FIRECLASS Fire detection system
Connect the Mains Cable and Protective Earths
Installation Guide
Doc. version 2.0
11
4.2
Connect the Mains Cable
and Protective Earths
How to connect the Mains cable and protective
earth
1 Make sure the Mains cable is not connected to the
supply, or that the supply is isolated.
2 On the PSU, locate the Mains connector at the top
of the unit. If the protective cover is fitted to this con-
nector, remove it.
3 Connect the Mains cable to its connector. Fix the
Mains cable using the clip near the Mains connector.
4 Connect the protective earth conductor of the Mains
to a terminal of the housing earthing point.
5 Connect a second earth wire (separate from the
mains lead earth) to a terminal of the housing earth-
ing point. This must be 2.5
mm
2
or greater in cross
sectional area. Connect this to a suitable earth bond-
ing point.
NOTE:
Most AC power distribution systems will
include a low impedance protective earth; however
IT power distribution systems either have no earth
or high impedance to earth. In these cases, a local
low impedance protective earth is required.
6 Re-fit the PSU Mains connector cover.
7 Make sure system 0
V is not connected to the earth,
as there is an earth fault monitoring circuit.
5
Install the Loops
As detailed below, the procedure is to install the loops
into the building, making temporary wiring arrange-
ments for testing. Then, once testing has been com-
pleted, the final loop connections can be made.
5.1
Run and Temporarily Connect the
Loops
1 Run the loop wiring around the building, and wire in
the bases, according to the system plan. Similarly,
run any other wiring required for ancillary modules.
Clearly label the loop conductors as being positive or
negative.
At this stage, do not wire in any isolator bases, or
other modules, or fit the detectors. This is to avoid
potential damage caused by the high voltage insula-
tion checks. Use strip connectors (Fig.
temporary connections, to preserve continuity.
For connection details see the individual leaflets or
labels provided with the products.
DANGER
Danger of death or serious injury.
Before working on the Mains
connection, verify that the cabling is not
live. Ensure the cabling is not connected
to the supply, or that the supply is
isolated.
DANGER
The FireClass Control Panel contains
high voltages, producing a danger of
death or serious injury.
You must ensure adequate earthing of
the system.
In addition to any earthing requirements
in the local regulations, additionally you
must, also follow these stipulations:
All exposed metalwork and cabling
conduits must be returned to earth at
the control panel.
The control panel housing must be
earthed, following the procedures as
mentioned in this guide.
WARNING
To ensure proper operation of the
control panel a second earth, separate
from the mains lead earth, must be
installed. This is described below.
Fig. 8: PSU Mains Connector Cover (detail)
1
– Cover
2
– PSU Mains connector
1
2
