Xtralis VESDA Sensepoint XCL Installation Manual page 16

VESDA Sensepoint XCL – Large Bore Installation Manual
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
1 mA
2/4 mA
4-20 mA
>21 mA
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
VE+
24 VDC
VE−
R
L
4–20mA
Detector Sink Mode with DC Power
VE+
24 VDC
VE−
R
L
4–20mA
10
VIN+
1 1
VIN−
2 2
4–20mA
3 3
COM
4
VIN+
1 1
VIN−
2 2
4–20mA
3 3
COM
4
Status Indicator
Fault
Inhibit
0 to 100% Full Scale
Over range
Legend
1
2
3
Legend
1
2
3
VESDA
System controller
VESDA Sensepoint XCL
detector
Current flow
System controller
VESDA Sensepoint XCL
detector
Current flow
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