ABB 266 HART Series, Operating Instruction

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30 OI/266/HART-EN Rev. M | 2600T Series Pressure transmitters
6 Transmitter wiring
Where:
L = Line length in meters
R = Total 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.
6.4 Wiring procedure
Follow these steps to wire the transmitter:
— Remove the temporary plastic cap from one of the two
electrical connection ports located at both sides in the
upper part of the transmitter housing.
— These connection ports may have a 1/2 inch internal
NPT-F or M20 threads. Various adaptors and bushings
can be fitted to these threads to comply with plant wiring
(conduit) standards.
— Remove the housing cover of the “field terminals” side.
See the indication on housing. In an Explosion-Proof/
Flame-Proof installation, do not remove the transmitter
covers when power is applied to the unit.
— Run the cable through the cable gland and the open port.
— Connect the positive lead to the + terminal, and the
negative lead to the – terminal.
— Plug and seal the electrical ports. Make sure that when
the installation has been completed, the electrical ports
are properly sealed against entry of rain and/or corrosive
vapors and gases.
65 x 10
6
R x C
L =
C
f
+ 10000
C
–
6.3 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 5,000 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
For Ex ia and other intrinsically safe approval power supply
must not exceed 30 V DC.
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 21 (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:
Warning - General risks. 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.
— If applicable, install wiring with a drip loop. Arrange the
drip loop so the bottom is lower than the conduit
connections and the transmitter housing.
— Before reassembling covers, the integrity of the cover
O-rings must be checked. If damaged they must be
replaced with an original spare part. A slight grease layer
should be applied for proper lubrication.
— Put back the housing cover, turn it to seat O-ring into the
housing and then continue to hand tighten until the cover
contacts the housing metal-to-metal. In Ex-d (Explosion
Proof) installation, lock the cover rotation by turning the
set nut (use the 2mm Allen key supplied with the
instrument).
6.5 Electrical connection via connectors
6.5.1 Harting connector (HART output versions) on DIN
housing
1 2
3
1 - DIN Housing with Harting angle connector
2 - DIN Housing with Harting straight connector
3 - Harting Han 8D socket insert for mating plug supplied
(view of sockets)
Figure 41: Harting HAN straight and angle connection connectors