Intrinsically Safe Device Entity Parameters; Table 3-1: I.s. Equipment And Associated Apparatus - L3Harris XL Extreme Series Operator's Manual

14221-1800-2050, Rev. G
PART NUMBER
Headset, Light Weight, Behind the Head, Dual In-Ear, In-Line
12082-0650-11 PTT
Headset, Light Weight, Behind the Head, Dual In-Ear, Pigtail
12082-0650-12 PTT
3.2

INTRINSICALLY SAFE DEVICE ENTITY PARAMETERS

Intrinsically Safe Device Entity Parameters:
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• Associated apparatus output current must be limited by a resistor such that the output voltage-
current plot is a straight line drawn between open-circuit voltage and short-circuit current.
Associated apparatus may be in a Division 2 or Zone 2 location if so approved.
•
• Selected associated apparatus must be third-party listed as providing intrinsically safe circuits
for the application, and have Voc or Vt not exceeding Vmax (or Uo not exceeding Ui), Isc or
It not exceeding Imax (or Io not exceeding Ii), and the Po of the associated apparatus must
be less than or equal to the Pmax or Pi of the intrinsically safe equipment, as shown in Table
3-1.
• Capacitance and inductance of the field wiring from the intrinsically safe equipment to the
associated apparatus shall be calculated and must be included in the system calculations as
shown in Table 3-1.
capacitance, Ci, must be less than the marked capacitance, Ca (or Co), shown on any
associated apparatus used. The same applies for inductance (Lcable, Li and La or Lo,
respectively). Where the cable capacitance and inductance per foot are not known, the
following values shall be used: Ccable = 60 pF/ft., Lcable = 0.2 µH/ft.
If Po of the associated apparatus is not known, it can be calculated using the formula Po =
(Voc * Isc)/4 = (Uo * Io)/4.
Associated apparatus must be installed in accordance with its manufacturer's control drawing
•
and Article 504 of the National Electrical Code (ANSI/NFPA 70) for installation in the United
States, or Section 18 of the Canadian Electrical Code (C22.1) for installations in Canada.
20
DESCRIPTION
V max (or Ui) = 8 V dc
I max (or Ii) = 500 mA
P max (or Pi) = 4 W
Ci = 69 µF
Li = 320 µH
Cable capacitance, Ccable, plus intrinsically safe equipment

Table 3-1: I.S. Equipment and Associated Apparatus

I.S. EQUIPMENT
V max (or Ui)
I max (or Ii)
P max (or Pi)
Ci + Ccable
Li + Lcable
ASSOCIATED APPARATUS
≥ Voc or Vt (or Uo)
Isc or It (or Io)
≥
Po
≥
Ca (or Co)
≤
La (or Lo)
≤
NFPA
N/A
N/A