35-3000RKA-10 PPM Hexane Sample Draw Detector Operator’s Manual Part Number: 71-0151RK Revision P1 Released: 10/11/07 RKI Instruments, Inc. www.rkiinstruments.
Product Warranty RKI Instruments, Inc. warrants gas alarm equipment sold by us to be free from defects in materials, workmanship, and performance for a period of one year* from the 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. Parts must be returned to RKI Instruments, Inc. for repair or replacement.
Table of Contents Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 Specifications. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 Housing . . . . . . . . . . . . . . . . . . . . . . . . . .
Overview This manual describes the 35-3000RKA-10 ppm hexane sample draw detector. This manual also describes how to install, start up, configure, maintain, and calibrate the sample draw detector when it is used with a gas monitoring controller. A parts list at the end of this manual lists replacement parts and accessories for the sample draw detector. Specifications Table 1 lists specifications for the sample draw detector.
Description This section describes the components of the sample draw detector. It is a 4 to 20 mA type detector head. The sample draw detector consists of the housing, flow system, and detection system.
Flow System The sample draw detector’s flow system consists of the inlet fitting, exhaust fitting, pump, flowmeter, bypass valve, flow block, status LEDs, and pressure switch (see Figure 1). Figure 2 below illustrates how the gas sample moves through the flow system. Bypass Valve Presure Switch Exhaust Inlet Hydrophobic Filter Pump Detector Flowmeter Figure 2: Flow Diagram Inlet Fitting The inlet fitting on the right side of the housing allows the gas sample to enter the sampledraw detector.
Bypass valve The bypass valve is to the left of the flowmeter. The bypass valve adjusts the flow rate to the detector. Use a flat-blade screwdriver to adjust the bypass valve. NOTE: The bypass valve allows fine adjustments of the flow rate to the detector. To adjust the total flow and for a wider range of adjustment, use the flow adjust pot (see Figure 1). Flow Block The flow block is an aluminum block with a chamber for the detector and passages that route the sample to and from the detector.
Amplifier The amplifier is mounted to the left of the detector. It is installed on a small plate with adhesive foam and the plate is mounted to two standoffs. The amplifier converts the nonlinear electrical output from the detector to a linear 4 to 20 mA signal that corresponds to the detection range and transmits the signal to a gas monitoring controller.
Main Circuit Board The main circuit board includes the interconnect terminal strip, detector/amplifier terminal strip, pump terminal strip, and relay (see Figure 1). NOTE: The flowmeter and status LEDs are mounted to the main circuit board but are considered part of the flow system. Interconnect Terminal Strip The interconnect terminal strip is the nine point terminal strip near the bottom edge of the main circuit board.
Installation This section describes procedures to mount the sample draw detector in the monitoring environment and wire the sample draw detector to a controller. Mounting the Sample Draw Detector 1. Select the mounting site. Consider the following when you select the mounting site.
NOTE: The sample draw detector is shipped with the mounting feet “tucked under” the housing to protect the mounting feet during shipment. 3. Slightly loosen the screw that secures one of the mounting feet to the housing, then rotate the mounting foot 180 degrees (see Figure 3). 4. Tighten the screw that secures the mounting foot to the housing. 5. Repeat steps 3 and 4 for the remaining three mounting feet. 6.
CAUTION: If using shielded cable, leave the cable’s drain wire disconnected and insulated at the sample draw detector. You will connect it to an available chassis ground at the controller. 7. Route the shielded cable or wires in conduit leading from the sample draw detector to the controller. 8. Connect the cable’s drain wire to an available chassis ground at the controller. A ground stud is typically a convenient location to connect to chassis ground in an RKI controller.
Start Up This section describes procedures to start up the sample draw detector and place the sample draw detector into normal operation. Introducing Incoming Power 1. Complete the installation procedures described earlier in this manual. 2. Verify that the wiring to the controller is correct and secure. 3. Turn on or plug in the power to the controller. 4. Turn on the controller. 5. Verify that the Pilot LED is on. 6. Verify that the flowmeter indicates a flow rate of approximately 1.5 SCFH.
1. Verify that the sample draw detector is sampling a fresh air environment (environment known to be free of combustible gas). 2. Open the housing door. 3. Set a voltmeter to measure in the millivolt (mV) range. 4. Plug the voltmeter leads into the test points on the amplifier. Plug the positive lead into the red + test point; plug the negative lead into the black - test point. 5. Verify a voltmeter reading of 100 mV (± 2 mV). 6.
NOTE: The following procedure assumes the use of a calibration kit that includes a calibration gas cylinder, a dispensing valve with an on/off knob, a gas bag, and a humidifier tube to connect the gas bag to the dispensing valve and to the sample draw detector inlet fitting. A demand flow regulator calibration kit is also available. WARNING: The controller is not an active gas monitoring device during the response test. Preparing for the response test 1.
11. Connect the humidifier tube from the gas collection bag to the dispensing valve, then open the clamp. 12. Turn the dispensing valve’s on/off knob counterclockwise to open it. The gas collection bag begins to fill. 13. Turn the dispensing valve’s on/off knob clockwise to close it when the gas collection bag appears full. 14. Close the tubing clamp, then disconnect the humidifier tube from the dispensing valve. 15. Remove the dispensing valve from the gas cylinder. Performing the response test 1.
Recommended action 1. Set the correct flow rate with the bypass valve or flow adjust pot. 2. If you cannot set the correct flow rate, check the sample lines for obstructions or kinks. 3. Inspect the hydrophobic filter to see if it is dirty or clogged with particulate matter or liquid. 4. Verify that the detector and amplifier wiring are correct and secure. “Installation” on page 10 describes sample draw detector wiring connections. 5.
2. Turn off power to the controller. 3. Open the sample draw detector’s housing door. 4. Unscrew and remove the two screws that secure the sensor retraining plate, then lift the plate, connector, and detector out of the housing. 5. Unplug the connector from the detector. 6. Verify that you are using the correct replacement sensor (SG-8521 is printed on the sensor), then plug the sensor into the connector. 7.
8. Lay the new amplifier (already installed on its mounting plate) on the mounting standoffs and install the retaining screws with the flat washers and split lock washers but do not tighten them down because you will need to pull out the amplifier for access to the load voltage adjust pot below. NOTE: When a sample draw detector is first powered up with a new amplifier, the initial output may be either high or below zero. Be sure to make arrangements so that this does not cause unwanted alarms. 9.
10. Place the controller and sample draw detector into operation 11. Verify that the flow rate is approximately 1.5 SCFH. If necessary, adjust the flow rate with the bypass valve and/or the flow adjust pot. 12. Close the sample draw detector’s housing door. Replacing the Ferrules The inlet and exhaust fittings each includes two ferrules that seal the incoming or exhaust tubing to the fitting. Replace the ferrules if the seal is bad or if you replace the sample tubing. Always replace the ferrules as a set.
5. Use the flow adjust pot (VR1) to set the flow to 1.5 SCFH. 6. Make sure the sample draw detector’s Fail LED is off. Setting the Detector Load Voltage The detector load voltage must be set when the detector or amplifier is replaced or if you suspect that it has been changed from the factory setting for your detection range. This procedure involves setting a voltage while applying calibration gas to the sample draw detector that matches the full-scale concentration for the sample draw detector.
7. Connect the humidifier tube from the gas collection bag to the inlet line. Allow the sample draw pump to draw out any residual gas in the gas collection bag. 8. Close the tubing clamp. NOTE: This step will cause a low flow alarm. 9. Disconnect the humidifier tube from the inlet line. 10. Connect the humidifier tube from the gas collection bag to the dispensing valve, then open the clamp. 11. Turn the dispensing valve’s on/off knob counterclockwise to open it. The gas collection bag begins to fill.
22. Wait 1 to 2 minutes to allow the combustible gas reading to decrease and stabilize. 23. Re-install the amplifier using the screws, flat washers, and lock washers removed in Step 4 above. 24. Calibrate the sample draw detector as described in “Calibration” on page 23 25. Verify that the controller display reading decreases and stabilizes at 0 ppm. 26. Store the components of the calibration kit in a safe and convenient place.
Preparing for Calibration NOTE: Calibrating the sample draw detector may cause alarms. Be sure to put the controller into calibration mode or disable external alarms before continuing. 1. Put the controller into calibration mode or disable external alarms. 2. Open the sample draw detector’s housing door. 3. Set a voltmeter to measure in the DC millivolt (mV) range. 4. Plug the positive lead into the red + test point; plug the negative lead into the black test point. 5.
6. Connect the humidifier tube from the gas collection bag to the dispensing valve, then open the clamp. 7. Turn the dispensing valve’s on/off knob counterclockwise to open the dispensing valve. The gas collection bag begins to fill. 8. Turn the dispensing valve’s on/off knob clockwise to close the dispensing valve when the gas collection bag appears full. 9. Close the tubing clamp, then disconnect the humidifier tube from the dispensing valve. Setting the Zero Reading 1.
8. If necessary, use the span pot on the amplifier to adjust the reading to match the correct mV output. 9. Allow the sample draw detector to draw out any residual gas in the gas collection bag. 10. Disconnect the sample tubing from the sample-draw detector’s inlet sample line. 11. Remove the test jacks from the test points. 12. Close the housing door. 13. Unscrew the dispensing valve from the calibration cylinder. 14. Wait 1 to 2 minutes to allow the combustible gas reading to decrease. 15.
