ZP3 Fire Control Panel Installation, Commissioning and Maintenance Manual
Page 100
REV 11 (ISS 08/03/2010)
Earth connection
The panels, power supplies and cables making up the fire detection system should be connected
to earth at one point only. This earth point must always be at the panel. The only exception to this
is when MICC cable is used. In this case the cable shield may be connected at other points in the
building.
The panel is typically located in a building, which allows only limited earth options. The following
are the preferred rules that should be followed if possible.
Normally the panel is connected to the nearest external earth point. This external earth point may
vary in quality, from a high quality instrumentation earth to the earth used by the electrical
network. This external earth point is in turn connected to the main building earth system.
The earth connection should preferably meet the following criteria:
It should be a clean earth, preferably not shared with other electrical devices. High-energy
equipment should be connected to an earth point that is as close as possible to true
earth.
Wiring codes normally require it to be bonded to the main building earth for safety reasons.
The resistance to true earth should be as low as possible.
See Figure 59 for a typical panel earth connection.
Figure 59: Typical panel earth connection
Legend:
Item Description
Item Description
1
Power supply
6
External earth point
2
Panel
7
Existing wire from earth point to main building
earth
3
ZP loop
8
Main building earth
4
Common earth point at panel
9
High energy equipment
5
Wire from panel to earth point
The wire from the panel to the external earth point should be at least 4 mm
2
cable and be
securely connected at both ends to ensure a good mechanical and electrical connection. Use
crimped lugs where possible.
