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2.7
Wiring (Continued)
2.7.1
Intrinsically Safe (IS) Applications
Hazardous Area
Group IIA, IIB, Zones 0, 1, or 2
(Red, + Loop)
(White, Program*)
(Black, - Loop)
(Shield, Earth Ground)
* Reference Section 6: Control Drawings 420-0004-233-CD for
installation wiring.
Or, if WHITE Program wire is installed in a non-hazardous area.
Transmitter Entity Parameters:
Vmax = 30 V
Imax = 216 mA
Ci = 0 uF
Li = 0 uH
Figure 2-13
Wiring Diagram
The intrinsically safe barrier must be selected with entity
parameters of:
Voc less than or equal to 30 V.
Isc less than or equal to 216 mA.
Total loop capacitance and inductance of wire should not exceed
the Ca and La of barrier for the appropriate Class and Group.
Use 60pF per foot and 0.2 micro H per foot for the wire, if these
parameters are not known.
Resistive impedance of all devices in current loop (including
wire, meter, or controller, and barrier) should not exceed
500 ohms.
Voltage output of the I.S. power supply should be at least
13.5 V at sensor after considering voltage drops across all other
resistance in loop. I.S. power supply voltage should not exceed
Vmax of barrier.
21
Installation
Non-Hazardous Area
Safety
+ Loop
Barrier
- Loop
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