Harmonic analysis: The total distortion rate and 31st harmonic content of voltage and current can be viewed through TapTalk.
Tap position recording: Record the number of times each gear has been passed, to assist in maintenance decision-making.
Operation counter: total number of operations and resettable counter for evaluating mechanical life.
The newly added M-2829 TapPlot software can plot, print, and trend analyze the above data, providing a basis for status maintenance.

Input/output and power backup
7.1 Main inputs
Control voltage: 90~140Vac, 50/60Hz optional, power consumption ≤ 8VA.
Motor power supply: 120~240Vac, maximum 6A, no need to change wiring.
Line current: 0.2A CT input (M-0121 or M-0169A auxiliary CT adapted to 5A/8.66A CT), burden ≤ 0.03VA.
Circulating current: 0.2A CT input, used for parallel connection.
Binary inputs: voltage drop by 1/2 (three-level voltage reduction), neutral point detection, counter/switch status input, non sequential/SCADA lockout input.
7.2 Output
Boost/buck output: 6A@120 ~240Vac, Can be set as continuous or pulse.
Seal In: in conjunction with B-0553/B-1711 motor sealing plate.
Dead zone alarm output: 6A@120Vac or 100mA@120Vdc .
Programmable alarm output: 3A@120Vac .
7.3 Control power backup (optional)
If Control Power Backup Input is selected, it can be connected to the backup power supply of M-2026 (AC/DC input, output+12Vdc/1.5A) or M-2027 (AC only, output+12Vdc/1.0A) to ensure that the control logic continues to operate in the event of AC power failure (voltage regulation can only be performed when the motor power supply is still present).
Display, Environment, and Authentication
Display screen: Standard LCD (-20~+70 ℃), optional VFD (-40~+80 ℃) suitable for cold or hot environments.
LED indicator lights: 10 in total, including boost/buck request, reverse power, CPU OK, LDC activation, voltage drop activation, manual/automatic status, SCADA lockout, COM1 transmit/receive indication.
Accuracy: Under the ANSI/IEEE C57.15.9-1999 standard, the accuracy is ± 0.3% for -30~+65 ℃ and ± 0.5% for the entire temperature range (-40~+85 ℃).
Transient protection: Meets ANSI/IEEE C37.90.1-1989 and IEC 60255 series, with 1500Vac isolation between ports.
Physical dimensions: 5.8125 "wide x 8.5" high x 3 "deep, weighing approximately 3.7 pounds, suitable for various conversion panels to directly replace old models.
Warranty: The entire machine and supporting accessories (M-2026/2027, M-2948, M-2025B (D)) are all for five years.
On site debugging and common problems
9.1 Debugging steps
Confirm that the model and optional features match the application requirements.
Connect the control voltage, motor power supply, CT/VT signals, and check the phase angle correction settings.
Set the center, bandwidth, delay mode, and values.
Calculate the line impedance and input the LDC parameters (R/X or Z).
If parallel connection is required, connect the circulating current CT and M-0115A (or configure the Δ VAR2 parameter).
Configure the parameters of the tap sensor (M-2948 model, rotation direction, degree of each gear, total number of gears).
Set voltage limits, rollback dead zone, and tap position limits.
Configure communication port protocol, address, baud rate, and test connectivity with SCADA.
Conduct no-load or light load trial operation, observe the voltage regulation response and compensation effect.
9.2 Common problem troubleshooting
Possible causes and solutions for the phenomenon
Long term voltage deviation: LDC setting is too large/too small, CT polarity error check CT wiring, recalculate R/X, adjust phase angle correction
Voltage regulation too frequent, bandwidth too narrow, delay too short, increase bandwidth or enable inverse time delay
Controller does not raise/lower voltage external lockout, reverse power lockout, limit out check lockout input, reverse status, voltage/position limit
Improper sensitivity of parallel loop flow through large M-0115A, CT polarity reversal adjustment sensitivity switch, check the circulating current CT wiring
Communication failure protocol mismatch, address error, physical wire breakage, verification of protocol settings, address, cable, and terminal resistance (RS-485)
SCADA heartbeat mode incorrect switching heartbeat detection cycle or network jitter adjust heartbeat timeout parameter, check network stability
