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5. How to Operate 

5-6. Description of operation (maintenance) 

- 22 -

 

5-6-3. External output test 

This is used to check the transmission status by outputting a signal equivalent to gas concentration to the 
external device. 

 

 

WARNING 

Before starting the external output test (transmission test), provide a notification to the related 
sections so that they can prepare for false abnormalities.   

 
(1)  Hold down the MODE switch over three seconds to enter the 

maintenance mode. 

 
 
 
 
(2)  "1-3. How to wire". Regular Maintenance Mode Switching" menu 

displayed. 

 
 
 
 
(3)  Holding down the SET switch while "----" is displayed enters the 

regular maintenance mode. 

 
 
 
 
(4)  Press the SET switch while "2-0" is displayed to display "2-0-1. 

Alarm Test". Then make a selection with the SET switch. 

 
 
 
 
 
 
 
 
 
 
(5)  Increase the reading with the 

/

  switch to check the 

transmission status.   
When the test is completed, hold down the MODE switch over 
three seconds to return to "2-0". 

 
 
(6)  While "2-0" is displayed, hold down the MODE switch over three 

seconds to return to the detection mode. 

 
 
 
 

 

     

 

2-0-1 

   

10.0 

AL 2 

 

     

 

1 - 1 

 

SPAN 

 

     

 

1 - 3 

 

M MODE 

 

     

 

2 - 0   

   

20.9 

TEST 

 

     

 

 

---- 

 

 

     

 

2-0-1 

   

20.9 

ALM TEST 

 

     

 

2 - 0   

   

20.9 

TEST 

Summary of Contents for GD-F88Ai

Page 1: ...PT2E 1941 2 Wire Gas Detector Head GD F88Ai Operating Manual PT2 194...

Page 2: ...ring 12 4 7 Compatible cables and terminal plate specifications 12 4 8 System connection example 13 5 How to Operate 15 5 1 Preparation for start up 15 5 2 Basic operating procedures 15 5 3 How to sta...

Page 3: ...pe gas detector head which detects oxygen concentration in the air When the detector head detects oxygen it outputs a current according to the gas concentration The indicator alarm unit indicates the...

Page 4: ...ad will be in danger Defects in protective functions When seeming defects are found in the protective functions such as protective grounding do not start the detector head Before starting the detector...

Page 5: ...s by power supply noises static electricity and electromagnetic noises Before using the detector head in an environment with such noises provide for protective measures against them 2 4 Operating Prec...

Page 6: ...stitution of Industrial Safety Applied standard Recommended Practices for Explosion Protected Electrical Installations in General Industries Electrical parameter Intrinsically safe circuit allowable v...

Page 7: ...meters to maintain explosion proof performance Perform wiring so that a current or voltage that disturbs intrinsically safe explosion proof performance of the intrinsically safe circuit is not induced...

Page 8: ...5 UP DOWN switch 6 Nameplate Displays the gas concentration Used at maintenance Switches the mode from the detection mode to maintenance mode Or exits the maintenance mode Used to set the mode during...

Page 9: ...2 Names and functions for each part 7 Power switch 8 Sensor 9 Terminal plate 10 Grounding terminal 11 Cable inlet Turns ON OFF the power of the unit Detects a gas Connects the power cable A terminal...

Page 10: ...ions or shocks and it cannot drop Do not install the detector head in a place exposed to direct sunlight or sudden changes in the temperature When selecting installation points avoid a place where it...

Page 11: ...he noise source if necessary Heat radiation designing When the alarm system is installed in a closed instrumentation panel or the like attach ventilation fans above and below the panel Introducing pro...

Page 12: ...ot securely installed it might fall causing an unexpected injury or a damage of the unit Do not install the detector head in a place where maintenance of the detector cannot be performed or where hand...

Page 13: ...a grounding terminal For stable operation of the detector head and safety it must be connected to a grounding terminal Do not connect the grounding wire to a gas pipe The g rounding must be made as D...

Page 14: ...Plate Rated voltage 250 VAC Rated current 20 A Supply Voltage The supply voltage is normally 24 VDC However the voltage at the terminal plate of the detector head becomes lower than the source voltage...

Page 15: ...ing to indicator DCS PLC etc non explosion proof system 4 8 2 Example of connecting to Zener Barrier indicator DCS PLC etc 1 2 GD F88Ai detector Upper unit DCS PLC Non hazardous location 1 2 GD F88Ai...

Page 16: ...and indicator 4 8 4 Example of connecting to insulating barrier indicator DCS PLC etc 1 2 GD F88Ai detector Upper unit DCS PLC Insulating barrier Hazardous location Non hazardous location OX 5002 1 2...

Page 17: ...e power supply voltage meets the specification and rating The external output may be fluctuated during adjustment Take an appropriate measure to avoid the influence on the gas monitoring system Make s...

Page 18: ...itch located on the left side of the power terminal plate Initial Clear approx 25 seconds System check of the unit External output 17 4 mA CAUTION Do not turn off the detector head during the initial...

Page 19: ...Test 2 0 3 LCD Test 2 0 4 Zero adjustment 2 1 Perform zero adjustment Span fresh air adjustment 2 2 Perform span fresh air adjustment 2 3 Environmental setting 2 4 Used for various environmental sett...

Page 20: ...n mode LCD display In the detection mode the sampling gas concentration is displayed on the LCD Normal display description Detected gas concentration Name of the gas to be detected Unit operation stat...

Page 21: ...lear 17 4 mA 3 Maintenance mode 17 4 mA 4 External output test 4 0 20 0 mA varies with the test value 5 Fault state 21 0 mA or more 6 Power off 0 0 mA The following figure shows the relation between g...

Page 22: ...etection mode automatically returns 17 4 20 0 mA 4 0 mA WARNING When the maintenance mode is entered while gas detection is performed the external output signal gas concentration signal becomes 17 4 m...

Page 23: ...played Draw a zero adjustment gas When the reading is stabilized press the SET switch again The display blinks and fresh air adjustment is performed 3 Press the SET switch to confirm the setpoint WARN...

Page 24: ...maintenance mode 2 1 3 How to wire Regular Maintenance Mode Switching menu displayed 3 Holding down the SET switch while is displayed enters the regular maintenance mode 4 Press the SET switch while...

Page 25: ...ower switch located on the left side of the power terminal plate Then turn off the power supply 24 VDC to the detector head WARNING Decide whether the power can be turned off by checking the operation...

Page 26: ...ate Gas concentration display Check that a gas to be detected is not present around the detector head and that the reading indicates a normal value Alarm test Inspects the alarm circuit by using the a...

Page 27: ...al diagnosis Checks dust or damage on the surface cover or internal parts of the unit and cleans or repairs such parts as needed Replaces parts which are cracked or damaged Unit operation check Uses t...

Page 28: ...k see 4 6 Wiring and 4 7 Compatible cables and terminal plate specifications The unpowered time must be minimized when the detector head is relocated CAUTION When using a relocated or stopped stored d...

Page 29: ...perations Causes and Actions A sudden surge noise can be the cause To recover turn OFF the detector head power and then turn it ON again to restart If such a symptom is observed frequently take approp...

Page 30: ...Sensor failure Trouble alarm indication Content display Trouble alarm action Non latching Transmission method 2 wire analog transmission digital transmission HART Communication Transmission specificat...

Page 31: ...y Trouble alarm action Non latching Transmission method 2 wire analog transmission digital transmission HART Communication Transmission specifications 4 20mADC load resistance 300 or less Communicatio...

Page 32: ...he sensor outputs 10 10 Definition of Terms Galvanic cell type This is a principle of the sensor installed in the detector head See for details vol A unit used to express the percentage of a specific...

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