Model GD-K77D Operator’s Manual Part Number: 71-0046RK Revision: B Released: 3/1/11 www.rkiinstruments.
WARNING Read and understand this instruction manual before operating detector. Improper use of the detector could result in bodily harm or death. Periodic calibration and maintenance of the detector is essential for proper operation and correct readings. Please calibrate and maintain this detector regularly! Frequency of calibration depends upon the type of use you have and the sensor types.
Warranty RKI Instruments, Inc. warrants gas alarm equipment sold by us to be free from defects in materials and workmanship, and performance for a period of one year from date of shipment from RKI Instruments, Inc. Any parts found defective within that period will be repaired or replaced, at our option, free of charge.
Table of Contents Overview. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 About this Manual. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 Important Safety Precautions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 Specifications. . . . . . . . . . . . . . . . . . . .
Troubleshooting. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37 Trouble Alarm: Flickering PW/TR Lamp . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . PW/TR Lamp Off . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Abnormal Performance. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Overview The Model GD-K77D has been specially developed for semiconductor gas-leak monitoring and is one of the most advanced units of its kind. It contains a long-life pump and electrochemical sensor to detect a wide variety of semiconductor gasses quickly and reliably. The long-life sensor has a memory so it can be calibrated separately from the monitor, then installed for quick and easy servicing. The Model GD-K77D’s narrow footprint and wall mounting bracket permit flexible placement.
DANGER: This label alerts you to the possibility of serious injury or death when using or servicing the Model GD-K77D improperly in potentially hazardous environments or conditions. The Model GD-K77D is not explosion proof. Do not use the Model GD-K77D for gas detection above the lower explosive limit (LEL). WARNING: This label alerts you to the potential danger of electrical shock, or other hazards. When electrical safety is not followed, injury or damage to the Model GD-K77D may result.
Specifications Table 1: Specifications for the Model KD-K77D Model GD-K77D GD-K77D-NT Relay output for remote alarm Electrochemical cell Relay output for remote alarm Refer to the RKI Instrument, Inc.
Description The Model GD-K77D is designed to measure gas leaks in an industrial setting. Gas leaks are detected by an internal electrochemical sensor, and the gas concentration is displayed by a four-digit LED display. PW/TR LED ALM1 LED 6.05 ALM2 LED SKIP LED LED Display Flow Meter Window 6.70 8.0 MAX ID Card Holder GAS DETECTOR M ODEL GD-K77D Cover Retaining Screw .36 Gas Inlet, for ø 4 x 6 mm PTFE Tube 2.
Detector unit Cover Wall mounting bracket Figure 2: Removing the Cover and Detector Unit 5 • Description Model GD-K77D Operator’s Manual
The Model GD-K77D provides a three-wire 4-20mA signal output for a controller. The Model GD-K77D-NT provides a two-wire digital signal which is used by the RM-77NT accessory and is then converted to either an RS-232C or RS-485 signal. It has two gas alarm levels, two sets of gas alarm relay contacts, a trouble alarm, and trouble relay contacts. The Model GD-K77D is a sample draw gas detection head. The Model GD-K77D draws in the sample gas from a remote location using an internal pump.
Internal and Back Panel Components Refer to the diagram below for the location of Model GD-K77D internal and back panel components, which are described below. After each component name is a number, which corresponds to the same number in the diagram. 13 10 12 14 16 11 20 19 15 17 18 Detector Unit Side View Detector Unit Front View Wall Mounting Bracket Front View Figure 3: Internal Components Power Switch (10). Turns power on or off to the Model GD-K77D. Power Fuse (11).
CAUTION: When the Model GD-K77D is not used for long periods of time, the lithium battery may lose power. The lithium battery, under normal operating conditions, has a life expectancy of about three (3) years from the date of manufacturing. When the lithium battery is replaced, put the unit into maintenance mode before replacing the battery by pressing the Mode switch for 3 seconds. Then calibrate the unit as described in the Calibration section.
Baffle Low flow sens or Pum p Flow meter Sens or GAS OUT GAS IN Figure 5: Flow Diagram Important Safety Procedures WARNING: Before installing and operating the Model GD-K77D, please read the following list of precautions before continuing: Power Source. Check the power source before turning on the Model GD-K77D. Make sure the power source voltage is within the specified voltage range. Ground Wire. Do not cut or remove the ground wire to the Model GD-K77D. Fault Protection.
Sensor. Use caution when handling the sensor. The electrolyte contains a dilute acid that can damage to clothing or other materials, and it can cause skin burns or blindness should the acid come in contact with the eyes. If the electrolyte makes contact with the skin or eyes, wash the affected area very thoroughly with water. With eye contact, seek medical attention immediately. High Gas Levels.
• Grounding. Make sure to ground the Model GD-K77D properly during installation. Wall Mounting the Model GD-K77D CAUTION: When installing the wall mounting bracket, make sure to attach it securely to the wall. If not securely attached, the Model GD-K77D may fall causing damage to the unit. Find a suitable location for the Model GD-K77D. Allow enough room around the wall mounting bracket for the Model GD-K77D to be mounted easily. See “Precautions” on the previous page for installation warnings. 1.
Removing the Model GD-K77D Detector Unit When connecting tubing, making electrical connections, or servicing the Model GD-K77D, it is more convenient to remove the Model GD-K77D detector unit from its wall mounting bracket. Loosen this screw Figure 5: Removing the Detector Unit 1. Loosen the large screw on the front of the unit and remove the cover. 2. Loosen the screw on the lower part of the unit. 3. Remove the Model GD-K77D detector unit from the wall mounting bracket.
Power Requirements Table 2: Power Requirements for the Model GD-K77D Power Voltage DC-24V +/- 10% (Terminal Voltage) Power Failure Tolerance (Time) Approximately 10 milliseconds. After a power failure of 10 milliseconds, the Model GD-K77D re-starts. To ensure continuous operation, install a standby battery. Requirements Do not connect power to the Model GD-K77D containing a high power load or with high frequency noise. If noise is present, use a line filter to separate the power from the noise source.
WARNING: The alarm contacts on the Model GD-K77D are designed to take a resistance load and not an inductive load. (An inductive load can be created by a patlight, external relay, buzzer, siren, fan, fluorescent light, motor, etc.) When an inductive load is present, a very high reverse voltage may be generated that can melt the alarm contacts on the Model GD-K77D, damage the external alarm, or damage the CPU if one is connected to the system.
Chassi s Ground GAS OUT GAS IN Chassi s Ground Figure 5: Grounding the GD-K77D 15 • Installation Model GD-K77D Operator’s Manual
Wiring WARNING: When hooking up wires to the Model GD-K77D at the installation site, be very careful not to damage the internal electronics of the Model GD-K77D by a static electric discharge or by improper grounding. Place the Model GD-K77D detector unit on its side. A vertical placement may cause the unit to fall over, which may damage the unit. For the power and signal cables, do not lay them out next to other power cables that carry an electrical load.
GD-K77D Terminal Strip N ot U sed ALM1 ALM2 NO NO 1 2 3 4 5 6 7 8 TR NO 9 10 11 12 - (DC Ground) + 24 VDC 4 - 20 mA In (FB) Power Source Controller or Recording Device Alarm Device Power Source Power Source Alarm Device Alarm Device Figure 7: Wiring to a Generic Controller, Typical 3-wire 17 • Installation Model GD-K77D Operator’s Manual
Tubing Connections Tube Fittings Two tube fittings are provided for sampling, one for inlet and one for exhaust. The fittings accept 4 mm (ID) x 6 mm (OD) Teflon tubing. Tubing Insert Ferrule Nut 4 x 6 mm Teflon PTFE Tubing Figure 8: Inlet/Exhaust Fitting Use Flow Rate The flow rate of the Model GD-K77D is 0.5 L/M (liters per minute) Tubing Material The tubing materials you choose will depend upon the target gas being detected. Some target gases are corrosive while others are absorptive.
Operation Start-up Preparations To avoid the possibility of electrical shock or damage to the Model GD-K77D, follow the precautions listed below before turning on the unit: • Make sure the Model GD-K77D has been properly grounded. • Check all wiring connections to external devices. • Make sure the power voltage is within specification (DC-24V +/- 10%, Terminal Voltage). • Check the wiring connections to any external alarms. • Make sure the correct dust filter has been properly installed.
The basic operation flow and the three operating modes are described in this section of the manual. Start Up Power On 1. Before turning on the power to the Model GD-K77D, read “Start-up Preparations” described above. 2. Remove the front cover of the Model GD-K77D if it is still attached to the Model GDK77D. See “Removing the Model GD-K77D Detector Unit” for more information. 3. The power switch is located on the front panel beneath the alarm lights and above the flowmeter. 4.
Operation Flow The diagram below shows the operation flow for Detection Mode. In Detection Mode, the PW/TR light is on and the LED display shows the concentration of the target gas. LED lamp function Light on Light off Flashing Start-up preparation Power on LED indication Initial warm-up (about 25 seconds) Display indication PW/TR ALM1 ALM2 SKIP PW/TR ALM1 ALM2 SKIP Detection mode 0.
Zero Suppression During Detection Mode, the display indicates “0” if the reading is below +6% of full scale. LED indication PW/TR ALM1 ALM2 Display indication 0. SKIP 0 0 During Detection Mode, the display shows readings above +6% of full scale. LED indication PW/TR ALM1 ALM2 Display indication 0. SKIP 0 6 “-0.00” displays when the reading falls below -10% of full scale. LED indication PW/TR WARNING: ALM1 ALM2 Display indication SKIP 0. 0 0 When the display shows a “-0.
4-20mA Output The following graph illustrates the relationship between the 4-20mA output and the gas concentration. External output 22mA 20mA 4 mA 2.5 mA 0 Full Scale 6% of full scale zero suppression Gas Concentration Measuring mode Maintenance mode Figure 10: 4-20 mA output vs. Gas Concentration Maintenance Mode There are two maintenance modes for the Model GD-K77D: Maintenance Mode 1 and Maintenance Mode 2. Under Maintenance Mode 1, you can perform a zero adjustment and confirm the alarm points.
Maintenance Mode Operation Flow LED indication Press mode switch for three seconds Display indication PW/TR ALM1 ALM2 SKIP PW/TR ALM1 ALM2 SKIP PW/TR ALM1 ALM2 SKIP Maintenance mode starts Maintenance Mode 1 1-1 Zero Adjustment 1 1 1 2 FLOW ADJ/select by ▲ ▼ SW 1-2 Alarm points PW/TR ALM1 ALM2 SKIP FLOW ADJ/select by ▲ ▼ SW 1-3 Maintenance mode 2 CAUTION: When Maintenance Mode is entered during a gas alarm, the alarm condition will be cancelled.
NOTE: If you suspect the target gas is in the area being monitored, supply zero air to the Model GD-K77D before setting the zero adjustment. 1. With the front control cover of the Model GD-K77D flipped open, press and hold the Mode switch for three seconds to start Maintenance Mode 1. The display will show 11 and the Skip light will flash. LED indication PW/TR ALM1 ALM2 Display indication SKIP 1 1 2. Press the TEST/SET switch. The display will indicate the current zero reading.
CAUTION: The gas alarms will only work in Detection Mode. If the Model GD-K77D is left in Maintenance Mode for ten hours or more, it will switch to Detection Mode automatically. Alarm Point Confirmation When checking the alarm point, follow these steps: 1. With the front control cover of the Model GD-K77D flipped open, press and hold the Mode switch for three seconds to start Maintenance Mode. The display will show 1-1 and the Skip light will flash.
4. To return to Maintenance Mode item 1-1, press and release the Mode switch. To return to Detection Mode, press and hold the Mode switch for three seconds. LED indication PW/TR ALM1 Display indication ALM2 0. SKIP 0 0 CAUTION: The gas alarms will only work in Detection Mode. If the Model GD-K77D is left in Maintenance Mode for ten hours or more, it will switch to Detection Mode automatically. Maintenance Mode Summary Mode No.
Alarm Test Mode Alarm Test Mode is used to increase the display reading and 4-20 mA output. Any external device connected to the 4-20 mA output will indicate upscale readings. This allows testing of any alarms it may control. CAUTION: Before making an alarm test, notify the appropriate departments at your site, or anyone who might hear the alarms, and let them know that alarm testing and maintenance are being performed on the Model GD-K77D. 1.
Alarms Alarm Types There are two types of alarms: gas alarms and trouble alarms. Gas Alarm. When the target gas reaches or exceeds an alarm set point, the gas alarm is activated. The gas alarms are self-resetting. They will automatically clear once the alarm condition has passed. NOTE: The alarm point is factory set to 1/3 (first alarm) and 2/3 (second alarm) of full scale. To prevent a false alarm, a three-second alarm time delay is provided. Trouble Alarm.
Alarm Point. When the target gas concentration reaches or exceeds the alarm point, the alarm contact is activated. The alarm contact is self-resetting when the gas concentration falls below the alarm point.
Maintenance This section covers maintenance, calibration, and storage. There are two levels of maintenance: • Monthly maintenance requires that you check the proper functioning of the flowmeter, power light, LED display, and dust filter. • Semiannual maintenance requires that you perform a zero adjustment, do an alarm test, check the gas inlet and outlet, and replace the sensor or dust filter if required. Monthly Maintenance • Flowmeter.
Calibration Calibration requires you to perform both a zero adjustment and a span adjustment while in Maintenance Mode 2. Calibration should be done on a periodic basis, or when you install a new sensor or notice unusual gas readings. RKI Instruments Inc. recommends you calibrate the Model GD-K77D every six months. NOTE: If the GD-K77D is installed in a clean room environment, the calibration frequency may be extended to yearly. Adjusting the Zero Setting 1. Turn on the power to the Model GD-K77D.
7. Press the TEST/SET switch to put the unit in Zero Adjustment Mode. 8. Press the TEST/SET switch to zero the unit. The GD-K77D is finished adjusting the zero after the display stops flashing. 9. Press the MODE switch to return to Maintenance Mode 2. Setting the Span Adjustment: Part Two of Calibration 1. After setting the zero for the unit, use the FLOW ADJ switch to show 2-3 on the display. LED indication PW/TR ALM1 ALM2 Display indication SKIP 2 3 2.
3. Use the FLOW ADJ switch to show 1-3 on the display. LED indication PW/TR ALM1 ALM2 Display indication 1 SKIP 3 4. Press the TEST/SET switch. The display will show “ADJ.” 5. Press and hold the TEST/SET switch until 2-1 appears on the display. The unit is now in Maintenance Mode 2. LED indication PW/TR ALM1 ALM2 Display indication 2 SKIP 1 6. Press the TEST/SET switch to display the sensor bias voltage on the screen. The bias voltage is displayed in mV (millivolts). 7.
5. Press and hold the TEST/SET switch until 2-1 appears on the display. The unit is now LED indication PW/TR ALM1 ALM2 Display indication 2 SKIP 1 in Maintenance Mode 2. 6. Use the FLOW ADJ switch to show 2-4 on the display. LED indication PW/TR ALM1 ALM2 Display indication SKIP 2 4 7. Press the TEST/SET switch to show S.SET on the display. 8. To set the initial value of the sensor, press the TEST/SET switch. 9. Press the MODE switch to return the unit to Maintenance Mode 2. 10.
Replacing Components of the GD-K77D This section describes how to change the sensor, pump, and fuse. Replacing the Sensor 1. Turn off the GD-K77D power switch. Also verify that the power to the unit is off. 2. Loosen the thumbscrew on the front of the cover and pull the cover away. 3. Loosen the detector unit set screw and carefully pull the detector unit away from the wall mounting bracket. 4. Disconnect the sensor cable on the right side of the sensor from the sensor.
Troubleshooting Trouble Alarm: Flickering PW/TR Lamp When the PW/TR lamp is flashing, this indicates a trouble condition. The following are typical trouble conditions: Table 4: Trouble Alarm: Condition, Cause, and Remedies LED Condition Cause Remedy E-00 System Fault Memory Problem in the Detector Call RKI Instruments, Inc. for assistance.
PW/TR Lamp Off • Check the power switch. Is it turned on? • Check power connection and re-connect if necessary. • Check fuse for proper connection and replace fuse if burned out. • Check the power voltage to the Model GD-K77D. Is the voltage normal? Abnormal Performance A sudden surge of line noise may be the source of the problem. Try turning off the Model GD-K77D, then turning the unit back on.
• Check that the Model GD-K77D is mounted firmly or that the fixing screw is fastened securely. • The tubing on the gas-in or gas-out side of the Model GD-K77D may be clogged or broken. Check and repair the pipes as required. Disconnected Fuse • If the Model GD-K77D’s fuse is disconnected or is burned out, the unit will not operate. • If the fuse has burned out, replace the fuse. When replacing the fuse, turn off the power to the Model GD-K77D.
