PEMTECH PT395 Series - Page 12

PT395 Series Detector
12
10. Note: Minimum voltage required for proper operation is 16VDC. If necessary
verify the input voltage by using Digital Multi Meter (DMM) at +V and –V terminals
on the connection board.
Reference Wire size Table
Assuming +24VDC or power input from the source, 8 volts of maximum voltage drop at the
detector power terminals, following would be power consumption of the detector
Cable Size
Cable resistance
Ω/km (Ω/1000Ft)
Max Cable Length*
Meters / (feet)
0.5 mm
2
(20AWG)
34 (10.4)
425
(1400)
0.82 mm
2
(18AWG) 21.4 (6.5)
670
(2200)
1.3 mm
2
(16AWG) 13.4 (4.08)
1030
(3400)
2.0 mm
2
(14AWG) 8.45 (2.57)
1490
(4900)
Data above is for a stranded copper type cable
* The max cable length is estimated based on 24 Volts DC power to the detector and
maximum load of 100 Ω on the controller or signal receiver.
Max resistance per core : R = V/I  8volts / detector consumption (A)
Max Loop resistance for toxic & infrared 67.8 Ω
Catalytic Bead: 29.8 Ω
Sensor Head
Types
Nominal Power
At VDC
With 8 Volts of drop,
V= 16 volts
I = P/V
Combustible
(Catalytic Bead)
4.3 watt 268 mA
All Toxics & Infrareds ~1.9 watt 118 mA
The wire size data below is for reference only. Refer to the manufacturer
specification of the cable that is being used to ensure the maximum cable length
and proper operation of the unit.