RKI INSTRUMENTS 65-2322RK Oxygen Transmitter User Manual

RKI INSTRUMENTS 65-2322RK Oxygen Transmitter User Manual

RKI Instruments, Inc.
www.rkiinstruments.com

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. Typical calibration frequencies for most applications are between 3 and 6 months, but can be required more often or less often based on your usage.

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 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. This warranty does not apply to those items which by their nature are subject to deterioration or consumption in normal service, and which must be cleaned, repaired, or replaced on a routine basis. Examples of such items are:

a) Absorbent cartridges
b) Pump diaphragms and valves
c) Fuses
d) Batteries
e) Filter elements

Warranty is voided by abuse including mechanical damage, alteration, rough handling, or repair procedures not in accordance with the operator’s manual. This warranty indicates the full extent of our liability, and we are not responsible for removal or replacement costs, local repair costs, transportation costs, or contingent expenses incurred without our prior approval.

THIS WARRANTY IS EXPRESSLY IN LIEU OF ANY AND ALL OTHER WARRANTIES AND REPRESENTATIONS, EXPRESSED OR IMPLIED, AND ALL OTHER OBLIGATIONS OR LIABILITIES ON THE PART OF RKI INSTRUMENTS, INC. INCLUDING BUT NOT LIMITED TO, THE WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT SHALL RKI INSTRUMENTS, INC. BE LIABLE FOR INDIRECT, INCIDENTAL, OR CONSEQUENTIAL LOSS OR DAMAGE OF ANY KIND CONNECTED WITH THE USE OF ITS PRODUCTS OR FAILURE OF ITS PRODUCTS TO FUNCTION OR OPERATE PROPERLY

This warranty covers instruments and parts sold to users by authorized distributors, dealers, and representatives as appointed by RKI Instruments, Inc.

We do not assume indemnification for any accident or damage caused by the operation of this gas monitor, and our warranty is limited to the replacement of parts or our complete goods.

Overview

This instruction manual describes the explosion proof capillary type oxygen transmitter 65-2322RK. This manual also describes how to install, start up, configure, maintain, and calibrate the transmitter when using it with a gas monitoring controller. A parts list at the end of this manual lists replacement parts and accessories for the oxygen transmitter. See the controller operator’s manual for information specific to the controller.

Specifications

Table 1 lists specifications for the oxygen transmitter.

Table 1: Specifications

NOTE: The following symbol on the detector label is a caution to the user to refer to this documentation for installation and operation instructions:

WARNING: When using the 65-2322RK, you must follow the instructions and warnings in this manual to assure proper and safe operation of the 65-2322RK and to minimize the risk of personal injury. Be sure to maintain and periodically calibrate the 65-2322RK as described in this manual.

Description

This section describes the components of the oxygen transmitter. The oxygen transmitter is a 4 – 20 mA type detector head. It consists of the oxygen detector, amplifier, and junction box.

Figure 1: Oxygen Transmitter Component Location

Oxygen Detector

The oxygen detector consists of the detector housing body, detector housing cap, cap gasket, and the plug-in sensor.

Figure 2: Oxygen Detector Component Location

Detector Housing Body

The detector housing body protects the electronic components within the housing. Use the mounting threads at the top of the housing to screw the oxygen detector into the 3/4 NPT hub on the bottom of the junction box. Two wires extend from the top of the detector housing body. Use these wires to connect the oxygen detector to the amplifier. One of the wires is white and one of the wires is green.

The housing includes two sockets installed on a circuit board. These sockets accept the plugin sensor’s two pins to provide electrical connection for the sensor. The circuit board with the sockets conditions the sensor’s signal before the signal reaches the amplifier.

Housing Cap & Cap Gasket

The housing cap screws onto the detector housing. It retains the plug-in sensor and protects it from damage. A foam gasket is installed inside the housing cap that seals against the sensor face. The housing cap also includes a flame arrestor which contains any sparks that may occur within the detector and a flame arrestor guard which protects the flame arrestor from damage. Unscrew the detector cap to access the plug-in sensor for maintenance or replacement. A cap gasket seals the interface between the housing and cap.

Plug-in Oxygen Sensor

The plug-in sensor is secured in the detector assembly by the housing cap. Through a series of chemical and electrical reactions, the sensor produces a millivolt output that corresponds to the detection range of the transmitter.

Amplifier

The amplifier converts the electrical output from the detector to a 4 to 20 mA signal that corresponds to the detection range and transmits the signal to a gas monitoring controller. A foam gasket that orients the amplifier and keeps it from rotating is installed on the bottom of the amplifier. The amplifier includes the controller terminal strip, detector terminal strip, zero pot, span pot, and test points (see Figure 1).

Controller Terminal Strip

The controller terminal strip is a two position plug-in style terminal strip located at the top edge of the amplifier. Use the controller terminal strip to wire the amplifier to a controller.

Detector Terminal Strip

The detector terminal strip is a four position plug-in style terminal strip located below the controller terminal strip. Two of the positions are for use with a toxic gas detector and are not used in the oxygen transmitter. Use the two detector terminal strip positions that are labelled “OXY” to connect the detector to the amplifier.

NOTE : The detector is factory-wired to the detector terminal strip. See “Wiring the Oxygen Transmitter to a Controller” on page 11 for all wiring procedures related to the transmitter.

Zero Pot

The zero pot is located in the upper left corner of the amplifier (see Figure 1). Use a small flat blade screwdriver to turn the zero pot’s adjustment screw and adjust the amplifier’s zero (oxygen free) output during the calibration procedure. Turn the adjustment screw clockwise to increase the zero output and counterclockwise to decrease the zero output.

Span Pot

The span pot is located to the right of the zero pot (see Figure 1). Use a small flat blade screwdriver to turn the span pot’s adjustment screw and adjust the amplifier’s fresh air output during the start up and calibration procedure. Turn the adjustment screw clockwise to increase the fresh air output and counterclockwise to decrease the fresh air output.

CAUTION : The amplifier includes an additional potentiometer. It is factory-set. Do not adjust it.

Test Points

The test points are on the left side of the amplifier (see Figure 1). The test points produce a 100 mV to 500 mV output that corresponds to the transmitter’s 4 to 20 mA output. Use the test points and a voltmeter to measure the amplifier’s output during the start-up and calibration procedures. The black test point in the lower left corner is the negative (-) test point and the red test point below the zero pot is the positive (+) test point.

Junction Box

Use the junction box to install the transmitter at a mounting site that is remote from the controller. The junction box protects the amplifier and wiring connections made to the amplifier. Use the top 3/4 NPT conduit hub to connect wiring from the amplifier to the controller. Use the cover on the front of the junction box to access the interior of the junction box. The detector and amplifier are factory installed in the junction box. Three spacers installed on the back of the junction box control the distance of the junction box from a mounting surface and ensure that there is enough room to install a calibration cup on the
detector during calibration.

Installation

This section describes procedures to mount the oxygen transmitter in the monitoring environment and wire the transmitter to a controller.

Mounting the Oxygen Transmitter

1. Select a mounting site that is representative of the monitoring environment. Consider the following when you select the mounting site.
   • Select a site where the transmitter is not likely to be bumped or disturbed. Make sure there is sufficient room to perform start-up, maintenance, and calibration procedures.
   • Select a site that is at normal breathing level.
   
   Figure 3: Mounting the Oxygen Transmitter

2. At the monitoring site you select, hang or mount the junction box with the detector facing down (see Figure 3).

Wiring the Oxygen Transmitter to a Controller

WARNING: If the controller’s construction is not explosion-proof, the controller must be installed in an ordinary location. Do non install a non- explosion-proof controller in a classified location.

1. Turn off the controller.
2. Turn off power to the controller.
3. Remove the junction box cover.
4. The detector leads are factory wired. Verify that the detector leads are wired to the amplifier’s detector terminal strip as shown in Figure 4.
5. To gain access to a plug-in terminal strip for wiring, pull it out of its socket by grasping the terminal strip and pulling. The detector terminal strip is keyed so that the controller and detector terminal strips cannot be reversed inadvertently.

WARNING: To maintain the explosion proof classification of the oxygen detector/junction box combination, a conduit seal must be used within 18 inches of the detector junction box conduit hub used for wiring to the amplifier. Do not install the detector in an environment with acetic acid. Adhere to your local electrical code when installing the conduit seal.

6. Guide either a two-conductor, shielded cable or two wires in conduit that is appropriate for hazardous locations through the top conduit hub of the junction box.

7. Pull out the controller terminal strip, and connect the two wires to the terminal strip as follows (see Figure 4).
   • Connect the positive wire to the SIG/PWR “+” terminal.
   • Connect the signal wire to the SIG/PWR “S” terminal.
   CAUTION : If shielded cable is used, leave the cable shield’s drain wire disconnected and insulated at the transmitter. You will connect the opposite end of the cable’s drain wire to the controller’s chassis (earth) ground.

8. Reinstall the controller terminal strip into its socket.

9. Secure the junction box cover to the junction box.

10. Route the cable or wires leading from the oxygen transmitter through one of the conduit hubs at the controller housing.
    CAUTION : Do not route power and transmitter wiring through the same controller conduit hub. The power cable may disrupt the transmission of the transmitter signal to the controller.

11. Connect the wires to the applicable detector/transmitter terminal strip at the controller as shown in Figure 4.

Figure 4: Wiring the Oxygen Transmitter to a Controller

12. If shielded cable is used, connect the cable’s drain wire to an available chassis (earth) ground at the controller. RKI controllers typically have a ground stud that can be used to ground the cable’s drain wire.

Start Up

This section describes procedures to start up the oxygen transmitter and place the transmitter into normal operation.

Introducing Incoming Power

1. Complete the installation procedures described earlier in this manual.
2. Verify that the power wiring to the controller is correct and secure. Refer to the controller operator’s manual.
3. Turn on power to the controller.
4. Turn on the controller.
5. Verify that the controller is on and operating properly. Refer to the controller operator’s manual.

CAUTION : Allow the transmitter to warm up for 5 minutes before you continue with the next section, “Verifying/Setting the Fresh Air Reading”.

Verifying/Setting the Fresh Air Reading

WARNING: Do not remove the detector housing cap or junction box cover while the circuits are energized unless the area is determined to be non- hazardous. Keep the detector housing cap and junction box cover tightly closed during operation.

NOTE : If you can verify that the detector is in a fresh air environment (environment known to be of normal oxygen content and free of toxic and combustible gases), it is not necessary to apply zero air when verifying or setting the fresh air reading.

The procedure below describes applying zero emission air, usually called zero air, using a calibration kit that includes a calibration cup, calibration gas, sample tubing, and a fixed flow regulator with an on/off knob. RKI Instruments, Inc. recommends using a 0.5 LPM (liters per minute) fixed flow regulator.

1. Unscrew and remove the junction box cover from the junction box.
2. Set a voltmeter to measure in the millivolt (mV) range.
3. 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.
4. Screw the calibration cup onto the bottom of the oxygen detector.
5. Screw the regulator into the zero air calibration cylinder.
6. Use the sample tubing to connect the regulator to the calibration cup.
7. Turn the regulator’s on/off knob counterclockwise to open it. Gas will begin to flow.
8. Allow the gas to flow for two minutes.
9. Verify a voltmeter reading of 434 mV (±2 mV).
10. If necessary, use a small flat-blade screwdriver to adjust the span pot until the voltmeter reading is 434 mV (±2 mV).
11. Turn the regulator’s on/off knob clockwise to close it.
12. Unscrew the calibration cup from the detector.
13. Unscrew the regulator from the zero air calibration cylinder. For convenience, leave the sample tubing connected to the regulator and the calibration cup.
14. Store the components of the calibration kit in a safe and convenient place.
15. Remove the voltmeter leads from the test points.
16. Secure the junction box cover to the junction box.

Maintenance

This section describes maintenance procedures. It includes preventive maintenance, troubleshooting, and component replacement procedures.

Preventive Maintenance

This section describes a preventive maintenance schedule to ensure the optimum performance of the oxygen transmitter. It includes daily and quarterly procedures.

Daily

Verify a display reading of 20.9% oxygen at the controller. Investigate significant changes in the display reading.

Quarterly

Calibrate the oxygen transmitter as described in “Calibration” on page 18 of this manual. See the calibration frequency discussion in “Calibration Frequency” on page 18 to determine if a quarterly calibration schedule fits your needs.

Troubleshooting

The troubleshooting guide describes symptoms, probable causes, and recommended action for problems you may encounter with the oxygen transmitter.

NOTE : This troubleshooting guide describes transmitter problems only. See the controller operator’s manual for problems you may encounter with the controller.

Table 2: Troubleshooting the Oxygen Transmitter

Replacing Components of the Oxygen Transmitter

This section includes a procedure to replace the plug-in oxygen sensor, a procedure to replace the entire oxygen detector assembly, and one to replace the amplifier. In most cases, it is not necessary to replace the entire detector assembly.

Replacing The Plug-in Oxygen Sensor

CAUTION : The plug-in sensor contains electrolyte that is an irritant. Do not disassemble the sensor when replacing it with a new one. If electrolyte comes in contact with your skin, wash affected area thoroughly with soap and water

1. Turn off the controller.

2. Turn off or unplug power to the controller.

3. Unscrew the detector housing cap from the detector housing body. Make sure not to lose the cap gasket.

4. Unplug and remove the oxygen sensor.

5. Carefully plug the replacement sensor into the socket pattern that is located in the detector housing.

6. Make sure the cap gasket is in place and screw the detector housing cap back onto the detector housing body.

7. Turn on power to the controller.

8. Turn on the controller and place into normal operation.
   CAUTION : Allow the replacement sensor to warm up for 5 minutes before you continue with the next step.

9. Calibrate the detector as described in “Calibration” on page 18.

Replacing the Oxygen Detector

NOTE : In most cases, it is only necessary to replace the plug-in sensor.

1. Turn off the controller.

2. Turn off or unplug power to the controller.

3. Remove the junction box cover.

4. Remove the detector terminal strip from its socket.

5. Disconnect the detector leads from the detector terminal strip. Note the position of the color-coded leads as you remove them.

6. Unscrew the detector from the junction box conduit hub.

7. Guide the detector leads of the replacement detector through the bottom conduit hub of the junction box, then screw the mounting threads of the detector into the conduit hub. If necessary for environmental conditions, apply thread sealant or Teflon tape to the hub and/ or detector threads to seal them.

8. Connect the detector leads to the appropriate detector terminal strip terminals. Connect the white wire to the terminal labelled Oxy + and the green wire to the terminal labelled Oxy -. See Figure 4 on page 12 for the detector wiring connections to the amplifier.

9. Reinstall the detector terminal strip into its socket.

10. Reinstall the junction box cover.

11. Turn on or plug in power to the controller.

12. Turn on the controller and place it into normal operation.
    CAUTION : Allow the replacement detector to warm up for 5 minutes before you continue with the next step.

13. Calibrate the replacement detector as described in “Calibration” on page 18.

Replacing the Amplifier

1. Turn off the controller.

2. Turn off or unplug power to the controller.

3. Remove the junction box cover.

4. Unplug the detector terminal strip and controller terminal strip from their sockets. You may leave the wires connected to the terminal strips.

5. Unscrew and remove the screw with the flat and lock washers that secures the amplifier to the junction box.

6. Remove the old amplifier.

7. Install the new amplifier into the junction box with the screw, lock washer, and flat washer you removed in Step 5 above. A foam gasket that orients the amplifier and keeps it from rotating is installed on the bottom of the amplifier. Make sure the amplifier is seated flat in the junction box.

8. Install the detector and controller terminals strips into their sockets on the new amplifier as shown in Figure 4 on page 12. If controller leads or detector leads were removed during this procedure, refer to Figure 4 on page 12 for the detector and amplifier connections.
   NOTE : When a transmitter is first powered up with a new amplifier, the initial output may be either high or below zero depending on the setting of the zero pot. Be sure to make arrangements so that this does not cause unwanted alarms.

9. Turn on power to the controller.

10. Turn on the controller and place it into normal operation.

11. Allow the transmitter to warm-up for 5 minutes.

12. Calibrate the transmitter as described in “Calibration” on page 18 of this manual.

Calibration Frequency

Although there is no particular calibration frequency that is correct for all applications, a calibration frequency of every 3 months is adequate for most oxygen transmitter applications. Unless experience in a particular application dictates otherwise, RKI Instruments, Inc. recommends a calibration frequency of every 3 months for the oxygen transmitter.
If an application is not very demanding, for example detection in a clean, temperature controlled environment, and calibration adjustments are minimal at calibration, then a calibration frequency of every 6 months is adequate.
If an application is very demanding, for example if the environment is not well controlled, then more frequent calibration than every 3 months may be necessary.

Calibration

This section describes how to calibrate the oxygen transmitter. It includes procedures to prepare for calibration, set the fresh air reading, set the zero reading, and return to normal operation. It describes calibration using a calibration kit that includes a calibration cup, calibration gas, sample tubing, and a fixed flow regulator with an on/off knob. RKI Instruments, Inc. recommends using a 0.5 LPM (liters per minute) fixed flow regulator.

Preparing for Calibration

1. Place the controller into its calibration mode or disable external alarms.
   WARNING: Do not remove the detector housing cap or junction box cover while the circuits are energized unless the area is determined to be non- hazardous. Keep the detector housing cap and junction box cover tightly closed during operation.

2. Unscrew and remove the junction box cover.

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. Use the following formula to determine the correct test points output for the calibrating sample.

Output (mV) = (calibrating sample/fullscale) X 400 + 100

The concentration of oxygen in the atmosphere is 20.9%, so when setting the fresh air reading, you will set the test points output to 434 mV (±2 mV).

434(mV) = (20.9/25) X 400 +100

NOTE : Calibrating the oxygen transmitter may cause alarms. Be sure to put the controller into its calibration program or disable external alarms before continuing.

6. Screw the calibration cup onto the detector housing cap.

Setting the Fresh Air Reading

NOTE : If you can verify that the oxygen transmitter is in a fresh air environment, you do not need to apply zero air to the detector before adjusting the fresh air reading.

1. Screw the regulator into the zero air calibration cylinder.
2. Use the sample tubing to connect the regulator to the calibration cup.
3. Turn the regulator knob counterclockwise to open the regulator.
4. Allow the gas to flow for two minutes and verify a reading of 434 mV (±2 mV). If necessary, use the span pot on the amplifier to adjust the reading to the correct value.
5. Turn the regulator knob clockwise to close the regulator.
6. Unscrew the regulator from the zero air calibration cylinder. Leave the sample tubing connected to the regulator and the calibration cup.
   NOTE : Depending on the size of your zero air cylinder, it is possible that you will have a different regulator for the zero air cylinder and the 100% nitrogen cylinder. If necessary to fit the nitrogen cylinder, change the regulator.

Setting the Zero Reading

1. Screw the regulator into the 100% nitrogen calibration cylinder.
2. Turn the regulator knob counterclockwise to open the regulator.
3. Allow the calibration gas to flow for two minutes and verify a reading of 100 mV (±2 mV). If necessary, use the zero pot on the amplifier to adjust the reading to match the correct response reading.
4. Turn the regulator knob clockwise to close the regulator.
5. Unscrew the regulator from the calibration cylinder.
6. Unscrew the calibration cup from the detector housing cap.

NOTE : For convenience, leave the regulator and calibration cup connected by the sample tubing

Returning to Normal Operation

1. Remove the voltmeter leads from the amplifier test points.

2. Secure the junction box cover to the junction box.

3. When the controller display reading rises above the decreasing alarm setpoint, return the controller to normal operation.
   NOTE : If you do not allow the gas reading to increase above the decreasing alarm point, then unwanted alarms may occur.

4. Verify that the controller display reading increases and stabilizes at 20.9% volume.

5. Store the components of the calibration kit in a safe and convenient place.

Parts List

Table 3 lists replacement parts and accessories for the oxygen transmitter.

Table 3: Parts List

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