ABB 266 DDS, Руководство пользователя

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2 6 6 DDS H A RT |
P R E SSU R E T R A N SM I T T ER S | O I/ 2 6 6 D DS - EN R E V. B
Application Permissible voltage range of power supply
Standard
Transmitter operated outside the potentially explosive atmosphere from 12 to 42 V
Transmitter operated inside the potentially explosive atmosphere from 12 to 30 V max (intrinsically safe)
Transmitter operated inside the potentially explosive atmosphere from 12 to 42 V max (explosion proof)
HART hand-held communicator may be connected at any wiring termination point in the loop, providing the minimum resistance is
250 ohm. If this is less than 250 ohm, additional resistance should be added to allow communications. The handheld terminal is
connected between the resistor and transmitter, not between the resistor and power source.
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 12 to 42 V DC with no load and is protected against reverse polarity connection.
For Ex ia and other intrinsically safe approval power supply must not exceed 30 V DC.
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 meters
R = Total line resistance in
Ω
(ohms)
C = Line capacitance in pF/m
Cf = Maximum internal capacitance of the HART field devices located in the circuit, in pF
Avoid routing cables with other electrical cables (with inductive load, etc.) or near large electrical equipment.
Cable, cable gland and unused port plug must be in accordance with the intended type of protection (e.g. intrinsically safe,
explosion proof, etc.) and degree of protection (e.g. IP6x according to IEC EN 60529 or NEMA 4x). See also the addendum for
“EX SAFETY” ASPECTS AND “IP” PROTECTION.
In particular, for explosion proof installation, remove the red temporary plastic cap and plug the unused opening with a plug
certified for explosion containment.
WARNING - GENERAL RISKS