Advanced MX-4200V, Руководство пользователя

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2.6.3 Detector Loop Installation
Section 12.5.2
ALL loop devices (except LVxxx devices) incorporate in-built isolators to protect
against short circuit wiring faults on the loop wiring. Under a single short circuit fault
condition, all devices will continue to operate as normal.
The number of devices assigned to a zone depends on the relevant installation
standards.
If LVxxx devices are installed, a maximum of only 32 LVxxx devices must be installed
between other devices and these must be in the same zone. Install a device with an
isolator at the zone boundary to ensure that not more than one zone can be affected
by an open or short circuit condition.
Section 13.7
Not more than 512 fire detectors and / or manual call points and their associated
mandatory functions shall be affected as a result of a system fault in the C.I.E.
The panel (or each chassis in the Mx-4800V) should be installed with not more than
512 fire input devices.
See Appendix 8 – Mx-4800V / Network Design Principles for further details on Mx-
4800V and network installations.
Form the loop starting at the Loop Out + and
–
terminals on the base card.
Route the wires around the loop connecting all
devices in accordance with the manufacturers’
data sheet supplied with each unit.
Ensure that the devices are correctly installed with
regard to their positive and negative terminal
polarity (especially Loop Isolator Modules).
Connect the return wires to the Loop IN + and
–
terminals on the base card.
The diagram opposite shows the typical
arrangement of the loop connections on the base
cards.
Refer to Section 2.4 for details on installing
additional loop drivers on the multi-loop panels.
IN
–
IN
+
OUT
–
OUT
+
Base Card Terminations (Typical).
It is recommended that shielded cable is used for the loops.
When screened cable is used, it is vital to connect the screen / drain wire to the chassis / earth at
the cable gland input / earth stud in the panel. Always ensure that all segments of the cable loop
have continuity of the screen and take care to ensure that the screen is not exposed to any other
earth point (e.g. metalwork, cable trays, junction boxes, etc.).
The Loop Driver Circuit on the Base card is
equipped with in-built isolators to take care of
short circuit conditions on the wiring between the
panel and the first device on the loop. Do not fit
loop isolators at the panel outputs.
The diagram opposite shows a typical loop
arrangement.
Maximum recommended cable loop length is 1500
to 2000 Metres. Refer to
Appendix 2
–
Recommended Fire Rated Cables for further
information on cable types to be used.
+
-
+
-
Isolators
Typical Loop Arrangement.
Take care that the voltage drop at full load is within the detector rating – refer to the device
data sheets for minimum values.
To maintain signal line wiring supervision, break the wiring run at each loop device.
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