T-Motor AT55A-UBEC 55A Fixed Wing ESC for Outdoor Aircraft, 2-6S LiPo, 5V/5A BEC, Programmable

Overview

The T-Motor AT55A is a Fixed Wing ESC for outdoor aircraft. It supports 2-6S LiPo power input and features an integrated 5V SBEC rated up to 5A. The ESC supports voltage protection, thermal protection, failsafe, brake, and soft start functions. Note: AT55A ESC does not have a connector for connecting a battery.

Key Features

• Fixed-wing ESC; supports 2-6S battery (as shown)
• Integrated UBEC/SBEC: 5V output, up to 5A (as shown and stated)
• High-speed throttle response (as shown)
• Multiple programmable parameters; supports LED programming card parameter setting (as shown)
• Protections mentioned across product text/manual pages: input voltage abnormal protection, battery low-voltage protection, overheat/thermal protection, throttle signal loss protection

For customer service and technical support, contact https://rcdrone.top/ or email support@rcdrone.top.

Specifications

AT-55A-UBEC (from the specification table shown)

Applications

• Outdoor fixed-wing aircraft power systems (as stated)

Manuals

Manual notes (as shown)

• Under a strong power system, incorrect operation may cause risk; read the manual carefully and follow the operating procedure.
• The manual states no responsibility for issues resulting from incorrect use or modification.

Product Features (from the manual page shown)

1. All devices are original made, ensuring that the ESC has high quality and high reliability.
2. Strong flow resistance.
3. Input voltage abnormal protection, battery low voltage protection, overheat protection, throttle signal loss protection, and other multi-protection functions.
4. Ordinary start, soft start, ultra-soft start modes; compatible with fixed-wing aircraft and helicopter (as written in the manual).
5. Throttle range can be set and compatible with various transmitter; smooth feel and good linearity for speed control.
6. Highest speed can reach 210,000 RPM (2-pole motor), 70,000 RPM (6-pole motor), 35,000 RPM (12-pole motor).

Programmable Items (manual)

Note shown in the manual: the option written in red font is the default setting.

1. Brake Setting: Enabled/Disabled.
2. Battery Type: Lipo/NiMH.
3. Low Voltage Protection Mode (Cut-Off Mode): limit power (Gradually reduce the output power) / Cut-Off (Immediately stop the output power).
   Remark shown: When protected by low voltage, the motor can be restarted after the throttle rocker is pulled to the minimum throttle position; however, because it is still at low voltage, the power output is small.
4. Low Voltage Protection Threshold: Low/Medium/High.
   • When battery type is set to Lipo, the battery cell number can be judged by ESC automatically. Low/medium/high cutoff voltage for each cell is: 2.85V/3.15V/3.3V. Example shown: for a 3S Lipo with “Medium” threshold, cutoff voltage is 3.15*3=9.45V.
   • When battery type is set to a NiMH battery, low/medium/high cutoff voltages are 0%/50%/65% of the startup voltage; 0% means the low voltage cut-off function is disabled. Example shown: for 6 cells NiMH, fully charged voltage is 1.44*6=8.64V; when “Medium” threshold is set, the cutoff voltage is 8.64*50%=4.32V.
5. Startup Mode: Normal/Soft/Super-Soft. The motor speed time from stationary to maximum is 300ms / 1.5s / 3s.
   • Normal mode is suitable for fixed-wing aircraft.
   • Soft or Super-soft modes are suitable for helicopters.
   • Manual note shown: if throttle is completely closed and opened again (throttle stick moved to top position) within 3 seconds after the first start, it will be automatically switched to normal mode to avoid slow throttle response.
6. Timing: Low/Medium/High (3.75°/15°/26.25°). Manual note: usually, low timing is suitable for most motors; after changing timing, test on the ground before flying.

Protection Function (manual)

1. Start up protection: if the motor fails to start up within 2 seconds when pushing the throttle, the ESC will cut-off the output power. In this case, the throttle stick must be moved to the bottom again to restart the motor. Cases listed: connection between ESC and motor is not reliable; output lines are disconnected; propellers are blocked by other objects; or slow-down teeth are stuck.
2. Temperature protection: when the temperature of the ESC is over about 110 Celsius degrees, the ESC will reduce the output power. It will not cut off all output power; it will turn down 40% of full power so the motor power does not drop, and then gradually regains maximum power.
3. Throttle signal loss protection: the ESC will reduce output power if throttle signal is lost for 1 second; further loss for 2 seconds will cause output power to be cut off completely. If the throttle control signal is restored during the power drop, the throttle control is restored immediately. Manual note: if the remote control signal is lost for a long time, the ESC reduces power gradually rather than cutting off output at once.
4. Overload protection: when the load suddenly becomes very large, the power will be cut off or restarted automatically. The motor blockage can lead to sudden load increase.

Throttle Range Calibration (manual)

1. Switch on the transmitter; move the throttle stick to the top position.
2. Connect the battery pack to the ESC; wait for about 2 seconds.
3. The “Beep-Beep-” tone should be emitted, which means the top point of throttle range has been confirmed.
4. Move the throttle stick to the bottom position and wait for 1 second.
5. The “Beep-Beep-” tone means the bottom point of the throttle range has been confirmed.
6. A long “Beep” tone should be emitted, which means LiPo battery cell number.
7. The system is ready for flight.

Normal Startup Procedure (manual)

1. Move throttle stick to bottom position and then switch on transmitter.
2. Connect battery pack to ESC; special tone like “123” means power supply is OK.
3. Several “beep-” tones should be emitted to present the amount of lithium battery cells number.
4. When self-test is finished, a long “beep-----” tone should be emitted.
5. Move throttle stick upwards to fly.

Trouble Shooting (manual table shown)

• After power on, motor does not work, and no sound is emitted: Possible reason: connection between battery pack and ESC is not correct. Action: check the power connection; replace the connector.
• After power on, motor does not work, alert tone “beep-beep-, beep-beep-, beep-beep-” (each “beep-beep-” interval about 1 second): Possible reason: battery pack and input voltage is abnormal, too high or too low. Action: check the voltage of battery pack.
• After power on, motor does not work, alert tone “beep-, beep-, beep-” (each “beep-” interval about 2 seconds): Possible reason: throttle signal is irregular. Action: check the receiver and transmitter; check the cable of throttle channel.
• After power on, motor does not work, alert tone “beep-, beep-, beep-” (each “beep-” interval about 0.25 second): Possible reason: throttle stick is not in the bottom (lowest) position. Action: move the throttle stick to bottom position; reset the throttle range.
• After power on, motor does not work, special tone “56712” is emitted after 2 beep tone (beep-beep-): Possible reason: direction of the throttle channel is reversed, so the ESC has entered program mode. Action: set the direction of throttle channel correctly.
• The motor runs in the opposite direction: Possible reason: errors in the sequence of the connection between the output line and the motor line. Action: swap any two of the three output lines.

Programming With Transmitter (4 steps, manual)

1. Enter program mode
2. Select programmable items
3. Set parameter value (programmable value)
4. Exit program mode

Manual note shown: make sure the throttle curve is set to 0 when the throttle stick is at bottom position and 100% for the top position.

1) Enter Program Mode (manual)

1. Switch on transmitter; move throttle stick to top position; connect the battery to ESC.
2. Wait for 2 seconds; the motor should emit a special tone like “beep-beep-”.
3. Wait for another 5 seconds; special tone like “56712” should be emitted, which means program mode is entered.

2) Select Programmable Items (manual)

After entering program mode, 8 tones are played in a loop. If the throttle stick is moved to bottom within 3 seconds after one kind of tone, that item is selected:

• 1. “beep” (1 short tone): brake
• 2. “beep-beep-” (2 short tone): battery type
• 3. “beep-beep-beep-” (3 short tone): cutoff mode
• 4. “beep-beep-beep-beep-” (4 short tone): cutoff threshold
• 5. “beep-----” (1 long tone): startup mode
• 6. “beep-----beep-” (1 long 1 short): timing
• 7. “beep-----beep-beep-” (1 long 2 short): set all to default
• 8. “beep-----beep-----” (2 long tone): exit

Manual note shown: 1 long “beep-----” equals 5 short “beep-”.

3) Set Item Value (Programmable Value) (manual)

Tones are played in a loop. Set the value matching a tone by moving the throttle stick to top when the tone is heard. A special tone “1515” indicates the value is set and saved. Keeping the throttle stick at top returns to item selection; moving the stick to bottom within 2 seconds exits program mode directly.

4) Exit Program Mode (manual)

Two ways are shown:

1. In step 3, after special tone “1515”, move throttle stick to bottom position within 2 seconds.
2. In step 2, after tone “beep-----beep-----” (item #8), move throttle stick to bottom within 3 seconds.

Details

The T-Motor AT55A-UBEC fixed-wing ESC is labeled for 2–6S LiPo use and includes a 5A/5V UBEC for powering onboard electronics.

The AT series ESC is described with a dedicated fixed-wing core algorithm program and an optimized software structure for motor control.

The AT55A-UBEC ESC supports BEC output to provide stable power delivery in different power supply environments.

The AT55A-UBEC ESC emphasizes fast throttle response with protection functions such as low-voltage and throttle signal loss safeguards.

The AT55A-UBEC ESC supports multiple programmable parameters, including brake, LiPo/NiMH battery type, cutoff settings, start mode, and timing.

The AT-series fixed wing ESC supports programmable brake, battery type (LiPo/NiMH), and low-voltage protection modes for safer setup.

The AT-55A-UBEC ESC is rated for 55A continuous current with up to 75A burst (≤10s) and a switch-mode 5V/5A BEC output.

The AT55A-UBEC ESC includes clear throttle range calibration steps and startup beep guidance to help with initial setup and transmitter matching.

The AT55A-UBEC ESC documentation outlines startup, temperature, throttle-signal loss, and overload protection plus basic troubleshooting steps.

The AT55A-UBEC ESC guide covers common startup beep warnings, connection checks, and the 4-step transmitter programming process.

The AT55A-UBEC ESC uses a beep-tone programming menu to set brake, battery type, cutoff mode/threshold, startup mode, and timing.