B
Wiring instructions
B.1
General instructions for electrical wiring
Follow the instructions detailed in this section for determining the correct wire gauge to
be used for this installation.
1. Use
to determine the required wire gauge/size for general wiring, such as
relay wiring. Calculate the permitted voltage drop with respect to load current, wire
gauge, and length of wires.
Table B-1: Maximum DC Resistance at 68 °F (20 °C) for Copper Wire
AWG #
mm
2
Ohm per 100 ft.
Ohm per 100 m
20
0.52 - 0.61
1.07
3.50
18
0.81 - 0.96
0.67
2.20
16
1.22 - 1.43
0.43
1.40
14
1.94 - 2.28
0.27
0.88
2. Use
to select wire gauge for power supply wires. Do not connect any
circuit or load to detectors' supply inputs.
•
Select number of detectors connected in one circuit.
•
Select wiring length per installation requirements.
•
Refer to power supply range for voltage extreme applied.
Table B-2: Wiring Length in Meters (Feet)
Number of
detectors
Recommended wire diameter (AWG)
Power supply
range (Vdc)
24
18
16
14
N/A
N/A
22-32
20
18
16
14
N/A
N/A
22-32
16
20
18
16
14
N/A
22-32
12
20
18
16
14
N/A
20-32
8
20
18
16
14
N/A
20-32
4 and less
20
18
16
16
14
20-32
m (ft)
50 (164)
100 (328)
150 (492)
200 (656)
240 (820)
Max. length from power supply to last detector
Reference Manual
Wiring instructions
00809-0100-4975
August 2019
Rosemount 975MR
53
Содержание Rosemount 975MR
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Страница 46: ...Maintenance and troubleshooting Reference Manual August 2019 00809 0100 4975 46 Emerson com Rosemount ...
Страница 52: ...Specifications and reference data Reference Manual August 2019 00809 0100 4975 52 Emerson com Rosemount ...
Страница 60: ...RS 485 communication network Reference Manual August 2019 00809 0100 4975 60 Emerson com Rosemount ...
Страница 67: ...Figure D 4 Duct Mount Reference Manual Accessories 00809 0100 4975 August 2019 Rosemount 975MR 67 ...
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