Emerson Rosemount 2521 Series User manual

Quick Start Guide
00825-0100-2521, Rev AB
October 2020
Rosemount™ 2521 Solids Level Switch
Vibrating Fork

Contents
Introduction.................................................................................................................................3
Mechanical installation...............................................................................................................10
Electrical installation.................................................................................................................. 15
Configuration.............................................................................................................................24
Operation...................................................................................................................................29
Maintenance.............................................................................................................................. 33
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1 Introduction
The level switch detects the presence and absence of a process media at its
installation point, and reports it as a switched electrical output.
Note
Other language versions of this Quick Start Guide can be found at
Emerson.com/Rosemount.
1.1 Safety messages
NOTICE
Read this manual before working with the product. For personal and system
safety, and for optimum product performance, ensure you thoroughly
understand the contents before installing, using, or maintaining this
product.
For technical assistance, contacts are listed below:
Customer Central
Technical support, quoting, and order-related questions.
•United States - 1-800-999-9307 (7:00 am to 7:00 pm CST)
•Asia Pacific- 65 777 8211
North American Response Center
Equipment service needs.
•1-800-654-7768 (24 hours a day — includes Canada)
•Outside of these areas, contact your local Emerson representative.
WARNING
Physical access
Unauthorized personnel may potentially cause significant damage to and/or
misconfiguration of end users’ equipment. This could be intentional or
unintentional and needs to be protected against.
Physical security is an important part of any security program and
fundamental to protecting your system. Restrict physical access by
unauthorized personnel to protect end users’ assets. This is true for all
systems used within the facility.
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WARNING
Failure to follow safe installation and servicing guidelines could result in
death or serious injury.
•Ensure the level switch is installed by qualified personnel and in
accordance with applicable code of practice.
•Use the level switch only as specified in this manual. Failure to do so may
impair the protection provided by the level switch.
Explosions could result in death or serious injury.
•In explosion-proof/flameproof, increased-safety, and dust ignition-proof
installations, do not remove the housing cover when power is applied to
the level switch.
•The housing cover must be fully engaged to meet flameproof/explosion-
proof requirements.
Electrical shock could cause death or serious injury.
•Avoid contact with the leads and terminals. High voltage that may be
present on leads can cause electrical shock.
•Ensure the power to the level switch is off, and the lines to any other
external power source are disconnected or not powered while wiring the
level switch.
•Ensure the wiring is suitable for the electrical current and the insulation is
suitable for the voltage, temperature, and environment.
Process leaks could result in death or serious injury.
•Ensure the level switch is handled carefully. If the process seal is
damaged, gas or dust might escape from the silo (or other vessel)
Any substitution of non-recognized parts may jeopardize safety. Repair
(e.g. substitution of components) may also jeopardize safety and is not
allowed under any circumstances.
•Unauthorized changes to the product are strictly prohibited as they may
unintentionally and unpredictably alter performance and jeopardize
safety. Unauthorized changes that interfere with the integrity of the
welds or flanges, such as making additional perforations, compromise
product integrity and safety. Equipment ratings and certifications are no
longer valid on any products that have been damaged or modified
without the prior written permission of Emerson. Any continued use of
product that has been damaged or modified without the written
authorization is at the customer’s sole risk and expense.
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CAUTION
The products described in this document are NOT designed for nuclear-
qualified applications.
•Using non-nuclear qualified products in applications that require
nuclear-qualified hardware or products may cause inaccurate readings.
•For information on Rosemount nuclear-qualified products, contact your
local Emerson Sales Representative.
Individuals who handle products exposed to a hazardous substance can
avoid injury if they are informed of and understand the hazard.
•If the product being returned was exposed to a hazardous substance as
defined by Occupational Safety and Health Administration (OSHA), a
copy of the required Safety Data Sheet (SDS) for each hazardous
substance identified must be included with the returned level switch.
1.2 Applications
A Rosemount 2521 Solids Level Switch is used for monitoring the level of
bulk materials in all types of containers and silos.
The level switch can be used with all powdery and granulated bulk materials
that do not show a strong tendency to form crusts or deposits. The
detection of solids in a liquid is also possible.
Three different housing options are available:
•Standard
—for installations in non-hazardous area (ordinary locations)
—for dust-ignition proof installations in hazardous areas
•Type 'D'
—for flameproof/explosion-proof/dust-ignition proof installations in
hazardous areas (classified locations)
•Type 'DE'
—same as Type 'D' but with a terminal box (increased safety)
Typical applications are:
•Building materials
—Lime, extruded polystyrene foam (XPS), molding sand, etc.
•Food and beverage
—Milk powder, flour, salt, etc.
•Plastics
—Plastic granulates, etc.
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•Timber
•Chemicals
The level switch has a threaded, flanged, or Tri Clamp process connection for
mounting it onto a silo (or other vessel). You can mount it on a side wall of
the silo, so that it is level with the filling limit to be monitored. Alternatively,
if it has an extended length, mount it vertically on top of a silo to monitor the
maximum filling limit.
The length of the fork can be up to 157.5 in. (4 m) with an extension tube or
up to 787 in. (20 m) with an extension cable.
The use of a sliding sleeve is recommended so that the switching point can
be changed easily during the live operation of the level switch.
Note
The Rosemount 2521 Product Data Sheet has all dimensional drawings.
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Figure 1-1: Typical Installation Examples
A
B
C
C
C
D
A. Rosemount 2521 with the cable-extended fork length
B. Rosemount 2521 with the tube-extended fork length and thermal tube-
extension
C. Rosemount 2521 with the standard length fork
D. Optional sliding sleeve
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Figure 1-2: Detection of solids in water
A
C
D
B
B
B
A. Rosemount 2521 with the tube-extended fork length and thermal tube-
extension
B. Rosemount 2521 with the standard length fork
C. Optional sliding sleeve
D. Solids in water
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1.3 Measurement principles
Using the principle of a tuning fork, a piezo-electric crystal oscillates the
forks at their natural frequency. Changes to the oscillation frequency are
continuously monitored by electronics which varies depending on whether
the fork is covered or uncovered by a solids medium.
When the solids medium in the vessel (silo) falls away from the fork, it causes
a change of oscillation frequency that is detected by the electronics and the
output switches to indicate an 'uncovered' state.
When the solids medium in the vessel (silo) rises and covers the fork, it
causes a change of oscillation frequency that is detected by the electronics
and the output switches to indicate a 'covered' state.
The electrical output will vary depending on the electronics selected when
the Rosemount 2521 was ordered.
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2 Mechanical installation
2.1 Mounting considerations
Before mounting the level switch on a silo (or other vessel), review the safety
and pre-mounting sections.
2.1.1 Safety
General safety
1. Installation of this equipment shall be carried out by suitably trained
personnel, in accordance with the applicable code of practice.
2. If equipment is likely to come into contact with aggressive
substances, it is the user’s responsibility to take suitable precautions
that prevent it from being adversely affected, thus ensuring the type
of protection is not compromised.
a. Aggressive substances: Acidic liquids or gases that may
attack metals or solvents that may affect polymeric materials.
b. Suitable precautions: Regular checks as part of routine
inspections or establishing from a material's data sheet that it
is resistant to specific chemicals.
3. It is the responsibility of the installer to:
a. Take protective measures, such as fitting an angled shield
(reverse V shape) to the silo or selecting an extension tube
option, when there are high mechanical forces.
b. Ensure that the process connection is tightened by the
correct amount of torque and sealed to prevent process
leaks.
4. Technical data
a. The Rosemount 2521 Product Data Sheet has all the technical
specifications. See Emerson.com/Rosemount for other
language versions.
Hazardous area safety
The Rosemount 2521 Product Certifications document has safety
instructions and control drawings for hazardous area installations. See
Emerson.com/Rosemount for other language versions.
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