Written by:.JBJ
Checked by: AC
Document Number: Premier MX Inst Rev: 2
Page 22 of 44
14/12/06
13.4
Pre-Commissioning Wiring Check
NOTE: This pre-commissioning wiring check procedure should be followed to test
all wiring prior to specific commissioning of any detection, alarm and auxiliary
circuits.
1. Ensure that no devices are connected to the detection zones and alarm circuits, but
that the cables are linked through at the device locations to achieve a continuous
circuit.
2. Ensure that the resistance of all cables to earth and between cores is at least 2M
Ω
.
Check the following:
i) Positive to earth resistance is 2M
Ω
or greater.
ii) Negative to earth resistance is 2M
Ω
or greater.
iii) Positive to negative resistance is 2M
Ω
or greater.
3. Connect a wire link as the end-of-line device on each of the zones and alarm
circuits. At the panel end, measure the resistance across the positive & negative
ends of the cables for each of the circuits; ensuring the value does not exceed 20
Ω
.
Remember to remove the wire links after the tests.
Correct polarity throughout all circuits must be maintained. Rectify any faults.
All bells, detector heads and call points should now be connected and the correct
end-of-line devices fitted. Use the spare end-of-line devices supplied and leave the
EOL devices in the panel terminals at this stage. Remember to remove any links
fitted to detector bases. Be very careful to maintain correct polarity at each device.
Warning: Intrinsically safe zone arrangement.
End-of-line capacitors cannot be connected to zones monitoring
Intrinsically Safe detection devices in hazardous areas. To do so will risk
causing an explosion in the hazardous area. End-of-line resistors with a
value of 3K9
Ω
must be used, which comply with the requirements laid
down in the installation data sheets provided with the I.S. barrier and the
I.S. fire detection devices.
In order for detector head removal monitoring to function correctly when
resistors are used as the end-of-line devices, any diodes in the detector
bases that are in circuit when the detector head is removed must be
disconnected.
The panel must be configured to monitor Intrinsically Safe zones.
The first device on an Intrinsically Safe zone must be an I.S. Zener
Barrier or Galvanic Isolator. Detectors and Manual Call Points on the
Safe side of the barrier are not permitted.
To comply with the requirements of BS5839, all manual call points should
be located in the zone cabling between the I.S. Barrier/Isolator and the
first detector. Any manual call point or detector located on the “end-of–
line” side of a detector will be rendered inoperative if the detector head is
removed.
