Emerson Rosemount 975MR, Rosemount 975HR Reference Manual

Rosemount™ 975MR

Multi-Spectrum Infrared Flame Detector

Reference Manual

00809-0100-4975, Rev DB

August 2019

Legal notice

The device described in this document is the property of Rosemount.
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
Rosemount.

While great efforts have been made to ensure the accuracy and clarity of this document, Rosemount 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. Rosemount 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. Rosemount 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.

WARNING

All individuals who have or will have responsibility for using, maintaining, or servicing this product must read this manual
carefully.

CAUTION

Equipment damage

This device is not field repairable due to the meticulous alignment and calibration of the sensors and the respective circuits.
Modifying or repairing the internal circuits may impair the system's performance and void the Rosemount product warranty.

Do not attempt to modify or repair the internal circuits or change their settings.

Warranty

1. Limited Warranty . Subject to the limitations contained in Section 2 (Limitation of Remedy and Liability) herein, Seller
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

2

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.

Technical support

To get technical support for this product, contact your local Rosemount representative or the Rosemount Technical Support
department at [phone] or [e-mail]

Return of material

To expedite the repair and return of this product, proper communication between the customer and the factory is important.
Before returning a product for repair, call [phone] or email [e-mail] for a return material authorization

(RMA) number.
On the return of equipment, provide the following information:

1. RMA number provided to you by Emerson

2. Company name and contact information

3. Purchase order from your company authorizing repairs of request for quote

Ship all equipment prepaid to:
Emerson Automation Solutions
Rosemount
8200 Market Blvd
Chanhassen, MN 55317
Mark all packages with "Return for Repair" and include the RMA number.
Pack items to protect them from damage and use anti-static bags or aluminum-backed cardboard as protection from electrostatic

damage.
Ship all equipment prepaid. Emerson will not accept collect shipments.

Abbreviations and acronyms

Abbreviation or acronym

Definition

ATEX Atmospheric explosives

AWG American wire gauge

BIT Built-in test

EMC Electromagnetic compatibility

EOL End of line

FOV Field of view

®

HART

Highway addressable remote transducer - communication protocol

IAD Immune at any distance

IECEx International Electrotechnical Commission Explosion

IPA Isopropyl alcohol

IR Infrared

JP5 Jet fuel

Latching Refers to relays remaining in the ON state even after the ON condition has been

removed.

LED Light emitting diode

LPG Liquefied petroleum gas

3

Abbreviation or acronym Definition

mA Milliamps (0.001 amps)

®

Modbus

Master-slave messaging structure

N.C. Normally closed

N .O. Normally open

N/A Not applicable

NFPA National Fire Protection Association

NPT National pipe thread

PN Part number

SIL Safety integrity level

UNC Unified coarse thread

Vac Volts alternating current

Vdc Volts direct current

4

Reference Manual Contents

00809-0100-4975 August 2019

Contents

Chapter 1 Introduction.................................................................................................................. 7

1.1 Overview.......................................................................................................................................... 7

1.2 Model and types............................................................................................................................... 7

1.3 Features and benefits..................................................................................................................... 10

1.4 Principles of operation....................................................................................................................11

1.5 Performance considerations...........................................................................................................14

1.6 Internal detector tests.................................................................................................................... 21

Chapter 2 Installing the detector..................................................................................................25

2.1 General guidelines..........................................................................................................................25

2.2 Unpack...........................................................................................................................................26

2.3 Required tools................................................................................................................................ 26

2.4 Certification instructions................................................................................................................ 27

2.5 Installing cables..............................................................................................................................28

2.6 Installing the tilt mount (PN 00975-9000-0001).............................................................................28

2.7 Connect the detector..................................................................................................................... 32

2.8 Configure the detector...................................................................................................................35

Chapter 3 Operating the detector................................................................................................ 39

3.1 Power up........................................................................................................................................ 39

3.2 Safety precautions..........................................................................................................................39

3.3 Testing procedures.........................................................................................................................40

Chapter 4 Maintenance and troubleshooting............................................................................... 43

4.1 Maintenance.................................................................................................................................. 43

4.2 Troubleshooting.............................................................................................................................44

Appendix A Specifications and reference data.................................................................................47

A.1 Technical specifications..................................................................................................................47

A.2 Electrical specifications.................................................................................................................. 47

A.3 Outputs..........................................................................................................................................48

A.4 Mechanical specifications...............................................................................................................50

A.5 Environmental specifications..........................................................................................................50

Appendix B Wiring instructions...................................................................................................... 53

B.1 General instructions for electrical wiring.........................................................................................53

B.2 Typical wiring configurations..........................................................................................................55

Appendix C RS-485 communication network.................................................................................. 59

Appendix D Accessories.................................................................................................................. 61

D.1 Flame simulator............................................................................................................................. 61

D.2 Tilt mount: PN 00975-9000-0001.................................................................................................. 66

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D.3 Duct mount: PN 00975-9000-0002................................................................................................66

D.4 Weather cover: PN 00975-9000-0003............................................................................................68

D.5 Air shield: PN 00975-9000-0005.................................................................................................... 69

Appendix E SIL-2 features............................................................................................................... 71

E.1 Safety relevant parameters.............................................................................................................71

E.2 Guidelines for configuring, installing, operating, and service.......................................................... 71

Appendix F End of line resistor........................................................................................................73

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Introduction

1 Introduction

1.1 Overview

The Rosemount 975MR Multi-spectrum Flame Detector uses improved multi-spectrum
infrared technology to provide state-of-the-art fire protection. The detector uses patented
digital signal processing to analyze the spectral and dynamic characteristics of the
measured infrared radiation to identify fire events with exceptional sensitivity and extreme
immunity to fire alarms.

All Rosemount 975 series detectors include a heated optical window for improved
performance in icing, snow, and condensation conditions.

The operator can easily adapt detection performance 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 (in models
with 0-20 mA output).

The detector enclosure is ATEX certified Exd flameproof with an integral, segregated, rear,
Exe terminal compartment (avoiding exposure of the sensors and electronics to
surrounding environment). Hence the combined approval:

Ex II 2G D
Ex db eb op is IIC T4 G
Ex tb op is IIIC T96 °C Db
(-55 °C ≤ Ta ≤ +75 °C)
or
Ex II 2G D
Ex db eb op is IIC T4 Gb
Ex tb op is IIIC T106 °C Db
(-55 °C ≤ Ta ≤ +85 °C)
The flame detector is designed to operate as a stand-alone unit directly connected to an

alarm system or an automatic fire extinguishing system. The detector can also be part of a
more complex system where many detectors and other devices are integrated through a
common control unit.

1.2 Model and types

The Rosemount 975MR is provided in various configurations depending on:

• Output configurations

• Temperature

• Housing style

Rosemount 975MR 7

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• Product certifications

The configuration detail is included in the product part number on the product label and
takes the form: 975MR-XXXXXXX, where XXXXXXX defines the model according to the
above requirements.

To modify the default or pre-ordered configuration and perform maintenance tasks,
please refer to the following manuals: HART Protocol 00809-0200-4975, the RS-485
Manual 00809-0300-4975, or 00809-0400-4975.

The starred offerings (★) represent the most common options and should be selected for
best delivery. The non-starred offerings are subject to additional delivery lead time.

The Rosemount model structure is defined as:

Table 1-1: Rosemount 975 Flame Detector Ordering Information

Product description

975 975 flame detector ★

Technology

MR Multi-spectrum infrared ★

HR Multi-spectrum infrared hydrogen ★

UF Ultra fast ultraviolet infrared ★

UR Ultraviolet infrared ★

Output configuration

Outputs Fault relay Alarm relay Auxiliary relay Current type ★

1A Analog/HART®/

RS-485/relays
(fault, alarm)

2A Analog/HART/

RS-485/relays
(fault, alarm)

3A Analog/HART/

RS-485/relays
(fault,alarm)

1R RS-485/relays

(fault, alarm,
auxiliary)

2R RS-485/relays

(fault, alarm,
auxiliary)

Housing style

Normally closed Normally open N/A Sink ★

Normally closed Normally open,

normally closed

Normally open Normally open,

normally closed

Normally closed Normally open Normally open N/A ★

Normally open Normally open Normally open N/A ★

N/A Source ★

N/A Source ★

Material Conduit entry

(1)

6A

(1)

8A

6S Stainless steel ¾-in. NPT ★

8S Stainless steel M25 ★

8 Emerson.com/Rosemount

Aluminum ¾-in. NPT ★

Aluminum M25 ★

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Table 1-1: Rosemount 975 Flame Detector Ordering Information (continued)

Temperature

1 167 °F (75 °C) ★

2 185 °F (85 °C) ★

Product certifications

A1 ATEX and IECEx flameproof ★

A2 FM and CSA flameproof ★

E2 INMETRO flameproof ★

EM Technical Regulations Customs Union (EAC) flameproof ★

Typical model number: 975MR1A6A1A1

(1) Aluminum housing is not available in FM/CSA product certification.

Table 1-2: Spare Parts and Accessories

Part number Description

00975-9000-0001 Tilt mount ★

00975-9000-0002 Duct mount ★

00975-9000-0003 Weather cover (plastic) ★

00975-9000-0004 Weather cover (stainless steel) ★

00975-9000-0005 Air shield ★

00975-9000-0007 2-in. (50,8 mm) pipe mount ★

00975-9000-0008 3-in. (76,2 mm) pipe mount ★

00975-9000-0009 Flame simulator kit (for Rosemount 975MR) ★

00975-9000-0011 USB RS-485 harness kit ★

00975-9000-0012 Spare battery pack for use with flame

simulator

00975-9000-0014 4-in. (101,6 mm) pipe mount ★

00975-9000-0015 Spare battery charger for use with flame

simulator

Table 1-3: Output Configurations

Output
configuration

1A Power Manual built-

Connections provided

in test

Fault relay
N.C.

Alarm relay
N.O.

0-20 mA sink RS-485 HART

★

★

2A Power Manual built-

in test

3A Power Manual built-

in test

Rosemount 975MR 9

Fault relay
N.C.

Fault relay
N.O.

Alarm relay,
N.O., N.C.

Alarm relay
N.O., N.C.

0-20 mA
source

0-20 mA
source

RS-485 HART

RS-485 HART

Introduction

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Reference Manual

Table 1-3: Output Configurations (continued)

Output
configuration

1R Power Manual built-

2R Power Manual built-

Connections provided

in test

in test

NOTICE

Output configuration 1A is default. You can change the mA sink output to source type,
with a link between terminals 1 and 8. You cannot change any other output configurations
on site.

For example, product number 975MR3A8S2A1 has the following options:

• Output configuration: 3A (analog/HART/RS-485/relays, fault N.O., alarm N.O./N.C.,

source)

• Housing style: 8S (stainless steel - M25 conduit entry)

• Temperature: 2 (185 °F [85 °C])

• Approvals: A1 (ATEX and IECEx flameproof)

NOTICE

Fault relay
N.C.

Fault relay
N.O.

Alarm relay
N.O.

Alarm relay
N.O.

Auxiliary
N.O.

Auxiliary
N.O.

RS-485 N/A

RS-485 N/A

Check your specific part numbers against the information in Checking the product type.

1.3 Features and benefits

The flame detector has the following features and benefits.

• Detection range: Up to 215 ft. (65 m) for a 1 ft.2 (0.1 m2) n-heptane fire.

• Ultra high immunity to false alarms. See Table 1-6.

• Advanced digital processing of the dynamic characteristics of fire: flickering, threshold,

correlation, and ratio.

• Multi IR channels: between two and five microns.

• Field programmable sensitivity: four ranges to avoid zone crossover.

• Built-in-test (BIT): manual and automatic (see Built-in test (BIT)).

• Heated window: prevents effects of icing, snow, and condensation.

• Electrical interface:
— Dry contact relays

— Communication network RS-485
— 0-20 mA output

• HART® protocol: communication protocol (see HART protocol).

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• Exde: integral junction box for easy wiring.

• SIL-2: TÜV approved.

• Hazardous area certification: ATEX, IECEx, FM, and CSA.

• Functionality approval:
— EN54-10 approved by VdS

— FM approved per FM3260

• Accessories are approved as part of ATEX and IECEx approval.

Introduction

1.4 Principles of operation

1.4.1 Hydrocarbon fire detection

The Rosemount 975MR uses four infrared sensors, each sensitive to its own wavelength
range. Two of the sensors are sensitive to wavelengths within the emission peak of hot
CO2. The other two sensors are sensitive to wavelengths above and below this peak.

1.4.2

1.4.3

In the event of fire, the signal measured in the first sensor is significantly higher than those
measured in the other two sensors. In order to issue a fire alarm, the detector requires that
this occurs, as well as other conditions (for example, radiation is flickering in frequencies
typical of flames). If exposed to non-fire radiation sources, the specific conditions required
do not occur, and the detector does not react.

Heated optics

The flame detector uses heated optics. The heater increases the temperature of the
optical surface by 5 to 8 °F (3 to 5 °C) above the ambient temperature to improve
performance in icing, condensation, and snow conditions.

The heated optics can be set to one of the following:

• Off, not operating.

• On continuously.

• Automatic, per temperature change (default): the operator can define the start

temperature below which the window is heated. The default is 41 °F (5 °C). The
operator can define this temperature between 32 °F (0 °C) and 122 °F (50 °C). The
heating stops when the temperature is 27 °F (15 °C) above the start temperature.

For more information, see Configure the detector.

HART® protocol

The flame detector uses the HART protocol.
HART communication is a bi-directional industrial field communication protocol used to

communicate between intelligent field instruments and host systems. HART is the global
standard for smart process instrumentation, and the majority of smart field devices
installed in plants worldwide are HART-enabled. HART is available in output configurations
1A, 2A, and 3A (see Table 1-1).

Rosemount 975MR 11

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Through the HART connection, you can do the following:

• Detector setup

• Detector troubleshooting

• Detector health and status

For more details, refer to HART Manual 00809-0200-4975.

Reference Manual

1.4.4 RS-485 Modbus

For more advanced communications, the flame detector has an RS-485 Modbus­compatible output that provides data communication from a network (up to 247
detectors) to a host computer or universal controller for central monitoring. This feature
allows for reduced installation costs, easy maintenance, and local or remote diagnostic
tools.

1.4.5

Product certifications

The flame detector has the following certifications:

• ATEX, IECEx

• FM, CSA

• SIL-2 (TUV)

• EN54-10

• Inmetro (UL)

• TR CU/EAC

ATEX, IECEx

The flame detector is certified to:

®

ATEX per SIRA 15ATEX1364X and IECEx per IECEx SIR 15.0138X.
Ex II 2G D
Ex db eb op is IIC T4 Gb
Ex tb op is IIIC T96 °C Db
(-55 °C ≤ Ta ≤ +75 °C)
or
Ex II 2G D
Ex db eb op is IIC T4 Gb
Ex tb op is IIIC T106 °C Db
(-55 °C ≤ Ta ≤ +85 °C)
The accessories: tilt mount (PN 00975-9000-0001), weather cover (PN 00975-9000-0003

[plastic] and PN 00975-9000-0004 [stainless steel]), duct mount (PN 00975-9000-0002),
and air shield (PN 00975-9000-0005), are included in the approval.

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This product is available to use in hazardous zones 1 and 2 with IIC gas group vapors
present and zones 21 and 22 with IIIC dust type present.

Introduction

FM, CSA

The flame detector is certified to FM and CSA explosion proof and functionality per
FM3260.

• Class I, Division 1, Groups B, C, and D, T5 Ta = 85 °C.

• Dust ignition proof - Class II/III Division 1, Groups E, F, and G.

• Ingress protection - IP67, IP66, NEMA 250 Type 6P

• Fuel test response including: gasoline, n-heptane, diesel, JP5, kerosene, ethyl, alcohol

95 percent, IPA, methanol, methane, LPG, polypropylene, and paper.

• For more details, see FM Report Project ID3029553 and CSA Report No. 2451134.

SIL-2 (TÜV)

The flame detector is certified to SIL-2 requirement per IEC 61508A, Chapter 3.5.12.
The alert condition according to SIL-2 can be implemented by:

• Alert signal via 0-20 mA current loop

or

• Alert signal via alarm relay and fault relay

For more details and guidelines for configuring, installing, operating, and service, see SIL-2

features and TUV Report No. 968/FSP 1223.

EN54-10

The flame detector is approved per EN54-10 and CPD.

• The detector is listed as Class 1 for sensitivity settings 15, 30, 45, and 60.

• The detector has been tested and approved per EN54-10 Vds.

• This test includes functional test, environmental test, EMI/EMC test, and software

check.

• For more details, see Vds Report Number BMA 150190-AU01+BZA02-PB01.

InMetro (UL)

The flame detector is in compliance with the following standards as of May 18, 2010:

• ABNT NBR IEC 60079-0

• ABNT NBRIEC 60079-1

• ABNT NBR IEC 60079-7

• ABNT NBR IEC 60079-18

• ABNT NBR IEC 60079-31

• INMETRO decree No. 179

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For further details, see the Certificate of Compliance No. UL-BR 16.065XX.

TR CU/EAC

The flame detector is in compliance with the standard TR CU 012/2011 per:

1Ex db eb op is IIC T4 Gb X
Ex tb op is IIIC T96 °C Db X

-55 °C ≤ Ta ≤ +75 °C

or
1Ex db eb op is IIC T4 Gb X
Ex tb op is IIIC T106 °C Db X

-55 °C ≤ Ta ≤ +85 °C

For more details, see TR CU certificate No. TC RU C-US MЮ 62.B05535.

1.5 Performance considerations

1.5.1 Detection sensitivity

Detection sensitivity is the maximum distance at which the detector reliably detects a
specific size of fire and typical type of fuel (standard fire).

Standard fire

Defined as 1 ft.2 (0.1 m2) n-heptane pan fire with maximum wind speed of 6.5 ft./sec
(2 m/sec).

Sensitivity ranges

The detector has four user-selectable sensitivity ranges. For each range, there are two
response levels:

• Warning (Pre-alarm)

• Alarm

The detection distance for the Warning level is approximately 10 percent higher than the

Alarm distance.

Alarm response times for a standard fire at a specified range are shown in Table 1-4.

Table 1-4: Sensitivity Range Levels

Level Response time (sec) Sensitivity range - ft. (m) (for

1 ft.2 (0.1 m2) n-heptane pan
fire)

1 3 50 (15)

2 default 5 100 (30)

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Table 1-4: Sensitivity Range Levels (continued)

Level Response time (sec) Sensitivity range - ft. (m) (for

1 ft.2 (0.1 m2) n-heptane pan
fire)

3 8 150 (45)

4 10 215 (65)

For some typical ambient conditions, the Zeta parameter as defined in NFPA 72 for the
detector is 0.005 (1/meter).

Note

Zeta parameters may vary significantly with changes in temperature, air pressure,
humidity, visibility conditions, etc.

Other fuels

The detector reacts to other types of fire as follows:

• The baseline fire refers to n-heptane 1 ft.2 (0,1 m2) and is defined as 100 percent

sensitivity.

• For fuel fire: standard pan fire size: 1 ft.2 (0,1 m2)

• For gas flame: 30 in. (0.75 m) high, 10 in. (0.25 m) wide plume fire

• Maximum response time: 10 sec.

Table 1-5: Fuel Sensitivity Ranges

Type of fuel Percent of max. distance at each sensitivity range Max. distance

(ft. / m)

Gasoline 100% 215 / 65

n-Heptane 100% 215 / 65

JP5 70% 150 / 45

Kerosene 70% 150 / 45

Diesel fuel 70% 150 / 45

Ethanol 95% 60% 135 / 40

IPA 60% 135 / 40

Methanol 55% 115 / 35

(1)

(1)

70% 150 / 45

70% 150 / 45

Methane

LPG

Paper 38% 82 / 25

Polypropylene 55% 115 / 35

(1) 30 in. (0.75 m) high, 10 in. (0.25 m) wide plume fire

Rosemount 975MR 15

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1.5.2 Cone of vision

• Horizontal: 100 °

Figure 1-1: Horizontal Field of View

• Vertical: +50 ° (down), -45 ° (up)

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Figure 1-2: Vertical Field of View

1.5.3 False alarms prevention

To prevent false alarms, the detector will not alarm or react to the radiation sources
specified in the table below.

Table 1-6: Immunity to False Alarm Sources

Radiation source Immunity distance ft. (m)

Indirect or reflected sunlight IAD

Vehicle headlights (low beam) conforming to
MS53023-1

Incandescent frosted glass light, 300 W IAD

Fluorescent light with white enamel reflector,
standard office or shop, 70 W (or two 35 W)

Rosemount 975MR 17

IAD

IAD

Introduction

August 2019 00809-0100-4975

Reference Manual

Table 1-6: Immunity to False Alarm Sources (continued)

Radiation source Immunity distance ft. (m)

Electric arc (15/32 in. [12 mm] gap at 4,000 Vac,
60 Hz)

Arc welding (5/16 in. [6 mm] rod; 210 A) See Table 1-7

Ambient light extremes (darkness to bright light
with snow, water, rain, desert glare, and fog)

Bright colored clothing, including red and safety
orange

Electronic flash (180 W-seconds minimum
output)

Movie light, 625 W quartz DWY lamp (Sylvania
S.G. - 55 or equivalent)

Blue-green dome light conforming to
M251073-1

Flashlight (MX 99 I/U) IAD

Radiation heater, 3,000 W > 3 (1)

Radiation heater, 1,000 W with fan IAD

Quartz lamp (1,000 W) > 3 (1)

Mercury vapor lamp IAD

Grinding metal IAD

Lit cigar > 1 (0.3)

IAD

IAD

IAD

IAD

> 6.5 (2)

IAD

Lit cigarette > 1 (0.3)

Match, wood, stick, including flare up > 13 (4)

1. IAD: Immune at any distance.

2. All sources are chopped from 0 to 20 Hz.

Table 1-7: Welding Immunity Distance

Sensitivity setting Detection range Immunity distance

1 50 ft. (15 m) > 6 ft. (2 m)

2 100 ft. (30 m) > 12 ft. (4 m)

3 150 ft. (45 m) > 17 ft. (6 m)

4 215 ft. (65 m) >25 ft. (7.5 m)

1.5.4 Visual indicators

One three-color LED indicator is located inside the detector window, as shown in Figure

1-3. The detector statuses are listed in Table 1-8.

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Introduction

Table 1-8: LED Indications

Detector status LED color LED mode

Fault, BIT Fault Yellow 4 Hz - flashing

Normal Green 1 Hz - flashing

Warning Red 2 Hz -flashing

Alarm Red Steady

Figure 1-3: Indication LED

A. Indicator LED

1.5.5

Output signals

Outputs are available according to the default configuration or the wiring options selected
for the detector.

Determine the outputs of your model according to Table 1-9.
The detector incorporates several types of output suitable to different control systems.

• 0-20 mA (stepped) with HART

®

• Relays (alarm, fault, auxiliary)

• RS-485 Modbus

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Table 1-9: Available Output Types

Output type Version Detector status

Alarm relay 975MR- output configurations

Auxiliary relay 975MR - output configurations

Fault relay 975MR - output configurations

0-20 mA current output 975MR - output configuration

RS-485 All versions Modbus protocol

1.5.6 Detector status

1AXXXXX, 1RXXXXX, and
2RXXXXX

975MR - output configurations
2AXXXXX and 3AXXXXX

1AXXXXX, 2AXXXXX, and
1RXXXXX

1AXXXXX, 2AXXXXX, and
1RXXXXX

975MR - output configurations
3AXXXXX and 2RXXXXX

1AXXXXX

975MR - output configurations
2AXXXXX and 3AXXXXX

The relay is N.O.

The relay is N.O. and N.C.

The relay is N.O.

The relay is N.C. energized.

The relay is N.O. energized.

Sink with the HART protocol
(can be changed to Source - see

Figure B-3, Figure B-4, and
Figure B-5).

Source with the HART protocol

The possible detector function statuses are listed in the table below. Use HART® or
Modbus® to see a more detailed fault analysis.

Table 1-10: Detector Statuses

Status Description

Normal Normal operation.

BIT Built-in test being performed.

Warning Fire detected - changed to Warning (pre-alarm state).

Alarm Fire detected - changed to Fire Alarm state.

Latched alarm (optional) The alarm outputs remain latched on following detection of a fire

that has already been extinguished.

BIT fault A fault is detected during built-in test sequence or other electric

failure. The detector will continue to detect for fire.

Fault A fault is detected when the power supply is too low or due to a

software fault or electrical failure. The detector will not detect fire
in this condition.

In each state, the detector activates different outputs, as specified in Table 1-11.

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Introduction

Table 1-11: Output Signals vs. Detector State

Detector state LED indicator LED mode Alarm relay Auxiliary relay Fault relay mA output

Normal Green 1 Hz Off Off On 4 mA

On

(1)

(1)

(1)

On 16 mA

On 20 mA

Off 16 mA

Warning Red 2 Hz Off On

(2)

Alarm

(3)

Latch

BIT Fault

Warning at BIT
Fault

(4)

Red Constant On On On 20 mA

Red Constant On Off On 20 mA

Yellow 4 Hz Off Off Off 2 mA

Red 2 Hz Off On

Alarm at BIT
Fault

Fault Yellow 4 Hz Off Off Off 0 mA

(1) The auxiliary relay can be activated at the Warning level or Alarm level, depending on programmed function.
(2) The alarm outputs are activated while alarm conditions exist and will stop approximately five seconds after a fire is no

longer detected.

(3) The Alarm state can be optionally latched via programmed function. (Default is non-latching).
(4) The detector will remain in BIT Fault state until it has passed a successful built-in test.

Red Constant On On Off 20 mA

Note

The outputs depend on the output configurations.

Optional latching

Alarms are set as non-latching by default. However, the detector includes a latched alarm
output capability, which operates according to the programmed function.

If selected, upon detection of a fire, the detection signal is latched until the operator
manually resets the detector (disconnecting the power supply or performing a manual
built-in test [see Manual built-in test]).

Latching affects the alarm relay, 0-20 mA output, and the alarm LED. The auxiliary relay is
latched only when the programmable function Auxiliary Relay is set to Yes.

NOTICE

The auxiliary relay is available only in models with output configurations - 1RXXXXX and
2RXXXXX.
The 0-20 mA is available only in models with output configurations - 1AXXXXX, 2AXXXXX,
and 3AXXXXX.

1.6 Internal detector tests

The detector performs two types of self-tests:

• Continuous feature test

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• Built-in test (BIT)

Reference Manual

1.6.1 Continuous feature test

During normal operation, the detector tests itself continuously and indicates a fault if a
failure is found. This type of test complies with SIL-2 requirements.

The detector continuously tests:

• Input voltage level

• All internal regulator voltage level

• Voltage level status of sensor and sensor circuitry for noise or disconnection in the

electronic circuitry

• 0-20 mA level output

• Relays and heater operation

• Processor watch dog

• Software

1.6.2

• Memory

• Oscillator frequency

Response to a fault indication

If a failure is found, the detector indicates it by:

• Fault relay:
— Opens in output configurations 1A, 2A, and 1R

— Closes in output configurations 3A and 2R

• 0-20 mA: indicates fault (0 mA or 2 mA) in output configurations 1A, 2A, and 3A

• LED - yellow flashes (4 Hz)

• Correcting the fault

The fault indications remain until the detector's power is removed. The fault indications
return if the fault is still found when power is restored.

Built-in test (BIT)

The detector's built-in test (BIT) also checks the following:

• Electronics circuitry

• Sensors

• Window cleanliness

The detector can be set to perform the built-in test in the following modes:

• Automatically and manually

• Manually only

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NOTICE

In a manual built-in test, the outputs may also be tested; apply control system inhibit if
this could initiate other systems.

How the built-in test operates

• The detector's status remains unchanged if the result of a built-in test is the same as

the current status (Normal or BIT Fault).

• The detector's status is changed (from Normal to BIT Fault or vice versa) if the built-in

test differs from the current status.

NOTICE

In BIT Fault status, the detector can continue to detect a fire.

Automatic built-in test

The detector automatically performs a built-in test every fifteen minutes. A successful
built-in test sequence does not activate any indicator.

All outputs of built-in test results function as described in Table 1-12 and Table 1-13, and
the built-in test is automatically executed every one minute.

This continues until a successful built-in test occurs, when the detector resumes normal
operation.

Table 1-12: Results of a Successful Built-in Test

Output Result

Fault relay • Output configurations 1A, 2A, and 1R:

remain CLOSED

• Output configurations 3A and 2R: remain

OPEN

0-20 mA output Output configurations 1A, 2A, and 3A: Normal

(4 mA)

Power LED Green, flashing, 1 Hz on (Normal)

Table 1-13: Results of an Unsuccessful Built-in Test

Output Result

Fault relay • Output configurations 1A, 2A, and 1R:

change to OPEN

• Output configurations 3A and 2R: change to

CLOSED

0-20 mA output Output configurations 1A, 2A, and 3A: BIT Fault

(2 mA)

Power LED Yellow, flashing, 4 Hz

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Table 1-13: Results of an Unsuccessful Built-in Test (continued)

Output Result

BIT procedure Performed every one minute

Manual built-in test

To intiate the built-in test manually, momentarily connect Terminal 3 to Terminal 2 (or a
switch across these terminals in a safe area).

The results of a successful and unsuccessful manual built-in test are listed in Table 1-14
and Table 1-15.

Table 1-14: Results of a Successful Manual Built-in Test

Output Result

Fault relay • Output configurations 1A, 2A, and 1R: remain CLOSED

(Normal).

• Output configurations 3A and 2R: remain OPEN (Normal).

Alarm relay Activated for three seconds (only when the function Alarm BIT is

set to YES).

Auxiliary relay For output configurations 1R and 2R, is activated for three

seconds (only when the function Auxiliary BIT is set to YES).

0-20 mA output Output configurations 1A, 2A, and 3A:

• Initiates 20 mA only when the function Alarm BIT is set to

YES.

• Initiates 16 mA when the function Auxiliary BIT is set to YES

and the function Alarm BIT is set to NO.

Power LED Green, flashing, 1 Hz

Table 1-15: Results of an Unsuccessful Manual Built-in Test

Output Result

Fault relay • Output configurations 1A, 2A, and 1R: change to OPEN.

• Output configurations 3A and 2R: change to CLOSED.

0-20 mA output Output configurations 1A, 2A, and 3A: indicates BIT Fault (2 mA)

Power LED Yellow, flashing, 4 Hz

Manual built-in test only selected

The built-in test is initiated manually by momentarily selecting Terminal Number 3 with
Terminal Number 2 or a switch across these terminals in a safe area.

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2 Installing the detector

This chapter provides basic guidelines for installing the detector. It does not attempt to
cover all of the standard practices and codes of installation. Rather, it emphasizes specific
points of consideration and provides some general rules for qualified personnel. Wherever
applicable, special safety precautions are stressed.

2.1 General guidelines

To ensure optimal performance and an 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

• 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. See Wiring

instructions.

— 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. Ground the shield 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 flickering IR sources may affect sensitivity.

• Aiming the detector:
— Aim the detector toward the center of the detection zone and make sure the view

of the protected area is completely unobstructed.

— Whenever possible, tilt the detector face down at a 45-degree angle to maximize

coverage and prevent accumulation of dust and dirt.

— Take into account all conceivable considerations regarding detection location

before starting an installation.

Installations must comply with NFPA 72E or any other local and international regulations
and standards, as applicable to flame detectors and installation of Ex approved products.

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2.2 Unpack

Procedure

1. Upon receipt of your detector, verify that you have received the following contents:

• Delivery form

• Flame detector

• Plastic weather cover

• Quality document

2. Check and record the following:

a) Verify the appropriate purchase order.

b) Record the model number and serial number of the detector and the

installation date in an appropriate log book.

c) Verify that all components required for the detector installation are readily

available before beginning the installation.

Postrequisites

If the installation is not completed in a single session, secure and seal the detectors and
conduits/cable entries.

2.2.1

Checking the product type

Confirm your product has the configuration options you ordered.
Check the detailed model number on the label and compare this information with the

descriptions contained in Model and types.

2.3 Required tools

The operator can install the detector using general purpose tools and equipment.

Table 2-1 lists the specific tools required to install the detector.

Table 2-1: Required Tools

Tool Function Comments

Hex key 3/16-in. Open and close the detector

Hex key ¼-in. Mount the detector on the tilt

Part of the kit

cover (for wiring).

Part of the kit

mount.

Flat screwdriver 6 mm Connect ground terminal. Standard tool

Flat screwdriver 2.5 mm Connect wires to the terminal

blocks.

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For wiring, use color-coded conductors or suitable wire markings or labels. You may use 12
to 20 AWG (0.5 mm2 to 3.5 mm2) wires for site wiring. Select wire gauge based on the
number of detectors used on the same line and the distance from the control to the
ground unit, in compliance with specifications. See General instructions for electrical

wiring.).

2.4 Certification instructions

WARNING

Flammable

Do not open the detector, even when isolated, in a flammable atmosphere.

Use the following certification instructions:

• The cable entry point may exceed 167 °F (75 °C). Take suitable precautions when

selecting the cable.

• The equipment may be used with flammable gases and vapors with apparatus groups

IIA, IIB, and IIC:

— T5 in the ambient temperature range: -67 °F (-55 °C) to 167 °F (75 °C)
— T4 in the ambient temperature range: -67 °F (-55 °C) to 185 °F (85 °C)

• Only suitably trained personnel should install the detector, in accordance with the

applicable code of practice, such as EN 60079-14: 1997, EN 60079-17, and EN
60079-19.

• Only suitably trained personnel should inspect and maintain the detector, in

accordance with the applicable code of practice, such as EN-60079-14: 1997, EN
60079-17, and EN 60079-19

• Only suitably trained personnel should repair the detector, in accordance with the

applicable code of practice, such as EN 60079-19, EN 60079-17, and EN 60079-19.

• The certification of this equipment relies upon the following materials used in its

construction:

— Enclosure: 316L stainless steel or aluminum
— Window: sapphire glass

• If the equipment is likely to come into contact with aggressive substances, take

suitable precautions to prevent it from being adversely affected, thus ensuring that the
type of protection provided by the equipment is not compromised.

— Aggressive substances: acidic liquids or gases that may attack metals or solvents

that may affect polymeric materials.

— Suitable precautions: regular checks as part of routine inspections or establishing

from the material's data sheets that it is resistant to specific chemicals.

Refer to Product certifications for more information about product certifications.

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2.5 Installing cables

When installing cables for the flame detector, consider the following:

• Ensure all cables to the detector are well shielded in order to comply with EMC

requirements.

• Ground the detector to the nearest ground point (not more than 9.8 ft. (3 m) from the

flame detector).

• Install the detector with the cable entries and conduit pointed downwards.

2.5.1 Installing conduit

The conduit used for the cabling must comply with the following:

• To avoid water condensation in the detector, install the detector with the conduits that

include drain holes pointed downwards.

• When using the optional tilt mount, use flexible conduits for the last portion

connecting to the detector.

• For installation in atmospheres as defined in group B of the NFPA 72E, seal the conduit

inlets.

• When pulling the cables through the conduits, ensure that they are not tangled or

stressed. Extend the cables about 12 in. (30 cm) beyond the detector location to
accommodate wiring after installation.

• After pulling the conductor cables through the conduits, perform a continuity test.

2.6 Installing the tilt mount (PN 00975-9000-0001)

The tilt mount (PN 00975-9000-0001) enables the detector to rotate up to 60 degrees in
all directions.

Figure 2-1 shows the detector mounted on the tilt mount.

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Figure 2-1: Detector with Tilt Mount

A. Cover bolts

B. Back cover

C. Tilt mount plate

D. Horizontal locking screw

E. Tilt mount

F. Vertical locking screw
G. Detector holding screw
H. Tilt mount holding plate

I. Conduit/cable inlet
J. Detector assembly

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2.6.1 Assemble the tilt mount

Figure 2-2: Tilt Mount Assembly

A. Tilt holding plate

B. Tilt mount

C. Horizontal locking screw

D. Vertical locking screw

E. Detector holding plate

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Figure 2-3: Tilt Mount Assembly Dimensions

To install the tilt mount:

Procedure

1. Place the tilt mount in its designated location and secure it with four (4) fasteners
through four (4) holes 0.14 in. (7 mm) in diameter. Use the four (4) screws and
spring washers according to the kit.

Refer to Figure 2-3, Table 2-2, and Table 2-3.

Note

You do not have to remove the tilt mount when removing the detector for
maintenance purposes.

2. Unpack the detector.

3. Place the detector with its conduit/cable entries pointing downwards on the
holding plate of the tilt mount. Secure the detector with 5/16-in. 18 UNC x 1-in.
screw to the tilt mount.

4. Release the horizontal and vertical locking screws using the supplied 3/16-in. hex
key, such that the detector can be rotated. Point the detector towards the
protected area and ensure the view of the area is unobstructed. Secure the detector
in 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.

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Postrequisites

Refer to Connect the detector.

2.7 Connect the detector

To connect the detector to the electrical cables:

Procedure

1. Disconnect the power to the electrical cables.

2. Remove the back cover of the detector by removing three (3) socket head screws in
the cover bolts.

Refer to Figure 2-1.
The terminal chamber is now revealed.

3. Remove the protective plug mounted on the detector conduit/cable entry; pull the
wires through the detector inlet.

4. Use a ¾-in. - 14 NPT explosion-proof conduit connection or M25 x 1.5 flameproof
gland to assemble the cable/conduit to the detector.

5. Connect the wires to the required terminals on the terminal board according to the
wiring diagram.

See Figure 2-4 and Table 2-2.

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Figure 2-4: Detector with Cover Removed

A. Terminal chamber
B. Terminals
C. Internal earth terminal

D. Earth terminal

E. Detector holding screw

F. Conduit/cable entry
G. See Table 2-2.
H. Alarm relay (C)

I. Alarm relay (normally open)
J. Fault relay (C)

K. Manual BIT

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6. Connect the grounding wire to the ground screw outside the flame detector (earth
terminal).

The detector must be well-grounded to earth ground.

7. Verify the wiring.

CAUTION

Equipment damage

Improper wiring may damage the detector.

8. Check the wires for secure mechanical connection and press them neatly against
the terminal to prevent them from interfering while closing the back cover.

Refer to Figure 2-4.

9. Place and secure the detector's back cover by screwing the three (3) socket-head
screws in the cover bolts.

Refer to Figure 2-1.

2.7.1

Verify the detector wiring

The flame detector has five output configurations within the Exde integral terminal
section of the enclosure. There are twelve terminals labeled 1 - 12.

For more information on the output configurations, see Wiring instructions.

Table 2-2 describes the function of each terminal for all the output configurations.

Table 2-2: Rosemount 975MR Output Configurations

Wire terminal
number

1 +24 Vdc +24 Vdc +24 Vdc +24 Vdc +24 Vdc

2 0 Vdc 0 Vdc 0 Vdc 0 Vdc 0 Vdc

3 Manual built-in

4 Fault relay N.C. Fault relay N.C. Fault relay N.O. Fault relay N.C. Fault relay N.O.

5

6 Alarm relay N.O. Alarm relay N.O. Alarm relay N.O. Alarm relay N.O. Alarm relay N.O.

7 Alarm relay C Alarm relay C Alarm relay C Alarm relay C Alarm relay C

8 0-20 mA in Alarm relay N.C. Alarm relay N.C. Auxiliary N.O. Auxiliary N.O.

9 0-20 mA out

1A (default) 2A 3A 1R 2R

test

(1)

Manual built-in
test

0-20 mA out

(1)

Manual built-in
test

0-20 mA out

(1)

Manual built-in
test

Auxiliary C Auxiliary C

Manual built-in
test

10 RS-485 + (1) RS-485 + (1) RS-485 + (1) RS-485 + (1) RS-485 + (1)

11 RS-485 - (1) RS-485 - (1) RS-485 - (1) RS-485 - (1) RS-485 - (1)

12 RS-485 GND RS-485 GND RS-485 GND RS-485 GND RS-485 GND

(1) Available with the HART® protocol.

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Output configuration notes

• RS-485 is used for network communication, as specified in RS-485 communication

network, (terminals 10, 11, and 12) and to connect (in safe areas) to PC/laptop for

configuration/diagnostics.

• Alarm relay
— N.O. in output configuration 1A, 1R, and 2R

— N.O. and N.C. in output configuration 2A and 3A

• 0-20 mA is Sink in output configuration 1A and Source in output configurations 2A and

3A.

• 0-20 mA output configurations 1A, 2A, and 3A are available with the HART® protocol.

• In output configuration 1A, link terminals 1 and 8 to change the mA output to Source.

• The fault output is N.C. energized SPST relay. The contacts are closed when the

detector is in its normal operational condition in output configurations 1A, 2A, and 1R
and available as N.O. energized in output configurations 3A and 2R.

• The auxiliary output is N.O. energized (SPST) relay. The auxiliary relay may act in

parallel with the alarm relay to activate another external device, or it may provide a
warning signal, depending on the function configuration.

2.8 Configure the detector

You can reprogram the function setup using the RS-485 connection or using the HART
protocol as follows:

• USB RS-485 harness kit (PN 00975-9000-0011): The USB RS-485 harness kit with

RS-485/USB converter, used with the Rosemount host software, enables you to
connect to any available PC or laptop to reconfigure settings or perform diagnostics on
all Rosemount 975 series flame detectors.

Refer to manual 00809-0300-4975 for programming instructions when using the USB
RS-485 harness kit.

• HART protocol: Refer to manual 00809-0200-4975 for programming instructions.

These functions enable you to set:

• Sensitivity

• Alarm delay

• Address setup

• Mode of operation

• Heated optics operation

The factory default settings listed for each function are:

• Sensitivity: 30

®

• Alarm delay: A

• Alarm latch: No

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• Auxiliary relay: No

• Automatic BIT: Yes

• Alarm BIT: No

• Auxiliary BIT: No

• Heated optics: Auto

• Temperature: 41 °F (5 °C)

2.8.1 Sensitivity

The detector offers four (4) sensitivity settings. The settings refer to an n-heptane or
gasoline fire of 1 ft.2 (0.1 m2), from the low sensitivity of 50 ft. (15 m) to 215 ft. (65 m).

For other types of fuel sensitivity, refer to Table 1-5.

2.8.2

2.8.3

2.8.4

Alarm delay

The flame detector is equipped with an alarm delay option, which provides programmable
time delay with settings at:

• Antiflare

Other delay settings are available:

• 0, 3, 5, 10, 15, 20, or 30 seconds

When an alarm (detection) level condition occurs, the flame detector delays the execution
of the alarm outputs by the specified period of time. The detector then evaluates the
condition for three seconds. If the alarm level is still present, the detector activates the
alarm outputs. If this condition no longer exists, the detector returns to its standby state.

The alarm delay option affects the output relays and the 0-20 mA output. The LEDs and
outputs indicate warning levels during the delay time only if the fire condition exists.

(1)

(default)

Address setup

The flame detector provides up to 247 addresses that can be changed with the RS-485
communication link or the HART® communication protocol.

Function setup

You can select the desired functions as detailed in Table 2-3.

Table 2-3: Functions

Function Setting

Alarm latch • Yes: Enable alarm latching.

• No: Disable alarm latching (default).

(1) The Antiflare mode is selected to prevent false alarms in locations where fast flares may be present. The time delay for fire

alarms in this mode ranges from 2.5 to 15 seconds (usually less than 10 seconds).

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Table 2-3: Functions (continued)

Function Setting

Auxiliary relay

Automatic BIT • Yes: Perform automatic and manual built-in test

Alarm BIT • Yes: Successful manual built-in test activates the

(1)

• Yes: Activate auxiliary relay at warning level.

• No: Activate auxiliary relay at alarm level (default).

(default).

• No: Perform manual built-in test only.

alarm relay for approximately three seconds (default).

• No: Successful manual built-in test does not activate

the alarm relay.

2.8.5

Auxiliary BIT

(1) Only available in output configurations 1R and 2R.

(1)

• Yes: Successful manual built-in test activates the

auxiliary relay for approximately three seconds
(default).

• No: Successful manual built-in test does not activate

the auxiliary relay.

Heated optics

To configure optical window heating, select one of the modes listed below.

• OFF: Optical window surface heating does not operate.

• ON: Optical window surface heating operates continuously.

• AUTO: Optical window surface heating operates according to temperature change.

Specify the start temperature below which the optical window surface is heated to
improve performance in temperatures where snow, ice, and condensation may occur.

In AUTO mode, the default Heat On setting is 41 °F (5 °C). Heating stops when the
temperature is 27 °F (15 °C) above the start temperature.

You can define the start temperature below which the window will be heated. The
temperature can be defined between 32 and 122 °F (0 and 50 °C).

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3 Operating the detector

This chapter describes how to power up and test the detector. It also includes some very
important safety checks that you should make before operating the detector.

3.1 Power up

Follow these instructions carefully to obtain optimal performance from the detector over
its life cycle.

To power up the detector:

Procedure

1. Turn on the power.

2. Wait approximately 60 seconds for the detector to finish the startup procedure.

Applying power initiates the following sequence of events:

• The yellow LED flashes at 4 Hz.

• Built-in test is executed.

If successful, the green LED flashes at 1 Hz, and the FAULT relay contacts close; mA
output is 4 mA.

3. Enter Normal mode.

NOTICE

The majority of detectors are used in the default non-latching alarm mode. Only
perform a reset when the latching alarm option has been programmed.

To reset the detector when it is in a Latched Alarm state, do one of the following:

• Disconnect power (terminal number 1 or terminal number 2).

• Initiate a manual built-in test.

3.2 Safety precautions

After powering up, the detector requires almost no attention in order to function properly,
but note the following:

• Follow the instructions in this Reference Manual and refer to the drawings and

specifications.

• Do not expose the detector to radiation of any kind unless required for testing

purposes.

• Do not open the detector housing while power is applied.

• 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.

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• Only access the wiring compartment to wire or remove the detector or access RS-485

terminals for maintenance.

• Disconnect or disable external devices, such as automatic extinguishing systems,

before carrying out any maintenance.

3.2.1 Factory default function settings

Table 3-1 lists the default function configurations supplied with the detector.

Table 3-1: Factory Default Function Settings

Function Value Notes

Sensitivity 30

Alarm delay A Antiflare

Alarm latch No

Auxiliary relay No In output configurations 1A,

2A, and 3A, the auxiliary relay is
not available. This function is
not used.

Automatic built-in test (BIT) Yes

Alarm built-in-test No

Auxiliary built-in test No In output configurations 1A,

Heated optics Auto

Heat on 41 °F (5 °C) The detector starts heating the

In order to change the default function, use:

• USB RS-485 harness kit PN 00975-9000-001

• HART® protocol. Refer to manual 00809-0200-4975 for instructions.

3.3 Testing procedures

This section describes the proof testing procedure for proper operation of the detector.
Test the detector using the manual built-in test (BIT) or the flame simulator.

The detector performs the internal test continuously and the automatic built-in test every
fifteen minutes; for more details, refer to Built-in test (BIT) .

2A, and 3A, the auxiliary relay is
not available. This function is
not used.

window for any temperature
below this value.

3.3.1

40 Emerson.com/Rosemount

Automatic built-in test

Check that the indicators show normal conditions.
See Power up.

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3.3.2 Manual built-in test

To perform a manual built-in test:

NOTICE

If the function setup Alarm BIT and or Auxiliary BIT are set to YES (default NO), the alarm,
auxiliary relay, and 0-20 mA outputs are activated during a manual built-in test. Therefore,
you must disconnect automatic extinguishing systems or any external devices that may be
activated during the built-in test.

Procedure

1. Verify that the detector is in Normal mode.

2. Initiate the manual built-in test.

The results of succcessful and unsuccessful manual built-in tests are detailed in

Table 1-14 and Table 1-15.

3.3.3

Testing with flame simulator

Use the flame simulator to simulate exposure of the detector to a real fire condition. The
flame simulator exposes the detector to radiation at the required detection level. As a
result, the detector generates a fire alarm signal.

See Flame simulator for more information.

NOTICE

If the detector is exposed to a flame simulator, the alarm and accessory relays and 0-20
mA are activated during the simulation. Therefore, disconnect automatic extinguishing
systems or any external devices that may be activated during this process.

To perform a flame simulator test:

Procedure

1. Power up the system and wait up to 60 seconds for the detector to turn to a normal

state.
The power LED turns on.

2. Aim the flame simulator at the target point of the detector, in a way that the

radiation emitted by it is facing directly towards the detector.
See Flame simulator.

3. Press Operation once.

After a few seconds, a successful test shows the results shown in Table 3-2.

Table 3-2: Results of a Successful Flame Simulator Test

Component Action Notes

0-20 mA Turns to 20 mA For a few seconds and then

returns to 4 mA

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Table 3-2: Results of a Successful Flame Simulator Test (continued)

Component Action Notes

Alarm relay Activated For a few seconds and then

returns to Normal

Auxiliary relay Activated For a few seconds and then

returns to Normal

Fault relay Remains active during the test

LED Red, steady

The detector is now ready for operation.

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4 Maintenance and troubleshooting

This chapter deals with preventative maintenance, describes possible faults in detector
operation, and indicates corrective measures. Ignoring these instructions may cause
problems with the detector and may invalidate the warranty. Whenever a unit requires
service, please contact Emerson or its authorized distributer for assistance.

4.1 Maintenance

This section describes the basic maintenance steps you should take to keep the detector in
good working condition.

4.1.1

4.1.2

General maintenance procedures

Only suitably qualified personnel who are familiar with local codes and practices should
perform maintenance. Maintenance requires ordinary tools.

Cleaning

Keep the detector as clean as possible. Clean the viewing window and the reflector of the
flame detector periodically.

The frequency of cleaning operations depends upon the local environmental conditions
and specific applications. The fire detection system designer will give his or her
recommendations.

To clean the detector viewing window and reflector:

Procedure

1. Disconnect power to the detector before proceeding with any maintenance,

including window/lens cleaning.

2. Use water and detergent and then rinse the viewing window with clean water.

3. Where dust, dirt, or moisture accumulates on the window, first clean only with a

soft optical cloth and detergent and then rinse with clean water.

Periodic maintenance procedures

In addition to preventive cleaning and maintenance, functionally test the detector every
six months or as dictated by local codes and regulations. Also perform these tests if the
detector has been opened for any reason.

Power-up procedure

Perform the power-up procedure every time power is restored to the system.
Follow the instructions described in Power up.

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Functional test procedure

Perform a functional test of the detector as described in Internal detector tests.

4.1.3 Keeping maintenance records

Emerson recommends that you record maintenance operations performed on a detector
in a log book. The record should include the following:

• Installation date and contractor

• Serial and tag number

• Entries for every maintenance operation performed, including the description of the

operation, date, and personnel ID

If you send a unit to Rosemount or a distributer for service, include a copy of the
maintenance records.

4.2 Troubleshooting

4.2.1

4.2.2

This section is intended to be a guide to correct problems that may happen during normal
operation.

Fault relay at N.O.

LEDs off

0-20 mA at 0 mA

No power to the unit

Recommended actions

1. Check that the correct power is sent to the detector.

2. Check power polarity.

3. Check wiring in the detector.

4. Send the detector back for repairs.

Fault relay at N.O.

Yellow/amber LED flashes at 4 Hz.

0-20 mA at 0 mA

Detector fault

• Low voltage

• Faulty detector

Recommended actions

1. Check the voltage at the detector; verify at least 24 V at the detector terminal.

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2. Send the detector back for repairs.

4.2.3 Fault relay at N.O.

Yellow/amber LED flashes at 4 Hz.

0-20 mA at 2 mA

BIT fault: faulty detector

Recommended actions

1. Clean detector window.

2. Re-power the detector.

3. Replace the detector.

4.2.4

4.2.5

Red LED constantly on

If no fire exists, the detector alarm may be latched.

Recommended action

Reset the detector.

Alarm relay at on

0-20 mA at 20 mA

Alarm condition

Recommended actions

1. Check cause of alarm.

2. If no alarm, re-power the detector.

3. Send the detector back for repairs.

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A Specifications and reference data

A.1 Technical specifications

Table A-1: Technical Specifications

Spectral response Multi IR bands

Detection range (at
highest sensitivity
setting for 1 ft.2 (0.1
m2) pan fire)

Response time Typically 5 seconds

Adjustable time delay Up to 30 seconds

Sensitivity ranges Four sensitive ranges for 1 ft.2 (0.1 m2) n-heptane pan fire from 50 ft. (15 m) to 215 ft. (65 m)

Fields of view Horizontal: 100 °, vertical: 95 °

Built-in test (BIT) Automatic (and manual)

(1) 30 in. (0.75 m) high, 10 in. (0.25 m) wide plume fire

Fuel ft. / m Fuel ft. / m

n-Heptane 215 / 65 Kerosene 150 / 45

Gasoline 215 / 65 Ethanol 95% 135 / 40

Diesel fuel 150 / 45 Methanol 115 / 35

JP5 150 / 45 IPA (isopropyl alcohol) 135 / 40

(1)

(1)

150 / 45 Polypropylene pellets 115 / 35

150 / 45 Office paper 83 / 25

Methane

LPG

A.2 Electrical specifications

Operating voltage: 18 - 32 Vdc
Power consumption: Table A-2

Table A-2: Electrical Specifications

Operating voltage Status All outputs Without 0-20 mA

Power consumption
(max. 24 Vdc)

Maximum current
(max. 24 Vdc)

Rosemount 975MR 47

Normal 1.61 W 1.56 W

Normal when heateron2.28 W 2.16 W

Alarm 2.64 W 2.28 W

Alarm when heater on 3.24 W 2.88 W

Normal 70 mA 65 mA

Normal when heateron95 mA 90 mA

Alarm 110 mA 95 mA

Alarm when heater on 135 mA 120 mA

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Table A-2: Electrical Specifications (continued)

Operating voltage Status All outputs Without 0-20 mA

Power consumption
(max. 18-32 Vdc)

Maximum current (18 ­32 Vdc)

Electrical input protection: The input circuit is protected against voltage-reversed polarity,
voltage transients, surges, and spikes according to MIL-STD-1275B.

A.3 Outputs

Electrical
interface

There are five output configurations. These configurations must be defined
at the factory per the customer order and cannot be changed at the
customer facility.
See General instructions for electrical wiring for the wiring/terminal
diagrams for each option.

Unless otherwise specified, the default is output configuration 1A. The
wiring arrangement is identified on the detector by the part number (see

Model and types).

Normal 1.95 W 1.85 W

Normal when heateron2.56 W 2.45 W

Alarm 3.04 W 2.56 W

Alarm when heater on 3.68 W 3.2 W

Normal 90 mA 85 mA

Normal when heateron105 mA 100 mA

Alarm 130 mA 115 mA

Alarm when heater on 160 mA 145 mA

• Output configuration 1A: power, RS-485, 0-20 mA (sink), fault relay

(N.C.), alarm rela (N.O.)

• Output configuration 2A: power, RS-485, 0-20 mA (source) and HART

®

protocol, fault relay (N.O.), alarm relay (N.O., N.C.)

• Output configuration 3A: power, RS-485, 0-20 mA (source) and HART

protocol, fault relay (N.O.), alarm relay (N.O., N.C.)

• Output configuration 1R: power, RS-485, fault relay (N.C.), auxiliary relay

(N.O.), alarm relay (N.O.)

• Output configuration 2R: power, RS-485, fault relay (N.O.), auxiliary relay

(N.O.), alarm relay (N.O.)

Electrical
outputs

48 Emerson.com/Rosemount

• Dry contact relays

Table A-3: Contact Ratings

Relay name Type Normal position Maximum

ratings

Alarm SPDT N.O., N.C. 2 A at 30 Vdc

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Table A-3: Contact Ratings (continued)

Relay name Type Normal position Maximum

ratings

Auxiliary SPST N.O. 2 A at 30 Vdc

Fault (see notes 1
and 2)

SPST N.C. or N.O. 2 A at 30 Vdc

1. The fault relay (in output configurations 1A, 2A, and 1R) is
normally energized closed during normal operation of the
detector. The relay is de-energized open if a fault condition or low
voltage situation occurs.

2. In output configurations 3A and 2R, the relay is normally energized
open during normal operation of the detector. The relay is de­energized closed contact if a fault condition or low voltage
situation occurs.

• 0-20 mA current output: The 0-20 mA can be Sink or Source according to

the output configuration (see General instructions for electrical wiring) .
The maximum permitted load resistance is 600 Ω.

Table A-4: 20 mA Current Output

State Output

Fault 0 + 1 mA

BIT fault 2 mA ± 10%

Normal 4 mA ± 10%

Warning 16 mA ± 5%

Alarm 20 mA ± 5%

• HART protocol: The HART protocol is a digital communication signal at a

low level on top of the 0-20mA. This is a bi-directional field
communication protocol used to communicate between intelligent field
instruments and the host system. HART is available in output
configurations 1A, 2A, and 3A.

Through the HART protocol, the detector can:

— Display setup
— Reconfigure the setup
— Display detector status and definition
— Perform detector diagnostics
— Troubleshoot

For more details, refer to HART Manual 00809-0200-4975.

• Communication network: The detector is equipped with an RS-485

communication link that can be used in installations with computerized
controllers.

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The communication protocol is Modbus® compatible.

— This protocol is standard and widely used.
— It enables continuous communication between a standard Modbus

controller (master device) and a serial network of up to 247 detectors.

Heated
optics

The front window can be heated to improve performance in icing,
condensation, and snow conditions. The heater increases the temperature
of the optical surface by 5 to 8 °F (3 to 5 °C) above the ambient temperature.
The heated optics can be configured in three ways:

• OFF: The optics are not heated.

• ON: The optics are heated continuously.

• AUTO: Operated only when the change of temperature requires heating

(default).

In AUTO mode, you can define the start heating temperature between 32
and 122 °F (0 and 50 °C). The detector stops heating the window when the
temperature is 27 °F (15 °C) above the start temperature.

A.4 Mechanical specifications

Enclosure
Water and dust tight

Electronic modules
Electrical connection (two entries)

Stainless steel 316

• NEMA® 250 type 6p.

• IP 66 and IP 67 per EN 60529

Conformal coated

• ¾-in. -14 NPT conduit or

• M25 x 1.5

Dimensions
Weight

4 x 4.6 x 6.18 in. (101.6 x 117 x 157 mm)

6.1 lb. (2.8 kg)

A.5 Environmental specifications

The Rosemount 975MR is designed to withstand harsh environmental conditions.

High
temperature

Low
temperature

50 Emerson.com/Rosemount

• Designed to meet MIL-STD-810C, method 501.1, procedure II

• Operating temperature: 167 °F (75 °C)

• Storage temperature: 185 °F (85 °C)

• Designed to meet MIL-STD-810C, method 502.1, procedure I

• Operating temperature: -57 °F (-50 °C)

• Storage temperature: -65 °F (-55 °C)

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Humidity

• Designed to meet MIL-STD-810C, method 507.1, procedure IV

• Relative humidity of up to 95 percent for the operational

temperature range

Salt fog

• Designed to meet MIL-STD-810C, method 509.1, procedure I

• Exposure to a 5 percent salt solution fog for 48 hours

Dust

• Designed to meet MIL-STD-810C, method 510.1, procedure I

• Exposure to a dust concentration of 0.3 grams/cubic ft at a

velocity of 1,750 fprn, for 12 hours

Vibration

• Designed to meet MIL-STD-810C, method 514.2, procedure VIII

• Vibration at an acceleration of 1.1 g within the frequency range of

5-30 Hz and an acceleration of 3 g within the frequency range
30-500 Hz

Mechanical
shock

• Designed to meet MIL-STD-810C, method 516.2, procedure I

• Mechanical shock of 30 g half-sine wave for 11 msec

CAUTION

RFI and EMI may cause interference.
To fully comply with EMC directive 2014/30/EU and protect against interference caused

by RFI and EMI, shield the cable to the detector and ground the detector. Ground the
shield at the detector end.

Table A-5: Electromagnetic Compatibility (EMC)

Test standard Level per

Electrostatic discharge (ESD) IEC 61000-4-2 EN 50130-4

Radiated EM field IEC 61000-4-3 EN 50130-4

Electrical fast transients IEC 61000-4-4 EN 50130-4

Surge IEC 61000-4-5 EN 50130-4

Conducted disturbances IEC 61000-4-6 EN 50130-4

Power frequency magnetic field IEC 61000-4-8 EN 50130-4

Radiated emission IEC 61000-6-3 EN 550022

Conducted emission IEC 61000-6-3 EN 550022

Immunity to main supply
voltage variations

IEC 61000-4-29 EN 50130-4

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B Wiring instructions

B.1 General instructions for electrical wiring

Follow the instructions detailed in this section for determining the correct wire gauge to
be used for this installation.

1. Use Table B-1 to determine the required wire gauge/size for general wiring, such as
relay wiring. Calculate the permitted voltage drop with respect to load current, wire
gauge, and length of wires.

Table B-1: Maximum DC Resistance at 68 °F (20 °C) for Copper Wire

AWG # mm

20 0.52 - 0.61 1.07 3.50

18 0.81 - 0.96 0.67 2.20

16 1.22 - 1.43 0.43 1.40

2

Ohm per 100 ft. Ohm per 100 m

14 1.94 - 2.28 0.27 0.88

2. Use Table B-2 to select wire gauge for power supply wires. Do not connect any
circuit or load to detectors' supply inputs.

• Select number of detectors connected in one circuit.

• Select wiring length per installation requirements.

• Refer to power supply range for voltage extreme applied.

Table B-2: Wiring Length in Meters (Feet)

Number of
detectors

24 18 16 14 N/A N/A 22-32

20 18 16 14 N/A N/A 22-32

16 20 18 16 14 N/A 22-32

12 20 18 16 14 N/A 20-32

8 20 18 16 14 N/A 20-32

4 and less 20 18 16 16 14 20-32

m (ft) 50 (164) 100 (328) 150 (492) 200 (656) 240 (820)

Recommended wire diameter (AWG) Power supply

range (Vdc)

Max. length from power supply to last detector

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B.1.1 Calculation formula

Use the following formula to calculate minimum wire gauge per wire length between the
power supply (controller) and the detector, considering the number of detectors on the
same power line, where:

L = Actual wire length between the detector and the power supply.
N = Number of detectors per loop
R = Resistance of wire per 100 m (see Table B-2)
V = Voltage drop on the wire
Calculate the voltage drop on the wire as follows:

20 + V = Minimum required voltage of the power supply.

0.2 A is the maximum power consumption of the detector.
For example:
If N = 1 (1 detector in loop), L = 1,000 m, wire size = 1.5 mm2 (see Table B-1, the resistance

per 100 m for 1.5 mm2 is 1.4 Ω).
You calculate the voltage drop in the wire as follows:

The minimum voltage of the power supply should be 20 V + 5.6 V = 25.6 V.

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B.2 Typical wiring configurations

This section describes examples of typical wiring configurations.

Figure B-1: Wiring terminals

Output configuration Terminals

5 8 9

1A Fault relay (N.C.) 0-20 mA (sink) 0-20 mA (sink)

2A Fault relay (N.C.) Alarm relay (N.C.) 0-20 mA (source)

3A Fault relay (N.O.) Alarm relay (N.C.) 0-20 mA (source)

1R Fault relay (N.C.) Auxiliary relay (N.O.) Auxiliary relay (C)

2R Fault relay (N.O.) Auxiliary relay (N.O.) Auxiliary relay (C)

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Figure B-2: Typical Wiring for 4-Wire Controllers (Using Output Configuration 1A or
2A)

Figure B-3: 0-20 mA Output Configuration 1A (Sink 4-Wire) - Default

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Figure B-4: 0-20 mA Output Configuration 1A (Converted to Source 3-Wire)

Figure B-5: 0 - 20 mA Output Configuration 1A (Non-Isolated Sink 3-Wire)

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Figure B-6: 0- 20 mA Output Configurations 2A and 3A (Source 3-Wire Available with
HART® Protocol)

NOTICE

There are no 0-20 mA outputs in output configurations 1R and 2R.

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C RS-485 communication network

By using the RS-485 network capability of the detector and additional software, you can
connect up to 32 detectors in an addressable system with four (4) wires only (two for
power and two for communication). Using repeaters, the number of detectors can be
much larger (32 detectors for each repeater) up to 247 on the same four (4) wires. When
using the RS-485 network, you can read each detector status (Fault, Warning, and Alarm)
and to initiate a built-in test to each detector individually.

For more details, consult Rosemount.

Figure C-1: RS-485 Networking

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D Accessories

This appendix describes the accessories that can help you maximize fire detection with the
Rosemount 975MR flame detector.

D.1 Flame simulator

Rosemount designed the flame simulators pecifically for use with Rosemount flame
detectors. The flame simulator emits IR radiation in a unique sequential pattern
corresponding to and recognizable by the detector as fire. This allows the detectors to be
tested under simulated fire conditions without the associated risks of an open flame.

Figure D-1: Flame Simulator

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D.1.1 Ordering information

The PN of the flame simulator kit is FS-IR-975. The kit is supplied in a carry case that
includes:

• Flame simulator

• Charger

• Tool kit

• Technical manual

D.1.2 Unpacking

Verify that you have received the following contents:

• Delivery form

• Flame simulator with integral battery

• User manual

D.1.3

• Factory acceptance test forms

• EC declaration

• Storage case

Simulate a flame

WARNING

Hazardous areas

Do not open the flame simulator to charge the batteries or for any other reason in a
hazardous area.

CAUTION

The following test simulates a real fire condition and may activate the extinguishing
system of other alarms.

If you don't want this to happen, disconnect/inhibit other alarms before the test and
reconnect after the simulation.

Procedure

1. Make sure that you are at the correct distance from the detector according to the
type of detector and the detector sensitivity.

When testing, keep a distance of at least 20 in. (50 cm) from the detector.

2. Press the Operation button once.
The flame simulation lasts for fifty seconds. The detector sends an alarm signal
(solid red LED).

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3. Wait 20 seconds before repeating the test.

4. Verify that the optical window is clean.

Accessories

D.1.4 Range

Table D-1: Sensitivity Ranges

Sensitivity Detection range (ft. / m) Standard test range (ft. / m)

1 (low) 50 / 15 6.6 / 2

2 100 / 30 19.6 / 6

3 150 / 45 29.5 / 9

4 (high) 215 / 65 39.3 / 12

1. The minimum distance from the detector is 20 in. (50 cm).

2. At extreme temperatures, there is a 15 percent maximum reduction in the range.

NOTICE

D.1.5

Keep the flame simulator in a safe place when not in use.

Charge the battery

The flame simulator uses lithium ion batteries as a rechargeable power source. When the
batteries are fully charged, the simulator operates for at least 1,000 times without having
to be recharged. The simulator will not operate when the voltage from the batteries is
lower than the required operational level.

Figure D-2: Flame Simulator Battery Replacement

A. Simulator

B. Battery pack

C. Locking disc

D. Back cover

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NOTICE

The item letters in this procedure can be found in Figure D-2.

Procedure

1. Place the flame simulator in a safe area, not exceeding 104 °F (40 °C).

2. Release the locking screw.

3. Unscrew the battery back cover (D) counter-clockwise.

4. Unscrew the locking disc (C) clockwise.

5. Pull out the battery from the flame simulator.

6. Connect the battery to the charger.

7. Charge for a maximum of two to three hours.

8. Disconnect the charger.

9. Insert the battery in the flame simulator.

10. Screw on the locking disc (C).

11. Screw on the back cover (D).

12. Lock the back cover with the locking screw.

D.1.6

Replace the battery

NOTICE

The item letters shown in this procedure can be found in Figure D-2.

Procedure

1. Place the flame simulator on a table in a safe area, not exceeding 104 °F (40 °C).

2. Release the locking screw.

3. Unscrew the battery back cover (D) counter-clockwise.

4. Unscrew the locking disk (C) clockwise.

5. Pull out the battery from the flame simulator.

6. Insert the new battery pack in the simulator housing.
Use only Rosemount battery pack, PN 00975-9000-0012.

7. Screw on the locking disc (C).

8. Screw on the back cover (D).

9. Lock the back cover with the locking screw.

NOTICE

For more information, refer to 00809-0500-4975.

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D.1.7 Technical specifications

Table D-2: Flame Simulator Technical Specifications

General • Temperature range: -4 to 122 °F (-20 to 50 °C)

• Vibration protection: 1 g (10 - 50 Hz)

Electrical • Power: 14.8 V (4 x 3.7 V rechargeable lithium battery)

• Max. current: 4 A

• Battery capacity: 2.2 AH

• Charging time: 2 A at 2 Hr

Physical • Dimensions: 9.1 x 7.3 x 5.4 in. (230 x 185 x 135 mm)

• Weight: 5.5 lb. (2.5 kg)

• Enclosure: aluminum, heavy duty copper free, black zinc

coating

• Explosion-proof enclosure

ATEX and IECEx

II 2 G D
Ex d ib op is IIB +H2 T5 Gb
Ex ib op is tb IIIC T135 °C Db

EMI compatibility See Table D-3 and Table D-4.

Table D-3: Immunity Tests

Title Basic standard Level to be tested

Electrostatic discharge (ESD) IEC 61000-4-2 6 kv / 8 kv contact / air

Radiated electromagnetic field IEC 61000-4-3 20 V/m (80 MHz to 1 GHz)

10 V/m (1.4 GHz to 2 GHz)
3 V/m (2.0 GHz to 2.7 GHz)

Conducted disturbances IEC 61000-4-6 10 Vrms (150 kHz to 80 MHz)

Immunity to mains supply
voltage variations

MIL-STD-1275B

Table D-4: Emission Tests

Title Basic standard Level to be tested Class

Radiated emission IEC 61000-6-3 40 dbuv/m (30 MHz to

230 MHz), 47 dbuv/m
(230 MHz to 1 GHZ

Like Class B of EN
55022

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D.2 Tilt mount: PN 00975-9000-0001

The tilt mount provides accurate directional selection for optimum area coverage.

Figure D-3: Tilt Mount

D.3 Duct mount: PN 00975-9000-0002

The duct mount is suitable for use with the Rosemount 975 series optical flame detector
for both the aluminum and stainless steel enclosures.

The duct mount allows flame detection in areas where high temperatures exist or in cases
where the detector cannot be installed inside the area. It comprises a special duct mount
arrangement with specific optical window to allow installation in high temperature duct
applications.

The duct mount limits the cone of vision of the installed detector to 65 degrees horizontal
and 65 degrees vertical.

The temperature allowed for the duct mount to be installed is -67 to 392 °F (-55 to 200 °C).
For more instructions, refer to 00809-0600-4975.

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Figure D-4: Duct Mount

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D.4 Weather cover: PN 00975-9000-0003

The weather cover protects the detector from different weather conditions, such as snow
and rain.

Figure D-5: Weather Cover

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D.5 Air shield: PN 00975-9000-0005

The air shield is suitable for use with the Rosemount 975 series flame detectors for both
the aluminum and stainless steel enclosures.

Optical flame detectors are often used in highly polluted or dirty areas that force
maintenance personnel to access the detector frequently to clean its optical window. The
special air shield, developed for the Rosemount 975 series optical flame detectors, allows
operators to install the flame detectors under tough environmental conditions where they
may be exposed to oil vapors, sand, dust, and other particulate matter.

The temperature of the air supply to the air shield should not exceed 140 °F (60 °C) at any
time.

Air pressure source: clean, dry, and oil-free air
Pressure: 2 - 3 bar (30 - 45 psi)
Fitting: 7/16 in. - 20 UNF - 2 A
Operation temperature: -67 to 185 °F (-55 to 85 °C)
For more instructions, refer to 00809-0700-4975.

Figure D-6: Air Shield

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70 Emerson.com/Rosemount

Reference Manual

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SIL-2 features

E SIL-2 features

This appendix details the special conditions to comply with the requirements of EN 61508
for SIL 2.

The Rosemount 975MR Flame Detector can only be used in low or high demand mode
applications; see IEC 61508.4, Chapter 3.5.12.

E.1 Safety relevant parameters

Perform the following functional checks of the detector.

• Alternative 1: Functional check of the detector every 180 days:
— HFT: 0

— PFD: 3.0 x 10-4 (≈ 3% of SIL-2) if only alarm relay is used for alerting.
— PFD: 3.2 x 10-4 (≈ 3.2% of SIL-2) if 0-20 mA interface is used as alarm.
— PFH: 1.5 x 10-7 1/h (≈14.9% of SIL-2) for 0-20 mA application.
— SFF: 95% fulfills the conditions of EN 61508 for SIL-2.

• Alternative 2: Functional check of the detector every 365 days:
— HFT: 0

— PFD: 4.5 x 10-4 (≈ 4.5% of SIL-2) if only alarm relay is used for alerting.
— PFD: 4.9 x 10-4 (≈ 4.9% of SIL-2) if 0-20 mA interface is used as alarm.
— PFH: 1.5 x 10-7 1/h (≈14.9% of SIL-2) for 0-20 mA application.
— SFF: 95% fulfills the conditions of EN 61508 for SIL-2.

E.2 Guidelines for configuring, installing,

operating, and service

The alert conditions according to SIL-2 can be implemented by an:

• Alert signal via 20 mA current loop

or

• Alert signal via alarm relay and the fault relay

E.2.1

Conditions for safe operating

1. The flame detector shall consist only of the approved hardware and software

modules.

2. The 24 V power supply must fulfill the requirements for PELV/SELV of EN 60950.

3. The automatic BIT (built-in test) must be activated.

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SIL-2 features

August 2019 00809-0100-4975

4. The setup parameters must be verified (as described in Using the 0-20 mA interface

for alerting and Using the alarm relay contact for alerting), and the function of the

Rosemount 975 flame detector (flame detection, function of the 0-20 mA interface,
relay functions) must be checked completely.

Reference Manual

E.2.2 Using the 0-20 mA interface for alerting

The following parameters shall be set:

• Automatic built-in test: ON

• Connected to 0-20 ma terminals

The following allowed output current must be supervised with an accuracy of ±5%.

• Normal state: 4 mA

• Warning state: 16 mA

• Alarm state: 20 mA

The output current must be supervised regarding the over-and under run of the 0-20 mA.

E.2.3

E.2.4

The 0-20 mA can be used as low and high demand mode.

Using the alarm relay contact for alerting

The following parameters shall be set:

• Automatic built-in-test: ON

• Connected to N.C. contact of alarm relay terminals

• Connected to fault relay terminals

The relay contacts (alarm and faulty relay) must be protected with a fuse rated at 0.6 of
the nominal specified relay contact current.

The maximum contact rating that is allowed per SIL-2 is 30 Vdc.
The contact of the alarm relay opens if there is a fire alarm.
During the forwarding and evaluation of the alarm, the relay contact opens.
The alarm relay can be used as low demand only.

Other

1. The complete function of the flame detector (flame detection, function of the

0-20 mA interface, and the relays) must be examined at least every six or twelve
months (see Safety relevant parameters) when the flame detector must be
switched OFF and ON.

2. The window of the sensor must be examined at appropriate time intervals for

partial contamination.

3. The HART® and the RS-485 interfaces must not be used for the transmission of the

safety-related data.

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Reference Manual End of line resistor

00809-0100-4975 August 2019

F End of line resistor

The Rosemount 975 series can be equipped with an EOL resistor inside the flameproof 'd'
terminal compartment.

The EOL resistor can be situated in the rear part, which is Ex e or Ex d, depending on the
application. When the resistor is assembled, the rear part can be used as Ex d only.

To meet the allowed power consumption, the total resistance should be higher than 1.5
KΩ.

Figure F-1: Rosemount 975MR Flame Detector

A. Terminal number 5

B. Terminal number 6

C. Rosemount 975MR flame detector

D. End of line resistor

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00809-0100-4975

Rev. DB

2019

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