Rosemount™ 975
Flame Detectors
Reference Manual
00809-1400-4975, Rev AB
February 2022
Legal notice
The device described in this document is the property of Emerson.
No part of the hardware, software, or documentation may be reproduced, transmitted, transcribed, stored in a retrieval system,
or translated into any language or computer language, in any form or by any means, without prior written permission from
Emerson.
While great efforts have been made to ensure the accuracy and clarity of this document, Emerson assumes no liability resulting
from any omissions in this document or from misuse of the information obtained herein. The information in this document has
been carefully checked and is believed to be entirely reliable with all of the necessary information included. Emerson reserves the
right to make changes to any products described herein to improve reliability, function, or design and reserves the right to revise
this document and make changes from time to time in content hereof with no obligation to notify any persons of revisions or
changes. Emerson does not assume any liability arising out of the application or any use of any product or circuit described herein;
neither does it convey license under its patent rights or the rights of others.
Warranty
Limited Warranty . Subject to the limitations contained in Section 2 (Limitation of Remedy and Liability) herein, Seller
1.
warrants that (a) the licensed firmware embodied in the Goods will execute the programming instructions provided by
Seller; (b) that the Goods manufactured by Seller will be free from defects in materials or workmanship under normal use
and care; and (c) Services will be performed by trained personnel using proper equipment and instrumentation for the
particular Service provided. The foregoing warranties will apply until the expiration of the applicable warranty period.
Sensors and detectors are warranted against defective parts and workmanship for 60 months from the date of purchase.
Products purchased by Seller from a third party for resale to Buyer (Resale Products) shall carry only the warranty
extended by the original manufacturer. Buyer agrees that Seller has no liability for Resale Products beyond making a
reasonable commercial effort to arrange for procurement and shipping of the Resale Products. If Buyer discovers any
warranty defects and notifies Seller thereof in writing during the applicable warranty period, Seller shall, at its option, (i)
correct any errors that are found by Seller in the firmware or Services; (ii) repair or replace FOB point of manufacture that
portion of the Goods found by Seller to be defective; or (iii) refund the purchase price of the defective portion of the
Goods/Services. All replacements or repairs necessitated by inadequate maintenance; normal wear and usage; unsuitable
power sources or environmental conditions; accident; misuse; improper installation; modification; repair; use of
unauthorized replacement parts; storage or handling; or any other cause not the fault of Seller, are not covered by this
limited warranty and shall be replaced or repaired at Buyer's sole expense, and Seller shall not be obligated to pay any
costs or charges incurred by Buyer or any other party except as may be agreed upon in writing in advance by Seller. All
costs of dismantling, reinstallation, freight, and the time and expenses of Seller's personnel and representatives for site
travel and diagnosis under this limited warranty clause shall be borne by Buyer unless accepted in writing by Seller. Goods
repaired and parts replaced by Seller during the warranty period shall be in warranty for the remainder of the original
warranty period or 90 days, whichever is longer. This limited warranty is the only warranty made by Seller and can be
amended only in a writing signed by an authorized representative of Seller. The limited warranty herein ceases to be
effective if Buyer fails to operate and use the Goods sold hereunder in a safe and reasonable manner and in accordance
with any written instructions from the manufacturers. THE WARRANTIES AND REMEDIES SET FORTH ABOVE ARE
EXCLUSIVE. THERE ARE NO REPRESENTATIONS OR WARRANTIES OF ANY KIND, EXPRESSED OR IMPLIED, AS TO
MERCHANTABILITY, FITNESS FOR PARTICULAR PURPOSE, OR ANY OTHER MATTER WITH RESPECT TO ANY OF THE GOODS
OR SERVICES.
Limitation of Remedy and Liability SELLER SHALL NOT BE LIABLE FOR DAMAGES CAUSED BY DELAY IN PERFORMANCE. THE
2.
REMEDIES OF BUYER SET FORTH IN THE AGREEMENT ARE EXCLUSIVE. IN NO EVENT, REGARDLESS OF THE FORM OF THE
CLAIM OR CAUSE OF ACTION (WHETHER BASED IN CONTRACT INFRINGEMENT, NEGLIGENCE, STRICT LIABILITY, OTHER
TORT, OR OTHERWISE), SHALL SELLER'S LIABILITY TO BUYER AND/OR BUYER'S CUSTOMERS EXCEED THE PRICE TO BUYER
OF THE SPECIFIC GOODS MANUFACTURED OR SERVICES PROVIDED BY SELLER GIVING RISE TO THE CLAIM OR CAUSE OF
ACTION. BUYER AGREES THAT IN NO EVENT SHALL SELLER'S LIABILITY TO BUYER AND/OR BUYER'S CUSTOMERS EXTEND
TO INCLUDE INCIDENTAL, CONSEQUENTIAL, OR PUNITIVE DAMAGES. THE TERM "CONSEQUENTIAL DAMAGES" SHALL
INCLUDE, BUT NOT BE LIMITED TO, LOSS OF ANTICIPATED PROFITS, REVENUE OR USE AND COSTS INCURRED INCLUDING
WITHOUT LIMITATION FOR CAPITAL, FUEL AND POWER, AND CLAIMS OF BUYER'S CUSTOMERS.
Safety precautions
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.
2
WARNING
Do not open the housing while the power is on.
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.
NOTICE
Disconnect external devices, such as fire alarms and automatic extinguishing systems, before performing maintenance.
• Do not expose the detector to radiation of any kind unless required for testing purposes.
• Do not open the electronic compartment. Keep this part closed at all times. It can only be opened in the factory. Opening the
electronic component side invalidates the warranty.
• Only access the wiring compartment to wire or remove the detector or access RS-485 terminals for maintenance.
Technical support
To get technical support for this product, contact your local Emerson representative or the Emerson Technical Support
department at +1 866 347 3427 or safety.csc@emerson.com.
Abbreviations and acronyms
Abbreviation or acronym
ATEX Atmospheric explosives
AWG American wire gauge
BIT Built-in test
EMC Electromagnetic compatibility
EOL End of line
FOV Field of view
®
HART
IAD Immune at any distance
IECEx International Electrotechnical Commission Explosion
IPA Isopropyl alcohol
IR Infrared
JP5 Type of jet fuel
Latching Refers to relays remaining in the ON state even after the ON condition has been
LED Light emitting diode
LPG Liquified petroleum gas
mA Milliamps (0.001 amps)
®
Modbus
Definition
Highway addressable remote transducer - communication protocol
removed.
Master-slave messaging structure
3
Abbreviation or acronym Definition
N/A Not applicable
NFPA National Fire Protection Association
NPT National pipe thread
RS485 Communication protocol allowing bi-directional communication
PN Part number
SIL Safety integrity level
UNC Unified coarse thread
Vac Volts alternating current
Vdc Volts direct current
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Reference Manual Contents
00809-1400-4975 February 2022
Contents
Chapter 1 Introduction.............................................................................................................. 7
1.1 Product overview.........................................................................................................................7
1.2 Models.........................................................................................................................................7
Chapter 2 Installation.................................................................................................................9
2.1 Installation guidelines..................................................................................................................9
2.2 Preparation for use...................................................................................................................... 9
2.3 Attach detector to tilt mount.....................................................................................................13
2.4 Open the back cover..................................................................................................................14
2.5 Wire terminals and ground cable............................................................................................... 15
2.6 Install the protective cover.........................................................................................................19
2.7 Aim the detector........................................................................................................................20
2.8 Changing default detector settings ...........................................................................................21
Chapter 3 Operation................................................................................................................ 23
3.1 Power up the detector............................................................................................................... 23
3.2 Test flame detectors..................................................................................................................23
Chapter 4 Initial setup..............................................................................................................25
4.1 Continuous feature test............................................................................................................. 25
4.2 Response to fault indication.......................................................................................................25
4.3 Built-in test (BIT)........................................................................................................................25
Chapter 5 Maintenance............................................................................................................27
5.1 Keeping maintenance records................................................................................................... 27
5.2 Clean the detector.....................................................................................................................27
Chapter 6 Troubleshooting...................................................................................................... 29
6.1 Light-emitting diode (LED) is off, fault relay is open, 0-20 mA shows 0 mA, analog voltage
output is 0 V................................................................................................................................29
6.2 Light-emitting diode (LED) flashes yellow at 4 Hz, fault relay is open, 0-20 mA shows 1 mA.......29
6.3 Light-emitting diode (LED) flashes yellow at 4 Hz, relay is open, 0-20 mA shows 2 mA...............29
6.4 Light-emitting diode (LED) constantly red, alarm relay energized, 0-20 mA indicates alarm.......30
6.5 No HART® communication, 0-20 mA shows 0 mA......................................................................30
Chapter 7 Specifications...........................................................................................................31
7.1 Technical specifications............................................................................................................. 31
7.2 Electrical specifications..............................................................................................................33
7.3 Mechanical specifications.......................................................................................................... 34
Appendix A Reference data......................................................................................................... 37
A.1 Ordering information, specifications, and dimensional drawings...............................................37
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A.2 Product certifications and installation drawings.........................................................................37
Appendix B FM fuel test responses ............................................................................................. 39
Appendix C Immunity to false alarm sources...............................................................................41
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Introduction
1 Introduction
1.1 Product overview
The Rosemount 975 series is based on proven technologies, including triple infrared (IR3)
and ultraviolet infrared (UV/IR). The Rosemount 975 series provides the fastest response
to fire, longest distance detection, and revolutionary UV/IR technology, coupled with
superior immunity to false alarms, functioning in harsh conditions with unparalleled
reliability and durability.
The series is suited to meet the challenges of wide range of industrial and commercial
applications with long distance and fast response detection, providing superior protection
of high value property and personnel to keep an eye on your safety.
Detection performance can be easily adapted to all environments, applications, and
requirements, by changing the detector’s configuration parameters. Adjusting these
parameters, as well as performing other maintenance and monitoring tasks, is possible by
means of RS-485-based Modbus® communication or HART® communication.
1.2 Models
The Rosemount 975 Flame Detectors are electro-optical devices designed to identify fire
events, enabling alarm activation. The detectors are intended for indoor or outdoor use
and can be used stand alone or connected to an alarm or automatic extinguishing system.
The Rosemount 975 series comprises the following detectors:
Rosemount 975MR
The Rosemount 975MR, an ultra-fast multispectrum triple infrared (IR3) flame detector,
provides superior, longest distance detection of hydrocarbon fires at up to 295.3 ft (90 m),
exceptional ultra-fast detection in under 50 msec, and unparalleled reliability. The
Rosemount 975MR is based on proven IR3 technology, ensuring highest sensitivity with
best immunity to false alarms.
Rosemount 975HR
The Rosemount 975HR is a multispectrum IR flame detector that provides superior,
longest distance detection of hydrogen (at up to 164.0 ft (50 m)) and hydrocarbon fires (at
up to 295.3 ft (90 m)), exceptional ultra-fast detection in under 50 msec, and unparalleled
reliability. The Rosemount 975HR is designed to deal with the challenges of invisible fires
based on proven triple IR (IR3) technology, ensuring highest sensitivity with best immunity
to false alarms.
Rosemount 975UF
The Rosemount 975UF is an ultra-fast ultraviolet (UV)/IR flame detector, which is able to
detect in under 20 msec and features a unique dual sensor with selectable UV and IR
channels that can be used separately or combined. The detector is designed to detect a
range of fires, such as hydrocarbon-based fuel and gas, hydroxyl, hydrogen, metal, and
inorganic.
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Introduction Reference Manual
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Rosemount 975UR
The Rosemount 975UR is an ultra-fast UV/IR flame detector that is able to detect in under
20 msec, and features a unique dual sensor with selectable UV and IR channels that can be
used separately or combined. The detector is designed to detect hydrocarbon-based fuel
and gas fires.
Table 1-1: Rosemount 975 Series General Technical Specifications
Spectral response Infrared and ultraviolet bands
Response time Varies according to model, typically under 5 seconds
Field of view Varies according to model, up to 100 degrees
Output 4-20 mA, relays, communication
Enclosure Stainless steel 316 or aluminum polyurethane painted
Operating voltage 18-32 Vdc
Maximum power rating 9.6 W
Relay contacts 2A/30 Vdc
Over voltage category 2
Relative humidity Non-condensing relative humidity up to 100%
NOTICE
If the product is used outside of specified limits, this voids the product certification, and
Emerson is not responsible for any incurred warranty expense.
NOTICE
Do not open this product, except for the terminal compartment as listed in this document,
under any circumstances.
NOTICE
The device is not field-repairable due to the meticulous alignment and calibration of the
sensors and the respective circuits.
Do not attempt to modify or repair the internal circuits or change their settings, as this will
impair the system's performance and void the Emerson product warranty.
NOTICE
Opening the attachment screws to dismantle the front part of the detector form the
remaining parts is restricted and voids the product warranty.
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Installation
2 Installation
2.1 Installation guidelines
Installation should comply with the National Fire Protection Association (NFPA) 72E or any
other local and international regulations and standards, as applicable to flame detectors
and installation of Ex approved products. To ensure optimal performance and efficient
installation, consider the following guidelines.
Sensitivity
To determine the level of sensitivity, consider the following:
• Size of fire at the required distance to be detected
• Type of flammable materials
• Proximity to false alarm sources
Wiring
The wire gauge must be designed according to the distance from the detector to the
controller and the number of detectors on the same power line.
To fully comply with EMC directive and protect against interference caused by RFI and EMI,
the cable to the detector must be shielded and the detector must be grounded. The shield
should be grounded at the detector end.
Spacing and location
The number of detectors and their locations in the protected area are determined by:
• Size of the protected area
• Sensitivity of the detectors
• Obstructed lines of sight
• Cone of view of the detectors
Environment
Dust, snow, or rain can reduce the detector’s sensitivity and require more maintenance
activities.
The presence of high intensity emission sources may affect sensitivity.
Related information
Wire terminals and ground cable
2.2 Preparation for use
The installation sequence may vary according to the physical structure of the site.
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Note
Installation steps are also detailed in the Quick Start Guide supplied with the detector.
The following tools are required for installation. These are standard tools and are not
supplied with the detector.
Table 2-1: Required tools
Tool Function
Hex key 1.5 mm Fasten back cover security screw.
Hex key 6 mm Adjust the tilt mount.
Hex key 10 mm Affix the detector to the tilt mount.
Hex key ⅛-in Attach protective cover to detector.
Flat screwdriver 6 mm Connect ground terminal.
Flat screwdriver 2.5 mm Connect wires to the terminal blocks.
Hex key ⅜-in Stop plug ¾-in NPT.
Open wrench 28 mm Stop plug M25 only.
2.2.1 Field of view
Figure 2-1: Horizontal field of view for Rosemount 975MR, 975UF, and 975UR
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Figure 2-2: Vertical field of view for Rosemount 975MR, 975UF, and 975UR
• +50 ° (down)
• -45 ° (up)
Gasoline
For Rosemount 975HR.
• Horizontal: 80 °
• Vertical: 80 °
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Figure 2-3: Vertical and horizontal field of view for gasoline
Hydrogen
For Rosemount 975HR.
• Horizontal: 90°
• Vertical: 90°
Figure 2-4: Horizontal field of view for hydrogen
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Figure 2-5: Vertical field of view for hydrogen
Installation
2.3 Attach detector to tilt mount
Procedure
1. Unpack the detector.
2. Insert location pins on the tilt mount into the openings on detector housing.
3. Thread the holding screw and tighten it.
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Note
To change the detector field of view, release the horizontal and vertical locking
screws.
4. Point the detector toward the protected area and ensure the view of the area is
unobstructed.
5. Secure the detector in that position by tightening the locking screws on the tilt
mount.
The detector is now correctly located, aligned, and ready to be connected to the
system.
2.4 Open the back cover
WARNING
Do not open the housing while the power is on.
Procedure
1. Loosen the back cover security screw.
A. Back cover security screw
B. Protective plug
2. Unscrew the back cover.
Note
The back cover is attached by a security cable.
3. Remove the protective plug.
14 Emerson.com/Rosemount
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