions for using the function:
• This function is available in the nominal diameter range
2)
of DN 10 … 300 (3/8 “ ... 12 “).
• The signal cable length of the external transmitter must not exceed a maximum value of
50 m (164 ft) .
• For this function, the conductivity of the fluid must be in the range
20 μ S/cm ... 20,000 μ S/cm.
Additional installation conditions:
• When using plastic tubes, install a grounding plate at the front and back of the device.
8.1.4 Conductivity monitoring
1)
The conductivity of the fluid is monitored by using an adjustable minimum/maximum limit value.
When the value falls below or exceeds the set limit value, an alarm is tripped via the
programmable digital output, depending on the configuration.
Conditions for using the function:
• This function is available in the nominal diameter range
2)
of DN 10 … 300 (3/8 “ ... 12 “).
• The signal cable length of the external transmitter must not exceed a maximum value of
50 m (164 ft) .
• For this function, the conductivity of the fluid must be in the range
20 μ S/cm ... 20,000 μ S/cm.
Additional installation conditions:
• When using plastic tubes, install a grounding plate at the front and back of the device.
• There must not be any deposits on the measuring electrodes.
1) At present, the function is only available for devices without explosion protection or with explosion protection for
Zone 2 / Div. 2. For devices in Zone 1 / Div. 1 this function is under preparation (the function is already implemented
in the software, but cannot be used for devices in Zone 1 / Div. 1).
2) The specified nominal diameter range is valid for ProcessMaster, only. The nominal diameter range valid for
HygienicMaster is DN 10 … 100 (3/8 “ ... 4 “).