Document:  LT0273    MX4428 MXP Engineering / Technical Manual 
    Device Information and Programming 
Issue 1.5  24 March 2006  Page 3-17 
3.8    814I IONISATION SMOKE DETECTOR  
 
3.8.1 GENERAL 
The 814I is an ionisation smoke detector. The detector senses the amount of smoke present 
and sends this value to the MXP. The MXP makes any decisions as to whether this is an 
alarm, fault, normal or whatever. The integral LED is turned on by the MXP when an alarm is 
detected. 
 
The remote LED and functional base outputs are programmable for their functionality (refer 
to section 
3.3). 
 
3.8.2 814I SPECIFICATIONS 
Line Connections  L(–), L1(+) 
Supply Voltage  20Vdc - 40Vdc 
Supply Current  330uA (typical quiescent) 
Alarm Current  3.0mA  (typical) 
Remote LED Current  7mA (Tyco E500Mk2) 
Dimensions  110mm (diameter) x 55mm (including MUB base) 
Weight 81g  
Base  MUB, 5B, 5BI, 814RB, 814SB, or MkII Sounder Base 
 
3.8.3 MX4428 PROGRAMMING OPTIONS - 814I 
The programmable values for the 814I are explained in the following table. 
 
Normally only the mode needs to be programmed, and then only if a functional base or 
remote LED is required and its operation is different from the default. Refer to section 
3.3. 
 
In some cases the alarm sensitivity (Parameter 1) may need to be changed from the default. 
The approved range for Australia is 0.22 MIC X (23) to 0.39 MIC X ( 66). The available range 
is 0.22 MIC X (23) to 0.59 MIC X (130). If the alarm sensitivity is changed, the pre-alarm 
sensitivity (Parameter 0) should normally be changed to about 75% of the alarm sensitivity. 
 
The remaining parameters should not need changing.