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PEMTECH PT495 Series Operator's Manual

Stand alone addressable gas detector
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Gas Detection Technology
PT495 Series
(Ultra1000 )
Stand Alone Addressable
Gas Detector
Toxic, Oxygen Deficiency, & Combustible (HC)
Revision 5.11
October 2020
Operator's
Manual
Pem-Tech, Inc.
Houston, Texas
U.S.A
www.pem-tech.com

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  • Page 1 Gas Detection Technology PT495 Series (Ultra1000 ) Stand Alone Addressable Gas Detector Toxic, Oxygen Deficiency, & Combustible (HC) Revision 5.11 October 2020 Operator’s Manual Pem-Tech, Inc. Houston, Texas U.S.A www.pem-tech.com...

  • Page 2: Table Of Contents

    Set Detector Address Set Alarm Levels Alarm Conditions Low Alarm, High Alarm & Fault Resetting Alarms Modbus RTU Communication Communication Parameters MAINTENANCE Routine maintenance Sensor Inspection, sensitivity and replacement Spare Parts Sub assemblies and calibration accessories PT495 Series Detector Rev 5.11 (Ultra1000)

  • Page 3: Notice And Limited Warranty

    • If needed the enclosure threads may be coated with silicone free grease. Silicone based lubricants must never be used. • Follow the wiring instruction for proper and safe operation under normal conditions. Be sure that all wiring complies with NEC and all local ordinances. PT495 Series Detector Rev 5.11 (Ultra1000)

  • Page 4: Specifications

    Reverse polarity protection Mechanical Specifications EMI/RFI Immunity Height: 7.4inches (188 mm) Width: 6.2 inches (159 mm) Cable Entry Hub Depth 4.9 inches (125 mm) ¾” NPT Female Adapter available for ½” NPT / M20 PT495 Series Detector Rev 5.11 (Ultra1000)

  • Page 5: Overview

    Overview PT495 series single point fixed detector and transmitter for the detection of toxic and flammable gases in ambient air. Detector is designed and built suitable to be used in hazardous area. The detector is approved for use in Class I Division 1 & 2 classified areas (North America) or Zone 1 and 2 (International).

  • Page 6: H2S

    Table 1. Reference Table for Target Gas Range and default parameters Toxic Gases Rev 2: 3/5/19 Target Gas Max Range Sensor Res. Calib Gas Default Response Recovery Operating Temperature Default alarm Levels / Time (T59) Type Range Calib Gas time (T50) Set Points seconds (user...

  • Page 7: Transmitter Board Assembly

    Transmitter Board The transmitter board assembly consists of the signal conditioning circuit, microprocessor, LC display and 4-20 mA output circuit. The transmitter board assembly is connected to the connection board via ribbon cable and secured onto the stand-off via two thumb screws. To remove the transmitter board simply move the thumb screws counter-clockwise and slowly pull the transmitter board away.

  • Page 8: Accessories

    / sand on the sintered disk of the head assembly. Also to protect against water splashes. Duct Mount Kit This is an optional kit designed to monitor the gas  vapors in Heating, ventilation and air conditioning duct (HVAC). PT495 Series Detector Rev 5.11 (Ultra1000)
  • Page 9 : A tool used to initiate the internal magnet sensitive  switches for alarm configuration and to initiate sensor calibration. Pipe Mount Assembly Includes hex bolts and stainless steel bracket  to mount the sensor to up to a 2” pipe. PT495 Series Detector Rev 5.11 (Ultra1000)

  • Page 10: Installation

    A CSA or ATEX approved plug must always be used. 4.9" 5.50" (125mm) (139.7mm) Cable Entry " NPT Female Both Sides 7.4" (188mm) Ø 0.3" (7.6 mm) 2 Places Figure 3. Sensor Dimensions PT495 Series Detector Rev 5.11 (Ultra1000)

  • Page 11: Transmitter Wiring

    Note: Do not apply excessive force to tighten the screws. Place the cover back on the enclosure. Caution Cable Shield wire should be grounded at the controller or PLC side not inside the detector enclosure. PT495 Series Detector Rev 5.11 (Ultra1000)
  • Page 12 Ω Max resistance per core : R = V/I  8volts / detector consumption (A) Max Loop resistance for toxic & infrared 67.8 Ω Catalytic Bead: 29.8 Ω PT495 Series Detector Rev 5.11 (Ultra1000)
  • Page 13                        Figure 4. Wiring Diagram for Power and 4-20 mA signal connection PT495 Series Detector Rev 5.11 (Ultra1000)

  • Page 14: Low And High Alarms Connections

                        Figure 5. Wiring diagram for Alarm Relay Connection PT495 Series Detector Rev 5.11 (Ultra1000)

  • Page 15: Start Up

    If calibration is required then follow the steps in the Calibration procedure. If the unit is powered up for the first time then allow at least 15 to 20 minutes before attempting calibration or bump test. PT495 Series Detector Rev 5.11 (Ultra1000)

  • Page 16: Normal Operation

    + 4 = Analog output (mA) Detection Range Formula to convert mA to gas reading: ( mA Output - 4 ) x Detection Range = gas_reading (Note: Detection Range is the full scale range of the sensor) PT495 Series Detector Rev 5.11 (Ultra1000)
  • Page 17 % / ppm mA Output Volume 12.0 16.0 20.0 The above table is for the detector with Full scale range of 100 ppm / % (volume) PT495 Series Detector Rev 5.11 (Ultra1000)

  • Page 18: Calibration

    Once the calibration is initiated the alarm relays will be inhibited and the 4-20mA analog signal will be held at approximately 2mA to avoid any false alarm. Calib Mode Figure 6. Magnetic switch position to activate calibration Mode switch PT495 Series Detector Rev 5.11 (Ultra1000)
  • Page 19 *** Note: For Oxygen deficiency pure nitrogen is applied as calib gas and thus value is not adjustable. Similarly for LEL detectors the Calib- Gas is fixed at 50% LEL. PT495 Series Detector Rev 5.11 (Ultra1000)
  • Page 20 The 2mA level on the analog output line is an indication to any connected gas monitor that the sensor is in calibration mode thus avoiding any false alarm. Also refer to “Sensor calibration Flow Chart” for quick calibration review and “Calibration Error and remedies” PT495 Series Detector Rev 5.11 (Ultra1000)

  • Page 21: Hydrogen

    In case of Oxygen sensor if the oxygen level around the sensor is not 20.9% then zero air must be applied to set zero calibration of the sensor. 0.5 to 1 LPM Flow Regulator Figure 7. . Sensor Calibration using Flow regulator and adapter PT495 Series Detector Rev 5.11 (Ultra1000)

  • Page 22: Response Check / Bump Test

    Note: In windy conditions perform Bump test as described in step 2 only. Also calibration adapter must be used for full calibration of the sensor. PT495 Series Detector Rev 5.11 (Ultra1000)

  • Page 23: Calibration Errors And Remedies

    This error can also occur when there is insufficient flow of the calibration gas to the sensor. Also check if the calibration gas has not expired and be sure to use the calibration adapter and check the calibration apparatus and tubing for any leaks. PT495 Series Detector Rev 5.11 (Ultra1000)

  • Page 24: Calibration Flow Chart

    ADJ is being seconds displayed Remove Calib Gas when display Display flashes rapidly for about Starts flashing rapidly 10 seconds. Returns to normal (approximately 5 times per operation when sensor has second) cleared Sensor Calibrated Successfully PT495 Series Detector Rev 5.11 (Ultra1000)

  • Page 25: Edit Configuration (Alarms And Unit Address)

    Typically the configuration options are edited during installation. All the configuration data is stored in non-volatile memory and are retained during power down of the detector. Alarm 1 Edit Config Figure 8. Edit Configuration using magnetic wand PT495 Series Detector Rev 5.11 (Ultra1000)

  • Page 26: Configuration Menu

    2 to 3 seconds. After selecting the option edit the data value by holding the magnet to its place. Remove magnet to end the data edit mode and return back to configuration options list. PT495 Series Detector Rev 5.11 (Ultra1000)

  • Page 27: Set Detector Address

    1 after 120. 2. A unique address is now assigned to the detector. This address will be retained in a non-volatile memory until modified by the user. PT495 Series Detector Rev 5.11 (Ultra1000)

  • Page 28: Set Alarm Levels

    Adjust Alarm Levels or Setpoints PT495 Series has two (2) fully programmable relays for Low and High alarms. The third relay is used for Sensor Fault or malfunction. The alarm levels can be set anywhere between 0 and the full scale range of the sensor. Also they can be configured as Latching or non-latching.
  • Page 29 Relay will stay active even after the gas concentration falls below the preset alarm level. The alarm relay must be manually reset using the internal magnetic switch. (next section) Factory defaults alarm relay settings are Non-Latching PT495 Series Detector Rev 5.11 (Ultra1000)

  • Page 30: Alarm Conditions

    In Fault condition the 4-20mA output generated would be less than 1.0 mA. The Display will show “Sensor Fail” Note: Fault Alarm relay is normally energized. This is to provide fail safe operation in the event of power supply failure to the unit. PT495 Series Detector Rev 5.11 (Ultra1000)

  • Page 31: Resetting Alarms

    Alarm 1 RESET Figure 10. Magnetic switch position 4 o'clock to RESET alarms and to adjust alarm set points PT495 Series Detector Rev 5.11 (Ultra1000)

  • Page 32: Modbus Rtu Communication

    Modbus RTU Communication (RS-485) In order to communicate digitally with a master controller on the RS-485 data network each PT495 series detector must be assigned with a unique address. This address is used by the main controller to collect the information from a particular detector.
  • Page 33 1/10, the alarm levels and the gas levels are updated as 10 in MODBUS Registers. For example the gas reading of 10.5 (ppm or %Vol) will be updated as 105. PT495 Series Detector Rev 5.11 (Ultra1000)
  • Page 34 The higher order byte 01 determines that it is an H2S sensor The low order byte when converted to binary bits gives ‘00000001’ Which means that either alarm 1, 2 or both are currently active PT495 Series Detector Rev 5.11 (Ultra1000)

  • Page 35: Maintenance

    If necessary install some protective shield on the unit before painting or cleaning. Be sure to remove the protective shield when finished. Routine Maintenance PT495 series Sensors do not require routine maintenance. However, the sensors should be inspected periodically to ensure proper operation. Sensor Inspection Keep the sensor flame arrestor clean.

  • Page 36: Sensor Inspection, Sensitivity And Replacement

    8. Plug in the ribbon cable to the transmitter board and secure the board with thumb screws. Do not over tight the screws. PT495 Series Detector Rev 5.11 (Ultra1000)
  • Page 37 “Start up” section in this manual. 10. Calibrate the sensor. Follow the instructions in calibration procedure in this manual. ** Note. Detector transmitter must be Calibrated any time a new sensor head assembly is installed or replaced. PT495 Series Detector Rev 5.11 (Ultra1000)

  • Page 38: Spare Parts

    Spare Parts Part Number Description S-61-403 Termination / Connection Board Assembly for PT495 Series For All Toxic Sensors and Infrared Combustible S-61-402 Connection Board for Combustible Hydrocarbons (LEL) Using Catalytic Bead (LEL) sensor head assembly ONLY C-301 Rain guard C- 800...
  • Page 39 500 ppm Hydrogen balanced in Air 14-087 For 1000 ppm Range Sensor 50 ppm Nitric Oxide in Air 14-120 10 ppm Nitrogen Dioxide in Air 14-110 25 ppm Hydrogen Chloride in Air 14-125 5 ppm Chlorine in air 14-131 PT495 Series Detector Rev 5.11 (Ultra1000)

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