3.1.2
CSA/FM
3.1.2.1
Safety information for installation in "Intrinsic safety "ia"
Hazardous Area CL I, Div 1, GP ABCD CL I, Zone 0 IIC
General installation instructions
● Install in accordance with the US the National Electrical Code (NEC) or for Canada the
Canadian Electrical Code (CEC).
● Equipment that is FM-approved for intrinsic safety may be connected to barriers based on
the ENTITY CONCEPT. This concept permits interconnection of approved transmitters,
meters and other devices in combinations which have not been specifically examined by
FM, provided that the agency's criteria are met. The combination is then intrinsically safe,
if the entity concept is acceptable to the authority having jurisdiction over the installation.
● The entity concept criteria are as follows: The intrinsically safe devices, other than barriers,
must not be a source of power. The maximum voltage Ui (Vmax) and current Ii (Imax), and
maximum power Pi (Pmax), which the device can receive and remain intrinsically safe,
must be equal to or greater than the voltage (Uo or Voc or Vt) and current (Io or Isc or It)
and the power Po which can be delivered by the barrier.
● The sum of the maximum unprotected capacitance (Ci) for each intrinsically device and the
interconnect-ing wiring must be less than the capacitance (Ca) which can be safely
connected to the barrier.
● The sum of the maximum unprotected inductance (Li) for each intrinsically device and the
interconnecting wiring must be less than the inductance (La) which can be safely connected
to the barrier.
● The entity parameters Uo,Voc or Vt and Io,Isc or It, and Ca and La for barriers are provided
by the barrier manufacturer.
● The transmitter must be installed in a suitable enclosure to meet installation codes
stipulated in the Canadian Electrical Code (CEC) or for US the National Electrical Code
(NEC).
● If the enclosure is made of non-metallic materials or of painted metal, electrostatic charging
shall be avoided.
● Use supply wires with a rating of at least 5 K above the ambient temperature.
WARNING: Substitution of components may impair intrinsic safety.
Installing/mounting
3.1 Basic safety notes
SITRANS TH320/TH420/TR320/TR420/TF320/TF420
Compact Operating Instructions, 03/2018, A5E41865021-AA
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