Page 18 of 91
Rev. 4.20
3.1 LINE CABLE TEST PROCEDURE BEFORE LOOP CONNECTION
For connection use twisted and shielded cable with electro conductive cable characteristics as reported on table:
LENGTH (m)
SIZE (mm
2
)
CAPACITY (pF/m)
Length up to 500 m
min
0,5
max.
150
Length up to 1000 m
min
1,0
max.
120
Length up to 2000 m
min
1,5
max.
100
Check if line isolators are present: they must have been installed with zero address. In this case, at unsupplied
line, the contact of isolator will be off to allow the test of negative-positive electro conductive cables and shielded
at both ends of the loop.
TESTS TO EXECUTE FOR A CORRECT OPERATION OF CONTROL PANEL:
3.1.1 Line continuity
Check the resistance of line electro conductive cables (-1B and -1A, ...) with tester at 200 •.
A resistance for line electro conductive cables superior to 40 • is too high!!
Possible causes can be:
-
the line is too long;
-
free clips;
-
false contacts;
-
cable of insufficient section;
-
partly cut off or damaged cable.
The cables must usually present a resistance between 20 and 25 •. Besides the resistance of the negative cable
and the positive one must result similar.
3.1.2 Shielded
It must present treble the resistance of line cables at most.
Warning: if shielded cable presents a resistance superior to treble line cables, it is necessary to check the path of
shielded itself.
The shielded must be shielded in the connection to the points (buttons, I/O modules, ...), to avoid the
short circuits with electronic parts..
3.1.3 Isolation between positive and negative of loop
A value superior to 20K• with 127 installed points or gradually increasing values of resistance with installed fewer
points can be found with tester at 200K• or higher range.
3.1.4 Isolation between SHI / –LOOP and SHI / +LOOP
Infinite Ohm value must be found for the isolation-make sure you are not powered up.
If the infinite value is not found, please check the positive and negative wiring for short circuit which may be found
throughout the loop circuit.
NOTE: the clip SHI gets inserted only in the shielded side (that is shielded of start). In the module isolator,
connect the shielded cable wire between the common terminal and the Common wire terminal.
PART 3
PRELIMINARY REMARKS FOR A CORRECT INSTALLATION
