Operation And Wiring; Standard Wiring - PCB Piezotronics IMI SENSORS 646B10 Installation And Operating Manual

Operation and Wiring

Standard Wiring

The Model 640/641/645/646 B Series operates from a standard 2-Wire, 4-20mA loop. If using a loop powered
unit, attach the positive (+) input from the power supply to Pin A or Red wire on the sensor and the negative (-)
input from the power supply to Pin B or Blue Wire of the sensor.
Figure 1 – wiring: loop powered Figure 2 – wiring: loop powered/DC source
If using a standard DC power supply, install either an ammeter and/or load resistor in line with the output, Pin B or
Blue Wire.
The resistor will generate a DC voltage that is proportional to current by:
V = IR
If R = 500 ohms and I = 6 mA, then V = 3 VDC
Note:
- Resistor value must be less than: (Vsupply – 12) x 50.
- For integral cable sensors: RED wire is positive, BLUE wire is negative.
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