Zener Barrier - 13 Pages
SOLID STATE RELAYS AND BARRIERS
GEMS Relays and Barriers Render Any Non-Voltage Producing Sensor or Switch Intrinsically Safe
► Provide method of eliminating explosive conditions
► Rapid, arc-free response provides positive, non-mechanical operation
► Solid-state reliability assures consistent performance
► Low-power switching; a few milliamps of current controls high-power loads
► Completely encapsulated construction
Units are impervious to dust, moisture or foreign material They are tamper-proof and shock- and vibration-resistant
► Modular housings for easier installation
► Exceptionally long, trouble-free service life
Intrinsic Safety and its Advantages.
Instrument Society of American Specification ISA-RP12.2 Defining Intrinsically Safe Equipment:
"Intrinsically safe equipment and wiring is equipment and wiring which is incapable of releasing sufficient electrical or thermal energy under normal or abnormal conditions to cause ignition of a specific hazardous atmospheric mixture in its most ignited concentration. Intrinsically safe terminations and wiring may be brought into any hazardous location of any Group classification for which it is accepted without requiring explosion-proof housing or other means of protection."
To be certified "intrinsically safe," a device or circuit must be so designed that no two simultaneous failures can cause an explosion. Intrinsically safe systems are more dependable. The I.S. circuit must function reliably per specifications, with no explosions, during and after cycling through a number of operations.
The units can also be installed more conveniently. Since no explosion is possible, no explosion-proof conduit or enclosures of any kind are needed in the hazardous area. Maintenance can be performed immediately as needed. And, intrinsically safe systems are more economical. Costly enclosures with their mounting requirements are unnecessary. No purging is required, thereby eliminating blowers, pressure switches, timers and relays.
SAFE-PAK® RELAYS: These intrinsically safe units amplify sensor load-handling capabilities in a wide diversity of AC and DC control switching applications.
Zener Barriers: These passive, energy-limiting devices, provide intrinsically safe DC outputs for a variety of sensors such as level and flow switches.. .level indicating transducers and transmitters.. .and many others. The maximum energy possible at the switch terminals of the SAFE-PAK and Zener Barriers is far below the explosive point of the most volatile surrounding gas conditions. The type of non-voltage-producing switch or sensor best suited for the application can be utilized, since the entire switching circuit is rendered intrinsically safe by the SAFE-PAK or Zener Barrier. As the switching circuit is low voltage, there is no shock hazard to operating or maintenance personnel.
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P. 2Gems._ 54800 Series Dual Channel Zener Barriers Provide Intrinsic Safety to Signal Producing Sensors ► Intrinsic safety with...
P. 3DUAL CHANNEL ZENER BARRIERS How To Order Specify Part Number based on the specifications tabulated below. DC Input to Barrier, Max....
P. 4Non-Intrinsically Safe Relays Boost Your Sensor's Load Handling Ability ► SPST, N.O. Operation ► AC or DC models ► Amplify...
P. 5LOAP-PAK / SPDT-PAK / FLIP-PAK Surge Current Ratings of LOAD-PAKS. Non-repetitive. Overload Time Switch or Sensor Wiring: Wires...
P. 6Typical Applications Switches Located in Hazardous Areas Important points to remember when selecting Zener Barriers and Safe Pak® : The...