Vaisala FS11, Руководство пользователя

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Chapter 3 ________________________________________________________________ Installation
VAISALA ________________________________________________________________________ 27
Table 6 AC (Mains) Cable Selection
Maximum Distance
from Voltage
Source
Wire Cross
Section Area
Nearest AWG
Gauge
Typical Non-
Armored Cable
Diameter
350 m
3 × 1.5 mm
2
No. 15 AWG 10 mm
600 m
3 × 2.5 mm
2
No. 13 AWG 14 mm
950 m
3 × 4.0 mm
2
No. 11 AWG 18 mm
NOTE Cables with diameters more than 15 mm require a separate junction box,
such as Termbox1200, available from Vaisala.
Communication Cable
The customer must provide cables and conduits. The cables used for the
transmission of digital and low-level analogue signals should be of the
following kind: All field cables should be armored, suitable for
underground use, and led to the equipment through conduits. Unless the
cables are armored, they have to be led through pipes. The signal cable
shields should be grounded at both ends.
For modem and RS signal cable use a screened 2 x 0.22 mm
2
(AWG 24,
conductor diameter 0.61 mm) twisted pair signal cable with a shield and
minimum external diameter of 8 mm. If the modem line length exceeds
50 km, consult Vaisala.
If RS-485 connections are used, pay special attention to the quality of the
cable. The shield should be continuous, in other words, also connected to
the distribution frames.
For more information, see section Communication Options on page 48.
NOTE Cables with diameters more than 15 mm require a separate junction box,
such as Termbox1200, available from Vaisala.