1. Product Overview

Electromagnetic flowmeters measure flow by detecting
the voltage generated when a conductive liquid moves
through a magnetic field. The measured voltage is
related to the velocity of the liquid. When combined
with the configured measuring tube dimensions, the
instrument can calculate the volumetric flow rate.

The measurement principle does not require a moving
mechanical measuring element inside the flow path.
This makes electromagnetic technology suitable for
many industrial liquids that have sufficient
electrical conductivity. The suitability of a specific
application depends on the liquid properties, pipe
conditions, process temperature, and selected meter
configuration.

The ProcessMaster FEP300 family combines flow
measurement with electronic signal processing,
configurable outputs, local operation, and diagnostic
functions. These capabilities support integration
into process instrumentation systems and help operators
monitor flow conditions during normal operation.

2. Product Identification and Technical Data

The following table summarizes family-level information
published for the ABB FEP311. These figures describe
available product capabilities and should not be
interpreted as the specification of every possible
ordering configuration.

The nominal diameter, pressure rating, liner, electrode
material, electrical supply, and communication protocol
must be confirmed from the full order code and the
applicable ABB technical data sheet.

3. Electromagnetic Flow Measurement Principle

The FEP311 operates according to Faraday’s law of
electromagnetic induction. When a conductive liquid
passes through the magnetic field generated by the
measuring system, an electrical voltage is induced.
Measuring electrodes detect this voltage, and the
transmitter electronics process the signal to determine
flow velocity.

The relationship between flow velocity and the internal
cross-sectional area of the measuring tube allows the
instrument to determine volumetric flow. Accurate
measurement depends on the selected meter size,
correct installation, appropriate grounding, and
operating conditions that meet the instrument’s
requirements.

Since electromagnetic measurement requires an
electrically conductive medium, the liquid must meet
the minimum conductivity specified for the selected
configuration. ABB documentation lists a conductivity
requirement greater than 5 µS/cm for the FEP300
family, with a higher requirement stated for
demineralized water. The applicable value should be
verified for the intended process.

4. Measuring Tube, Liner and Electrode Selection

The wetted construction is an important part of
electromagnetic flowmeter selection. The liner
separates the process liquid from the meter body,
while the electrodes detect the induced measurement
signal. Their materials must be suitable for the
liquid composition and the process operating
conditions.

ABB lists several liner options within the ProcessMaster
FEP300 family, including hard rubber, soft rubber,
PTFE, PFA, and ETFE. Availability depends on the
nominal diameter and specific ordering configuration.
These materials have different chemical, thermal,
and mechanical characteristics, so selection should
be based on the actual medium and operating range.

Electrode material options documented for the family
include stainless steel, Hastelloy B, Hastelloy C,
platinum-iridium, tantalum, and titanium. Not every
material is available for every meter size or
configuration. Compatibility should be evaluated
against the liquid’s chemical properties and any
potential corrosion or contamination requirements.

5. Process Connections and Installation

The FEP311 is available with flange-type process
connections. ABB documentation references standards
including DIN 2501, EN 1092-1, ASME B16.5,
ASME B16.47, and JIS, depending on the selected
version. The nominal pressure and flange dimensions
must be checked against the actual order code.

Installation should follow the flowmeter manual and
the requirements of the process piping system. The
selected meter size, flange standard, pressure class,
liner, and electrode materials must be appropriate
for the medium and the expected operating conditions.
The installation must also provide the grounding
and electrical connections required for stable
measurement.

Before commissioning, verify the flow direction,
pipe arrangement, mechanical support, electrical
supply, and signal wiring. The meter should be
installed in a location that meets the manufacturer’s
requirements for the selected application. Site
conditions and process piping geometry should be
considered when evaluating the installation.

6. Transmitter Outputs and Communication

The ProcessMaster FEP300 transmitter provides
electronic measurement processing and interfaces
for transmitting flow information to a control
system. ABB documentation lists a 4–20 mA current
output, which may be configured as active or
passive according to the selected version.

The family also supports configurable pulse and
contact functions. The exact capabilities depend
on the transmitter configuration and the relevant
hardware options. Signal wiring, load requirements,
output mode, and control-system input specifications
should be checked before connection.

HART communication is listed as a standard option
in the applicable FEP300 documentation. PROFIBUS PA
and FOUNDATION Fieldbus are also available for
supported configurations. These interfaces allow
the instrument to exchange measurement and
configuration information with compatible
automation systems.

The communication protocol should be confirmed
from the complete order code and device identification.
A general FEP311 designation alone does not establish
that a particular fieldbus option is installed.

7. Configuration, Display and Diagnostics

ABB describes the ProcessMaster FEP300 family as
supporting straightforward configuration and local
operation. Depending on the version, the transmitter
provides a graphical display and menu-based setup
functions for measurement parameters and output
assignments.

Configuration should reflect the actual process
requirements, including engineering units, measuring
range, output scaling, and any applicable totalizer
or digital output settings. Changes should be
documented so that the configured instrument can
be maintained consistently throughout its service
life.

The product family also includes diagnostic
capabilities for supporting fault investigation.
ABB describes functions such as empty-pipe and
partially filled pipe detection for applicable
configurations. Available diagnostics depend on
the instrument version and installed options.
Diagnostic messages should be interpreted using
the relevant operating manual rather than treated
as universal indicators of a specific fault.

8. Industrial Applications

The ABB FEP311 is intended for conductive-liquid
flow measurement in industrial process applications.
Depending on material selection and process
requirements, electromagnetic flowmeters may be
used in water treatment, utility systems, chemical
processing, and other liquid-handling operations.

Application suitability depends on more than the
nominal diameter. Conductivity, liquid chemistry,
temperature, pressure, flow range, liner selection,
electrode material, and installation conditions
must all be considered. A meter configuration
suitable for one process may not be appropriate
for another.

For demanding applications, the selected process
connection and material combination should be
checked against the plant’s design requirements.
Where regulatory or hazardous-area requirements
apply, verify that the specific model and its
documentation meet those requirements. The FEP311
should not be confused with explosion-protected
variants in the broader FEP300 family.

9. Maintenance and Replacement Verification

Routine maintenance should follow ABB’s instructions
and the operating procedures of the facility.
Review diagnostic messages, check the condition
of electrical connections, and investigate
unexpected measurement behaviour systematically.
Before performing inspection or service, follow
the site’s applicable isolation and safety
procedures.

When replacing an FEP311, compare the complete
order code and the existing nameplate information.
Verify the nominal diameter, flange standard,
pressure rating, liner, electrode material,
supply voltage, output configuration, and
communication interface. These details determine
whether a replacement matches the existing
process and control-system requirements.

If the original order code is unavailable, collect
the information from the nameplate, installation
drawing, process documentation, and transmitter
configuration. Do not assume that two FEP311
instruments are identical merely because they
share the same base model designation.

10. Product Summary

The ABB FEP311 ProcessMaster is an electromagnetic
flowmeter for conductive-liquid measurement in
industrial processes. The FEP300 family offers
multiple measuring sizes, liner and electrode
materials, process connections, output functions,
and communication options.

Correct selection requires verification of the
complete ordering configuration and operating
conditions. Consult the applicable ABB ProcessMaster
FEP300 technical data sheet and operating manual
for the exact specifications, wiring, installation,
and commissioning requirements of the individual
instrument.