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2 6 6 D D S H A R T | P R E S S U R E T R A N S M I T T E R S | O I/ 2 6 6 D D S - E N R E V. A
5 Transmitter wiring
WARNING - GENERAL RISKS
Observe the applicable regulations governing electrical installation. Wiring must be executed in absence of power supply.
Since the transmitter has no switch-off elements, overvoltage protection devices, lightning protection, and voltage separation
capacity must be provided at the plant (overvoltage/lightning protection is optional). Check that the existing operating voltage
corresponds to the voltage indicated on the name plate.The same lines are used for both the power supply and output signal. In
case the surge protection option is present and the transmitter is installed in a Hazardous area, the transmitter has to be power
supplied from a voltage source isolated from mains (galvanic separation). Furthermore the potential equalization for the entire
powering cable must be guaranteed since the intrinsic safety circuit of the transmitter is grounded.
Electrical shock can result in death or serious injury.
Avoid contact with the leads and terminals. High voltage that may be present on leads can cause electrical shock.
Do NOT make electrical connections unless the electrical code designation stamped on the transmitter data plate agrees with
the classification of the area in which the transmitter is to be installed.
Failure to comply with this warning can result in fire or explosion.
Supply requirement
For signal/power connection use twisted, stranded pairs of wiring no 18 to 22 AWG / 0.8 to 0.35mm2 ø up to 5000 feet (1500
meters). Longer loops require larger wire. If a shielded wire is used, the shield should be grounded only at one end, not both ends.
In case of wiring at transmitter end, use the terminal located inside the housing marked with the appropriate sign. The 4 to 20 mA
dc output signal and the dc power supply to the transmitter are carried from the same pairs of wires. The transmitter operates
from 10.5 to 42 V DC with no load and is protected against reverse polarity connection Minimum operating voltage increase to 12.3
V DC with optional surge protector or to 10.8 V DC with optional conformity to NAMUR NE 021 (2004).
For maximum power supply voltage please refer to the top identification plate of the transmitter.
The actual possible line length of the electrical circuit depends on the total capacitance and resistance, and can be estimated
using the following formula:
Where:
L = Line length in m
R = Total line resistance in Ω (ohms)
C = Line capacitance in pF/m
Cf = Capacitance of the devices located in the circuit in pF
Avoid routing cables with other electrical cables (with inductive load, etc.) or near large electrical equipment.
Cable connection
Depending on the design supplied, the electrical connection is established via a cable entry, M20 x 1.5 or 1/2-14 NPT thread.
Connectors related to different protocols are available on request. The screw terminals are suitable for wire cross sections of up to
2.5 mm2 (AWG 14).It is recommended that you strip approx. 30 to 35 mm (1.18 to 1.38 inch) off the cable jacket (see figure 14). Use
wiring rated 10 °C minimum above ambient temperature.
Figure 14 - Stripped connecting cable
IMPORTANT
For transmitters with "Flameproof enclosure" (Ex d) type of protection, the housing cover must be secured using the locking
screw. The screw plug that may have been supplied with the transmitter must be sealed at the plant using Molykote DX.
The installer assumes responsibility for any other type of sealing medium used. At this point, we wish to draw your attention to
the fact that increased force will be required to unscrew the housing cover after an interval of several weeks.
This is not caused by the threads, but instead is due solely to the type of gasket.
30 - 35 mm
1.18 - 1.38 inch
M10708
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