User manual for - FLOW METER SPP-N118
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Use of screened signal cables is recommended. Signal cable screens should be
connected to the earthing only at one of the ends of the screened cable.
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In the case of magnetically induced interference the use of twisted couples of signal
cables (so-called “spirals”) is recommended. The spiral (best if shielded) must be used
with RS-485 serial transmission connections.
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In the case of measurement or control signals are longer than 30m or go outside of the
building then additional safety circuits are required.
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In the case of interference from the power supply side the use of appropriate anti-
interference filters is recommended. Bear in mind that the connection between the filter
and the unit should be as short as possible and the metal housing of the filter must be
connected to the earthing with largest possible surface. The cables connected to the filter
output must not run in parallel with cables with interference (e.g. circuits controlling relays
or contactors).
Connections of power supply voltage and measurement signals are executed using the
screw connections inside of the unit’s housing.
Figure 4.2. Method of cable insulation replacing and cable terminals
•
All connections must be made while power supply is disconnected !
•
Flow sensor connected to current input of flow meter should be installed
accordingly to local regulations, and recommendations of the producer.
•
Correct installation and application of flow sensor is essential for correct
operation of flow meter type SPP-N118.
9
!
6-7 mm
m
ax
.
2
m
m
