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© 2020 All rights reserved. Data subject to change without notice.
cGas Detector for Indoor Public Spaces - Installation Manual
Rev. A | 2020.11
6.5.2 Analog Wire Gauge vs Run Length
The table below shows the maximum cable length between the cGas Detector
and the controller for normal installations (a separate signal line from the
controller for each cGas Detector is required).
SUPPLY
VOLTAGE
MAXIMUM LOAD
(Wire +
Termination
Resistor) (ohms)
WIRE GAUGE
(awg)
MAXIMUM
CABLE LENGTH
(feet)
24 VDC
592
20
4,400
18
7,100
16
10,700
16 VDC
216 (assume a
200 Ω termination
resistor)
20
700
18
1,200
16
1,800
24 VAC
1,060
20
27,000
18
43,200
16
65,500
12 VAC
316 (assume a
200 Ω termination
resistor)
20
5,600
18
8,900
16
13,583
NOTE:
The termination resistor could be as high as 500 Ω (10 volt
measurement at 20 mA). A poor quality 24 VAC transformer might supply as
little as 14 volts at low line conditions.