Avoid Electric and Magnetic Field
Disturbances
Introduction
In the installation of electronic measuring and control systems, it is important to run the
cables and select the cable types in such a manner that the system will be affected as little
as possible by electric and magnetic field disturbances.
Sources and susceptibility
Sources: Potential sources of disturbance include
• Relay Coils
• Solenoid Valves
• Contactors
• Thyristor Units
• Earth (ground) currents
• Static Discharges.
• Variable Freqency Drives (VFD’s)
Susceptibility: The susceptibility to disturbances varies with the electrical environment, for
example:
• Cable Length
• Screening (shielding)
• Electrical noise suppression installation (line reactors, power filters, etc)
Overvoltage protection
Xylem recommends that overvoltage protection with lightning protection should be used
both for the mains power supply to the power supply unit and for the telecommunications
cable. This protection will make the product less sensitive to overvoltage and will therefore
enable it to be used in a more difficult environment.
The overvoltage protection for the mains power supply should be connected in series with
the mains power supply connection.
The overvoltage protection for the telecommunications cable should be in series with the
telecommunications cable.
Avoid Electric and Magnetic Field Disturbances
8 Hardware for APP700 and APX700 Installation
To Next Page
Loading...