Loop 'Positive line' break test
A positive line break test should be carried out at this stage. A ve line break should not
cause the loss of any part of the system. If the test is unsuccessful then after the rectification work
is complete, re-allocate the loop circuit by using the
'Power-Down'
and
'Power-Up'
functions
followed by
'Start Detection'
.
¨
Disconnect the
+ve line
connection at one
End-1
of the loop circuit. The display will
show a wiring changed message with location of device where the positive break was
found.
¨
If necessary run the
'Repair'
function to clear the system.
Loop 'Earth fault' tests
Earth fault tests should be carried at this stage:
0V-line earth fault test
¨
Connect the
0V line
to the earth of the control panel. This may have to be sustained
for up to 1 minute for the fault to be detected. The display will show an 'Earth fault'.
¨
Restore the wiring and the display will show 'Earth Fault cleared'.
+ve line earth fault test
¨
Now connect the
+ve line
to earth via a
10K ohm
resistor. This may have to be
sustained for up to 1 minute for the fault to be detected. The display will show an
'Earth fault' message and after restoration of the wiring a cleared message is
displayed. If the resistance between 'Earth' and 'Loop +ve' is in the order of a few
ohms then this will be registered as a ‘short circuit’.
Type of earth fault
Interrogate the
Diagnostics
and check the readings given for Earth fault.
Type of Earth fault
Earth (Ear) reading
No earth fault
around 89
+ve line and earth
around 75
-ve line and earth
less than 40
Commissioning instructions
32
4188-949 issue 3_05/10_Nano Comms inst.
Loop
'Positive
line'
break
test
L1 (+ve)
LINE
BREAK
TEST
TERMINALS
BOARD
PANEL
enclosure
L1 0V
DRN
LOOP END 1
PB1
PANEL
enclosure
L1 0V
DRN
LOOP END 1
PB1
TERMINALS
L1 0V
DRN
LOOP END 1
PB1
PANEL
enclosure
10K
resistor
