VESDA Sensepoint XCL – Large Bore Installation Manual
VESDA by Xtralis
1.
Detector sink mode:
With this switch in the upper position, the analog output drives current through the
controller sensing circuit.
2.
Detector source mode:
With this switch in the lower position, the analog output draws current through
the controller sensing circuit.
mA Output
Status Indicator
1 mA
Fault
2/4 mA
Inhibit
4-20 mA
0 to 100% Full Scale
>21 mA
Over range
Notes:
The load resistance of the controller must be between 33 Ω and 250 Ω. When the mA output is not
being used, a 33 Ω, 0.125 W load resistor should be connected between terminal 3 (4–20 mA) and
terminal 2 (0 V) for source mode or terminal 1 (+24 V DC) for sink mode. Failure to do so will cause
the unit to enter a fault condition.
When operating the detector from an AC power supply, the current loop (mA) wiring should be
connected between terminals 3 (4-20 mA) and 4 (COM).
Detector Source Mode with DC Power
1
2
3
1
2
3
4
VE−
24 VDC
VIN−
VIN+
VE+
4–20mA
4–20mA
R
L
COM
Legend
1
System controller
2
VESDA Sensepoint XCL
detector
3
Current flow
Detector Sink Mode with DC Power
1
2
3
1
2
3
4
VE−
VIN−
VIN+
VE+
4–20mA
4–20mA
R
L
COM
24 VDC
Legend
1
System controller
2
VESDA Sensepoint XCL
detector
3
Current flow
