FISCHER DE28 User manual

2.6.08 BA_GB_DE28.fm
Instruction Manual
DE28 Differential Pressure Transmitter
1. Safety Instructions
1.1. General
This manual contains detailed
information about the product,
and instructions for its installati-
on, operation and maintenance.
Operators and other technical
personnel responsible for the
equipment must read this thoroughly before at-
tempting to install or operate this equipment. A
copy of this manual must always be kept accessi-
ble at the place of work for reference by concerned
personnel.
Chapter 1 (sections 1.2 through 1.7) contains ge-
neral as well as specific safety instructions. Chap-
ters 2 through 10, covering topics ranging from
intended purpose of the equipment to its final dis-
posal, also include important points relating to
safety. Overlooking or ignoring any of these safety
points can endanger humans and animals, and
possibly cause damage to other equipment.
1.2. Personnel Qualification
Personnel responsible for installation, operation,
maintenance and inspection of this product must
have the qualifications, training and experience
necessary to carry out such work on this type of
equipment.
1.3. Risks of Disregarding Safety Instructions
Disregarding safety instructions, use of this pro-
duct for purposes for which it is not intended, and/
or operation of this product outside the limits spe-
cified for any of its technical parameters, can result
in harm to persons, the environment, or the plant
on which it is installed. Fischer Mess- und Regel-
technik GmbH will not be responsible for conse-
quences in such circumstances.
1.4. Safety Instructions for Operators
Safety instructions for the proper use of this pro-
duct must be followed.
Table of Contents
1. Safety Instructions
2. Intended Applications
3. Product Description and Functions
4. Installation
5. Commissioning
6. Maintenance
7. Transport
8. Service
9. Accessories
10. Disposal
11. Specifications
12. Dimensions
13. Ordering Code
14. CE-Certificate

2
This information must be available at all times to by per-
sonnel responsible for installation, operation, mainte-
nance and inspection of this product. Adequate steps
must be taken to prevent the occurrence of hazardous
conditions that can be caused by electric energy and the
convertible energy of the process media. Such conditi-
ons can, for example, be the result of improper electrical
or process connections. Detailed information is available
in relevant published norms (DIN EN, UVW in Germany;
and equivalents in other countries), industrial standards
such as DVWG, Ex-, GL-, VDE guidelines, as well as re-
gulations of the local authorities (e.g., EVUs in Germa-
ny).
1.5. Modifications Forbidden
Modification or other technical alteration of the product is
not permissible. This also applies to the use of unautho-
rized spare parts for repair / maintenance of the product.
Any modifications to this product, if and as necessary,
should be done only by Fischer Mess- und Regeltechnik
GmbH.
1.6. Operational Restrictions
The operational reliability of the product is guaranteed
only when used for intended purposes. The product must
be selected and configured for use specifically with defi-
ned process media. The limiting values of operating pa-
rameters, as given in the product specification sheet,
must never be crossed.
1.7. Safety Considerations during Installation and
Maintenance
The safety instructions given in this manual, existing na-
tional regulations relating to accident prevention, and the
internal safety rules and procedures of the user organi-
zation regarding safety during installation, operation and
servicing must all be followed meticulously.
It is the responsibility of the users to ensure that only sui-
tably qualified and experienced technical personnel are
used for installation, operation and servicing of this
equipment.
2. Intended Applications
Measuring Transmitter for overpressure, partial vacuum
and differential pressure of liquid and aerial media. The
product may be used only for applications and under
conditions specified by the manufacturer. Please confer
with Fischer Mess- und Regeltechnik prior to using this
transmitter along with polluted or aggressive media. For
use with this media it needs to be adjusted in every part
with direct contact to the media.
3. Product Description and Functions
3.1. Block Schematic Diagram
3.2. Principles of Operation
This transmitter is based on a rugged and uncomplicated
diaphragm movement. The operating principle of the sy-
stem is identical for all applications of this type. In a state
of equilibrium, the forces of the springs on both sides of
the diaphragm are balanced.
The pressure or differential pressure to be measured
creates an unbalanced force of the springs for the
measuring range until a new equilibrium is reached.
A centre-mounted tappet transfers the motion of the dia-
phragm system to the core of an inductive displacement
transducer. The subsequent converter circuit converts
this motion into an electrical output signal 0(4) - 20 mA li-
near, 3-wire connection.
4. Installation
The electronic module is mounted on a flat plate or panel,
for which it has integral hole flanges. The pressure trans-
mitters are calibrated at the factory while mounted up-
right, pressure ports downward and must be mounted
this way.
4.1. Process Connections
• Only technicians who are qualified and authorized for
this type of work should undertake installation.
• Only for intended mechanic process connection - see
ordering code on type plate on the instrument for mo-
del specification.
• Ensure that the process equipment and pressure li-
nes are at atmospheric pressure before making pres-
sure connections to the instrument.
• The instrument should be provided with suitable pro-
tection against pressure surges.
• Ensure that the mechanical configuration and materi-
als of construction of the instrument are compatible
with the process media.
• Ensure that process pressure is always less than the
specified safe pressure rating.
1 pressure chamber
2 inductive
displacement
transducer
3 measuring springs
4 measuring
diaphragm

3
4.2. Electrical Connections
• Only technicians who are qualified and authorized for
this type of work should undertake installation.
• Electrical connections must conform to relevant inter-
national, national and local regulations and norms re-
lating to electrical and instrumentation installations.
• Switch off electrical power to the plant before attemp-
ting electrical installation work of any kind.
• Make electrical connections to the transmitter though
a suitable energy-limiting safety device (isolation or
zener barrier).
5. Commissioning
Power supply, pressure lines, switching lines and signal
cabling to the pressure transmitter must be correctly sel-
ected to meet operational requirements, and installed in
a way that does not cause physical stress to the instru-
ment.
5.1. Pressure Connections
The instruments pressure ports are marked by +and −
symbols. The pressure applications need to be installed
according to the label.
Differential pressure measurement:+higher pressure
−lower pressure
Pressure measurement: +pressure port
Negative pressure measurement: −negative pressure
port
5.2. Shock Pressure Moderation
During pulsating pressure on the plant mechanical wear
and disturbances in functional capability may occur. To
avoid this we recommend installing absorbers into the
pressure lines.
5.3. Location of Connectors
5.4. Electrical Connection
6. Maintenance
The instrument is inherently maintenance-free.
However, to ensure reliable operation and maximize the
operating life of the instrument, it is recommended that
the instrument is regularly inspected, e.g.:
• Check the output signal.
• Check the pressure connections for leaks.
• Check the electrical connection (screw terminals).
Inspection and test schedules depend on operating and
site conditions. The operating manuals of other equip-
ment to which the differential pressure transmitter is con-
nected must be read thoroughly to ensure that all of them
work correctly when connected together.
7. Transport
The product must be protected against shock and vibra-
tion during transport. It must therefore be properly pak-
ked, preferably in the original factory packaging,
whenever it is to be transported.
8. Service
Any defective devices or devices with missing parts
should be retourned to Fischer Mess- und Regeltechnik
GmbH. For quick service contact our service department.
Remaining medium in and on dismant-
led measuring instruments may cause
danger to persons, environment and
equipment. Take reasonable precauti-
ons! Clean the instrument thoroughly if necessary.
9. Accessories
N.A.
connectors
Signal
24 V DC / AC

4
10. Disposal
Protect your environment!
Use the product in accordance with re-
levant regulations. Please be aware of
environmental consequences of dispo-
sal at the end of the product's life, and
take care accordingly.

5
11. Specifications
General
Measuring ranges 0-0.4 0-0.6 0-1 0-1.6 0-2.5 0-4 0-6 bar
Nominal pressure 16 bar
Max. pressure load one-sided overpressure protected up to nominal pressure,
on (+) and (-) side of diaphragm, partial vacuum protected
Permissible ambient temperature 0 up to +70°C
Max. storage temperature 70 °C
Protection class IP54 per DIN EN 60529
Linearity ≤2% FS
Hysteresis ≤1% FS
Electrical
Electrical connection 3-wire
Operating voltage 24 V DC / AC 24 V DC / AC
range 15...30 V DC range 15...30 V DC
20...30 V AC 20...28 V AC
Output signal 0...20 mA 0...10 V
4...20 mA
Load ≤380 Ω for all ≥2 K Ω
operating voltages
Connections
Pressure connection female thread G 1/8
cutting ring connection (brass) for 6mm tube
cutting ring connection (brass) for 8mm tube
Electrical connection fixed numbered cable, prewired
Materials
Case material polycarbonate
Pressure chamber brass
Measuring diaphragm NBR / Viton®
Mounting
Mounting position upright, pressure ports downward
Measuring transmitter is reverse battery and short circuit protected.

6
12. Dimensions (all units in mm unless stated otherwise)
cutting ring connection for ø 6 mm M12x1.5 cable gland

7
13. Ordering Code
Differential Pressure Transmitter DE 28
Measuring Range
0 ... 400 mbar.................................................................... > 83
0 ... 0.6 bar.................................................................... > 01
0 ... 1 bar.................................................................... > 02
0 ... 1.6 bar.................................................................... > 03
0 ... 2.5 bar.................................................................... > 04
0 ... 4 bar.................................................................... > 05
0 ... 6 bar.................................................................... > 06
Pressure Chamber / Gaskets
pressure chamber, measuring diaphragm, gasket: Ms/NBR ............ > M
pressure chamber, measuring diaphragm, gasket: Ms/Viton®..........> N
Pressure Connection
Female thread G 1/8................................................................................> 00
Cutting ring connection (brass) for 6mm tube..........................................> 28
Cutting ring connection (brass) for 8mm tube..........................................> 29
Electrical Connection
Numbered cable, 1m, prewired.................................................................................> 1
Numbered cable, 2.5m, prewired..............................................................................> 2
Numbered cable, 5m, prewired.................................................................................> 5
Output Signal
0 - 20 mA linear, 3-wire connection ..................................................................................> A
4 - 20 mA linear, 3-wire connection ..................................................................................> P
0 - 10 V DC linear, 3-wire connection ...............................................................................> C
Power supply
24 V DC / AC ...........................................................................................................................> L
0
0L 00

Technische Änderungen vorbehalten • Subject to change without notice • Changements techniques sous réserve
Fischer Mess- und Regeltechnik GmbH • Bielefelder Str. 37a • D-32107 Bad Salzuflen • Tel. [phone] • Fax [phone]
eMail: [email protected] • www.fischermesstechnik.de
8
14. CE-Certificate