Detcon FP-624D - Manual (Page 10)

Model FP-624D
FP-624D Instruction Manual Rev. 1.2 Page 6 of 42
2. Installation
2.1 Operational Guidelines for Safe Use
1. Install sensor only in areas with classifications matching with those described on the approval label.
Follow all warnings listed on the label.
2. Ensure that the sensor is properly mounted in a vertical orientation with sensor facing down. Avoid
use of excessive Teflon Tape, or any type of non-conductive pipe thread coating on the NPT threaded
connection. All NPT connections should remain grounded to the junction box.
3. Use ¾” NPT plugs properly rated for hazardous locations to block any unused connections.
4. Removal of the Junction box cover or threaded sensor housing (612-820000-000) violates the Ex
Proof protection method and hence power must be removed from the sensor prior to its safe removal.
5. Ensure that the threaded insert and plug-in sensor are installed during operation. The threaded insert
should be secured tightly to the sensor housing. Removal of the threaded insert violates the Ex Proof
protection method and hence power must be removed from the sensor prior to its safe removal.
6. Proper precautions should be taken during installation and maintenance to avoid the build-up of static
charge on the plastic components of the sensor. These include the splashguard and splashguard
adapter.
7. Do not operate the sensor outside of the stated operating temperature limits.
8. Do not operate the sensor outside the stated operating limits for voltage supply.
2.2 Sensor Placement
Selection of sensor location is critical to the overall safe performance of the product. Six factors play an
important role in selection of sensor locations:
(1) Density of the gas to be detected
(2) Most probable leak sources within the industrial process
(3) Ventilation or prevailing wind conditions
(4) Personnel exposure
(5) Maintenance access
(6) Additional Placement Considerations
Density
Placement of sensors relative to the density of the target gas is such that sensors for the detection of heavier
than air gases should be located within 4 feet of grade as these heavy gases will tend to settle in low lying
areas. For gases lighter than air, sensor placement should be 4-8 feet above grade in open areas or in pitched
areas of enclosed spaces.
NOTE: Methane and Hydrogen are lighter than air. Most other combustible gases are heavier
than air. Compare the molecular weight, density, or specific gravity of the target gas(es) with
that of air to determine appropriate placement.