Detcon DM-700 SIL 2 Safety Manual - Manual (Page 3)

- Shall be zero and span calibrated every 180 days using a calibrated gas standard. After calibration, the sensor shall
be proof tested by applying the calibration gas and checking for the proper response of the 4-20mA output.
- After the DM-700 has been off power for more than 24 hours, it shall be allowed a 1 hour start-up period before
performing its safety function
- When the DM-700 detects a fault condition it will drive the output to 0mA for at least 5 seconds. Any PLC, DCS,
or other control system used to monitor the DM-700 shall indicate a fault when the output from the sensor drops
below 1.8mA for more than 4 seconds
- Any PLC, DCS, or other control system used to monitor the DM-700 shall indicate that the sensor is in calibration
mode when the output is greater than 1.8mA but less than 2.2 mA. When in calibration mode, the DM-700 cannot
perform its safety function.
- Any PLC, DCS, or other control system used to monitor the DM-700 shall indicate an over-range condition when
the output from the sensor is above 21.5mA. When the DM-700 is over-range, the actual gas concentration may
be higher than what is being reported by the 4-20mA output.
- The sensor shall not be installed in applications where it will be exposed to:
o Temperatures or humidity levels that exceed the specified limits
o Silicone vapors, routine long term exposure to any alcohols and solvents (especially from strong cleaning
agents), vapors from lead, and phosphates that might act as poisons that cause permanent damage.
- Shall be operated with an input power of 11VDC – 30VDC
- Shall be installed oriented vertically and mounted more than 1ft. above the ground
- Shall not be operated, stored, or transported outside the temperature range of -40ºC to 50ºC
- The DM-700 enclosure and connected cabling shall be properly grounded and shielded
- The Modbus interface shall not be connected when the DM-700 is used in SIL2 applications
- The magnetic switches on the DM-700 shall not be used while the DM-700 is performing its safety function
- The user shall validate the initial configuration and any subsequent configuration changes of the DM-700 before
using it for its safety function. This validation shall be accomplished by performing a proof test after all
configurations are complete.
- No online software tools are needed or are to be used when the DM-700 is performing its safety function.
9 INSTALLATION
NOTE:
For complete information regarding performance, installation, operation, maintenance and specifications of
Model DM-700, refer to instruction manual Document #3207.
No specific or additional detector installation requirements exist above and beyond the standard installation practices
documented in the Model DM-700 Instruction Manual.
Environmental operating specifications are applicable as published in the general specifications section in the Model DM-
700 instruction manual.
The DM-700 operating power distribution system should be designed and installed so the terminal voltage does not drop
below 11 VDC when measured at any specific location. The maximum current limit must be less than 0.5 amperes. The
over-voltage protection on the power distribution system must be set for 30 VDC.
10 START-UP AND COMMISSIONING
The Safety Certified DM-700 gas detector can be commissioned by any qualified person with knowledge of gas detection
instruments and the configuration device being used. Refer to the Start-Up and Commissioning sections provided in the
DM-700 instruction manual.