Installation and Wiring
5-6
Operating Manual: PMImicro diag
Screening
• Connect the power cable screening with low impedance to earth.
• Use screened data lines only.
• Due to high frequency, we recommend that the screening on the data
line cable (RS 232/RS 485 cable) is earthed on both sides. If you are
using longer cables and there is the possibility of transient currents, we
recommend one of the following methods:
- use equipotential bonding cable
- isolate the potentials
• Data line screening should be connected to a bus bar.
• The connection between the bus bar and the control cabinet/system
should be as short as possible and with low impedance.
• Fasten the braided screening to the screen bar over as large a surface
area as possible (e.g. with metal hose clips or polyurethane (PU) cable
clips).
Measures to protect against interference voltages
• Wire inductive loads (e.g. contactor coils, relay coils and solenoid valve
coils) using suppression elements (e.g. RC elements). This is particularly
important if these inductive loads are close to the supply voltage or are
fed from the same supply voltage.
• If strong magnetic fields are present, we recommend you use a bulkhead
separator, i.e. metal sheet (MU-metal).
