Ziton ZP3, Руководство по установке и обслуживанию, Страница: 132 / 163

Appendix A: ZP wiring guide
124 ZP3 Fire Control Panel Installation, Commissioning, and Maintenance Manual
ÿ
1
2
3
1. Control Unit
2. Detectors 3. Isolators
1. Isolators should be located on the Z-Address loop either at the beginning and
end of each zone, or at regular intervals.
2. To comply with BS 5839 Part 1, no more than 1 zone, or 20 detectors or call
points, must be grouped between two isolators. Other standards allow up to
32 devices between isolators.
3. A maximum of 16 isolators can be used on each Z-Address loop.
4. The total loop cable resistance must not exceed 75
ȍ
(37.5
ȍ
for each
positive and negative leg).
5. The maximum cable resistance between any two isolators, or from the panel
to the first isolator, is 18
ȍ
for both cores (9
ȍ
for each positive and negative
leg).
6. The Z-Address loop is pulsed at nominal 20 Vp-p. When loops are installed in
accordance with this wiring guide, then the maximum volt-drop across the
loop is 4 V. This ensures that isolators always receive a supply of at least
16 V.
Shielded cable provides the greatest protection against external interference, as
well as protecting other equipment from interference generated by the fire
detection system.
Shielded cable must be used where possible.
Shielded cable must be earthed at the panel at both ends and must never
be left with the shield floating.