IM 01C25R01-01E
7-1
7. WIRING
7.
WIRING
7.1 Wiring Precautions
IMPORTANT
• The information in the sections from 7.2
throught 7.5(except for 7.5.2) is specific to
HART protocol type. Refer to IM01C25R03-01E
for FOUNDATION Fieldbus protocol type.
• Lay wiring as far as possible from electrical
noise sources such as large capacity transform-
ers, motors, and power supplies.
• Remove the electrical connection dust cap
before wiring.
• All threaded parts must be treated with water-
proofing sealant. (A non-hardening silicone
group sealant is recommended.)
• To prevent noise pickup, do not pass signal
and power cables through the same ducts.
• Explosion-protected instruments must be wired
in accordance with specific requirements (and,
in certain countries, legal regulations) in order
to preserve the effectiveness of their explosion-
protected features.
• The terminal box cover is locked by an Allen
head bolt (a shrouding bolt) on ATEX flame-
proof type transmitters. When the shrouding
bolt is driven clockwise using an Allen wrench,
it goes in. The cover lock can then be released
and the cover can be opened by hand. See
subsection 8.4 “Disassembly and Reassembly”
for details.
• Plug and seal an unused conduit connection.
• Do not turn on power until all wirings including
RTD finished.
7.2 Selecting the Wiring Materi-
als
(a) Use stranded leadwires or cables which are the
same as or better than 600 V grade PVC insulated
wire (JIS C3307) or its equivalent.
(b) Use shielded wires in areas that are susceptible to
electrical noise.
(c) In areas with higher or lower ambient temperatures,
use appropriate wires or cables.
(d) In environment where oils, solvents, corrosive gases
or liquids may be present, use wires or cables that
are resistant to such substances.
(e) It is recommended that crimp-on solderless terminal
lugs (for 4 mm screws) with insulating sleeves be
used for leadwire ends.
7.3 Types of Output
Table 7.1 shows the wiring example according to the
output types.
(1) Analog Output (4 to 20 mA DC)
This instruments uses the same two wires for both, the
signal and power supply. A DC power supply is
required in a transmission loop. The total leadwire
resistance including the instrument load and power
distributor (supplied by the user) must conform to a
value in the permissible load resistance range. Refer to
Figure below.
600
250
0
10.5
16.4
24.7
30
42
load resistanceR (
Ω
)
Power supply voltage E (V)
F0701E.EPS
Communication
Applicable range
R=
E–10.5
0.0236
Figure 7.1 Relation between Power Supply Voltage and
Load Resistance (4 to 20 mA DC Output)
(2) Pulse output and Alarm, Status Output
This instruments uses three wires between the
converter and the power supply.
A DC power and load resistance are required, and
pulse output is connected to a totalizer or an electric
counter.
Low level of the pulse output is 0 to 2V. No
communication is possible over a transmission line.
(3) Simultaneous Analog-Pulse Output
When using the simultaneous analog-pulse output
mode, the communicable distance of the transmission
line is restricted on the wiring method.
Table 7.1 shows the examples of connection for this
output mode.
