Input; Output - Endress+Hauser Liquicap M FTI51 Operating Instructions Manual

Technical data
70
10.2

Input

10.2.1 Measuring range
• Measuring frequency:
500 kHz
• Span:
C = 5 to 1600 pF
C = 5 to 500 pF (with FEI58)
• Final capacitance:
C = max. 1600 pF
E
• Adjustable initial capacitance:
C = 5 to 500 pF (range 1 = factory setting)
A
C = 5 to 1600 pF (range 2; not with FEI58)
A
• The minimum change in capacitance for point level detection must be  5 pF.
Minimum probe length for nonconductive media (<1s/cm)
= C
l / (C * [r - 1])
min min s
l = Minimum probe length (m)
min
C
= 5 pF
min
= Probe capacitance in air  ? 69 "Capacitance values of the probe"
C
s
r
= Dielectric constant e.g. oil = 2.0
10.3

Output

10.3.1 Switch behavior
Binary or s operation (pump control, not with FEI58)
10.3.2 Switch-on behavior
When the power supply is switched on, the switching status of the outputs corresponds to
the signal on alarm.
The correct switch condition is reached after max. 3 seconds.
10.3.3 Failsafe mode
Minimum/maximum quiescent current safety can be switched at the electronic insert (for
FEI53 and FEI57S only on the associated Nivotester: FTC325 3-Wire, FTC325 PFM and
FTC625)
MIN = minimum safety: The output switches safety-oriented when the probe is uncovered
(signal on alarm). For use for dry running protection and pump protection for example
MAX = maximum safety: The output switches safety-oriented when the probe is covered
(signal on alarm). For use with overfill protection for example
10.3.4 Galvanic isolation
FEI51, FEI52
between rod probe and power supply
FEI54:
between rod probe, power supply and load
Liquicap M FTI51, FTI52
Endress+Hauser