ABB TCC300, User Manual, Page: 33 / 716

2.3.8 M-2948 tap position sensor
The M-2948 tap position sensor is a rotary shaft encoder that includes a built-in
microprocessor that provides stepped output signals in 9 or 10 degree increments. The
M-2948 is available with 0 to 297°, 306°, 315°, 330°, 340° and 350° rotation for ±16 taps
and 1, 2 or 3 neutral positions. The electrical output of the sensor is a 4-20 mA current loop
that converts easily to a voltage signal at the input of the M-2025B(D) with the addition
of a proper value shunt resistor. For a 4-20 mA Current Loop, 150 ohms is required on the
input of the M-2025B(D). The signal from the M-2025B(D) is then conditioned and sent
to TCC300 as an analog signal. The M-2948 Tap Position Sensor is available with either
a positive or negative slope. Negative slope (clockwise rotation) causes a decrease in Tap
Position. Positive slope (clockwise rotation) causes an increase in Tap Position. M-2948
Tap Position Sensor directly mechanically replaces the Selsyn-Type Tap Position Sensor.
1VAC388793-MB A
Section 2
TCC300 overview
TCC300 27
User Manual