FLAMMABLE GAS DETECTOR INSTALLATION, OPERATING AND MAINTENANCE INSTRUCTIONS DAX3FC_MAN01_EN.indd Ver. V1R2
Introduction These instructions must be read carefully by any person who has or will have the responsibility for the installation, the use and/or the maintenance of this equipment. The warranty provided by DALEMANS will be voided if installation, use and maintenance of this equipment are not in accordance with the instructions given in this manual. By respecting these instructions you guarantee the correct operation of the apparatus. Should you require any further information about the use or the maintenance of this product, do not hesitate to contact Dalemans PRIOR to carrying out installation works. Each apparatus must be installed, operated and maintained according to the instructions, the warnings and the operational limits detailed in this manual. Use only DALEMANS original parts when you assume the maintenance of this product as specified in this manual. The use of non-dalemans spare parts may seriously impair the performances of the apparatus. Repair or maintenance attempts carried out without observing the procedures described in this manual or without the assistance of our after-sales service may prevent the equipment from working properly and, consequently, from ensuring the safety of the occupants of the building and of the plants. Always make sure to switch off power and declassify the hazardous area before carrying out replacement or modification works on components of the gas detection system. Application The gas detector is intended for industrial and commercial environment and is suitable for use in explosive atmospheres of hazardous areas (zone 1 or 2). It is designed to operate as part of a gas detection system, and to provide, in association with a suitable control unit, early warnings of flammable gas hazard before gas concentration reaches the Lower Explosive Limit (LEL). For further information about the detectable gases or the list of compatible control units, please contact Dalemans. Approval - Standards As a manufacturer, Dalemans Company declares that the products hereby described are certified for hazardous areas with an ingress protection degree IP6X corresponding to non-aggressive indoor environments, and that they fulfil the provisions of the following directives and standards : Directive 94/9/EC (ATEX) EN 60079-0:2006 EN 60079-1:2007 EN 60079-7:2007 EN 61241-0:2006 EN 61241-1:2004 The said products comply with the acceptable variations originating from the type that has received the EC-Type Examination Certificate Nr FTZU 10 ATEX 0033X. Moreover, they have been designed, manufactured and controlled within the framework of an ISO9001 certified quality assurance system which has been assessed by a notified body according to annex IV and VII of the Directive 94/9/EC. 1
Marking The label below is affixed to the junction box of the detector. This marking applies to the detector overall assembly. The marking label affixed to the sensing head applies only to the sensing head. 2 Device Type ATEX certificate number Notified Body identification code Serial Nr - year of production Target gas Measuring range Operating temperature range 1026 II 2G Ex d e IIC T6 II 2D Ex td A21 IP6X T85 C Tamb: -10 C to +50 C FTZU 10 ATEX 0033X Remicourt Belgium Gas: CH4 100% LEL Use: -10..+50 C D040BAAA - 91099042-2010 Certification (ATEX) II : non-mining electrical equipment group for potentially explosive atmospheres. 2G : category 2 equipment intended for use in areas where GAS explosive atmospheres are likely to occur (zone 1). Ex d e : protection by flameproof enclosure d and increased safety e. IIC : equipment group II subdivision according to the nature of the explosive GAS atmosphere (methane, propane, ethylene, hydrogen, acetylene). T6 : temperature class according to the maximum surface temperature of the equipment in explosive GAS atmosphere (T6=85 C). 2D : category 2 equipment intended for use in areas where DUST explosive atmospheres are likely to occur (zone 21). Ex td : dust ignition protection by enclosure td. A21 : method of determining the maximum surface temperature of equipment (with 5 mm layer of dust) for use in areas where an explosive atmosphere of combustible DUST is likely to occur, occasionally, in normal operation (method A - zone 21). IP6X : dust tight ingress protection. T85 C : maximum surface temperature of the equipment for DUST explosive atmospheres. Tamb : ambient temperature range according to the rated temperature class and the maximum surface temperature (Tamb = -10 C to +50 C for T6 and T85 C).
Description The is a gas detector designed to detect flammable gas present in ambient air at concentrations up to 100 % of the Lower Explosive Limit (LEL). It operates using a catalytic sensor which provides a 3-wire mv output signal. The detector can be connected to a control unit as part of a Wheatstone bridge measuring circuit. For details of compatible control unit please contact Dalemans. The flammable gas detector comprises the following main parts : The sensing head. The junction box equipped with a terminal block for electrical connection. The cable gland. The overall assembly has a combined type of protection d e and an ingress protection IP6X. 3 Increased safety e junction box Increased safety e cable gland Increased safety e terminal block Flameproof d sensing head Figure 1 : detector
Sensing head The sensing element of the operates on the principle of catalytic combustion. The sensor consists of a matched pair of elements typically referred to as a passive P element and an active A element. Both are made of an electrically heated (400 C) platinum wire coil embedded within a bead. The bead of the active element is covered with a catalyst layer. The passive element is used as a reference compensating for external temperature. If combustible gas/air mixture is present in ambient air, catalytic combustion reaction takes place on the active element. The heat of reaction on the catalyst layer produces a variation in the resistance of the active element. This resistance variation, which is a function of gas concentration, can be measured by a control unit equipped with a 3-wire Wheatstone bridge input. The sensing head of the consists of : A flameproof d sensor housing (body + top). A sintered metal filter. A catalytic sensor (pellistor). An O-ring. The sensor housing is a stainless steel assembly (body and top) which can be dismantled to allow plug-in sensor or sintered metal filter replacement. 4 Top Catalytic sensor Sintered metal filter Body O-ring Figure 2 : Sensing head
5 Dimensions 80 68 7.5 mm MAX MAX 139 75 45 4.5 mm MAX 45 Figure 3 : mechanical pattern
Caution Detectors using catalytic sensors are not suitable for use in atmospheres with oxygen level over 21 %, or below 15 % or variable. Atmospheres with flammable gas level over 100 % LEL may damage the catalytic sensor in the long run. The sensor may become unusable after long periods of exposure to poisons such as silicone, halogens, heavy metals. Ensure that local or national regulations relating to the site or the monitored plant are met. The operator must have knowledge of the safety procedure to follow in case of gas alarm. Modification, disassembling and total or partial destruction of the sensing head and its contents, of the cable gland or of the junction box and its contents, may invalidate the essential safety requirements of the whole plant. No additional drilling is allowed on the junction box. The existing openings cannot be enlarged. Possible defective parts must be replaced by original parts delivered by Dalemans only. No additional terminal can be installed on the existing terminal block. The length of the wires of the sensing head may not be modified. Do not open the junction box or the sensing head while explosion hazard might be present. Only clean or wipe the detector surface with a wet cloth so as to avoid the risk of electrostatic sparks. The detector must be protected from any risk of mechanical impact. 6 Flammable limits and setpoints Relationship between percent of Lower Explosive Limit (% LEL) and percent by volume (% v/v) differs from gas to gas. The IEC 60079-20-1 standard gives the method for determination of flammable limits. Examples include : Ethane (C 2 H 6 ) Ethylene (C 2 H 4 ) Hydrogen (H 2 ) Methane (CH 4 ) Pentane (C 5 H 12 ) Propane (C 3 H 8 ) 100 % LEL = 2.4 % v/v 100 % LEL = 2.3 % v/v 100 % LEL = 4.0 % v/v 100 % LEL = 4.4 % v/v 100 % LEL = 1.1 % v/v 100 % LEL = 1.7 % v/v Typical alarm setpoints for combustible gas detection devices are 20 % LEL for the low alarm (A1) and 40 % for the high alarm (A2). Never use alarm setpoints over 60 % LEL. The LEL of a gas is affected by temperature and pressure. When the ambient temperature increases, the LEL decreases and the explosion hazard is higher. The relationship between LEL and pressure is very complex. However, a pressure increase usually lowers the LEL. The LEL of a gas is not significantly affected by the humidity fluctuations that may normally occur in the average industrial environment.
Installation & commissioning Installation and commissioning must be carried out by the manufacturer or his local representative. All the operations described hereafter can be carried out only by specialized personnel who will have been trained beforehand exclusively by Dalemans. Gas detection equipment should be installed as late as possible in any program of construction operations (i.e. construction of a new plant, refitting or maintenance) but before the presence of gas or vapours in the system, so as to avoid damage to sensors resulting in particular from such activities as welding and painting. If already installed, sensors should be protected by an airtight seal to avoid contamination during construction works, and should be clearly marked as being non-operational. Please follow the recommendations hereafter so as to avoid premature ageing of the detector and to guarantee its optimal operation. These recommendations are general directives. Always refer to local regulations/standards in force before proceeding with installation works (i.e. standards IEC 60079-14 and IEC 60079-29-2). Local regulations/standards in force have always precedence on the recommendations of the manufacturer. 7 Location Detectors must be placed so that potential gas accumulations are detected before they create a significant hazard. Inappropriate location of a detector can nullify the effect and the integrity of the gas detection system. The placement of the detectors should be determined in consultation with experts having specialist knowledge of gas dispersion, with those who have knowledge of process plant system and equipment involved, and with safety and engineering personnel. Should you require any further guidance or assistance please contact Dalemans. Detectors should be readily accessible to permit regular calibration, maintenance and electrical safety inspection. It must be possible to access and fit all accessories or test equipment needed for these operations on the detector. The location of every detector must be recorded and available to the safety personnel. The following points should be taken into account when selecting locations to install the gas detector : Hazard level and potential sources of gas leak. The combination of sources of gas release with propagation effects. Access for maintenance including calibration and verification. Protection of the system against operational hazards of the plant. Protection of the detector against mechanical impact. Vibration isolation mountings if necessary. The detector should never be positioned directly above or below a water point. For outdoor installation, a protection against rain and/or sun exposition shall be installed. Detector should not be located in air currents, close to air extractors or in ventilation ducts. Always observe the operational temperature range of the sensor (refer to specifications). If target gas is lighter than air (density with respect to air < 1), place the detector at a high level. If target gas is heavier than air (density with respect to air > 1), place the detector at a low level. If target gas has a unit weight close to air unit weight, place detectors at both high and low level. Gas density increases when temperature decreases.
8 Examples of placement for some flammable gases * : Gas Formula Density (air=1) Detector(s) position Acetylene (CH) 2 0.90 Ceiling + floor Butane C 4 H 10 2.05 Floor Cracked gas - 0.47 Ceiling Ethylene oxide C 2 H 4 O 1.52 Floor Hydrogen H 2 0.07 Ceiling Isobutane (CH 3 ) 3 CH 2.00 Floor Methane CH 4 0.55 Ceiling Natural gas - 0.68 Ceiling Propane C 3 H 8 1.56 Floor Propane-air - ±1.15 Ceiling + floor * This list is not exhaustive. Contact Dalemans for further information. Mounting The detector should be mounted flat on a wall and according to the mechanical pattern given on Figure 3. Attach the detector to the wall using suitable screws (max. 4.5 mm diameter) and plugs. The screw head diameter must not exceed 7.5 mm. The sensing head should never be installed pointing upwards. Make sure that dust will not block the filter and that water will not run into the sensing head. Electrical wiring Wiring must comply with local regulations and standards in force and meet the electrical requirements of the detector. Dalemans recommends the use of colour coded cable with solid wires. The acceptable cross sectional area of the cable is 1.5 to 2.5 mm² depending on the type of sensor used and the distance between the detector and the control unit. For more information about the cross sectional area of the cable and the maximum cable length, please refer to the instruction manual of the control unit. The overall cable diameter must be within the range given in figure 4 below. The cable gland must be sufficiently tightened on the cable to ensure a good sealing. 8 mm MAX 6 mm - 12 mm 1.5-2.5 mm² 15 mm 100 mm Figure 4 : Cable stripping
9 To connect the detector : Unscrew the four screws of the junction box cover and remove the cover. Loosen the clamping nut of the cable gland. Insert the cable in the junction box through the cable gland and tighten the clamping nut. Connect wires according to the diagram given in figure 5 below. Wires must be stripped and plugged so that the gap between the insulation and the metallic edge of the terminal connection does not exceed 1 mm distance. Put the cover back in place on the junction box and tighten the four screws. C : common Clamping nut P : passive A : active WHITE BLUE RED Figure 5 : Electrical connection
10 Maintenance (according to ATEX Directive - Appendix II art. 1.0.3.) Regularly remove dust from the sensing head and the junction box with a wet cloth ONLY so as to limit the risk of electrostatic sparks. The sintered metal filter must be checked and cleaned at least once a year. If contamination of the filter by solvent, gas or gas vapour has occurred, the sensing head must be replaced and the inspection interval should be reduced by a factor of 2. Gas detection equipment must be calibrated at least once a year, in some cases three or four times a year, or even more to mitigate the loss of sensitivity of the sensor. This calibration must be performed according to the procedure given by the manufacturer or his local representative, and in any case by qualified personnel who will have been trained by Dalemans. WARNING! Declassify hazardous area PRIOR to operating maintenance, calibration or service works and check with a portable apparatus that no gas is present in the atmosphere. Sintered metal filter replacement Unscrew the sensing head top using the suitable tool OUT00000113. Replace the sinter metal filter with a new one (MEC00000010). Screw up the sensing head top and tighten. Make sure the sensing head is still correctly fastened to the junction box. Perform calibration according to the procedure given by Dalemans or his local representative. Sensing head replacement Prior to replacing the detector sensing head, inhibit the safety function of the detector on the gas detection system and secure any output device connected to the system to prevent unintended actuations and false alarms. Unscrew the four screws of the junction box cover and remove the cover. On the APC terminal block, disconnect the three wires (red, blue and white) of the sensing head. Unscrew the sensor head and remove it. Screw up the new sensing head and tighten with tool OUT00000113. Connect the three wires of the sensing head on the APC terminal block (figure 5) : - RED on terminal A, - BLUE on terminal P, - WHITE on terminal C, Put the cover back in place on the junction box and tighten the four screws. Power on the detector and restore its safety function on the gas detection system. Perform calibration according to the procedure given by Dalemans or his local representative.
11 Troubleshooting The control unit gives a Fault signal for the detector : Check wiring and connections. Possible defect in sensing head connection (APC terminal block). The sensor inside the sensing head may be disconnected or out of order. The detector gives a non-zero measure : There may be gas in the atmosphere. The detector gives a non-zero measure even though no gas is present in the atmosphere : Perform full calibration of the detector. The detector measure is either too high or too low : Perform full calibration of the detector. The detector gives a null measure although gas is present in the atmosphere : Check wiring and connections. Check if sintered metal filter is not blocked by dust. If sintered metal filter pollution is detected, replace both filter and sensor and perform full calibration. Spare parts Article code Cable gland - Ex e M20 (6-12 mm) PRE00000018 Instruction manual IMP00000040 Junction box - Ex e BOI00000138 Nut - M20 plastic PRE00000007 O-ring - M20 x 2 mm MEC00000012 Screw - M4 x 6 mm VISVIS00042 Sensing head - FPH02 + DAL50 DET00000023 Sensinghead - FPH02 + DAL-AC (acetylen) DET00000028 Sensor - DAL50 SEN00000042 Sensor - DAL-AC (acetylen) BASDET00030 Sintered metal filter MEC00000010 Spanner for top of sensing head OUT00000113 Terminal block - Ex e 3p BOR00000089
12 Specifications MODEL Sensing head Sintered metal filter Junction box Dimensions Weight Sensor type Output signal Measuring range Resolution Response time (T90) Expected operating life span Stainless steel 1.4404 (AISI 316L) Glass-fibre reinforced Polyester 139 x 80 x 55 mm 640 g Catalytic (Pellistor) 3-wire mv (Wheatstone bridge) 0-100 % LEL ± 3 % of measuring range < 60 % LEL ± 5 % of measuring range > 60 % LEL < 30 sec. > 2 years Sensor characteristics * DAL50 DAL-AC (acetylene) Supply voltage 2.50 V ± 0.25 V 2.00 ± 0.10 V Supply current 170 ma ± 10 ma 145-160 ma Power consumption 0.5 W 0.4 W Storage temperature -10 C to +50 C Operating Conditions Temperature range -10 C to +50 C Ambient humidity 20-90 % HR Intermittent humidity 10-99 % HR Pressure 90-110 kpa Cable cross sectional area 1.5-2.5 mm² (solid wires) Max. cable length Refer to the installation instructions of the control unit Ingress protection IP6x (dust tight) Cable entries 1 x M20 (cable diameter 6-12 mm) Hazardous areas Zones 1 or 2 (gas) - Zones 21 or 22 (dust) Equipment gas grouping IIC (methane, propane, ethylene, hydrogen, acetylene) Standards EN 60079-0:2006, EN 60079-1:2007, EN 60079-7:2007 EN 61241-0:2006, EN 61241-1:2004 Approval II 2G Ex d e IIC T6 II 2D Ex td A21 IP6X T85 C Ambient temperature Tamb = -10 C to +50 C Certificate FTZU 10 ATEX 0033X * Please refer to the marking label of the sensing head. * Ensure that the sensor electrical characteristics meet the capability of the associated control unit.
Glossary 13 Ex d : mode of protection by flameproof enclosure d in compliance with standards EN 60079-0 and EN 60079-1 applying to electrical equipment intended for use in explosive gas atmospheres. The parts which can ignite the explosive atmosphere are placed in an enclosure which can withstand the pressure developed during an internal explosion of an explosive mixture, and which prevents the transmission of the explosion to the explosive atmosphere surrounding the enclosure. Ex e : mode of protection by increased safety e in compliance with standard EN 60079-7 applying to electrical equipment intended for use in explosive gas atmospheres. Additional measures are applied so as to give increased security against the possibility of excessive temperatures and of the occurrence of arcs and sparks in normal service or under specified abnormal operations. Ex td : mode of protection by enclosure td in compliance with standards EN 61241-0 and EN 61241-1 applying to electrical equipment for use in presence of combustible dust. The protection is based on the limitation of the maximum surface temperature of the enclosure and on the restriction of dust ingress into the enclosure to avoid ignition of a combustible dust layer or cloud. 94/9/EC : European Council and Parliament directive (March 23, 1994) on the approximation of the laws of the member states concerning equipment and protective systems intended for use in potentially explosive atmospheres. EN 60079-0 : standard general requirements applying to equipment intended for use in explosive atmospheres. EN 60079-1 : standard applying to equipment protected by flameproof enclosure d and intended for use in explosive gas atmospheres. EN 60079-7 : standard applying to equipment protected by increased safety e and intended for use in explosive gas atmospheres. EN 61241-0 : standard general requirements applying to electrical apparatus intended for use in the presence of combustible dust. EN 61241-1 : standard applying to electrical apparatus protected by enclosure td and intended for use in the presence of combustible dust. Environment - WEEE Directive The crossed-out wheelie bin logo on this product indicates that you are held to respect the regulation in force on the collection and recycling of Waste Electrical and Electronic Equipment (WEEE). These provisions are intended to preserve the natural resources used for manufacturing this product and to avoid the dispersion of substances potentially harmful for the environment and human health. Therefore, to dispose of your end-of-life product, you MUST hand it over to a designated collection point for the recycling of electrical and electronic Equipment. For further information about the collection points in your area, contact your local city office.
14 Notes
OFFICIAL DEALER DALEMANS s.a. rue Jules Mélotte 27 B-4350 Remicourt Tel.: +32 (0)19 54 52 36 Fax: +32 (0)19 54 55 34 info@dalemans.com www.dalemans.com