Bradley Keltech SNA Série Manuel D'installation page 20

SNA-Series Tankless Heater
Purge Gas Supply Notes
An alarm shall be provided to indicate failure of the protective gas supply to maintain the required pressure . Piping for
the protective gas shall be protected against mechanical damage .
Where the compressor intake line passes through a classified location, it shall be constructed of noncombustible
material, designed to prevent leakage of flammable gases, vapors, or dusts into the protective gas, and protected
against mechanical damage and corrosion .
The electrical power for the protective gas supply (blower, compressor, etc .) shall be supplied either from a separate
power source or from the protected enclosure power supply prior to any service disconnects of the protected
enclosure . Any protected enclosure that can be isolated from the protective gas supply shall be equipped with an
alarm . Where an alarm is used to indicate the loss of pressure in the cabinet:
• The alarm shall be located at a constantly attended location .
• The alarm actuator shall take its signal from the protected enclosure and shall not be installed between the
enclosure and the protective gas supply .
• The alarm actuator shall be mechanical, pneumatic, or electrical .
• Electrical alarms and electrical alarm actuators shall be approved for the location in which they are installed .
• No valves shall be permitted between the alarm actuator and the enclosure .
Intrinsically Safe (IS) Installation
Hazardous Location
Class I , Division 2
Groups A, B, C, D
T5 Hazardous (classified) Areas
Simple apparatus
device
MiniPurge: Option Code /IS
Vmax = 30v
Imax = 350mA
Ci = 0 Li = 0
1 . Electrical equipment connected to associated apparatus should not use or generate more than 250 volts .
2 . Installation shall be in accordance with the manufacturer's instructions and the National Electrical Code (NFPA 70) .
3 . For guidance on Installation see ANSI/ISA RP12 .6 (Installation of IS Instrument System in Class I
Hazardous Locations) .
4 . Voc or Vt of associated apparatus is less than Vmax
Isc or IT of associated apparatus is less than Imax
Ci plus capacitance of interconnecting cabling is less than Ca of the associated apparatus
Li plus inductance of interconnecting cabling is less than La for the associated apparatus
5 . "Simple Apparatus" is a device that will not generate or store more than 1 .2V, 0,1A, 25mW or 20uJ
20 6/10/2016
Non- Hazardous Location
(or suitably protected enclosure)
Intrinsically Safe
Interface Unit
Bradley • 215-1815 Rev. E; ECN 16-17-016
Installation
Power Supply
Outputs to relays or
power contactors