CALogix
installation
sheet
Page
3
of
6
−
Output wiring should be within a protectively earthed cabinet.
−
Sensor sheaths should be bonded to protective earth or not be accessible
−
Live parts should not be accessible without the use of a tool.
EMC GUIDELINES
We make a number of general recommendations that can reduce the possibility of EMC problems.
1)
It is important to suppress CALogix relay contacts, this will reduce switching interference and
also prolongs life of the contacts.
RC Networks fitted across the relay contacts are recommended for resistive and larger
inductive loads, values such as 0.1
µ
F capacitor in series with a 100
Ω
resistor.
For small inductive loads, a suitable rated VDR is recommended.
For small inductive dc loads, relays etc, a suitably rated diode fitted in parallel with the load is
recommended.
2)
CALogix should be mounted into a metal cabinet which is properly earthed, good all round
metal shielding is important.
3)
It should be borne in mind that the wiring of the installation can significantly reduce the
efficiency of the instrumentation immunity. This is due to the ease with which high frequency
RF can enter via unprotected incoming and outgoing cables.
Earthed thermocouples or sensors with screened cable, should be earthed at the cabinet
entry point.
Any long cables entering the control cabinet should be protected at the point where they
enter the cabinet, large diameter ferrite sleeves are an economical and effective method of
reducing high frequency RF, looping the cables through ferrite sleeves a number of times
will improve the efficiency of the filtering.
Alternatively for mains cables, the fitting of a suitable mains filter can provide good results.
Data or communications cables should be screened. If using Belden 8132 connect drain
wire to PIN 5 of a shielded RJ45 connector.
Ideally data and sensor cables should be routed separately from power cables and away
from inverters or other high power/frequency devices.
SUPPLY AND RS485 COMMUNICATIONS CONNECTIONS
INPUT OPTIONS
7P---0A000
7P---0A000
7P---0A000
7P---0B000
= 4-20mA
7P---0C000
= 0-5V
7P---0D000
= 0-10V
7L---0E000
