Level Pro ITC 450 User Manual page 11

ITC 450/470
User manual
Avoid running signal cables and transmission cables together with power supply cables and cables
controlling inductive loads (e.g. contactors). Such cables should cross at a right angle.
Contactor coils and inductive loads should be equipped with interference protection systems, e.g. RC-
type.
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.
In the case of magnetically induced interference the use of twisted pair of signal cables is recommended.
Twisted pair (best if shielded) must be used with RS-485 serial transmission connections.
In the case of measurement or control signals are longer than 30m or go outside of the building then
additional safety circuits are required.
In the case of interference from the power supply side the use of appropriate 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 earth with the largest possible
surface. The cables connected to the filter output must not be run 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
on the back of the unit's housing.
Figure 4.5. Method of cable insulation replacing and cable terminals
6-7 mm
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