BASIC TROUBLESHOOTING
9
Mains power generates interferences because of numerous parallel connected appliances and
devices (motors, spot lights, fluorescent lighting, etc . . .
The behaviors of metal frames or guide bars sometimes like resonance circuits tuned to the system
frequency.
Install antennas remotely from these structures or fit bonding braids in order to cancel resonance
phenomena.
In case of implementing problems because of the site configuration, perform testing in order to
determine the best location.
Avoid installing antennas to close to such metallic masses while keeping to a minimum distance of 40
cm away from antenna.
Metallic masses generate interference because of system absorbed and reverberated
electromagnetic waves.
A number of switching power supplies as used for example, in Electronic Information Systems (EIS)
operate at a harmonic frequency similar to that of the EAS system and may cause system jamming.
Therefore, under no circumstances should the power supply unit be connected to a line backed up by
an Uninterrupted Power Supply (UPS) (rectified current).
and therefore, a dedicated line shall be
provided directly from the switching board. This line shall be installed by an approved installer.
)
INTERFERENCE SOURCES
Steel frames of doors sometimes behave in the same manner. Install antennas remotely from such
structures or fit shunts or bonding braids in order to cancel resonance phenomena.
Position the system away from steel frame doors
,
then open and close doors and check the
DC Noise
level
for evidence of distorted signals (tag signal).
Defective fluorescent lighting
,
e . g . neon type
,
generates interference because of permanent DC
energizing on switching on. Please feel free to have this type of lighting switched off and compare
results with the
DC Noise level.
Some transformers use in this type of lighting appliances may be
defective and cause similar interference.
All electromagnetic filed generating appliances typically incorporate transformers
,
motors or mobile
magnets
,
including: fluorescent neon tubes
,
halogen quartz bulbs
,
cashiers conveyor belts
,
etc.
Power leads may also be a cause for interference. Prevent antennas from standing too close to
electrical leads. Move antennas and perform various tests to assess the best location.
