KROHNE IFC 110 Converter - Manual (Page 66)

Sect. 6.10 Part C Special applications, functional checks, service, and order numbers
66 IFC 110 F 05/2003
6.10 Stable signal outputs with empty measuring tube
Important, please note!
• Observe the directions and regulations and the electrical data specified in the
EC type test certificate.
• In addition to the regulations for heavy-current installations (VDE 0100),
pay particular attention to the requirements specified in EN 60079-14 “Electrical
equipment in hazardous areas”.
• Assembly, installation, commissioning and maintenance work may only be carried
out by “personnel trained in explosion protection”!
Output signals can be stabilized to values as for ”zero” flow to prevent undefined output signals
when the measuring tube is empty.
– Display 0
– Current output 0 or 4 mA, see setting in Fct. 1.05
– Pulse output P no pulses (= 0 Hz), see setting in Fct. 1.06
– 2nd pulse output A1 no pulses (= 0 Hz), see setting in Fct. 1.07
Prerequisite: • electrical conductivity of process liquid ≥ 200 mS/cm,
≥ 500 mS/cm for sizes DN 2.5 - 15 and 1
/
10
” -
1
/
2
”.
• Signal cable length ≤ 20 / ≤ 65 ft and vibration free with signal
converter.
LA / S2 Empty Tube stabilization LA / S4 electrode cleaning
steady display at “0“ flow and Empty Tube stabilization
LA / S2 should be used when problems are
encountered with EPD or the limits of the
application are exceeded.
At “0“ flow, the electrodes are connected to 0 V
(chassis) via high-resistance resistors. LA / S4 prevents any deposits of high-
resistance layers on the electrodes (e.g. fat
from very creamy milk) and effects stabilization
similar to the LA / S2.
For this purpose, the electrodes are connected
to –12 V via high-resistance resistors.
To join the “semicircles“ of the three soldering
points S1, S2 and S4, see under ”Point 8“. To join the “semicircles“ of the three soldering
points S1, S3 and S4, see under ”Point 8“.
Possibly reset low-flow cutoff (SMU),
see under Point 11 Possibly reset low-flow cutoff (SMU),
see under Point 11
Please note!
Only use the two functions, if Empty Pipe Detection (EPD) is switched off, see Sect. 6.9 and in
Fct. 3.06 Application
→ EMPTY PIPE.
0 V
- 12 V - 12 V