Emerson Rosemount 2555 User manual

Quick Start Guide
00825-0100-2555, Rev AC
October 2020
Rosemount™ 2555 Solids Level Switches
Capacitance Probe

Contents
Introduction.................................................................................................................................3
Mechanical installation.................................................................................................................9
Electrical installation.................................................................................................................. 14
Configuration.............................................................................................................................20
Troubleshooting........................................................................................................................ 39
Maintenance.............................................................................................................................. 44
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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™ 2555 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,
slurry and liquids.
Four different housing options are available:
•Standard local
—for installations in non-hazardous area (ordinary locations)
—for dust-ignition proof installations in hazardous areas
•Type 'D' local
—for flameproof/explosion-proof/dust-ignition proof installations in
hazardous areas (classified locations)
•Type 'DE' local
—as Type 'D' but with a terminal box (increased safety)
•Standard Remote
—separated electronics connected to probe by a cable
Typical applications are:
•Building materials
—Lime, extruded polystyrene foam (XPS), molding sand, etc.
•Food and beverage
—Milk powder, flour, salt, etc.
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•Plastics
—Plastic granulates, etc.
•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 capacitance probe can be up to 98.4 in. (2.5 m) with a rod
extension tube or up to 787 in. (20 m) with an extension rope.
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 2555 Product Data Sheet has all dimensional drawings.
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Figure 1-1: Typical Installation Examples
A
B
C
D
E
F
GHI
J
B
K
A. Inactive length to reach distance from silo wall
B. Inactive length due to long mounting nozzle
C. Short length (full-silo detection)
D. Short length (on-demand detection)
E. Short length (empty-silo detection)
F. Application in down pipe
G. Inactive length to bring active probe to required level
H. Inactive length and sliding sleeve for adjustable height
I. Rope version (full-silo detection)
J. Rope version (empty-silo detection)
K. Optional sliding sleeve
Active and inactive probe lengths
The active length is always inside the silo and generates an electrical field
between the probe and the silo wall. With active shield technology, the RF
measurements are unaffected by product build-up on the probe. The
inactive length is used to extend the overall probe length.
Note
See the Rosemount 2555 Product Data Sheet for extended length options.
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1.3 Measurement principles
Using the principle of measuring capacitance through RF (Radio Frequency),
the presence or absence of a solids medium is detected by monitoring the
change in capacitance between the probe and the bottom of the silo.
When the solids medium in the vessel (silo) falls away from the probe level, it
causes a decrease in capacitance 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 rod, it
causes an increase of capacitance 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 2555 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 2555 Product Data Sheet has all the technical
specifications. See Emerson.com/Rosemount for other
language versions.
Hazardous area safety
The Rosemount 2555 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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2.1.2 Hygienic applications
Hygienic approvals and compliance requirements are in the Rosemount
2555 Product Certifications document (see Emerson.com/Rosemount for
other language versions).
2.1.3 Tightening threaded process connections
When tightening the threaded process connection of a Rosemount 2555:
•Use an open-ended wrench on the hexagonal boss of the level switch or
the sliding sleeve.
•Never tighten by using the housing.
•Do not exceed the maximum torque of 80 Nm.
2.1.4 Sliding sleeve
Tighten both M8 screws with a torque of 20 Nm to establish a seal and
maintain the process pressure.
2.1.5 Mechanical load
The load at points A and B (Figure 2-1) must not be exceeded. All ratings are
for 104 °F (40 °C).
Figure 2-1: Maximum Mechanical Loads
A
B
Table 2-1: Maximum Mechanical Loads
Rosemount 2555S
Rosemount 2555R
Rod version:
Rope version:
A: 125 Nm
4 kN tensile load
B: 20 Nm
Rosemount 2555M
Rosemount 2555P
Rod version:
Rope version:
A: 525 Nm
40 kN tensile load
B: 90 Nm
Rosemount 2555E
Rosemount 2555V
Rod version:
Rope version:
A: 525 Nm
10 kN tensile load
B: 20 Nm
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2.1.6 Orientation of cable glands
When the level switch is mounted horizontally, ensure the cable glands are
pointed downwards to avoid water getting inside the housing. Unused
conduit entries must be completely sealed with a suitably rated stopping
(blanking) plug.
2.1.7 Future maintenance
It is advisable to grease the screws of the housing cover (lid) when a
corrosive atmosphere is present. This will help prevent difficulties when the
cover needs to be removed during future maintenance tasks.
2.1.8 Minimum distances
Figure 2-2 shows the minimum distances required between installed level
switches, the walls of a silo, and a protective shield. The installation of a
protective angled shield above the level switch is recommended depending
on the type of bulk solids.
Figure 2-2: Minimum Distances
> 2 (50)
> 3.9
(100)
> 3.9
(100)
> 7.9
(200)
> 7.9 (200)
> 19.7 (500)
Note
Avoid installing the level switch directly under the flow of solids material
(filling point).
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2.2 Mounting the level switch
Figure 2-3 and Figure 2-4 show how the Rosemount 2555 should be
mounted.
Figure 2-3: Correct and Incorrect Mounting (Rod Version)
> 1.8
(50)
A
> 1.8
(50)
A
> 1.8
(50)
A
> 1.8
(50)
A
OK
OK OK
OK
EFG
CD
B
A. Active probe
B. Mounting the level switch at an angle helps solids material to fall away
and prevent build-up
C. Correct installation: The inactive length is correctly used with a long
socket
D. Correct installation: The inactive length is correctly used even though
there is a build-up of solids material
E. Incorrect installation: The active probe is inside the socket
F. Incorrect installation: The active probe is covered by a build-up of
material and is not detecting the true level
G. Incorrect installation: The active probe is located where solids material
would remain, even in an empty silo
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Figure 2-4: Correct and Incorrect Mounting (Rope Version)
> 1.8 (50) > 1.8 (50)
A A
OK OK
B C D E
A. Active probe
B. Correct installation: The socket height is short
C. Correct installation: The inactive length is correctly used within a long
socket
D. Incorrect installation: The active probe is inside the socket
E. Incorrect installation: The active probe is covered by a build-up of
material and may not be detecting the true level
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3 Electrical installation
3.1 Wiring considerations
Note
See the Rosemount 2555 Product Data Sheet for the full electrical
specifications.
3.1.1 Handling
In cases of improper handling or handling malpractice, the electrical safety
of the device cannot be guaranteed.
3.1.2 Grounding (earthing)
Before any electrical installation, connect the internal or external Potential
Earth (PE) terminal to a grounding point at the installation site if the
Rosemount 2555 is mounted to a non-metal silo or other storage vessel.
Note
See Wiring the level switch for the location of the PE terminals.
3.1.3 Installation regulations
Local regulations or VDE 0100 (Regulations of German Electrotechnical
Engineers) must be observed.
When using 24 V supply voltage, an approved power supply with reinforced
insulation to mains is required.
3.1.4 Fuse
Use a fuse as stated in the connection diagrams.
For details, see Wiring the level switch.
3.1.5 Residual Current Circuit Breaker (RCCB) protection
In case of a defect, the distribution voltage must automatically be cut-off by
an RCCB protection switch to protect against indirect contact with
dangerous voltages.
3.1.6 Power supply
Power supply switch
A voltage disconnection switch must be provided near the device.
Supply voltage
Compare the supply voltage applied with the specifications given on the
electronic module and nameplate before switching on the device.
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3.1.7 Wiring
Field wiring cables
The diameter has to match the clamping range of the used cable gland.
The cross-section has to match the clamping range of the connection
terminals and the maximum current must be considered.
All field wiring must have insulation suitable for at least 250 Vac.
The temperature rating must be at least 194 °F (90 °C).
Use a shielded cable when there are electrical interferences present that are
higher than stated in the EMC standards. Otherwise, an unshielded
instrumentation cable can be used.
Guiding the cables in the terminal box
The field wiring cables must be cut to a length to be able to properly fit them
into the terminal box.
Connection terminals
When preparing cable wires for connection to terminals in a standard or type
'D' housing, the wire insulation must be stripped to show no more than 0.31
in. (8 mm) of the copper strands. For Type 'DE' housings, remove insulation
of no more than 0.35 in. (9 mm). Always check that the power supply is
disconnected or switched-off to avoid coming into contact with dangerous
live parts.
3.1.8 Cable glands
The screwed cable gland and stopping plug must have the following
specifications:
•Ingress protection IP67
•Temperature range from -40 °C to +80 °C
•Hazardous area certification (depending on where the unit is installed)
•Pull relief
Ensure the screwed cable gland safely seals the cable and is tight enough to
prevent water ingress. Unused conduit or cable entries must be sealed with a
stopping (blanking) plug.
A strain relief must be provided for the field wiring cables when the device is
installed with the factory-provided cable glands.
Cable glands and conduit system for ATEX or IECEx
The installation must comply with the regulations of the country where the
level switch is installed.
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Unused entries have to be closed with suitably rated stopping (blanking)
plugs.
Where available, the factory-provided parts must be used.
The diameter of the field wiring cable must match the clamping range of the
cable clamp.
If factory-provided parts are not used, the following must be ensured:
•The parts must have an approval adequate to the approval of the level
sensor (certificate and type of protection).
•The approved temperature range must be between the minimum
ambient temperature of the level sensor and the maximum ambient
temperature of the level sensor increased by 10 K.
•The parts must be mounted according to the instructions of the
manufacturer.
3.1.9 Conduit system
When a threaded conduit system is used instead of a cable gland, the
regulations of the country must be observed. The conduit must have a ½-in.
NPT tapered thread to match a NPT threaded conduit entry of the level
switch and comply with ANSI B 1.20.1. Unused conduit entries must be
closed tightly with a metal stopping (blanking) plug.
Conduit system for FM
The regulations of the country must be observed. The flameproof seals and
stopping (blanking) plugs must have an adequate type approval and a
temperature range of at least -40 to 176 °F (–40 to +80 °C). In addition, they
must be suitable for the conditions and correctly installed. Where available,
the original provided parts of the manufacturer must be used.
Installation with a conduit system in a hazardous area
In a conduit system, single electric conductors are installed in a certified pipe
system. This pipe system must also have a flameproof or explosion-proof
construction.
For ATEX and IECEx approvals, both enclosure of the level switch and pipe
system need to be isolated from each other by using a certified flameproof
or explosion-proof seal. The seal must be installed directly in, or at, the
conduit entries of the level switch. Unused conduit entries must be sealed
using suitably certified blanking elements (stopping plugs).
For FM approval, both enclosure of the level switch and pipe system need to
be isolated from each other by using a certified flameproof seal. The seal
must be installed within 18 inches of the enclosure wall. Unused conduit
entries must be sealed using suitably certified blanking elements (stopping
plugs).
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3.1.10 Remote housing
The remote cable must be installed separately from the power supply lines
to avoid immunity interferences The minimum bending radius of 2 in. (50
mm) must be observed.
3.1.11 Relay and transistor protection
Provide protection for relay contacts and output transistors to protect the
device against inductive load surges.
3.1.12 Static charging
The Rosemount 2555 must be grounded to avoid a static electrical build-up.
This is particularly important for applications with pneumatic conveying and
non-metallic containers.
3.1.13 Opening the lid
Before opening the lid, ensure no dust deposits, no airborne dusts, and no
hazardous atmosphere are present.
Do not remove the lid (cover) in hazardous areas while circuits are alive.
3.2 Wiring the level switch
Figure 3-1: Connections Overview for Standard Housing
1 1 2 345678
B
C
A
A. Connection terminals
B. Internal Protective Earth (PE) terminal
C. External Protective Earth (PE) terminal
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Figure 3-2: Connections Overview for Type 'D' Housing
B
A
112345678
A. Connection terminals
B. Internal Protective Earth (PE) terminal
Figure 3-3: Connections Overview for Type 'DE' Housing
A
B
C
A. Connection terminals (in a terminal box for increased safety).
The fixing torque is 0.5 to 0.6 Nm
B. Internal Protective Earth (PE) terminal
C. External Protective Earth (PE) terminal
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3.2.1 Wiring the power supply and the DPDT relay
Power supply
•21 to 230 Vac (50/60 Hz) ±10%, 1.5 VA
•21 to 230 Vdc ±10%, 1.5 W
•Fuse on power supply: maximum 10 A, 250 V, HBC, fast or slow
Signal output (floating relay DPDT)
•Maximum 250 Vac, 8 A (non-inductive)
•Maximum 30 Vdc, 5 A (non-inductive)
•Fuse on signal output: maximum 10 A, 250 V, HBC, fast or slow
Figure 3-4: Power Supply and Signal Output
1 1 2 3 4 56 7 8
PE +- L N
A
B
A. Power supply
B. Signal output
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4 Configuration
4.1 User interface
Figure 4-1: Features of the User Interface
1 1 2 6 7 8 3 4 5
CAL
TEST
MENU
LED
Display
Table 4-1: LEDs
Green Relay is energized
Yellow Relay is de-energized
Red Maintenance (flashing) or error (not flashing)
4.2 Powering up the first time (calibration)
Calibration automatically starts when the Rosemount 2555 is powered up
for the first time. If the level switch is powered off and then on again, this
calibration procedure is not repeated when starting up.
Prerequisites
•The level switch must be correctly mounted and wired.
•The level of the solids material must be below the probe.
Procedure
1. Ensure the level of the solids material is not covering the probe.
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