detcon inc. Detcon MicroSafe™ TP-624C Hydrogen Sulfide Sensor This manual covers the following ranges: 0-20 PPM, 0-50 PPM, and 0-100 PPM Operator’s Installation & Instruction Manual February 01, 2010 • Document #2017 • Version 8.
Table of Contents 3.0 Description 3.1 Principle of Operation 3.2 Application 3.3 Specifications 3.4 Operating Software 3.5 Installation 3.6 Start-up 3.7 Calibration 3.8 Status of Programming: Software Version, Alarms, Calibration Level, RS-485 ID, Heater Voltage, Range, and Sensor Life 3.9 Programming Alarms 3.10 Program Features 3.11 RS-485 Protocol 3.12 Display Contrast Adjust 3.13 Trouble Shooting Guide 3.14 Spare Parts List 3.15 Warranty 3.16 Service Policy 3.
.0 DESCRIPTION Detcon MicroSafe™ Model TP-624C, hydrogen sulfide sensors are non-intrusive “Smart” sensors designed to detect and monitor H2S in air. Ranges of detection are user-settable between 0-20 ppm, 0-50 ppm, and 0-100 ppm. One of the primary features of the sensor is its method of automatic calibration which guides the user through each step via instructions displayed on the backlit LCD.
3.0.2 Microprocessor Control Circuit The control circuit is microprocessor based and is packaged as a plug-in field replaceable module, facilitating easy replacement and minimum down time. Circuit functions include a basic sensor pre-amplifier, on-board power supplies, microprocessor, back lit alpha numeric display, alarm status LED indicators, magnetic programming switches, an RS-485 communication port, and a linear 4-20 mA DC output.
3.1 PRINCIPLE OF OPERATION Method of detection is by diffusion/adsorption. Air and gas diffuse through a sintered stainless steel filter and contact the heated surface of the metal oxide sensor film. As hydrogen sulfide gas molecules react with oxygen ions on the film, there is a decrease in electrical resistance proportional to the gas concentration. The heater film elevates the temperature of the sensor film creating convection and promoting a quick response to changing gas concentrations.
3.3 SPECIFICATIONS Method of Detection Solid state metal oxide diffusion/adsorption Electrical Classification CSA-NRTL approved Class I; Groups B, C, D; Div. 1.
3.4.2 Calibration Mode Calibration mode allows for sensor span adjustments. Unless otherwise specified, span adjustment is performed at 10 ppm H2S in air for the range 0-20 ppm, and 25 ppm H2S in air for the ranges 0-50 ppm and 0-100 ppm. “AUTO SPAN” 3.4.3 Program Mode The program mode provides a program status menu (View Program Status) to check operational parameters.
3.5.1 Field Wiring Table (4-20 mA output) Detcon Model TP-624C solid state H2S sensor assemblies require three conductor connection between power supplies and host electronic controllers. Wiring designators are + (DC), – (DC) , and mA (sensor signal). Maximum single conductor resistance between sensor and controller is 10 ohms. Maximum wire size for termination in the sensor assembly terminal board is 14 gauge.
Figure #1 Plug any unused ports. “T” Drain EYS Seal Fitting 3.5.3 Local Electrical Codes Sensor and transmitter assemblies should be installed in accordance with all local electrical codes. Use appropriate conduit seals. Drains & breathers are recommended. The sensor assemblies are CSA-NRTL approved for Class I; Groups B, C, D; Div. 1 environments. 3.5.
Alarm Dry Contacts FAULT ALM-2 ALM-1 Figure #3 NO/NC COM NO/NC COM NO/NC COM Optional Voltage Developing Resistor Use 250 ohm 1/4w R1 ALARM 1 NC NO ALARM 2 NC NO VDC Power In MA A B A B RS-485 In RS-485 Out Jumper Programmable Alarm Outputs Normally Open or Normally Closed NC NO UN-USED FAULT WHT BLK YEL BLU 4-20 mA Output Place un-used alarm programming jumper tabs here JUMPERS Sensor e) Program the alarms via the gold plated jumper tab positions located on the CPU board (see figure 4).
f) If applicable, set the RS-485 ID number via the two rotary dip switches located on the preamp board (see figure 5). There are 256 different ID numbers available which are based on the hexadecimal numbering system. If RS485 communications are used, each sensor must have its own unique ID number. Use a jewelers screwdriver to set the rotary dip switches according to the hexadecimal table listed below.
3.5.6 Remote Mounting Applications Some sensor mounting applications require that the gas sensor head be remotely mounted away from the sensor transmitter. This is usually true in instances where the gas sensor head must be mounted in a location that is difficult to access. Such a location creates problems for maintenance and calibration activities.
Note 1: All alarms will be disabled for 1 minute after power up. In the event of power failure, the alarm disable period will begin again once power has been restored. Note 2: If the display contrast needs adjustment, refer to section 3.12. Note 3: If the sensor has been installed using the remote mounting configuration as described in section 3.5.6, the sensor heater voltage must be adjusted after initial power up. If this is the case, first adjust the heater voltage as described in section 3.6.
i) Replace the junction box cover on the remote sensor enclosure. Heater voltage adjustment is complete. 3.6.3 Programming Magnet Operating Instructions Operator interface to MicroSafe™ gas detection products is via magnetic switches located behind the transmitter face plate. DO NOT remove the glass lens cover to calibrate or change programming parameters.
NOTE: When switching between ranges, remember to readjust your Cal Level setting if necessary (see section 3.7.2). Also remember to adjust your alarm setpoints if necessary (see section 3.9.1) 3.6.5 Setting Heater Voltage The Detcon TP-624C H2S sensor is factory set for the correct heater voltage and should be ready to install without further adjustment being required. The correct heater voltage for the sensor is 5.25 VDC when set at 25°C room temperature.
a) Verify the current calibration gas level setting as indicated by the programming status menu. To do this, follow the instructions in section 3.8 and make note of the setting found in listing number 12. The item appears as “CalLevel @ xxPPM”. b) If the calibration gas level setting is equal to your calibration span gas concentration, proceed to item “f”. If not, adjust the calibration gas level setting so that it is equal to your calibration span gas concentration, as instructed in items “c” through “e”.
3.7.4 Calibration Frequency In most applications, monthly to quarterly calibration intervals will assure reliable detection. However, industrial environments differ. Upon initial installation and commissioning, close frequency tests should be performed, weekly to monthly. Test results should be recorded and reviewed to determine a suitable calibration interval. 3.7.
number, heater level, range of detection, and estimated remaining sensor life. The programming menu also allows the changing of alarm levels (see section 3.9), the programming of the calibration gas level setting (see section 3.7.2), the sensor heater level (see section 3.6.2), the range of detection (see section 3.6.4), and the linearize sensor (see section 3.7.5).
c) ALARM 2 LEVEL From the programming menu scroll to the alarm 2 level listing. The menu item appears as: “SET ALARM 2 LEVEL”. Enter the menu by holding the programming magnet stationary over “PGM 1” for 3 seconds until the display reads “SET ALM2 @ ##PPM”, then withdraw the magnet. Use the programming magnet to make an adjustment to “PGM 1” to increase or “PGM 2” to decrease the display reading until the reading is equal to the desired alarm set point.
“System Fault”, “Zero Fault”, and “Range Fault” will also cause the mA output to drop to zero (0) mA until the condition is corrected. Sensor Life The sensor life feature is a reference based on signal output from the sensor cell. When a sensor life of 25% or less remains, the sensor cell should be replaced within a reasonable maintenance schedule. 3.
This is the trip point for the second alarm.
Reg40004 Data Hi Reg40004 Data Lo Reg40005 Data Hi Reg40005 Data Lo CRC CRC 00 14 05 50 ## ## 0 20 5 80 0000 0000 0001 0100 0000 0101 0101 0000 #### #### #### #### Additional Notes: The calibration LED will light when the transmitter is sending a response to a Master Query. Communications are 9600 baud, 8 data bits, 1 stop bit, No parity, half duplex 485. 3.12 DISPLAY CONTRAST ADJUST Model TP-624C MicroSafe™ sensors feature a 16 character backlit liquid crystal display.
6. Check sensor lot # and report to Detcon. 7. Check area for presence of reducing gases such as Cl2 and ozone which may cause low readings. Unstable output/ Sudden spiking Unstable power supply, Inadequate grounding, Inadequate RFI protection. 1. Verify Power source. 2. Contact Detcon to optimize shielding and grounding. 3. Add RFI protection accessory. Nuisance Alarms 1. Check condulet for accumulated water and abnormal corrosion. If Nuisance alarms happening at night suspect condensation in condulet. 2.
Programming Magnet Figure #8 Enclosure glass lens cover Plug-in control circuit Rain Shield Spash Guard Calibration Adapter Connector Board Enclosure less cover H2S Sensor in Housing Condensation Prevention Packet (replace annually) 3.15 WARRANTY Detcon, Inc.
3.17 SOFTWARE FLOW CHART AUTO SPAN PGM1 (3) PGM2 (3) PGM1 (3) PGM1 (M) ALARM RESET NORMAL OPERATION PGM2 (30) PGM2 (M) ALARM RESET VIEW PROG STATUS SET ALARM 1 LEVEL SET ALARM 2 LEVEL SET CAL LEVEL PGM1 (3) PGM2 (M) PGM1 (3) PGM2 (M) PGM1 (3) PGM2 (M) PGM1 (3) PGM2 (M) PGM2 (3) PGM2 (3) PGM2 (3) PGM2 (3) GAS RANGE V#.
