Voltage At The Load; 14 Awg Cable - VES Compas Fire Alarm Control Panel Installation Manual

Appendix C: Calculations

Voltage at the load

V = V - (V
load source conductor 1
A voltage of 20.7872 VDC is available to operate the device at this circuit location.
Shading of the SLC tables identify cable length and load combinations that are not permitted for SLC loop
devices. Light shading represents cable lengths that are not permitted when SLC circuits contain five or more
isolators. Dark shading represents cable lengths that are not permitted without the connection of isolators in the
SLC circuit.
Twin cables are connected to SLC loop terminals of the Compas Fire Alarm Control Panel. Data provided in
SLC tables of this section represent resistance and voltage from a single cable-conductor. Resistance and
voltage levels obtained from these tables must include the secondary conductor of the twin cable during the
evaluation process. SLC tables are provided for the following recommended wire gauges:
14 AWG 2.525 Ohms / 1000 ft
16 AWG 4.016 Ohms / 1000 ft
18 AWG 6.385 Ohms / 1000 ft

14 AWG Cable

Resistance
Length
in feet
100 0.2525
200 0.505
300 0.7575
400 1.01
500 1.2625
600 1.515
700 1.7675
800 2.02
900 2.2725
1000 2.525
1100 2.7775
1200 3.03
1300 3.2825
1400 3.535
VES Fire Detection Systems
Compas Fire Alarm Control Panel Installation Manual
+ V ) = 24V DC - (1.6064V DC + 1.6064V DC) = 20.7872V DC
conductor 2
Ω @ 0.1 A
0.02525
0.0505
0.07575
0.101
0.12625
0.1515
0.17675
0.202
0.22725
0.2525
0.27775
0.303
0.32825
0.3535
Voltage Drop per Conductor
@ 0.2 A @ 0.3 A
0.0505 0.07575
0.101 0.1515
0.1515 0.22725
0.202 0.303
0.2525 0.37875
0.303 0.4545
0.3535 0.53025
0.404 0.606
0.4545 0.68175
0.505 0.7575
0.5555 0.83325
0.606 0.909
0.6565 0.98475
0.707 1.0605
Version 4.00 | January 2024 | MAN-1431COM
@ 0.4 A @ 0.5 A
0.101 0.12625
0.202 0.2525
0.303 0.37875
0.404 0.505
0.505 0.63125
0.606 0.7575
0.707 0.88375
0.808 1.01
0.909 1.13625
1.01 1.2625
1.111 1.38875
1.212 1.515
1.313 1.64125
1.414 1.7675
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