Emerson Rosemount 8600 Series - Page 42

Reference Manual
00809-0100-4860, Rev BF
Installation
May 2019
34
Rosemount 8600 Vortex Flow Meter
Typical single loop wiring diagram:
Loop Load Calculation
R
loop(max)
= (V
ps
– 10.8) / 0.024
Where:
 R
loop(min)
= 250 Ω. Required for HART communication.
 R
loop(max)
= The maximum value the loop load resistor can be.
 V
ps
= Power Supply Voltage
 10.8 = minimum terminal voltage “V
terminals
” in Vdc.
 0.024 = maximum transmitter current in Adc
Figure 3-11. Power Supply Load Limitations
Note
R
loop(max)
in the equation above refers to the total loop load resistance. Technically, the
total loop load resistance is the sum of the loop load resistor, signal wiring resistance, and if
applicable, any intrinsic safety barriers. In a typical installation, the loop load resistor will
largely determine the total loop resistance. In some installations, depending on signal wire
gauge and signal wire length, and/or any IS barriers, the additional resistance may need to
be accounted for.
To minimize noise pickup on the 4-20 mA signal and any digital communications signal:
 Twisted pair wiring is recommended.
 Shielded signal wire is preferred.
 For high EMI/RFI environments, shielded signal wire is required.
8600
V
ps
R
loop
V
terminals
