Wiring Diagram; Wiring For 4-20Ma Transmitters - Universal Flow Monitors FlowStream OFS User Manual

WIRING DIAGRAM

Wiring for 4-20mA Transmitters

Figure 2 shows a typical 2-wire, 4-20mA transmitter wiring for use with FlowStream
flowmeters. Maximum loop resistance is related to the available supply voltage. Since the
flowmeter requires 10 volts to operate, the voltage drop across the loop resistance at full-scale
flow output (20mA) must be added in to determine the minimum supply voltage. For example,
if a 100-ohm resistor is used to convert the current signal to voltage, the voltage drop across the
resistor will be 0.4-2 volts for 4-20 mA, respectively. Minimum required loop voltage in this
case is 12 volts, as shown. Likewise, the voltage drop for a 250-ohm resistor is 1-5 volts,
requiring a minimum of 15 volts supply. Please refer to the graph in
Wire Color
Red Supply +
Black Supply -
Brown Tare
White Not Used
Shield Internally Grounded to
Chassis
Blue High Alarm Output
Orange Low Alarm Output
Green Alarm Common
Note: Shield wire (shown as gray) may be connected to an external chassis ground to improve
electrical noise immunity. However, care must be taken not to connect this ground to signal
ground.
FSMAN.6 081214
Figure 2. Standard Transmitter Wiring
(DO NOT Use for Intrinsically Safe Applications)
Figure
Function
12-30VDC (Standard)
12-24 VDC (Intrinsically Safe)
DC GND
Short to GND for 5 seconds to tare at zero
flow
Do not connect
Open-collector
Open-collector
Emitter for both alarms
3.
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