Delta Controls DPT-2000 - Manual (Page 18)

16 IOM-DPT-A: FEB 2014
6.2.1. Transmitter casing
A casing of DPT... transmitter is made of high-pressure casting of aluminium alloy or 316L steel. It consists of a
body, two bolted side covers (full and with pane), cable inlets and plug with M20x1,5 or ½ NPT thread
.
Inside the casings is divided into two chambers, separated by a header. An additional header, with a ribbon
cable is intended for transmitting a signal from temperature sensor to the inside of a transmitter.
The casing is equipped with internal and external earth terminals.
6.2.2. Electronic board with display
The electronic board, along with a display, is installed in a housing made of polycarbonate, in the bigger of two
casing’s chambers, where it is possible to rotate it by

180

every 90

. A connecting board with terminal strip
(fig. 2a) and the elements of interference filter and protecting elements are installed in the second chamber.
6.2.3. Shields of the measuring insert
Within the framework of basic version there is a possibility to select one of five types of casings shown on fig.6.
The SW1 and SW2 shields are high-tension shields designed to welding.
The GB1, GN1 and G1 shields have threaded process connection and designed to screw in assembly sockets.
The T1 shield have flange process connection.
7. INSTALLATION OF TRANSMITTERS
The DPT –2000ALW transmitters can operate in any position.
During the installation of temperature transmitters the casing of electronic system should be protected against
exceeding of allowed temperatures. Suitable thermal covers should be used or the transmitters should be
mounted in such a position so the heat from medium does not heat up the casing.
When the transmitters are mounted, particularly in areas endangered by explosion, also the
heat conduction of sensor metal casing and ambient temperature for ensuring proper work
conditions and temperature classes should be taken into consideration.
Data specified in ”Annex Exi” are applicable for intrinsically safe versions.
Data specified in ”Annex Exd01” are applicable flameproof versions.
8. ELECTRICAL CONNECTION
8.1. General recommendations
8.1.1 . It is recommended that twisted pair cabling be used for the signal lines. If the transmitter and signal line
are subject to a large amount of electromagnetic interference, then shield pair cable should be used. The signal
wires should not run alongside network power supply cables or near to large electrically-powered devices.
The devices used together with the transmitters should be resistant to electromagnetic interference from the
transmission line in accordance with compatibility requirements. It is also beneficial to use anti-interference
filters on the primary side of the transformers, the power supplies used for the transmitters and apparatus used
in conjunction with them.
8.1.2. Wet or rising damp inside transmitter can cause its damage.
When the isolation of the wires in the packing gland is ineffective (for example, when single
wires are used) the opening of the gland should be carefully sealed with an elastic sealing
compound to obtain IP66 protection. It is useful to form the segment of the signal wire leading
to the packing gland into a protective loop to prevent condensation from running down in the
direction of the gland..
8.2. Electrical connections
The DPT-... transmitters are to be connected as shown in fig. 2a – 2d.
In DPT-... transmitters, a 240Ω resistor is permanently fitted in series in the transmitter’s current circuit
and blocked up with jumper between –> and as shown in fig.2a and 2b.
When the resistance in the current loop is lower than 240Ω it is necessary to jumper disassemble to
Hart communication.
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