User Manual. PolyGard NO 2 AT Electrochemical analog nitrogen dioxide transmitter serial no. EC-C 003. July 31, 2004

Transcription

1 PolyGard NO 2 AT-30 Electrochemical analog nitrogen dioxide transmitter serial no. EC-C 003 User Manual July 3, 2004

2 User Manual - PolyGard NO 2 AT-30 Page 2 Electrochemical analog nitrogen dioxide transmitters General Overview Description Installation Assembly information Enclosure Electrical Connection Instructions Wiring connection Mounting optional relay package AT-2R Start-up operation Calibration Control span voltage calculation Commissioning optional relay package AT-2R Selection of open-circuit or closed-circuit operation Select switching differential Adjust switching voltage Calculation of the switching voltage (U threshold ) Inspection and Service Inspection Calibration Replacing of the sensor element Troubleshooting Diagnostics of the transmitter Diagnostics of optional relay package AT-2R... 8 Cross-sensitivy Data Specifications Wiring Configuration and Enclosure Dimensions... 5 Notes and General Information Intended product application Installers` responsibilities Maintenance Limited Warranty Return instructions... 8

3 User Manual - PolyGard NO 2 AT-30 Page 3 Electrochemical analog nitrogen dioxide transmitters General Overview The PolyGard NO 2 analog gas transmitter is used for detection of nitrogen dioxide in the ambient air to warn of the presence of Nitrogen Dioxide gas. 2 Description The sensor portion of the PolyGard AT-30 analog gas transmitter is a micro-fuel cell, which is completely sealed. The measurement is a gas-in-liquid chemical reaction rather than a surface area measurement. With no surface area to coat, this sensor retains its sensitivity to nitrogen dioxide even after a prolonged exposure to clean air. The cell consists of a diffusion barrier, O-ring seal, electrolyte reservoir and three electrodes; sensing, counter and reference. The target gas, nitrogen dioxide, enters the cell through a diffussion barrier. The chemical process of the measurement is one of oxidation where one molecule of the target gas is exchanged for one molecule of oxygen. The reaction drives the oxygen molecule to the counter electrode, generating a DC microampere signal between the sensing and counter electrodes. This signal is linear to the volume concentration of the sensed gas rather than the partial pressure. The integrated two-wire transformer converts this DC microampere signal in standard 4-20 ma signal. In some cases, biasing is required to maintain a voltage differential between the reference and sensing electrode in order to facilitate the necessary reaction in the cell. The transmitter electronics will provide the necessary bias voltage when configured for one of these sensor types. Most sensors produce a small amount of baseline current in clean air. This is adjusted out with the zero potentiometer on the transmitter. This oxidation at the electrodes causes wear of the sensor. Typical life for this sensor is approximately two years in normal operation. This will vary somewhat from sensor to sensor, with some working lifetimes less than two years and same greater then 2 years. This wear also changes the characteristics of the sensor, requiring periodic re-calibration. It is recommended that the sensor accuracy be verified every six months and recalibrated as necessary. Caution! Replacement sensor elements, which are not bias types, are shipped with a thiny spring of wire shorting the sensor and reference electrodes. This spring MUST BE REMOVED prior to installing the element into the sensor assembly.

4 User Manual - PolyGard NO 2 AT-30 Page 4 Optional relay package AT-2R: The PolyGard AT-2R relay package is used in conjunction with the AT-30 NO 2 analog gas transmitter. The AT-2R provides the transmitters with two relay outputs with adjustable trip/setpoints, switching differential. Once plugged on the master PCB transmitter the relay outputs will change and notify if gas concentration exceeds the adjusted trip/setpoint. If the gas concentration falls below the adjusted trip/setpoint and switching differential the relays again will change state and fall back into their starting position. The relay will trigger depending on its adjusted power mode. If de-energized it will trigger on. If energized it will trigger off (fail-safe mode) with increasing value. LED number 9 for relay R9 and LED number 0 for relay R0 indicate status of each relay.

5 User Manual - PolyGard NO 2 AT-30 Page 5 3 Installation Note: Avoid any force (e.g. by thumb) during operation or installation on the sensor element. This could destroy the element. Electronics can be destroyed through static electricity. Therefore, do not work on the equipment without a wrist strap connected to earth ground or standing on conductive floor. 3. Assembly information The specific weight of nitrogen dioxide is is heavier than that of air (factor.59). Location of the sensor must conform to the layout of the area being monitored. Disregard the ventilation ratio! Do not mount sensor in the center of the airflow. In larger rooms, it might be necessary to install two or more transmitters where there is adequate air movement. Do not mount in corners or directly in front of air inlets (e.g. doors, windows, open ramps, dampers, etc.). In areas with undefined air movement, it might be necessary to distribute several transmitters in a vertical and horizontal direction over the whole area to be monitored. Avoid locations where water, oil etc. may influence proper operation and where mechanical damage might be possible. Mounting height is one feet above floor. Provide adequate space around sensor for maintenance and calibration work. Duct model mounting: Mount only in a straight section of duct with minimum air vortex. Keep a minimum distance of 3.5 feet (m) from any curve or abstacle. Mount only in a duct system with a maximum air velocity of 2000 ft/min (0 m/s) or lees. Mounting must be made so that the airflow is in line with probe openings. (see Fig. 6, page 6). 3.2 Enclosure Un-screw cover of enclosure. Carefully unplug the basic PCB mounted on fixed terminal blocks. Screw the base vertically on wall or on single gang electrical box. (see Fig. 5, page 6). For duct model mounting: Cut a hole in the duct and install the probe in the hole. (see Fig. 7, page 6). Screw the housing to the duct using the mounting holes inside enclosure. Plug in the basic PCB and replace the cover after wiring connection is completed (see 4.2 wiring connection).

6 User Manual - PolyGard NO 2 AT-30 Page 6 4 Electrical Connection 4. Instructions Note: Electrostatic discharge (ESD) may damage electronic components. During wiring, open the cover only when completely grounded via grounding strap or standing on conductive floor. Connections should be made without any power applied to conductors. Installation of the electrical wiring should be according to the connection diagram and only performed by a trained specialist. Avoid any influence from external interference by using a shielded cable. Recommended cable: 8 AWG shielded, maximum resistance 20.8 /000 ft (73 /000 m) Cable for Relay Package AT-2R: Does not need to be shielded. Cable insulation: Since the PCB mounts on top of the wiring terminations, it is important to ensure that the wire shields or any bare wires do not short the PCB. Terminal strip X4: Connector 3 Connector 4 Connector 5 Connector 2 Terminal strip X5: Connector -3 Connector 4-5 Power supply (+) 24 VDC, 7 28 VDC Signal 4 20 ma Shield 0 VDC (DC common, only needed with option relay package AT-2R) (functions only with option relay package AT-2R). Potential free relay contact (R9) Potential free relay contact (R0) 4.2 Wiring connection Unscrew cover of enclosure. Unplug basic PCB from terminal blocks. For single gang electrical box mounting: Pull through cable via hole in base; connect cable leads on terminal block X4. Snap the ferrite core on the cable into the enclosure. (see Fig., page 5). For surface mounting (cable entry always from the top) and also for duct mounting: Remove cover to access cable. Connect cable leads on terminal block X4. Snap the ferrite core on the cable into the enclosure. (see Fig., page 5). Plug the PCB on fixed terminal blocks on base. Screw cover on base. Option Relay package AT-2R: Connect cable leads on terminal X5. Snap the ferrite core also on the cable into the enclosure. (see Fig., page 5). (This ferrite core is delivered with the relay package). Note: (Ferrite core installation) Prior to terminating the wire, secure enough cable length within the enclosure to snap-on the supplied ferrite core. The ferrite core must be within the enclosure and located such that the PCB can be installed.

7 User Manual - PolyGard NO 2 AT-30 Page Mounting optional relay package AT-2R Static Electricity (see section 4.). Unplug basic PCB from the terminal blocks fixed on base. Plug Relay Package female header X2 on the basic PCB. (see Fig. 3, page 5). Secure on back of PCB the washer and nut. Plug basic PCB into terminal blocks on base. 5 Start-up operation Only trained technicians should perform the following: Check mounting location. Check airflow direction for duct mounting. Check power voltage. Check PCB EC-C for proper mounting at X4 and X5. Check for correct sensor element (7 NDH) at terminal X3 PCB EC-C. Optional relay package AT-2R: Check proper mounting of relay package AT-2R at board EC-C. Select the desired hysteresis and relay function. Adjust threshold value if not ordered from the factory with setpoint calibrated. Verify transmitter operation (sensor/transmitter was factory calibrated). Note: If calibration is necessary, the sensor element must be powered and be fully stabilized for at least hour. Required instruments to calibrate the transmitter: Test gas bottle with synthetic air. Test gas bottle with 5 ppm NO 2. Gas pressure regulator with flow meter to control the gas flow to ml/min. Sensor head calibration adapter with tubing. Digital voltmeter with range 0 2 VDC, accuracy % and a small screwdriver. Note: Please observe proper handling procvedures for test gas bottles! 5. Calibration Zero adjustment Zero-point calibration (4 ma): (After sensor warm-up) Connect digital voltmeter to test pins - and + (with a range selected that will display 2 VDC max.). Connect the calibration adapter to sensor element. Apply sensor element zero calibration gas, ( ml/min; 4.5 psi ± 0 %), or other clean air source. Wait two minutes until the signal is stable, adjust signal with zero potentiometer Zero until the signal is 200 mv ± 2 mv and stable. Remove calibration adapter carefully by turning lightly.

8 User Manual - PolyGard NO 2 AT-30 Page 8 Span adjustment Note: NO 2 calibration gas is toxic, never inhale the gas! Symptoms: Dizziness, headache and nausea. Procedure if exposed: Bring into fresh air at once, consult doctor. (After sensor warm-up) Connect calibration adapter on the sensor element. Apply sensor element span calibration gas (5 ppm NO 2 ), ( ml/min; 4.5 psi ± 0%). Wait two minutes until the signal is stable, adjust signal with span potentiometer Span until the signal reads the appropriate mvdc( ± 3 mv, see calculation for control voltage 5.2) and is stable. Remove calibration adapter with a careful light turn. Inspect the seating of the sensor element! 5.2 Control span voltage calculation 800 (mv) x test gas concentration (ppm) (mv) Measuring range NO 2 (ppm) Example Measuring range NO 2 concentration Test gas concentration Control voltage 0 ppm 5 ppm 600 mv 800 (mv) x 5 (ppm) (mv) = 600 mv 0 (ppm) 5.3 Commissioning optional relay package AT-2R 5.3. Selection of open-circuit or closed-circuit operation Each relay can be configured for normally de-energized operation or normally energized operation (faile-safe) via jumper. Operation Relay R9 Jumper pos. Relay R0 Jumper pos. Normally de-energized operation 9 to 8 to 20 Normally energized operation 0 to 2 9 to 2 Factory setting is for closed circuit operation Select switching differential Switch threshold calculation format: U out = U threshold - U differential (see section for U threshold calculations) Two different values of switching differential can be selected via jumper per relay. The jumpers need to be plugged into the correct position to select either 5% or 0% of the transmitters full range as switching differential. (see table for jumper positions).

9 User Manual - PolyGard NO 2 AT-30 Page 9 Threshold calculation Voltage (V) Switch differential (%) Relay R9 Jumper pos. Relay R0 Jumper pos * 3 * Note: At a voltage below.50 V it is not allowed to have a switching differential of 0%. The triggered alarm trip/setpoint would not allow the relay to return to its starting position. * Factory set Adjust switching voltage Required instruments: Digital multimeter with 0 0 VDC range, % accuracy. Small screwdriver. Switching voltage can range from V 9 V, 0 % - 90 % NO 2 concentration by adjustment. Adjust switching voltage for relay R 9 Connect digital mulltimeter at X9 + and -. Adjust potentiometer P9, calculate the switching voltage ± 0 mv. (see section 5.3.4). Adjust switching voltage for relay R 0 Connect digital multimeter at X0 + and X9-. Adjust potentiometer P0, calculate the switching voltage ± 0 mv. (see section 5.3.4) Calculation of the switching voltage (U threshold ) U threshold = 8 (V) x Alarm threshold (ppm) + 2 (V) Measuring range NO 2 (ppm) Example Measuring range NO 2 0 ppm NO 2 Alarm threshold 5 ppm NO 2 U threshold + 6 V 8 (V) x 5 (ppm) + 2 (V) = 6 V 0 (ppm)

10 User Manual - PolyGard NO 2 AT-30 Page 0 6 Inspection and Service 6. Inspection Inspection and service of the transmitters should be done by a trained technician and executed on a periodic interval. It is recommended that the sensor operation be verified at least every six months. 6.2 Calibration (See part 5. and 5.2) Service at periodic intervals is to be decided by the person responsible for the gas detection system. If span calibration voltage of 600 mv (see note below) is no longer attainable when applying 5 ppm Nitrogen Dioxid in air, then the sensor element has to be replaced. After the sensor element has been replaced a calibration is required. Note: If using a different level of span test gas ppm, or different sensor range, then the mv needs to be calculated. 6.3 Replacing of the sensor element Static electricity ( see section 4.). Sensor should always be installed without voltage applied: Unplug basic PCB EC-C carefully from the terminal blocks on the base. Unplug old sensor element out from the PCB EC-C. Take new sensor element out of original packing and remove the shorting wire on the sensor element contacts. Plug sensor element into the PCB EC-C. Plug the PCB EC-C in terminal block X4, X5 carefully. After sensor warm-up, turn potentiometer Span to its center position. (Turn the pot 25 rotations counter-clockwise, then rotations clockwise to get centered.) Calibrate (see section 5.).

11 User Manual - PolyGard NO 2 AT-30 Page 7 Troubleshooting 7. Diagnostics of the transmitter Trouble Reason Solution Output signal 0 ma and control voltage 0 V Output signal less then 4 ma Control current signal not correct Power not applied Basic PCB EC-C X4 and X5 not plugged in correctly. Sensor element not calibrated Sensor span not attainable Measure power voltage terminal block X4 terminal 3 (+) and 4 (7 28 VDC) Plug in the basic PCB EC-C into X4 and X5 correctly. Calibrate sensor element output Replace sensor element 7.2 Diagnostics of optional relay package AT-2R Trouble Reason Solution No relay switching No or incorrect relay switching No relay switching at calculated threshold setting Relay return differential too long Board AT-2R not installed correctly Jumper JP 9 2 and 8-2 not installed correctly Switching voltage not adjusted correctly Differential jumper not correct Plug AT-2R correctly into board See section 5.3. for correct setting Check switching voltage (see section 5.3.4) Check jumper position (see section 5.3.2)

12 User Manual - PolyGard NO 2 AT-30 Page 2 8 Cross-sensitivity Data The table shows the typical response to be expected from the sensor when exposed to the following gases. Gas Chemical mark Gas concentration Tolerance ppm NO 2 Chlorine CL 2 ppm ~ ppm Ethylene C 2 H 4 00 ppm 0 ppm Hydrogen H 2 00 ppm 0 ppm Hydrogen chloride HCI 5 ppm 0 ppm Hydrogen cyanide HCN 0 ppm 0 ppm Hydrogen sulphide H 2 S 5 ppm -.5 ppm Nitric oxide NO 35 ppm 0 ppm Carbon monoxid CO 300 ppm 0 ppm Sulphur dioxide SO 2 5 ppm ppm

13 User Manual - PolyGard NO 2 AT-30 Page 3 9 Specifications Electrical Power supply: 7-28 VDC (polarity protected) Power consumption: 22 ma, (0.6 VA), max. - w/relay package 35 ma, (.0 VA), max. RFI/EMI protection 5.0 ft. (0.3 m) radiated Sensor Performance Gas detected Nitrogen dioxide NO 2 Sensor element Electrochemical, diffusion Range 0 0 ppm factory set 0 0 to 0-20 ppm, adjustable via calibration Stability & resolution ± 0. ppm of reading Repeatability 2 % of reading Long term output drift 2 % signal loss/month Response time t sec. Sensor life expectancy 2 year, normal operating environment Sensor coverage 4,000 sq.ft. (372 m 2 ), to 6,000 sq.ft. (558 m 2 ) under ideal conditions Mounting height ft. (0.3 m) above floor Type of Control Analog output signal Option Proportional, 4 20 ma, load 450 (2) relay contacts, potential free, max. 30 VAC/DC 0.5 A Operating Environment Working temperature 4 F to 04 F (-0 C to + 40 C) Storage temperature -4 F to 04 F (-20 C to + 40 C) Humidity 5 to 95 % RH non-condensing Pressure range Atmospheric ± 0% Physical characteristics Enclosure material Galvanized steel w/zinc coating, corrosion resistant Enclosure color Light gray Wall mounting NEMA (IP 42) Installation Wall (surface) mounted or single gang electrical box Dimensions (HxWxD) 5.59 x 5.59 x 2.48 in. (42 x 42 x 63 mm) Cable entry hole for ½ in. conduit for wall (surface) mounting, and hole on back side of base plate for single gang electrical box mounting Wire connection Terminal blocks, screw type for lead wire Wire size Min. 24 AWG (0.25 mm 2 ) max. 4 AWG (2.5 mm 2 ) Wire distance Max. loop resist. 450 (= wire resist. + controller input resist.) Weight 0.7 Ibs. (0.3 kg) Approvals/Listings Warranty City of Los Angeles CE VDI 2053 EMV-compliance 89/336/EWG Two years material and workmanship

14 User Manual - PolyGard NO 2 AT-30 Page 4 Options Enclosures Duct mounted NEMA 3 (IP 44) - w/probe 7/8 in. (22 mm) diameter and 7.6 in. (82 mm) length - cable entry hole for ½ in. conduit Wall mounted NEMA 4X w/splash guard (IP 65) - material ABS UL94V0 - color Light gray - Dimensions (HxWxD) 4.80 x 4.72 x 3.42 in (22 x 20 x 87 mm) Relay Package Type Contact rating Setpoint Switching differential Relay mode Status indicator Heater, built-in Power supply Power consumption For ambient temperature Thermostatic control () SPDT (R9), () SPST (R0) 30 VAC/DC, 0.5 A, max. Adjustable setting for each relay within 0-90 % of full range Jumper selectable, 5% or 0% of full range Jumper select., de-energized or energized (fail-safe) for each relay (2) LED s, one for each relay 24 VAC ± 5%, 50/60 Hz.0 A (24 VA), max. -40 F (-40 C) 32 F (0 C) ± 5 F (3 C)

15 User Manual - PolyGard NO 2 AT-30 Page 5 0 Wiring Configuration and Enclosure Dimensions Wiring Configuration Fig. Power supply 7-28V/DC -0V/DC 3-wire configuration with -Optional relay package mA shield Controller Snap ferrite core X Transmitter AT-00 0V DC 24V DC 4-20mA Shield Shield Shield R0 R9 X X 2 Snap ferrite core Optional heater 24V AC/DC A 0V Shield: Connect Shield to either terminal 5, 6 or 7. Shield should be grounded at either the sensor or controller. DO NOT ground Shield at both ends. For stand-alone relay operation (w/o controller) place resistor between terminals 2 (common) and 4 (signal). Printed circuit board EC-C Option relay package AT 2R Fig. 2 Fig. 3 Position Jumper No. X2 X4 C S X3 Sensor X6 R + - JP7 EC-C X5 VR3 Span Position Jumper No. Position Jumper No. VR2 Zero Platin3

16 - User Manual - PolyGard NO 2 AT-30 Page 6 Assembly Dimensions Fig. 4 Fig in. (42 mm) 2.75 in. (70 mm) PCB EC-C 2R-AT X0 P0 X9 P9 X6 + option AT-2R X X2 K9 K0 K0 K9 gas outlet (closed with duct enclosure) D=0.6 in. (4 mm) D=0.88 in. (22,5 mm) Cable entry in. (2 mm) 2.48 in. (63 mm) 3.3 in. (84 mm) Hole for mounting 5.59 in. (42 mm) X4 S C X3 R Sensor JP7 EC-C VR3 VR2 X5 Span Zero X4 5 X5 d=0.6 in. (4 mm) Platin3 gehaem0 Gehaem2 gas inlet (closed with duct enclosure) Duct mounting enclosure Cutout for duct model Fig. 6 Fig. 7 D=0.6 in. (4 mm) D=0.88 in. (22.5 mm) 2.48 in. (63 mm) 0.83 in. (2 mm) 7.6 in. (82 mm) Gehäuse gehaem20 D=0.6 in. (4 mm)

17 User Manual - PolyGard NO 2 AT-30 Page 7 Splash guard enclosure Fig in. (22 mm) 4.33 in. (0 mm) 0.63 in. (6 mm) 4.72 in. (20 mm) 3.54 in. (90 mm) X4 X6 S C X3 R Sensor + - X2 JP7 EC-C X5 VR3 Span VR2 Zero Platin in. (6 mm) atsplash Splash guard enclosure Fig in. (85 mm) atsplash

18 User Manual - PolyGard NO 2 AT-30 Page 8 Notes and General Information It is important to read this user manual thoroughly and clearly understand the information and instructions. The PolyGard transmitters must be used within product specification capabilities. The appropriate operating and maintenance instructions and recommendations must be followed. Due to ongoing product development, MSR reserves the right to change specifications without notice. The information contained herein is based upon data considered to be accurate. However, no guarantee is expressed or implied regarding the accuracy of this data.. Intended product application The PolyGard NO 2 AT-30 transmitters are designed and manufactured for control applications for energy savings and OSHA air quality compliance in commercial buildings and manufacturing plants (i.e.,detection and automatic exhaust fan control for automotive maintenance facilities, enclosed parking garages, engine repair shops, warehouses with forklifts, fire stations, tunnels, etc.)..2 Installers` responsibilities It is the installer`s responsibility to ensure that all PolyGard transmitters are installed in compliance with all national and local codes and OSHA requirements. Installation should be implemented only by individuals familiar with proper installation techniques and with codes, standards and proper safety procedures for control installations and the latest edition of the National Electrical Code (ANSI/NFPA70). It is also essential to strictly follow all instructions as provided in the user manual..3 Maintenance It is recommended that the PolyGard transmitter performance check is done on a routine schedule. Any performance deviations may be serviced based on needed requirements. Re-calibration and part replacement may be implemented in the field by a qualified individual and with the appropriate tools. Alternatively, the easily removable plug-in transmitter card with the sensor may be returned for service to INTEC Controls..4 Limited Warranty MSR and INTEC Controls warrant the PolyGard transmitters for a period of two (2) years from the date of shipment against defects in material or workmanship. Should any evidence of defects in material or workmanship occur during the warranty period, MSR or INTEC Controls will repair or replace the product at their own discretion, without charge. This warranty does not apply to units that have been altered, had repair attempted, or been subjected to abuse, accidental or otherwise. The warranty also does not apply to units in which the sensor element has been overexposed or gas poisoned. The above warranty is in lieu of all other express warranties, obligations or liabilities. This warranty extends only to the PolyGard transmitter. MSR and INTEC Controls shall not be liable for any incidental or consequential damages arising out of or related to the use of the PolyGard transmitters..5 Return instructions If the PolyGard transmitter needs to be returned to INTEC Controls for service, an RMA number must be obtained prior to sending.