Air check O2 Ex Oxygen Deficiency Monitor - Manual Brochure

Air ChecküüEX O2 Deficiency Monitor Instruction Manual PureAire Monitoring Systems, Inc. 557 Capital Drive Lake Zurich, Illinois 60047 Phone: 847-726-6000 Fax: 847-726-6051 Toll-Free: 888-788-8050 pureairemonitoring.com PureAire Monitoring Systems, Inc. 1 Please Read Before Installation The following will damage the Air Check Oxygen monitor. 1. The Air Check O2 monitor requires 24 VDC regulated power. Please Do Not connect the monitor to any voltage that exceeds 24 Volts DC, or ANY AC Voltage. 2. Do not power the Air Check Oxygen monitor with the oxygen sensor unplugged from the main PC board. Do Not Connect the O2 sensor to the PC board while the monitor is powered. This Will Damage the O2 sensor. 3. When calibrating or challenging the Air check O2 Ex monitor, a. Do not expose the monitor to flow rates that exceed ½ liter per minute, (500 cc per minute) flow. b. Please open the valve on the span gas cylinder before connecting the tubing to the Oxygen monitor to prevent a flow fault. c. Expose the monitor to span gas blends that consist of Oxygen and Nitrogen only. Do Not expose the monitor to any combustible gas, i.e. Methane, Hydrogen, etc. Exposure to combustible span gases can damage the oxygen zirconium sensor cell. Contact PureAire for questions about specific applications 4. Do not expose the Oxygen monitor to silicone compounds. They can cause a loss of sensitivity. 5. When using the ambient, (non-extractive) Air Check O2 monitor, Do not expose the oxygen sensor directly to a water stream. In areas requiring wash downs, cover and protect the monitor. Contact PureAire for details on a waterproof enclosure. Table of Contents 1: Introduction .....................................................................................................................2 1.1 Key Features ........................................................................2 1.2 Component identification ....................................................3 2: Specifications ...................................................................................................................6 2.1 Performance Specifications .................................................6 2.2 Gas Detection System..........................................................6 2.3 Signal Outputs .....................................................................6 2.4 Electrical Requirements .......................................................6 2.5 Physical Characteristics .......................................................6 2.6 System Default Factory Settings .........................................7 3: Installation .......................................................................................................................8 3.1 Site Requirements ................................................................8 3.2 Mounting..............................................................................8 3.3 Wiring ................................................................................10 3.4 Initial Startup .....................................................................10 4: Normal Operation..........................................................................................................11 4.1 Signal Outputs ...................................................................11 4.2 Instrument Faults ...............................................................11 4.3 Routine Maintenance Schedule .........................................11 4.4 Loss of Power Indicator .....................................................12 4.5 Alarm Reset .......................................................................12 5: Air Check O2 Monitor Programming ............................................................................13 5.1 Joystick Operation .............................................................13 5.2 Program Flowchart ............................................................14 5.3 Entering the Password .......................................................17 5.4 Entering the Menus ............................................................18 5.4.1 Set 4-20mA Loop .....................................................18 5.4.2 Set Formats ...............................................................20 5.4.3 Set Alarm Threshold Polarity...................................22 5.4.4 Set Latching ..............................................................24 5.4.5 Set Alarm Delay .......................................................27 5.4.6 Set Zero Suppression................................................28 5.4.7 Set Alarm Thresholds ...............................................28 5.4.8 Set Alarm Hysterisis .................................................30 5.4.9 Set Sensor Adjust......................................................32 5.4.10 Main Operation Mode.............................................33 6: Maintenance & Cell Verification ..................................................................................34 6.1 Sensor Verification............................................................35 6.2 Sensor Verification Procedure ...........................................35 7: Appendix .......................................................................................................................38 Revised 03/18/10 PureAire Monitoring Systems, Inc. 21: Introduction The Air Check üüO2 EX series monitoring system is a self-contained sample draw Oxygen deficiency detection system suitable for Class 1 Division 1 environments. It’s a compact gas monitoring system that’s ideal for the continuous monitoring of inert gas storage areas, confined spaces, and other locations where low oxygen levels may pose a hazard to personnel. Unlike electrochemical sensor cells the Air Check üüO2 zirconium cell provides stable oxygen readings even in areas where temperature and humidity levels are changing. The PureAire Air Check üüO2 Deficiency Monitor is suitable for either indoor or outdoor use. The heart of the monitoring system is a long lasting zirconium sensor, which responds to low oxygen conditions within seconds and provides accurate measurements over a wide temperature and humidity range. The zirconium O2 sensor cell will operate continuously for 8 or more years and requires an absolute minimum of maintenance. There are no zero or span calibration pots to adjust and when compared to disposable type sensors, our long life zirconium O2 sensor can save up to hundreds of dollars in annual maintenance. Ideal for continuously monitoring oxygen levels in confined spaces or areas where inert gases are used, the Air Check üüO2 Deficiency Monitor does not drift or loose sensitivity when the weather or temperature changes. The electronics are housed in an explosion proof housing designed for installation in Class I, Division 1, Group B C and D environments. Each system consists of a long life zirconium oxide sensor cell and three-wire transmitter. The Air Check üüO2 monitor may be used as a stand-alone gas detector, linked to optional PureAire single and multipoint controllers, or connected to your own centralized control and surveillance system. This manual covers the installation, operation, and maintenance of the Air Check üüO2 deficiency monitor. 1.1 Key Features The Air Check üüO2 EX monitor incorporates a number of user-friendly features designed to simplify installation, operation, and maintenance. 1.1.1 Long Life Zirconium Oxide O2 Sensor The system’s O2 sensor cell has a life of well over 8 years of continuous operation. Unlike concentration O2 cells, PureAire’s exclusive zirconium oxide sensor cell does not need an oxygen reference gas for proper operation. The Air Check üüO2 monitor can detect low oxygen levels in confined spaces and process tools without the need of a reference gas. 1.1.2 Smart Electronics The Air Check üüO2 monitor incorporates a special electronic circuit that continuously monitors sensor operation. With the addition of the alarm relay option, any cell degradation or complete failure will immediately be detected. This smart circuitry alerts the user to sensor faults, flow system faults and other electrical problems that may interrupt surveillance through the standard mA signal output signal or through the optional fault relay option. PureAire Monitoring Systems, Inc. 31.1.3 Calibration The Air Check üüO2 monitor incorporates a stable zirconium oxide sensor that rarely requires calibration. Changing barometric pressure changes or changes in temperature and humidity do not affect the zirconium oxide oxygen cell. The earth is a wonderful source of calibrated oxygen at 20.9%, therefore under ambient conditions verification of the Air Check üüO2 monitor to 20.9% oxygen is constantly being performed. There are no zero or span pots to adjust. The O2 monitor only requires periodic testing with nitrogen to verify the cells response to low oxygen levels. See Section 6.2 for the testing procedure to nitrogen. 1.2 Component Identification 1.2.1 Front View Exterior 1. Front Cover — This is a removable, waterproof cover that protects the interior of the transmitter. It threads onto the metal transmitter housing. 2. Digital Display — This displays the Oxygen levels in percentage. The normal oxygen level on earth is 20.9% 3. Sample Inlet — This inlet permits the flow of oxygen to enter the sensor cell. 4. Sample Exhaust — This permits the flow of oxygen to exit the enclosure. 5. Conduit fitting — This is the sealed opening in the transmitter housing for connecting the 4-20 mA output and 24 VDC wiring. 6. Transmitter Mounting Tabs — Mounting holes are provided on both sides of the transmitter housing to permit convenient wall mounting. 7. Alarm Indicators — 3 multi colored LED indicators for showing: Alarm level 1 Orange LED Alarm level 2 Red LED Fault Alarm Yellow LED Front Cover Digital Display Mounting Tab Sample Inlet Mounting Tab Conduit Fitting Joystick Sample Exhaust PureAire Monitoring Systems, Inc. 4 8. Joystick — Used for selecting and adjusting the built-in menus. The Air Check üüO2 monitor is available with optional dual level user selectable 9. Front Panel Cover Screws — These captive screws are used to mount the display front panel and O2 electronics to the enclosure. 10. Sample Pump — Used to bring in a sample to the oxygen cell. Flow rate is preset at the factory. Flow rate is continuously protected with a built-in flow sensor. See Section 4.2; Instrument Faults 11. Oxygen Sensor chamber — Used to mount the zirconium O2 sensor cell O2 monitor with Internal relays Front cover removed Internal View Front Panel Cover Screws For systems with Relay Option Alarm Relays Alarm 1 Fault Alarm Alarm 2 Sample Pump Oxygen Sensor Chamber PureAire Monitoring Systems, Inc. 5 1.2.3 Transmitter Interior 1. Power Analog Terminal Block — This terminal block is where the 24VDC power and 4-20 mA analog output connection is made. 1.2.4 Alarm Relay Board Option 1. Power Analog output Terminal Block Common mA output + 24VDC 24 VDC Power Terminal Block Flow Sensor (Factory set) Alarm 2 Relay CONN 1 Alarm 1 Relay CONN 2 Fault Relay CONN 3 NO NC C NO NC C NO NC C Remote Reset PureAire Monitoring Systems, Inc. 62: Specifications èè NOTE: Due to our commitment to continual product improvement, all specifications are subject to change without notice. 2.1 Performance Specifications Sensor Type: Long Life Zirconium Oxide Sensor Cell Response Time: Within 5 seconds of any change in O2. Repeatability: ± 1% of reading Fault Indicators: Loss of VDC power (analog signal drops to 0 mA). Sensor cell failure: Fault relay activated. (Must have Alarm relay option for cell failure to operate) Operating Temp: - 40° to 122°F (-40° to +50°C); consult PureAire for lower or higher operating temperatures. Humidity: 0 to 95% RH; consult PureAire for sensors which can operate in 100% condensing RH environments. 2.2 Gas Detection System Type: Long Life Zirconium Oxide Sensor Cell Sensor Life: 8 years under normal conditions. Transmitter: Microprocessor electronics with built-in 3-digit backlit LCD display Joystick operated menus 2.3 Signal Outputs Standard Analog Output: DC 4-20 mA Optional Relay Output: Dual level user selectable alarm relays and one fault relay Rated, 2amps @ 30VDC; 2amps @ 250VAC 2.4 Electrical Requirements Power: 24 VDC external power. A regulated 24VDC power supply is required. Consumption: Approximately 700mA current (17 watts) 2.5 Physical Characteristics Dimensions: 6.625 (W) x 5.50 (H) x 5.25 (D) inches; 168 x 140 x 134 mm Weight: 12 pounds (5.5 kg) Enclosure Type: Explosion proof designed for installation in Class I, Division 1, Group B C and D hazardous areas. PureAire Monitoring Systems, Inc. 7 2.6 AirCheck O2 System Default Factory settings The Air Check üüO2 Deficiency Monitor, when supplied with the optional Relay module, is shipped with factory defaults for the alarm relay settings. The following are the factory defaults: èè NOTE: The built in relay settings may be changed by the user in the field. Refer to Section 5.4.2 * NOTE: The Audio alarm feature is optional. ** NOTE: The LED indicators on the front panel are connected directly to the alarm relays. Menu Function Factory Default Menu Defined Alarm Thresholds Alarm 1 = 19.5% Alarm 2 = 18% Audio = 19.5% * At what level do you want to alarm? Set Alarm Threshold Polarity Alarm 1 = Inverted Alarm 2 = Inverted Audio = Inverted * Do you want to alarm at a level higher, (normal) or lower, (inverted) than the alarm threshold? Alarm Delay Alarm 1 = 5 seconds Alarm 2 = 5 seconds How long do you want to wait until the alarm activates? Set Alarm Hysterisis Alarm 1 = 0.0 % Alarm 2 = 0.0 % Audio = 0.0 % For use when using the O2 monitor for control. See Section 5.4.8 Relay Latching Alarm 1 = Non-latching Alarm 2 = Non-latching Audio = Non-latching Do you want the alarm to automatically reset? (non-latching) or do you want to manually reset the alarm? (latching) Format Relay - LED State ** Alarm 1 = Normal Alarm 2 = Normal Fault = Normal Do you want the relays to energize, (normal) or de-energize, (fail safe) when the alarm activates? PureAire Monitoring Systems, Inc. 83: Installation 3.1 Site Requirements The Air Check üüO2 monitor enclosure should be mounted in an area free of vibration and electrical noise or interference. If possible, avoid areas with high temperatures or condensing humidity. 3.2 Mounting 3.2.1 Transmitter Enclosure The Air Check üüO2 monitor is designed primarily for wall mounting and should be installed at a height convenient for operation, maintenance, and viewing of the instrument display. 3.2.2 Air Check üü O2 monitor The Air Check Ex enclosure should be installed in a location where gas leaks are likely to occur or where released gases may accumulate. It should be mounted no closer than 12 inches above floor level. Airflow within the monitored area, the characteristics of the gas (lighter or heavier than air), and the position of workstations and personnel should all be considered in determining the most suitable installation location. èè NOTE: Leave clearance room on the bottom of the Oxygen monitor for the flame arrestors and inlet dust filter 5.75 “ 5.75 “ 6.50 “ PureAire Monitoring Systems, Inc. 93.2.3 Air Check üü Sample Inlet Filter The Air Check üü Ex monitor is a sample draw type. The internal sample pump flow rate is programmed at the factory and cannot be changed in the field. A flow sensor on the relay board continually monitors flow rate. When a loss of flow is detected, a signal is sent to the fault relay and the front mounted LED will activate. Sample flow to the monitor is continuously monitored and controlled by the flow control microprocessor. NOTE: If the sample line is blocked, the fault indicator will illuminate and the pump will accelerate to try and re establish the proper flow rate. If the line is cleared, the pump will speed will slow down and the fault light will turn off when the flow rate is back to factory setting. To protect the pump and flame arrestor from dust, the use of a particulate filter is supplied. On installation, attach the particulate filter to the inlet using the tygon sample tubing supplied. Insure the correct flow by aligning the arrow towards the flame arrestor. Depending on the environment, replacement of this filter should be performed every 6 to 12 months. In dusty environments, filter replacement may need to be replaced more frequently. If the filter becomes completely blocked, the internal flow sensor will detect the loss of flow and activate the fault relay and LED. Order filter part number 9933-05-AAQ Threaded fitting ¼” NPT PureAire Monitoring Systems, Inc. 10 3.3 Wiring The Air Check üü O2 monitor requires a single, 3-wire shielded cable for analog output and 24 VDC power input. A three-wire shielded cable; 3-conductor, 18 AWG stranded General Cable E2203S.30.860, or equivalent is recommended for the connection. The maximum permissible cable length is 0.62 miles (1 km). The analog out and VDC power in connections are made on the terminal block inside the transmitter housing. These connections are made as follows: Pin # Connection Description 1 Power DC +24V Input 2 Signal Out DC 4-20mA Output 3 Common (Signal Ground) 0V 3.4 Initial Startup Once installation of the gas detector has been completed, it is ready for startup. The following procedures should be performed before putting the instrument into operation: 1. Check the integrity of all wiring. 2. Apply 24 VDC power. The instrument should now be powered up. Upon power up, the Air Check üü O2 monitor LCD displays the PureAire logo and then starts a 4-minute, (240 second) count down as the zirconium oxide O2 sensor stabilizes. The monitor will output a 4 mA signal during the entire warm-up period è NOTE: The Air Check üü O2 monitor requires a 4-minute warm-up before detecting oxygen. è NOTE: The Air Check üü O2 monitor’s reading may be adjusted to the ambient oxygen level. See section 5.4.8. for instructions on adjusting. C Common signal ground (Pin 3) mA 4-20mA signal output (Pin 2) (connects to PLC) + 24VDC Power (Pin 1) Oxygen 239 WARM PureAire Monitoring Systems, Inc. 11 4: Normal Operation The Air Check O2 monitor is a single point monitor designed for the continuous detection and measurement of ambient oxygen concentration levels. 4.1 Signal Outputs The Air Check üü O2 monitor outputs a continuous 4-20 mA analog signal proportional to the measured concentration of oxygen. 4 mA represents 0% O2 and 20 mA represents 25% O2 which is the full range. In the event of a system fault, a specific factory defined code will be displayed on the local digital display. This code will indicate the exact nature of the system fault. 4.2 Instrument Faults The Air Check üüO2 monitor incorporates a number of self-checking features to ensure reliable operation. In the event that a fault condition is detected, the analog output signal is altered as follows: Condition Analog Signal Power to transmitter lost Analog output drops to 0 mA Transmitter cable cut Analog output drops to 0 mA O2 Cell complete failure Fault Code 128 Analog output drops to 2 mA (0 mA on request) Fault Relay activates (Available with Relay Option Only) O2 System Warm Up Analog output drops to 4 mA Fault Relay activates and turns off when system is in the Oxygen operation mode (Available with Relay Option Only) O2 Cell degrades Fault Code 128 Analog output drops to 2 mA (0 mA on request) Fault Relay activates (Available with Relay Option Only) No Flow to the Oxygen sensor Fault Code 32 Analog output drops to 2 mA (0 mA on request) Fault Relay activates (Available with Relay Option Only) EEPROM Fault 08 Analog output drops to 2mA (0 mA on request) è NOTE: All system faults are displayed on the front panel. Each fault has it’own specific code to identify the specific problem. Please contact PureAire whenever a fault is displayed. 4.3 Routine Maintenance Schedule Continuous gas detection systems depended upon to measure and detect hazardous gas leaks in the workplace requires periodic maintenance to ensure proper operation. The frequency with which this routine maintenance is required depends on the environment. The following table is intended to serve as a general guideline for routine maintenance. The conditions in your particular application, as well as your organization’s maintenance policies, will ultimately determine the best routine maintenance schedule for your equipment. PureAire Monitoring Systems, Inc. 12 4.3.1 Routine Visual Checks Items to check Check for power and proper operation Condition / status when operating properly Unit should be outputting a 17.37 mA signal when the oxygen level is at 20.9%. The LCD digital display should also indicate 20.9% 02 when the oxygen is at ambient levels. 4.3.2 Recommended Routine Maintenance Schedule Routine Visual Checks Every 6 - 12 months Sensor Verification with nitrogen Every 6 - 12 months** ** The ambient oxygen level is 20.9%; therefore, under ambient conditions verification of the Air Check üüO2 monitor to 20.9% oxygen is constantly being performed. The O2 monitor only requires periodic testing with nitrogen to verify the cells response to low oxygen levels. See Section 5.4.8 or how to make minor adjustments. 4.4 Loss of Power Indicator In the event the Air Check üüO2 monitor loses 24VDC power, the 4-20 mA analog output signal drops to 0mA. The LCD display will also display a blank screen. 4.5 Alarm Reset It the Air Check üüO2 monitor is supplied with the optional alarm relays, whenever the monitors alarms are activated, the built-in alarm relays, panel mounted LED’s and optional audio horn will also activate. When the relay settings are non latching, the alarm relays, LED’s and horn will automatically reset. If the relay settings are latching, then a manual reset of the alarms are required. Resetting the alarms can be performed through use of the joystick or through the use of the remote reset function. Joystick – You must enter the password to enter the reset function. After the password is entered and accepted, push the joystick in; (enter) to reset the alarms. Remote Reset – See Pg. 7. The alarm relay board has a two pin connector for wiring to a remote switch. When connected to a switch, this remote reset will bypass the joystick and a password will not be needed to reset the alarms. èè NOTE: The oxygen levels must recover above the alarm thresholds before the horn can be reset from the remote reset switch or joystick. PureAire Monitoring Systems, Inc. 13 5: Air Check üüO2 Monitor Programming The Air Check üüO2 Deficiency Monitor is supplied with user selectable settings to adjust the alarm settings, 4 and 20mA output and minor sensor adjustments. The settings are arranged in menus that are accessed by moving the joystick. To access the menus a factory set password is used. NOTE: The Air Check üüO2 Deficiency Monitor will continuously monitor oxygen while accessing the menus. The alarm, fault relays and mA output are all active and on line while making any changes to the menus. 5.1 Joystick Operation The Air Check üüO2 monitor uses an 8-position joystick with a center pushbutton for selecting menus and changing values. The joystick is programmed to standard protocol as follows: èè NOTE: The joystick has a built-in delay to prevent accidental tampering of the menus. deliberate entries are required. èè CAUTION: Only qualified personnel should perform programming, maintenance and sensor verification + Plus - Minus Previous Next Plus – Pushing the joystick in this direction increases the value Minus – Pushing the joystick in this direction decreases the value Next – Pushing the joystick in this direction moves you to the next level of the menu hierarchy. Previous – Pushing the joystick in this direction takes you out to the last level of menu hierarchy. Enter – Pushing the joystick directly in the center enters the information into the microprocessor èè NOTE: The joystick has four other positions that are only used to only access factory menus. A separate factory password is required obtain entry. PureAire Monitoring Systems, Inc. 14 5.2 Program Flowchart Password ok Password ok Set 4-20mA loop Set 4mA Zero 255 Set 20mA Span 255 Oxygen 20.9% Enter Password A Force loop 255 Set Formats Format Relay 2 Format Relay1 Normal Invert Normal Invert Format Fault Relay Normal Invert èè NOTE: All numerical values shown are only examples and are Not Factory Defaults PureAire Monitoring Systems, Inc. 15 Set Alarm Threshold Polarity Set Alarm 1 Polarity Invert Normal Set Alarm 2 Polarity Invert Normal Alarm Delay 255 Set Audio Alarm Invert Normal Password ok Nonlatch Set Latching Relay 2 Set Latching Latch Set Latching Relay 1 Nonlatch Latch Nonlatch Latch Set Latching Audio Zero Suppression 255 èè NOTE: All numerical values shown are only examples and are Not Factory Defaults PureAire Monitoring Systems, Inc. 16 Sensor Adjustment Set sensor zero 255 Set sensor span 255 Set Relay 1 Alarm Threshold 255 Set Relay 2 Alarm Threshold 255 Set Audio Threshold 255 Set Alarm Thresholds Password ok Set Alarm 1 Hysterisis 0.2% Set Alarm 2 Hysterisis 0.3% Set Audio Alarm Hysterisis 0.0% Set Alarm Hysterisis èè NOTE: All numerical values shown are only examples and are Not Factory Defaults PureAire Monitoring Systems, Inc. 17 5.3 Entering the Password The Air Check üüO2 monitor is supplied with a factory set password to prevent unauthorized access to the menus. The Password is 557. The following explains how to enter the password. 1. Push the joystick once to the right. Enter Password will scroll on the first line of the digital display. The second line will still display the current oxygen level. 2. Push the joystick again once more to the right to enter the input screen. The letter A will appear and flash. èè NOTE: The display has characters that start with A through Z and 0 through 9. Pushing the joystick up or down will permit you to scroll through the alphanumeric characters. 3. Push the joystick up or down to enter the first digit. The display is an alphanumeric display and toggles from A through Z followed by 0 to 9. The character to be entered will flash. 4. Push the joystick again to the right to select the second entry. Push the joystick up or down to select the second digit. The character being entered will flash and the first character entered will remain lit. 5. Push the joystick again to the right to select the third entry. Push the joystick up or down to select the third and final digit. The character being entered will flash and the first and second characters entered will remain lit. You are now ready to enter the 3-digit password. 6. Push the joystick in the center to enter the password. If you entered it correctly the display will scroll Password OK. ...Password OK…… 20.9% ..Enter password… 20.9% A 20.9% 5 20.9% 55 20.9% 557 20.9% PureAire Monitoring Systems, Inc. 18 èè NOTE: If an incorrect password has been entered, the display will indicate Password Failed. Push the joystick to the left to access the monitoring mode. From this mode you can reenter the password again. 5.4 Entering the Menus The Air Check üüO2 monitor is supplied with main menus with sub menus to adjust mA outputs, alarm relay settings, sensor adjustments and zero suppression for toxic and corrosive gas sensor cells. 5.4.1 Set 4-20mA loop This main menu will permit the adjusting of the 4mA and 20mA output from the Air Check O2 Monitor. It also provides a function that will send an actual output between 4mA and 20 mA to test any remote control and alarm system attached to the O2 monitor. è NOTE: To read the mA output, Air Check O2 monitor must either be connected to a remote PLC controller or SCADA system. You can also connect the Air Check O2 monitor to a volt meter to read the mA output. You’ll need to add a 200 ohm resistor between the mA and common terminals. Please consult PureAire for more information. From this main menu, pushing the joystick to the right will select the sub menu and the digital display will scroll the following: This is the menu at which to adjust the 4mA output being sent from the Air Check O2 Monitor. To change this value, push the joystick right to display the 4 mA setting. The display will indicate a value between 0 and 255 counts. Pushing the joystick up increases the value and pushing the joystick down decreases the value. The 4mA output being sent from the Air Check O2 monitor will change as the number on the digital display changes. Press ENTER to accept the value. Push the joystick to the left brings you back to the pervious Main menu. The digital display will scroll the following: .Set 4-20mA loop.. 20.9% ..Set 4mA zero… 20.9% 255 20.9% ...Set 4mA zero….. 20.9% PureAire Monitoring Systems, Inc. 19 Push the joystick down to access the next sub menu; Set 20mA Span will scroll. This is the menu at which to adjust the 20mA output being sent from the Air Check O2 Monitor. To change this value, push the joystick right to display the 20mA span setting. The display will indicate a value between 0 and 255 counts. Pushing the joystick up increases the value and pushing the joystick down decreases the value. The 20mA output being sent from the Air Check O2 monitor will change as the number on the digital display changes. Press ENTER to accept the value. Push the joystick to the left brings you back to the pervious Main menu. The digital display will scroll the following: Push the joystick down to access the next sub menu; Force loop will scroll. This is the sub menu at which to test the full 4mA to 20mA output from the Air Check O2 Monitor. Increasing and decreasing the value will send out an oxygen reading from 0% to a maximum of 25%. By increasing or decreasing the value, the O2 monitor will transmit a continuous mA signal in a range between 4 to 20 milliamps. èè NOTE: The Force Loop function is not available on the Air Check O2 monitor. It was designed for toxic and corrosive gases. To access this function push the joystick right to display the numeric setting. The display will indicate a value between 0 and 100% of the full scale. Pushing the joystick up increasesthe value and pushing the joystick down decreases the value. The mA output being sent from the Air Check O2 monitor will change as the number on the digital display changes. Press ENTER to exit this menu. èè NOTE: The Force Loop function will automatically reset back to 0 when the Enter button is pushed. ...Set 20mA Span… 20.9% 255 20.9% .…Force Loop…. 20.9% ...Set 20mA span….. 20.9% PureAire Monitoring Systems, Inc. 20 Push the joystick to the left brings you back to the pervious menu. The digital display Will scroll the following: 5.4.2 Set Formats This is the menu at which to adjust the relay states for the two gas alarm relays and the individual instrument fault relay. è NOTE: The O2 system must have the relay module installed to access this menu. If no relay module is installed the display will indicate N/A, (not available) Push the joystick down to access the next main menu, Set Formats. The display will scroll the following: This menu will permit the setting of the two alarm relays and the fault relay settings from normally de-energized state, Normal, to normally energized state, Inverted. From this main menu, pushing the joystick to the right will select the sub menu and the digital display will scroll the following: This is the menu at which to adjust the first level alarm relay state on the Air Check O2 Monitor. To change this value, push the joystick right to display the relay state. The display will Indicate INVERT. Pushing the joystick down will change the relay state from INVERT to NORMAL. . Press ENTER to accept the value. 0 20.9% ...Set 4mA loop….. 20.9% …Set Formats… 20.9% ..Format Relay 1… 20.9% INVERT 20.9% NORMAL 20.9% PureAire Monitoring Systems, Inc. 21 After entering the relay state the display will default back to the Set Formats menu. The display will scroll the following: From this main menu, pushing the joystick to the right will select the sub menu and the digital display will scroll the following: Push the joystick down to access the next main menu, Set Formats. The display will scroll the following: This is the menu at which to adjust the second level alarm relay state on the Air Check O2 Monitor. To change this value, push the joystick right to display the relay state. The display will Indicate INVERT. Pushing the joystick down will change the relay state from INVERT to NORMAL. . Press ENTER to accept the value. After entering the relay state the display will default back to the Set Formats menu. The display will scroll the following: From this main menu, pushing the joystick to the right will select the sub menu and the digital display will scroll the following: ..Set Formats… 20.9% INVERT 20.9% NORMAL 20.9% ..Set Format … 20.9% ..Format Relay 1… 20.9% … Format Relay 2.. 20.9% ..Format Relay 1… 20.9% PureAire Monitoring Systems, Inc. 22 Push the joystick twice to select the fault relay to be adjusted. The display will scroll; Format Fault Relay. This is the menu at which to adjust the fault alarm relay state on the Air Check O2 Monitor. To change this value, push the joystick right to display the relay state. The display will Indicate INVERT. Pushing the joystick down will change the relay state from INVERT to NORMAL. . Press ENTER to accept the value. After entering the relay state the display will default back to the Set Formats menu. The display will scroll the following: 5.4.3 Set Alarm Threshold Polarity Alarm Threshold Polarity determines if an alarm concentration is set above or below a threshold value. For example, if an alarm of 19.0% for Oxygen is selected, the Alarm Threshold Polarity must be set to Invert for the monitors alarm to activate when the reading goes below 19.0%. For toxic and corrosive gases selecting a Normal setting for the Alarm Threshold Polarity means that the system will alarm when the gas concentration exceeds, goes above, an alarm set point. This menu will permit the selection of the alarm polarity. To access this menu from the “Set Formats” menu, push the joystick down to display the Set Alarm Threshold Polarity adjustment menu. This will scroll on the digital display. Push the joystick right to access the first sub menu; Set Alarm 1 Polarity will scroll on the display. This is the menu at which to adjust the first level alarm polarity state on the Air Check O2 Monitor. ..Set Formats... 20.9 ..Format Fault Relay... 20.9% INVERT 20.9% NORMAL 20.9% ..Set Alarm Threshold Priority.. 20.9% PureAire Monitoring Systems, Inc. 23 To change this value, push the joystick right to display the relay state. The display will Indicate INVERT. Pushing the joystick down will change the relay state from INVERT to NORMAL. Press ENTER to accept the value. After entering the relay state the display will default back to the Set Alarm 1 Polarity menu. The display will scroll the following: Push the joystick down to access the next sub menu; Set Alarm 2 Polarity will scroll on the display. This is the menu at which to adjust the second level alarm polarity state on the Air Check O2 Monitor. To change this value, push the joystick right to display the relay state. The display will Indicate INVERT. Pushing the joystick down will change the relay state from INVERT to NORMAL. Press ENTER to accept the value. After entering the relay state the display will default back to the Set Relay 2 Alarm Threshold menu. The display will scroll the following: INVERT 20.9% NORMAL 20.9% ..Set Alarm Polarity.. 20.9% ..Set Alarm 1 Polarity... 20.9% INVERT 20.9% NORMAL 20.9% ..Set Alarm 2 Polarity.. 20.9% ..Set Alarm 2 Polarity .. 20.9% PureAire Monitoring Systems, Inc. 24 Push the joystick down to access the next sub menu; Set Audio Alarm Polarity will scroll on the display. This is the menu at which to adjust the second level alarm polarity state on the Air Check O2 Monitor. è NOTE: The O2 system must have the audio alarm option module installed to access this menu. If this option is installed the display will indicate N/A, (not available) To change this value, push the joystick right to display the relay state. The display will Indicate INVERT. Pushing the joystick down will change the relay state from INVERT to NORMAL. Press ENTER to accept the value. After entering the relay state the display will default back to the Set Audio Alarm Polarity menu. The display will scroll the following: 5.4.4 Set Latching This is the menu at which to adjust the relay alarm state for the two gas alarm relays and the individual instrument fault relay. The selection permits setting the relays to a latching or non-latching state. In a latching state, the relay will remain activated until the user manually selects the Enter Key. In a non-latching state, the alarm relay will automatically reset once the gas concentration has returned to 20.9% for oxygen. è NOTE: The O2 system must have the relay module installed to access this menu. If no relay module is installed the display will indicate N/A, (not available) INVERT 20.9% NORMAL 20.9% ..Set Audio Alarm Polarity... 20.9% ..Set Audio Alarm Polarity... 20.9% .Set Latching… 20.9% PureAire Monitoring Systems, Inc. 25 This menu will permit the setting of the two alarm relays and the fault relay settings from a latching to a non latching state when they are activated. From this main menu, pushing the joystick to the right will select the sub menu and the digital display will scroll the following: This is the menu at which to adjust the first level alarm relay state on the Air Check O2 Monitor. To change this value, push the joystick right to display the relay state. The display will Indicate LATCH. Pushing the joystick down will change the relay state from LATCHING to NON-LATCHING. Press ENTER to accept the value. After entering the relay state the display will default back to the Set Latching menu. The display will scroll the following: From this main menu, pushing the joystick to the right will select the sub menu and the digital display will scroll the following: Push the joystick down to select the next relay to be adjusted. The display will scroll the following, Set Latching Relay 2. This is the menu at which to adjust the second level alarm relay state on the Air Check O2 Monitor. ..Set Latching Relay 1… 20.9% LATCHING 20.9% NONLATCH 20.9% ..Set Latching.… 20.9% ..Set Latching Relay 2… 20.9% ..Set Latching Relay 1… 20.9% PureAire Monitoring Systems, Inc. 26 To change this value, push the joystick right to display the relay state. The display will Indicate LATCHING. Pushing the joystick down will change the relay state from LATCHING to NONLATCH. Press ENTER to accept the value. After entering the relay state the display will default back to the Set Latching menu. The display will scroll the following: From this main menu, pushing the joystick to the right will select the sub menu and the digital display will scroll the following: Push the joystick twice to select the Audio Alarm relay to be adjusted. The display will scroll; Set Latching Audio Alarm. This is the menu at which to adjust the Audio alarm relay state on the Air Check O2 Monitor. è NOTE: The O2 system must have the audio alarm option module installed to access this menu. If this option is installed the display will indicate N/A, (not available) To change this value, push the joystick right to display the relay state. The display will Indicate LATCHING. Pushing the joystick down will change the relay state from LATCHING to NONLATCH. Press ENTER to accept the value. LATCHING 20.9% NONLATCH 20.9% ..Set Latching…. 20.9% ..Set Latching Audio Alarm… 20.9% ..Set Latching Relay 1… 20.9% PureAire Monitoring Systems, Inc. 27 After entering the fault relay state the display will default back to the Set Latching menu. The display will indicate the following: 5.4.5 Set Alarm Delay Push the joystick down to access the next main menu, Alarm Delay. The display will scroll the following: This is the amount of time an alarm level concentration of oxygen must be present before the instrument’s gas concentration alarm(s) will be activated. This menu will permit setting a user selected time delay for activating alarm relays 1 and 2. You can select from 0 seconds up to 255 seconds after an alarm level has been exceeded before the alarm relays to activate. To change this value, push the joystick right to display the time screen. The display will indicate a value between 0 and 255 seconds. Pushing the joystick up increases the value and pushing the joystick down decreases the value. Press ENTER to accept the value. After entering the alarm delay, the display will default back to the Alarm Delay menu and the display will scroll the following: èè NOTE: The alarm delay is only available for alarms 1 and 2. There is no delay for the fault relay. Any system fault will immediately activate the Fault Relay. ..Set Latching.… 20.9% LATCH 20.9% NONLATCH 20.9% …Alarm Delay… 20.9% 005 20.9% …Alarm Delay… 20.9% PureAire Monitoring Systems, Inc. 28 5.4.6 Set Zero Suppression This setting is used to decrease the sensitivity of selected gas sensors. It essentially programs the instrument to ignore gas measurements that are below the programmed % level (% full scale). èè EXAMPLE: If the measurement range of the instrument is 0 to 10 ppm, gas measurements below 0.5 ppm will be displayed and output as 0 (zero) when the suppress level is set at 5%. èè NOTE: This function is not available on the Air Check Oxygen monitor. To change this value, push the joystick right to display the Zero Suppression screen. The display will indicate a value between 0 and 100%. Pushing the joystick up increases the value and pushing the joystick down decreases the value. Press ENTER to accept the value. After entering the zero suppression value, the display will default back to the Zero Suppression menu and the display will scroll the following: 5.4.7 Set Alarm Thresholds This main menu will permit adjusting the oxygen concentration percentage that will activate alarm levels 1 and 2. If the Audio alarm output module is installed, it will also permit setting the level at which the audio alarm will activate. è NOTE: To activate the audio alarm, the AirCheck O2 monitor must have the audio alarm option. From this main menu, pushing the joystick to the right will select the first sub menu and the digital display will scroll the following: Set Relay 1 Alarm Threshold. 005 20.9% …Zero Suppression… 20.9% …Zero Suppression… 20.9% ..Set Alarm Thresholds.. 20.9% PureAire Monitoring Systems, Inc. 29 This is the gas concentration at which the instrument’s first level alarm will be activated. To change the displayed value, push the joystick to the right to display the first level alarm setting. The display will indicate a value between 00.0% and 25.5%. (A value of 195 = 19.5% oxygen). Pushing the joystick up increases the value and pushing the joystick down decreases the value. Press ENTER to accept the value. After entering the relay state the display will default back to the Set Relay 1 Alarm Threshold Menu. The display will scroll the following: Push the joystick down to access the next sub menu; Set Relay 2 Alarm Threshold, will scroll on the digital display. This is the gas concentration at which the instrument’s second level alarm will be activated. To change the displayed value, push the joystick to the right to display the second level alarm setting. The display will indicate a value between 00.0% and 25.5%. (A value of 180= 18.0% oxygen). Pushing the joystick up increases the value and pushing the joystick down decreases the value. Press ENTER to accept the value. After entering the relay state the display will default back to the Set Relay 2 Alarm Threshold Menu. The display will scroll the following: ..Set Relay 1 Alarm Threshold… 20.9% 195 20.9% ..Set Relay 2 Alarm Threshold… 20.9% 180 20.9% ..Set Relay 1 Alarm Threshold… 20.9% ..Set Relay 2 Alarm Threshold… 20.9% PureAire Monitoring Systems, Inc. 30 Push the joystick down to access the next sub menu; Set Audio Alarm Threshold, will scroll on the digital display. This is the gas concentration at which the instrument’s audio alarm will be activated. To change the displayed value, push the joystick to the right to display the second level alarm setting. The display will indicate a value between 00.0% and 25.5%. (A value of 195= 19.5% oxygen). Pushing the joystick up increases the value and pushing the joystick down decreases the value. Press ENTER to accept the value. è NOTE: The O2 system must have the audio alarm option module installed to access this menu. If this option is installed the display will indicate N/A, (not available) èè NOTE: The audio can be set into only one alarm level. You can choose between alarm level 1 or alarm level 2 or set a completely different setting. After entering the relay state the display will default back to the Set Audio Threshold. Menu. The display will scroll the following: 5.4.8 Set Alarm Hysterisis PureAire’s oxygen monitor may be used as a control system. When used to regulate oxygen levels the need of a dead band, “hysterisis” may be required. This menu will permit the setting of the alarm hysterisis to a desired concentration of Oxygen. When using hyserisis, the alarm set point now becomes an average alarm setting for an action to occur. When adding the hysterisis value to the alarm set point, this then defines the alarm and dead band for an action to occur. For example, if you require a valve to close at 14.9% oxygen level and to reopen again at 15.5% oxygen level, you would set the Alarm Threshold at 15.2% and set the hystersis value at 0.3%. Average Alarm set point = 15.2% - Hysterisis 0.3% = 14.9%, Valve Off Average Alarm set point = 15.2% + Hysterisis 0.3% = 15.5%, Valve On ..Set Audio Alarm Threshold… 20.9% 145 20.9% ..Set Audio Alarm Threshold… 20.9% PureAire Monitoring Systems, Inc. 31 NOTE: If you wish to calculate the upper and lower set point, you can use the following formula to calculate the hysterisis: Upper Limit – Lower Limit = Alarm Hysterisis Value 2 20.9% - 20.5% = 0.2% 2 Alarm Hysterisis + Lower Limit = Alarm Set Point 0.2% + 20.5% = 20.7% To access this menu push the joystick down to display the Set Alarm Hysterisis menu. This will scroll on the digital display. Push the joystick right to access the Set Alarm 1 Hyserisis. Pushing the joystick again to the right will display a value 0.0%, (factory default). Pushing the joystick up increases the percentage up to a maximum value of 2.5%. Adjust the digital display until the desired hysterisis value is selected. Press ENTER to accept this value. The digital display will revert back to Set Alarm 1 Hysterisis. Push the joystick down to access the next sub menu; Set Alarm 2 Hysterisis will scroll on the digital display. Pushing the joystick again to the right will display a value 0.0%. Pushing the joystick up increases the percentage up to a maximum value of 2.5%. Adjust the digital display until the desired hysterisis value is selected. Press ENTER to accept this value. The digital display will revert back to Set Alarm 2 Hysterisis. ..Set Alarm Hysterisis… 20.9% 0.3% 20.9% ..Set Alarm 1 Hysterisis… 20.9% ..Set Alarm 2 Hysterisis… 20.9% ..Set Alarm 2 Hysterisis… 20.9% PureAire Monitoring Systems, Inc. 32 Push the joystick down to access the next sub menu; Set Alarm Audio Hysterisis will scroll on the digital display. Pushing the joystick again to the right will display a value 0.0%. Pushing the joystick up increases the percentage up to a maximum value of 2.5%. Adjust the digital display until the desired hysterisis value is selected. 5.4.9 Set Sensor Adjust This menu will permit fine-tuning of the oxygen readout to a known concentration of Oxygen. It is recommended to adjust the oxygen display to ambient oxygen levels of 20.9%. To access this menu push the joystick down to display the Sensor Adjustment menu. This will scroll on the digital display. è NOTE: It is recommended to warm up the Air Check Oxygen monitor For two hours before making any adjustments to the sensor. Push the joystick right to access the first sub menu; Set Sensor Span will scroll on the display. This is the menu that will permit fine adjustment of the ambient oxygen reading to 20.9%. Push the joystick right to access the sensor span. The display will indicate a value between 0 and 255 counts. Pushing the joystick up increases the counts and decreases the percent oxygen value displayed on the Air Check. Pushing the joystick down decreases the counts and increases the oxygen value displayed on the Air Check. As the counts increase and decrease the percent oxygen displayed will also increase and decrease. Adjust the digital display until 20.9% + / - 0.1% is displayed. The actual oxygen reading will fluctuate from 20.8% to 21.0%. ..Sensor Adjustment… 20.9% ..Set Sensor Span.. 20.9% 093 20.9% ..Set Audio Alarm Hysterisis… 20.9% PureAire Monitoring Systems, Inc. 33 Press ENTER to accept this value. The digital display will revert back to Set Sensor Span. Push the joystick down to access the next sub menu; Set Sensor Zero will scroll on the digital display. èè NOTE: The Set Sensor Zero function is not available on the Air Check O2 monitor. It was designed for toxic and corrosive gases. When selected, the display will indicate N/A, (not available) Press the joystick to the left to revert back to the Set Sensor Zero menu. 5.4.10 Main Operation Mode To select the main menu from any sub menu, push the joystick left until the Main Menu appears. The digital display will indicate the following: ..Set Sensor Span.. 20.9% ..Set Sensor Zero.. 20.9% ..Set Sensor Zero.. 20.9% Oxygen 20.9% PureAire Monitoring Systems, Inc. 34 6: Maintenance & Sensor Verification Only qualified personnel should perform maintenance and sensor verification 6.1 Sensor Verification The earth is a wonderful source of calibrated oxygen at 20.9%, therefore under ambient conditions; verification of the Air Check üü Lite O2 monitor to 20.9% oxygen is constantly being performed. There are no zero and span pots to adjust. The O2 monitor only requires periodic testing with nitrogen to verify the cells response to 0% oxygen. 6.1.1 Sensor Verification Gas For testing the Air Check üü Lite O2 monitor, PureAire recommends the use of nitrogen. This can be purchased from your gas supplier or from PureAire Monitoring Systems. Nitrogen test gas cylinders and regulators are available by separate order. 6.1.2 Sensor Verification Equipment The following equipment is available from PureAire to facilitate gas calibration: Part Number Description Quantity 8880110 Nitrogen 105 liter cylinder 1 8880001 Regulator, 500 cc per minute flow 1 èè NOTE: If the instrument is connected to a controller, set the controller to the standby mode to avoid accidental alarms. PureAire Monitoring Systems, Inc. 35 6.2 Sensor Verification Procedure èè CAUTION: Be sure to observe all safety guidelines when generating and using nitrogen. Under ambient non-oxygen deficient environments, Air Check üü O2 monitor will indicate a display reading of 20.9%. As the sensor ages, the reading may decrease in value. The following procedure should be used to adjust the reading to 20.9%. 1) Insure that the Air Check üü O2 monitor is in a clean non-oxygen deficient environment. 2) Enter the password. Refer to Section 5.3 3) Select the Sensor Adjust menu. This menu will permit fine-tuning of the oxygen readout to a known concentration of Oxygen. It is recommended to adjust the oxygen display to ambient oxygen levels of 20.9%. To access this menu push the joystick down to display the Sensor Adjustment menu. This will scroll on the digital display. è NOTE: It is recommended to warm up the Air Check Oxygen monitor for two hours before making any adjustments to the sensor. Push the joystick right to access the first sub menu; Set Sensor Span will scroll on the display. This is the menu that will permit fine adjustment of the ambient oxygen reading to 20.9%. Push the joystick right to access the first sub menu; Set Sensor Span will scroll on the display. This is the menu that will permit fine adjustment of the ambient oxygen reading to 20.9%. Push the joystick right to access the sensor span. The display will indicate a value between 0 and 255 counts. Pushing the joystick up increases the counts and decreases the percent oxygen value displayed on the Air Check. Pushing the joystick down decreases the counts and increases the oxygen value displayed on the Air Check. As the counts increase and decrease the percent oxygen displayed will also increase and decrease. Adjust the digital display until 20.9% + / - 0.1% is displayed. The actual oxygen reading will fluctuate from 20.8% to 21.0%. ..Sensor Adjustment… 20.9% ..Set Sensor Span.. 20.9% PureAire Monitoring Systems, Inc. 36 Press ENTER to accept this value. The digital display will revert back to Set Sensor Span. Push the joystick down to access the next sub menu; Set Sensor Zero will scroll on the digital display. èè NOTE: The Set Sensor Zero function is not available on the Air Check O2 monitor. It was designed for toxic and corrosive gases. When selected, the display will indicate N/A, (not available) Press the joystick to the left to revert back to the Set Sensor Zero menu. 6.2.1 Sensor Verification to Nitrogen PureAire recommends challenging the O2 monitor with nitrogen every 6 to 12 months. The sensor inlet has a ¼” compression tube fitting designed for connecting the dust filter. You can connect ¼” OD sample tubing from a Nitrogen cylinder directly to the dust filter. Expose the O2 cell directly to the nitrogen cylinder at a flow rate of 500 cc/min. The reading will drop off to 1% or below in less than one minute when the O2 sensor is exposed to pure N2. The system will recover to 20.9% when the nitrogen is removed. èè NOTE: Please open the valve on the span gas cylinder before connecting the tubing to the Oxygen monitor to prevent seeing a flow fault. The O2 monitor will display a flow fault when flow is completely blocked for approximately 5 seconds. èè NOTE: To see a true zero oxygen level, the entire Air Check ü O2 monitor needs be completely immersed into a zero oxygen environment. 093 20.9% ..Set Sensor Span.. 20.9% ..Set Sensor Zero.. 20.9% ..Set Sensor Zero.. 20.9% PureAire Monitoring Systems, Inc. 37 6.2.2 Sensor Verification to a known concentration of Oxygen When testing the O2 monitor to a known concentration of oxygen, the sensor inlet has a ¼” compression tube fitting designed for connecting the dust filter. You can connect ¼” OD sample tubing from a Nitrogen cylinder directly to the dust filter. Expose the O2 cell directly from the nitrogen cylinder at a flow rate of 500 cc/min. The reading will drop off to the span gas concentration in less than 1 minute. The final reading should be within ± 0.3% of the span gas concentration. To see the exact span gas concentration the entire Air Check ü O2 monitor needs be completely immersed into a the span gas environment. èè NOTE: Please open the valve on the span gas cylinder before connecting the tubing to the Oxygen monitor to prevent seeing a flow fault. The O2 monitor will display a flow fault when flow is completely blocked for approximately 5 seconds. èè NOTE: To see a true reading the entire Air Check ü O2 monitor needs be completely immersed into a zero oxygen environment. O2 EX monitor connected to gas cylinder PureAire Monitoring Systems, Inc. 38 7.0 Appendix Remote Display for Oxygen monitor (part number DPM942-R) This optional Remote display is designed to send remote oxygen concentration information from any of PureAire’s’ oxygen monitors. All PureAire O2 monitors have a built in 4-20mA output and the remote display easily connects to the monitor’s input power and mA output connection. An 18 AWG, two conductor, stranded control and instrumentation cable, Belden 8461 or equivalent is recommended for the connection. The maximum permissible cable length is 250 feet. You can connect up to two remote displays to one Air Check Oxygen monitor. èè NOTE: When connecting two remote displays, they must be connected to the Oxygen monitor in series. Max distance 250 feet DPM942-R PureAire Monitoring Systems, Inc. 39 + + - - - -T1000-P5P-ND Power supply 115 VAC / 24 VDC 1 amp Regulated power supply Common NC NO Common + 24 VDC Oxygen Main Power Board Fault Alarm Alarm 1 Oxygen Alarm 2 Relay Board Federal Signal Horn & Strobe LP7-18-30R * This drawing shows how to connect a remote Horn and strobe to PureAire’s Oxygen monitor with the Alarm 1 relay set to a Normally Open position. * Note: Federal Signal Horn/Strobe or equivalent