Emerson Rosemount 248 User manual

Quick Start Guide
00825-0300-4825, Rev AA
December 2021
Rosemount™ 248 Rail Mount
Temperature Transmitter
with RK Option and HART® 7 Protocol

Contents
About this guide...........................................................................................................................3
Installation................................................................................................................................... 5
Configuration...............................................................................................................................8
Mount the transmitter................................................................................................................10
Product certifications................................................................................................................. 12
Quick Start Guide December 2021
2 Emerson.com/Rosemount

1 About this guide
This guide provides basic guidelines to install the Rosemount 248R Rail
Mount Temperature Transmitter. It does not provide instructions for
detailed configuration, diagnostics, maintenance, service, troubleshooting,
or installations. Refer to the Rosemount 248R Temperature Transmitter
Reference Manual for more instruction. The manual and this guide are also
available electronically at Emerson.com/Rosemount.
1.1 Safety messages
WARNING
Explosions
Explosions could result in death or serious injury.
Installation of device in an explosive environment must be in accordance
with appropriate local, national, and international standards, codes, and
practices.
Review the Hazardous Locations Certifications for any restrictions
associated with a safe installation.
Process leaks
Process leaks could result in death or serious injury.
Install and tighten thermowells and sensors before applying pressure.
Do not remove the thermowell while in operation.
Electrical shock
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.
Unless marked, the conduit/cable entries in the housing use a ½–14 NPT
thread form. Entries marked “M20” are M20 × 1.5 thread form. On
devices with multiple conduit entries, all entries will have the same
thread form. Only use plugs, adapters, glands, or conduit with a
compatible thread form when closing these entries.
When installing in a hazardous location, use only appropriately listed or
Ex certified plugs, glands, or adapters in cable/conduit entries.
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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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2 Installation
2.1 Safety messages
Instructions and procedures in this section may require special precautions
to ensure the safety of the personnel performing the operations.
Information that potentially raises safety issues is indicated by a warning
symbol ( ). Please refer to the following safety messages before performing
an operation preceded by this symbol.
WARNING
Failure to follow these installation guidelines could result in death or
serious injury.
Ensure only qualified personnel perform the installation.
Explosions could result in death or serious injury.
Do not remove the housing covers in explosive atmospheres when the
circuit is live.
Before connecting a handheld communicator in an explosive
atmosphere, ensure the instruments are installed in accordance with
intrinsically safe or non-incendive field wiring practices.
Verify that the operating atmosphere of the transmitter is consistent
with the appropriate hazardous locations certifications.
All connection head covers must be fully engaged to meet explosion-
proof requirements.
Process leaks could result in death or serious injury.
Do not remove the thermowell while in operation.
Install and tighten thermowells and sensors before applying pressure.
Electrical shock could cause death or serious injury.
Use extreme caution when making contact with the leads and terminals.
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2.2 Connections
Single input
2 w / 3 w / 4 w RTD
or lin. R
TC (internal CJC or
external 2 w / 3 w /
4 w CJC)(1)
mV 3 w / 4 w
potentiometer
42 44
43
41
43 I1
41 42 44
43
+
-
CJC
3
41 42 44
43
+
41 42 44
43
4I1
(1) When using thermocouple input, the transmitter can be configured for either
constant, internal or external CJC via a Pt100 or Ni100 sensor. This must be
selected during device configuration.
2.3 Multidrop mode
The communication is either by means of a HART® communicator or a HART
modem.
The HART communicator or a HART modem can be connected across BC or
CD.
The outputs of maximum 63 transmitters can be connected in parallel for a
digital HART 2-wire communication.
Before it is connected, each transmitter must be configured with a unique
number from 1 to 63. If two transmitters are configured with the same
number, both will be excluded. The transmitters must be programmed for
multidrop mode (with a fixed output signal of 4 mA). Maximum current in
the loop is therefore 252 mA.
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B
C
D
+
-
+
-
A
E
F F F
A. Power supply
B. Connection
C. Connection
D. Connection
E. 250 Ω < Rload < 1100 Ω
F. Transmitter
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3 Configuration
3.1 Safety messages
Instructions and procedures in this section may require special precautions
to ensure the safety of the personnel performing the operations.
Information that potentially raises safety issues is indicated by a warning
symbol ( ). Please refer to the following safety messages before performing
an operation preceded by this symbol.
WARNING
Failure to follow these installation guidelines could result in death or
serious injury.
Ensure only qualified personnel perform the installation.
Explosions could result in death or serious injury.
Do not remove the housing covers in explosive atmospheres when the
circuit is live.
Before connecting a handheld communicator in an explosive
atmosphere, ensure the instruments are installed in accordance with
intrinsically safe or non-incendive field wiring practices.
Verify that the operating atmosphere of the transmitter is consistent
with the appropriate hazardous locations certifications.
All connection head covers must be fully engaged to meet explosion-
proof requirements.
Process leaks could result in death or serious injury.
Do not remove the thermowell while in operation.
Install and tighten thermowells and sensors before applying pressure.
Electrical shock could cause death or serious injury.
Use extreme caution when making contact with the leads and terminals.
3.2 Configuration methods
The device can be configured in the following ways:
•With AMS Device Manager
•With a HART® communicator with Emerson's DDL driver
•Via programming framework (e.g. DCS, PACTware™)
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HART communicator
To get access to product-specific commands, the HART communicator must
be loaded with Emerson's DDL driver. This can be ordered through either the
FieldComm Group or Emerson.
44
43
42
41
51
11121314
12
11
A
BC
D
E
F
G
A. Rosemount transmitter
B. Ex area
C. Safe area
D. 250 Ω < Rload < 1100 Ω
E. Receiving equipment
F. +V supply
G. Input
Programming framework
Support for both EDD and FDT®/DTM™ technology, offering configuration
and monitoring via relevant DCS/Asset Management Systems and
supported management packages (e.g. PACTware).
12
11
+
-
44
43
42
41
51
11121314
A
B
D
C
A. Rosemount transmitter
B. 250 Ω < Rload < 1100 Ω
C. Process computer
D. DCS, etc.
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4 Mount the transmitter
4.1 Rail mount transmitter with remote mount sensor
The least complicated assembly uses:
•a remote mounted transmitter
•an integral mount sensor with terminal block
•an integral style connection head
•a standard extension
•a threaded thermowell
Refer to the Metric Sensor Product Data Sheet for complete sensor and
mounting accessory information.
4.1.1 Assemble the device
To complete the assembly:
Procedure
1. Attach the transmitter to a suitable rail or panel.
2. Attach the thermowell to the pipe or process container wall. Install
and tighten the thermowell before applying pressure.
3. Attach the sensor to the connection head and mount the entire
assembly to the thermowell.
4. Attach sufficient lengths of sensor lead wire to the sensor terminal
block.
5. Attach and tighten the connection head cover. Enclosure covers
must be fully engaged to meet explosion-proof requirements.
6. Run sensor lead wires from the sensor assembly to the transmitter.
7. Attach the sensor and power leads to the transmitter. Avoid contact
with leads and terminals.
4.2 Rail mount transmitter with threaded sensor
The least complicated assembly uses:
•a threaded sensor with flying heads
•a threaded sensor connection head
•a union and nipple extension assembly
•a threaded thermowell
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