Check F014 (current limit): if it is too low (such as 200% FLA, not enough to drive the load), it can be increased to 350-400% FLA;
Check the power supply and wiring:
Measure the main power supply voltage: whether it is lower than the rated value (such as the actual 180V of the 208V system, causing an increase in starting current), and repair the power supply is required;
Check the motor wiring: T1/T2/T3 for looseness (high contact resistance, sudden increase in current), re tighten the terminals;
Verification and adjustment: After troubleshooting, restart and observe the current curve. If the overload still persists, evaluate whether the capacity of the soft starter matches the motor (e.g. motor 100HP, soft starter only 75HP, need to be replaced with a larger capacity model).
Question 3: What are the types of wiring for TE2 series soft starters? How to configure 3-wire control and analog output (4-20mA) wiring? What are the functions and wiring precautions of bypass contactors?
Answer:
Wiring classification: TE2 series wiring is divided into three categories according to function: power wiring (main circuit), control wiring (signal circuit), and communication wiring (optional):
Power wiring: Connect the main power supply (L1/L2/L3) and the motor (T1/T2/T3), carry high currents, and match the wire diameter and torque according to the model;
Control wiring: including 3-wire/2-wire start control, interlock signal, jog signal, analog output, fault output, etc., using low voltage (DC 24V/AC 120V);
Communication wiring: RS485 Modbus communication, used for remote monitoring and parameter configuration of upper computer (PLC/touch screen), using shielded twisted pair cables.
Key control wiring configuration:
(1) 3-wire control (Start/Stop button) wiring:
Terminal selection: Terminals 1, 2, and 3 of TB1 (DC 24V terminal block);
Wiring logic:
Terminal 1: One end connected to the Start button (normally open NO contact);
Terminal 2: Connect the other end of the Start button and one end of the Stop button (normally closed NC contact);
Terminal 3: Connect the other end of the Stop button to form a series circuit of "Start NO+Stop NC";
Attention: TB1 has a built-in 24V DC power supply and does not require an external power supply; The Stop button needs to have normally closed contacts to ensure that the motor stops when the power is cut off.
(2) Analog output (4-20mA) wiring:
Function: Output signals such as motor current, voltage, and thermal capacity for PLC or instrument monitoring;
Terminal selection: Terminal 9 (signal+) and Terminal 10 (signal -) of TB1;
Wiring steps:
Connect TB1-9/10 to the analog input module (4-20mA channel) of the PLC using shielded twisted pair cables;
Programming parameter F108: Select monitoring signal (e.g. "1"=A-phase current, "12"=thermal capacity);
Programming parameters F109 (corresponding value of 4mA) and F110 (corresponding value of 20mA): If monitoring phase A current from 0-200A, set F109=0 and F110=200;
Attention: Single ended grounding of shielding layer (soft starter side) to avoid interference; The distance between the analog line and the power line is ≥ 10cm to reduce electromagnetic interference.
Function and wiring precautions of bypass contactor:
Function:
After the soft starter completes the start-up (when the motor reaches full speed and the "At Speed" LED lights up), the bypass contactor is closed to short-circuit the SCR and prevent it from overheating during long-term operation, thereby extending its lifespan;
When there is a fault (such as SCR short circuit), the bypass contactor will disconnect and cut off the motor power supply;
Some models (BP series) support "emergency bypass start". When the soft starter fails, the motor can be directly started by controlling the bypass contactor through external contacts (requiring external overload protection).
Wiring precautions:
Built in bypass contactor (BP series): The factory has completed internal wiring, no on-site wiring is required, only ensure that the control power supply (A1-A2, TB2-21/22) is normal;
Emergency bypass wiring (optional):
Terminal selection: B1 (coil+) and B2 (coil -) terminals of TB4 (only available in BP series);
Wiring requirements: External normally closed contacts (such as emergency buttons), directly engage the bypass contactor when closed; External overload relay (OLR) contacts need to be connected in series to avoid unprotected operation of the motor;
Capacity matching: The rated current of the bypass contactor should be ≥ the rated current of the motor. In case of emergency bypass, the selection should be based on "full voltage starting" (e.g. motor 100A, contactor 125A);
Interlocking logic: Before closing the bypass contactor, it is necessary to confirm that the motor has reached full speed to avoid a sudden increase in current caused by the bypass at half speed (the soft starter has a built-in "At Speed" detection, which automatically controls the contactor).

Email:wang@kongjiangauto.com