If polarity is reversed on a 2-wire transmitter, the transmitter will:

If polarity is reversed on a 2-wire transmitter, the transmitter will:

• A. Power up with reverse polarity.
• B. Continue normal operation.
• C. Show a fault indication on the display.
• D. Not power up.

Answer: (D)

In a 2-wire transmitter, power comes from the loop through a specific polarity, and the internal circuits rely on that orientation to bias correctly. If the leads are reversed, reverse-polarity protection (such as a diode or FET designed to block current when polarity is wrong) prevents current from flowing into the transmitter. Without proper bias, the device cannot power up, so no loop current is generated and the display will not show any fault or status. That’s why the transmitter does not power up when polarity is reversed.

In a 2-wire transmitter, power comes from the loop through a specific polarity, and the internal circuits rely on that orientation to bias correctly. If the leads are reversed, reverse-polarity protection (such as a diode or FET designed to block current when polarity is wrong) prevents current from flowing into the transmitter. Without proper bias, the device cannot power up, so no loop current is generated and the display will not show any fault or status. That’s why the transmitter does not power up when polarity is reversed.