EXPro Installation Manual
Approved Document No: GLT-212-7-1
Page 12
Issue: 1.7 Author: MF/NRPJ Date: 05/07/2021
DETECTORS AND SOUNDERS
The detector and sounders must be connected using fire resisting 1.5mm² 2-core + screen cable. The
screen of each detector and sounder circuit must be connected to one of the terminations of the
earth bar, which is bolted to the back box, above the terminations PCB.
WIRING THE DETECTORS
The detection zone on the Premier EXPRO are Co-incidence (Double Knock) zones which use a 4.7KΩ
end of line resistor. Call points can NOT be connected to these zones. A maximum of 32 detectors
can be fitted to a zone.
Figure 5. Wiring the detectors
WIRING THE SOUNDERS
The Premier EXPRO has 2 first stage / fire sounder circuits, each rated at 150mA. Each sounder
circuit must be fitted with 18KΩ end of line resistor. The EXPRO also has 1 x second stage sounder
circuit rated at 250mA. This also uses an 18KΩ end of line resistor. This second stage sounder circuit
is designed for an alarm device that gives a constant sound pattern (either sounder or bell) because
it uses on/off sound patterns to indicate different gas release conditions.
Figure 6. Wiring sounders
SOUNDER
SOUNDER
SOUNDER
SOUNDER
SND +
SND -
+ + - -
+ + - -
+ + - -
+ + - -
18KΩ
