Siemens SIROTEC Planning Manual page 50

Troubleshooting and Fault Elimination
·
Elimination of coupling paths to prevent interference sizes on reaching the
interference sink from the interference source (e. g. increase distance between
power and signal lines, inserting shielded lines, conduct lines to mass
proximity).
·
Check the adherence of the measures requested in this EMC Guideline and
the product-specific documentation.
Table 8-1 Fault clearance
Misconduct Possible cause
Sporadic failure Non-wired coils of contactors, valves,
horns, ...
Adjacent sparking machines (welding
equipment)
Transmitter, round control system
Lines with incorrect shield connection,
incorrect core twisting or incorrect
parameters
Interruption in the line shield
(e.g. with intermediate switching of a line
distributor)
Incorrectly routed equipotential bonding
line
Contamination of the control
Remaining offset Such as sporadic failure
Actual value line
Irregular processing Poor equipotential bonding connection
surface between position transmitter and control
Large compensating current on setpoint
line shields (analog setpoint)
Foreign drive control: Setpoint input of the
drive control does not suit the Siemens
EMC concept
Flickering screen Adjacent magnetic field-producing device
characters or screen (e.g. transformer, electric motor) or line
with current flowing through it
Extensive off-colours of Magnetic field of an adjacent permanent
the screen display solenoid
Transmitter error Transmitter line shield is interrupted
Lines with poor shield features
Transmitter line shield put on via separate
wire/line
Electrostatic charging/discharging of belts
or rotor
Telephones, fax Short-circuit capacity of the mains is too
machines, copying small
machines are whistling
Fuse case with small
power supply units
8-50
Fault elimination
Wire the coils
Route the lines of the control in another way
(increase the distance to the interference
source)
Additional shielding
Use original lines, check the core occupancy
Connection of the line shields, shielding of the
interruption point
Reroute equipotential bonding line
(see Chapter 4)
Clean control and assemblies, provide for
clean supply air
Such as sporadic failure
Route equipotential bonding line between
transmitter housing and control housing or
improve equipotential bonding
· Provide for extensive, blank, corrosion-
resistant earth connection between
control and position transmitter
· Equipotential bonding line: Increase
cross-section, create direct connection
Interrupt shield connection on the control side
Change the input wiring of the drive control
(according to the wiring of the Siemens drive
controls)
·
Increase the distance between the screen
and the interference source
· In extreme cases, shield the screen or
interference source with MUMETALL
· Eliminate the interference source
·
Shield the interference source with
MUMETALL
Note: Picture disturbance disappears without
demagnetization measures only some days
after the elimination of the cause
Insert original lines (product-specific)
Insert shields on both sides
Use belts with antistatic coating, earth rotor via
earthing brush.
·
Increase the short-circuit capacity of the
mains
·
Supply the affected devices from another
mains
·
Insert original filter module
EMC Installation Guideline – Planning Guide (EMV) – 03.2004 Edition
®
© Siemens AG, 2004. All rights reserved
®
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