Emerson Rosemount 925FGD User manual

Quick Start Guide
00825-0100-4925, Rev AC
April2023
Rosemount™ 925FGD Fixed Gas
Detector
Integrated Gas Detection

Safety information
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.
Before connecting a hand-held communication device 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 location certifications.
When connecting an external device to transmitter's discrete output in a hazardous area,
ensure that the external device is installed in accordance with Intrinsically Safe or non-
incendive field wiring practices.
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.
WARNING
Explosion hazard
Substitution of components may impair suitability for Class I, Division 1.
WARNING
AVERTISSEMENT - Risque d'explosion
La substitution de composants peut rendre ce materiel inacceptable pour les emplacements
de Classe I, Division 1.
CAUTION
Refer to the Product Certification section of this Quick Start Guide for documentation.
CAUTION
For safety reasons this equipment must be operated and serviced by qualified personnel
only. Read and understand the instruction manual completely before operating or servicing.
Quick Start Guide April2023
2 Rosemount 925FGD

CAUTION
ATTENTION
Pour des raisons de sécurité, cet equipment doit être utilisé, entretenu, et réparé
uniquement par un personnel qualifié. Étudier le manuel d'instructions en entier avant de
utiliser, entretenir, ou de réparer l'equipment.
NOTICE
Nuclear applications
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 nuclear-qualified products, contact an Emerson sales representative.
Contents
Device overview............................................................................................................................5
Installation.................................................................................................................................... 6
Configuration............................................................................................................................. 22
Sensor calibration...................................................................................................................... 24
Functional specifications...........................................................................................................28
Product certifications................................................................................................................ 30
Declaration of Conformity........................................................................................................ 34
April2023 Quick Start Guide
Quick Start Guide 3

Quick Start Guide April2023
4 Rosemount 925FGD

1 Device overview
The Rosemount 925FGD is a fixed gas detector compatible with the
Rosemount 625 Sensor Module.
The Rosemount 925FGD is a fully-assembled unit for only sensor-
direct-mount installations. For this configuration, you can order the
Rosemount 925FGD with or without the sensor module for instances
where sensor modules will be installed after the initial transmitter
installation.
The Rosemount 925FGD Transmitter consists of the transmitter
electronics, an LOI display, and infrared touch buttons contained
in an explosion-proof housing. The transmitter provides outputs,
including 4-20 mA analog signal, fault relay, alarm relays (2),
and HART® protocol. The transmitter is also equipped with status
indication LEDs.
All Rosemount 625 Sensors are smart sensors, meaning all
configuration, calibration, and gas sensing data is stored directly
on or generated directly from the sensor. This data is then
communicated to the Rosemount 925 Transmitter, which displays
information on the local operator interface (LOI) and generates
outputs for communication with site control systems.
For combustible hydrocarbon gas detection, the Rosemount 925FGD
incorporates the Rosemount 625ND Sensor Module. The Rosemount
625ND Sensor Module uses non-dispersive infrared technology
to measure combustible hydrocarbon gas using absorption
spectroscopy in the infrared sensor bands.
April2023 Quick Start Guide
Quick Start Guide 5

2 Installation
2.1 Safety messages
Instructions in this section may require special precautions to ensure
the safety of personnel performing the operations.
WARNING
Follow installation guidelines
Failure to follow these installation guidelines could result in death or
serious injury.
Ensure that only qualified personnel perform the installation.
WARNING
If the equipment is used in a manner not specified by the
manufacturer, the protection provided by the equipment may be
impaired.
WARNING
Explosions
Before connecting a handheld communication device 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.
When connecting an external device to the Rosemount 925FGD's
discrete output in a hazardous area, ensure that the external device
is installed in accordance with Intrinsically Safe or non-incendive field
wiring practices.
Quick Start Guide April2023
6 Rosemount 925FGD

2.2 Mounting
The Rosemount 925FGD Gas Transmitter must be mounted with the
sensor directly attached to the transmitter as in Figure 2-1. You can
also mount the transmitter either on the surface or on a pole.
For the surface mounting with direct-mount sensors, refer to Figure
2-1.
Figure 2-1: Surface Mount with Direct-Mount Sensor
For pole mounting with direct-mount sensors, select the BP optional
model code, which includes the necessary pole mount bolts in the
box with the transmitter. Refer to Figure 2-2.
Figure 2-2: Pole Mount with Direct-Mount Sensor
April2023 Quick Start Guide
Quick Start Guide 7

2.3 Wiring
2.3.1 Analog output, isolated supply, non-isolated supply, and
jumper configuration
The analog output may be powered from the main instrument power
supply or a separate, isolated power supply, in which case an isolated
wiring configuration is necessary.
An isolated loop uses 4-wires, 2 to power the device, and 2 for the
analog output. A non-isolated loop uses 3-wires, as the analog output
is tied into the power supply loop. Ensure the loop jumper is correctly
set for the wiring configuration you are using. See Figure 2-3
Figure 2-3: 925 Transmitter Terminal Block
2.3.2 Field wiring
The power to the transmitter is supplied over the signal wiring. Signal
wiring must be shielded, twisted pair. Do not run unshielded signal
wiring in conduit or open trays with power wiring or near heavy
electrical equipment because high voltage may be present on the
leads and may cause an electrical shock.
To meet EMC requirements, for the transmitter power wiring (V+
and COM) and signal wiring (mA+ and mA-) it is required to use
twisted shielded pair wires between the user power supply and the
925 transmitter. All flameproof entry devices, including plugs, must
be rated to a pressure greater than 2450 kPa (356 psi).
Seal all threads with an approved thread sealant, such as silicone or
PTFE tape (if required). When attaching the cover; tighten at least
one-third turn after the O-ring contacts the transmitter housing. The
Quick Start Guide April2023
8 Rosemount 925FGD

transmitter cover must be fully engaged to meet explosion proof
requirements
Note
Do not apply high voltage (e.g., AC line voltage) to the power or
sensor terminals, since high voltage can damage the unit
To wire the transmitter:
Table 2-1: Sensor terminals
Sensor terminals
Sensor wires Transmitter sensor board terminal designation
Red +Vdc (from transmitter)
Blue Signal A
White Signal B
Black Communication
Green Earth ground
Table 2-2: Transmitter power terminals
Transmitter power terminals
Transmitter terminal
designation
Function
V+ 18-30Vdc Power (+)
COM Power (-)
RST Remote reset
mA+ Current loop output
mA- Current loop output
April2023 Quick Start Guide
Quick Start Guide 9

Figure 2-4: Direct mount wiring diagram
Note
Ground wire from 625 sensor must be connected to ground inside of
925 transmitter housing.
Isolated four-wire loop wiring
For a four-wire loop setup, ensure the loop jumper is set to the
ISOLATE position and that shielded, twisted pairs are used.
Figure 2-5: Isolated four-wire wiring diagram
A. Power supply (18-30 VDC)
B. 200 ≤ RL ≤ 800
C. Power/4-20 mA analog loop terminals
D. HART® modem
Quick Start Guide April2023
10 Rosemount 925FGD