Emerson Rosemount 248 User manual

Quick Start Guide
00825-0300-4825, Rev BB
January2024
Rosemount™ 248 Rail Mount
Temperature Transmitter
with RK Option and HART® 7 Protocol

Contents
About this guide...........................................................................................................................3
Installation.................................................................................................................................... 6
Configuration............................................................................................................................. 10
Mounting the transmitter......................................................................................................... 13
Product certifications................................................................................................................ 17
China RoHS................................................................................................................................. 31
Quick Start Guide January2024
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.
WARNING
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.
WARNING
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.
WARNING
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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Quick Start Guide 3

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.
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.
Quick Start Guide January2024
4 Emerson.com/Rosemount

WARNING
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.
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.
January2024 Quick Start Guide
Quick Start Guide 5

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 that 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.
Quick Start Guide January2024
6 Emerson.com/Rosemount

2.2 Connections
Table 2-1: Single input connection
2 w / 3 w / 4 w
RTD or lin. R
Thermocouple
(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, you can configure the transmitter for
either constant, internal, or external CJC via a Pt100 or Ni100 sensor. You
must select the input 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 a maximum of 63 transmitters can be connected in
parallel for a digital HART two-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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Figure 2-1: Multidrop connection
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
2.4 Installation best practices
The terminal connectors can be removed to install sensor and power
wiring. After re-installation back into the device:
1. Align the terminal connectors with the internal pins.
2. Rotate the plastic hooks so that they are properly engaged in
the supporting plastic piece.
Quick Start Guide January2024
8 Emerson.com/Rosemount

3. Push down on the terminal connector to properly set it into
place.
Note
Improper seating can cause the hooks to wedge against the
supporting plastic and cause the connector to unseat.
January2024 Quick Start Guide
Quick Start Guide 9

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 that 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.
Quick Start Guide January2024
10 Emerson.com/Rosemount