SINGLE-CHANNEL GAS-DETECTOR GAS ALARM DG510/1P

Transcription

1 SINGLE-CHANNEL GAS-DETECTOR GAS ALARM DG510/1P 2 Alarm Levels Bargraph + LED Indication of Gas Concentration Visual and Audible Signalization of Activated Alarm Levels 2 SPDT 5A/250V Output Relays Shock-Proof & Ex-Proof Sensor Housing Intrinsically Safe Shunt Barriers Back-up Accumulator Power Supply (optional) I. APPLICATION The single-channel gas-detector GAS ALARM DG510/1P is purposed for signaling anytime, when concentration of flammable and explosion-hazardous gases exceeds permissible limits. Its application includes mounting in pump units, gas stations, filling stations, dyeing cameras and other areas, where gaspowered equipment is used, or where combustible or toxic vapors and gases are found. The device consists of a microprocessor Control Block, which is to be mounted in areas with normal risk of fire, and a Sensor, which is placed in the hazardous zone. There are two programmable alarm levels for the gas concentration - pre-alarm and alarm level. The measured gas concentration is visualized on the LED bargraph indication in % LEL (lower explosion limit). If the gas concentration exceeds 10% LEL the prealarm level (AL1) and relay output LL are activated. LED AL1 is lighted. The relay output may operate a shut-off valve for stopping the gas flow, switch on a siren or fan, etc. If despite all taken measures the gas concentration exceeds 20% LEL the alarm level (AL2) and relay output HL are activated. A local buzzer is switched on if the gas concentration exceeds one of the alarm levels. The pre-alarm and alarm levels can be individually set. The alarm level cannot be set to a level greater than 50% LEL because of safety precautions. In case of Sensor or Cable Fault the LED "FLT" is lighted and the audible alarm is activated. On customer s request there can be mounted additionally a back-up power supply module, thus guaranteeing continuous working conditions for the gas detector. Switching to the back-up power supply is automatic in case of central power supply failure. The recommended capacity of a 12V accumulator is 6-8Аh. A lighted up Accu LED indicates the charging process of the accumulator from the electricity grid. Gas alarm s explosion-proof operation is guaranteed through shock- and explosion-proof Sensor housing EEx d IIC T5 and intrinsically safe shunt barriers ЕEx i a IIC. DELTA INSTRUMENTS Ltd. 23 A. Saharov blvd., Mladost 1, 1784 Sofia, Bulgaria Tel , , ; Fax: Web Site: [email protected]

2 II. TECHNICAL SPECIFICATIONS Power Supply 230V, 50Hz Detected Gas methane (natural gas), propane-butane, hydrogen, ammonia, ethylene, organic dissolvent vapors, fuel vapors, etc. Sensor catalytic (pelistor type) Pre-alarm level /АL1/ 10 % LEL programmable in the range 0 < AL1 < AL2 Alarm level /АL2/ 20 % LEL (in the range AL1 < AL2 50% LEL) Pre-alarm level AL1 output SPDT relay, 5A/250V /LL/ Alarm level AL2 output SPDT relay, 5A/250V /HL/ Indication bargraph, LED, 0-50% LEL Ambient temperature for sensors С Ambient temperature for control unit 0 50 С Reaction delay of sensors 20s Back-up power supply (optional) accumulator 12V DC Dimensions of control unit 1/8 DIN ( 96 x 48 x 132 mm ) Protection degree of control unit IP 30 Explosion-proof sensor housing ЕEx d IIC T5 Intrinsically safe shunt barriers EEx i a IIC CONNECTION SCHEME CONNECTION DIAGRAM Sensor cable connection legend: Vcc red wire INPUT white wire GND blue wire

3 Dimensions 96 ( width 48) 92 ( width 44) III. MOUNTING INSTRUCTIONS 3.1. Mount gas-detector to panel or metal construction in an area with normal risk of fire, fixing it by two supplied attaching clamps Connect the sensor to the blue marked intrinsically safe terminals via a 3-wire cable, according to the connection diagram Mount the sensor in explosion-hazardous area vertically (Sintered Filter downwards). When mounting, the following factors have to be considered: relative weight of the detected gas In case of gases with relative weight lower than that of the ambient air, place Sensor above the possible gas leakage location, or at the top possible place, where gas is accumulating. In case of gases, heavier than ambient air, place Sensor below the leakage location, or at the lowest possible place, where gases may accumulate. If there are airflows present, place Sensor between eventual leakage or accumulation locations, and possible combustion source. dust and water presence In areas with a high degree of dust loading, use a dust-proof filter, which at the same time should not obstruct the freeway from gas to sensor. In damp areas a water drop protection has to be made. vibration presence The Sensor is vibration-sensitive and should either be mounted in a place where vibrations are not present, or measures for their reduction have to be taken.

4 IV. OPERATING INSTRUCTIONS 4.1. CONTROL PANEL DESCRIPTION The control panel of the gas-detector consists of a control block for setting the alarm levels and a bargraph, indicating the actual value of gas concentration in % of LEL (lower explosion limit). The 5 LEDs indicate different gas-detector states, as listed in Table 1: NAME POWER FLT AL1 AL2 ACCU Table 1 FUNCTION After turning on the power supply follows an activation process of the sensor for appr. 1 min. During this time the AL1 and AL2 diodes are blinking. When this initialization has finished the both diodes go off, but the POWER LED remains on while there is power supply available. The FLT LED is activated only in case of faulty sensor or cable. Indicates the state of the output relay, corresponding to the pre-alarm level. Lighted up LED means that the relay LL is activated. After pressing the RESET button to deactivate the sound alarm signal the AL1 diode remains blinking. The LL relay stays active until the concentration drops below the set LEL percentage level. Indicates the state of the output relay, corresponding to the alarm level. Lighted up LED means that the relay HL is activated. After pressing the RESET button to deactivate the sound alarm signal the AL2 diode remains blinking. The HL relay stays active until the concentration drops below the set LEL percentage level. It is turned on only while charging the accumulator (only by existent backup power supply) The bargraph indicates the process value of measured concentration 0-50% of the lower explosion limit (LEL) of the corresponding gas. If the concentration has reached over any of the set alarm levels, the corresponding segment of the bargraph scale starts blinking AUDIBLE SIGNALIZATION By exceeding the concentration of the set pre-alarm and alarm levels is activated an integrated sound alarm. For the pre-alarm level AL1 the buzzer emits a short signal every 3 sec, while for the alarm level AL2 the sound signal is continuous. A short beep is emitted also every time when a button from the keypad is pressed VISUALIZING THE SET ALARM LEVELS By pressing the MODE button while in standard operation mode, the display switches to visualization of the set alarm levels. Only the bargraph s segments which correspond to the set alarm levels remain lighted. If the gas concentration is higher than any of the set alarm levels, the corresponding LED remains blinking as well. Another click on the MODE button leads back to standard operation mode.

5 4.4. TESTING THE ALARM OUTPUT RELAYS The output relays can be activated from the control panel in order to test the functionality of connected control mechanisms (siren, air ventilating system, gas-flow closing valve, power supply switching-off, etc.). By holding the TEST button pressed the relays are activated (AL1 and AL2 diodes become lighted up) and by releasing it the relays get deactivated DEACTIVATION OF THE AUDIBLE SIGNALIZATION By any activated alarm level the operator can use the keypad to turn off the sound alarm until the problem is solved. By active alarm state pressing the RESET button turns off the sound signalization until the concentration drops below the set alarm level. After the deactivation of the sound alarm, the corresponding alarm LED starts blinking. The output relays remain open (active) until normalizing the concentration under the set levels PROGRAMMING THE ALARM LEVELS ATTENTION: In the mode of programming the alarm levels the output relays are deactivated and the different LEDs serve as indication of the ongoing level setting regime. While in standard operation mode simultaneous pressing and holding the buttons MODE and ENT activates the mode for programming the alarm levels. - By simultaneously pressed MODE and ENT buttons the LED AL2 starts blinking, which indicates that the device is ready for adjusting the alarm level. The segment of the bargraph, which corresponds to the set alarm level, starts blinking, while the segment for pre-alarm level remains turned on. With buttons and the operator can move the blinking segment up and down the scale to select a new desired value. To save the newly selected value should be pressed the ENT button. Then if the value has been saved successfully the newly set segment should stop blinking. The alarm level can be set only between the value of pre-alarm level and 50% LEL. If the operator doesn t wish to change the alarm level, it is recommended to proceed to the pre-alarm level setting just by pressing the MODE button. - By pressing MODE after entering the mode for programming the alarm levels, the LED AL1 should start blinking, which indicates that the device is in regime for setting the pre-alarm level. Identically a new desired level can be selected by moving the lower blinking segment of the bargraph with and between 0% and the value of AL2 and saved by pressing ENT. - By pressing the MODE button once again, the indication returns to standard mode of operation and the gas-detector starts functioning with the newly selected level values.

6 V. GENERAL CONDITIONS GAS ALARM DG510/1P gas-detector may be used only in applications, approved by its manufacturer - DELTA INSTRUMENTS Ltd. Test and calibration have to be made every 12 months. The test overall performance will be ensured in a best way through a periodical maintenance servicing contract with the manufacturer. Device safe-operation guarantee is not valid, if DG510/1P is maintained with unauthorized personnel or if the corresponding to the term of question Test and Calibration Report is not available. CAUTION! It is absolutely forbidden to disassemble the explosion-proof sensor housing and change safety fuses or other electronic elements, connected to the proper functionality of the intrinsically safe shunt barriers! VII. REPAIR Any repair activities, concerning GAS ALARM DG510/1P Electronic Block and DGS 510 Sensor have to be carried out only in manufacturer DELTA INSTRUMENTS Ltd laboratories.