DANGER!
Hazardous voltage can cause severe injury or death. Shut off the power before wiring
transmitter outputs.
DANGER!
Improper wiring in a hazardous environment can cause an explosion. Install the transmitter
only in an area that complies with the hazardous classification tag on the transmitter.
Safety parametersTable 8-1:
Parameter 4–20 mA Frequency/discrete
Voltage (U
i
) 30 V 30 V
Current (I
i
) 300 mA 100 mA
Power (P
i
) 1.0 W 0.75 W
Capacitance (C
i
) 0.0005 μF 0.0005 μF
Inductance (L
i
) 0.0 mH 0.0 mH
Voltage The transmitter’s safety parameters require the selected barrier’s open-
circuit voltage to be limited to less than 30 VDC (V
max
= 30 VDC). This
voltage is the combination of the maximum safety barrier voltage
(typically 28 VDC) plus an additional 2 VDC for HART communications
when communicating in the hazardous area.
Current The transmitter’s safety parameters require the selected barrier’s short-
circuit currents to sum to less than 300 mA (I
max
= 300 mA) for the
milliamp outputs and 100 mA (I
max
= 100 mA) for the frequency/discrete
output.
Capacitance The capacitance (C
i
) of the transmitter is 0.0005 μF. This value added to
the wire capacitance (C
cable
) must be lower than the maximum allowable
capacitance (C
o
) specified by the I.S. barrier. Use the following equation to
calculate the maximum length of the cable between the transmitter and
the barrier: C
i
+ C
cable
≤ C
o
Inductance The inductance (L
i
) of the transmitter is 0.0 mH. This value plus the field
wiring inductance (L
cable
), must be lower than the maximum allowable
inductance (L
o
) specified by the I.S. barrier. The following equation can
then be used to calculate the maximum cable length between the
transmitter and the barrier: L
i
+ L
cable
≤ L
o
I/O wiring for Model 1700 and Model 2700 transmitters with intrinsically safe outputs
Installation Manual 85
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