What does 'Faulty usage' mean on my ABB PSTX370?
- Ssamuel34Sep 23, 2025
Do not use jog forward, jog backward, heat motor, or stand-still break functions with an Inside delta motor connection.
 

What does 'Faulty usage' mean on my ABB PSTX370?
Do not use jog forward, jog backward, heat motor, or stand-still break functions with an Inside delta motor connection.
What does it mean when my ABB PSTX370 Controller displays 'Ground fault'?
A ground fault indicates that the sum of the instantaneous line currents in your 3-phase system differs more than the specified value. Examine the motor cables and the motor itself for any issues.
What should I do if my ABB PSTX370 displays 'Locked rotor'?
Examine the bearings of the motor and the load to ensure they run easily. A damaged bearing or a load stock could be the cause.
What does it mean when my ABB Controller displays 'Overvoltage'?
An overvoltage error indicates that the main voltage is too high. Perform a check of the main voltage.
What does it mean when my ABB PSTX370 displays 'Under voltage'?
An undervoltage error indicates that the main voltage is too low. Perform a check of the main voltage.
What does 'High current' mean on my ABB PSTX370 Controller?
A high current fault indicates that a fault current, higher than 8 times the softstarter's rated current, has occurred. Check the circuits and the motor for an insulation fault between phases or a ground fault.
What does 'Voltage imbalance' mean on my ABB Controller?
Voltage imbalance indicates that there is a voltage imbalance between the phases. Check the main voltage and restart the motor.
Why does my ABB PSTX370 display 'Too long start time'?
This indicates that the time taken to soft start the motor is longer than the set value. Check the starting conditions and current limit.
How do I fix an ABB PSTX370 Controller that shows a blank screen and no LED is active?
First, ensure that the supply voltage is properly connected, referring to the circuit diagram. Also check that the RJ45 plug is connected between the HMI and the softstarter, and that the RJ45 network cable is not damaged.
What to do if my ABB Controller motor is humming or starts without a given start signal?
This issue could be due to a few reasons. If it's a PSTX30...170 model, a bypass relay might be closed due to inaccurate handling. To resolve this, disconnect the operation voltage and the control supply voltage, remove the USB cable if connected, and then reconnect the voltage in the following sequence: first, the control supply voltage on terminals 1 and 2 (refer to chapter 5.1.2), wait 4 seconds, and then connect the operation voltage on terminals L1, L2, and L3. Alternatively, the bypass contactor/relay could be stuck in a closed position, or there might be a shorted thyristor. In either of these cases, it is best to speak to your ABB Sales Office.
| Product Type | Softstarter | 
|---|---|
| Rated Operational Current - In Line Connection | 370 A | 
| Rated Operational Current - Inside Delta Connection | 640 A | 
| Enclosure Rating | IP00 | 
| Rated Frequency | 50/60 Hz | 
| Overload Protection | Yes | 
| Coasting Stop | Yes | 
| Built-in Bypass Contactor | Yes | 
| Degree of Protection | IP00 | 
| Communication Options | Modbus RTU | 
| Protection Features | Overload protection | 
| Trip Class | 10 | 
| Initial Voltage During Start | Adjustable 30-70% | 
| Ramp Time | 30 s | 
Critical safety warnings for handling hazardous voltage, installation, and power supply connection.
Instructions for connecting the main power circuit to the softstarter terminals.
Guidelines for connecting control supply voltage and functional earth to the softstarter.
Instructions for connecting start/stop circuits, programmable inputs, and signal output relays.
Details on switching operational voltage, Modbus, sensor, and analog output interfaces.
Detailed description of all Human Machine Interface (HMI) components and their functions.
Procedures for first start-up using the assistant and configuration menu.
Important note on setting the motor rated current 'le' based on connection type.
Guide to navigating the HMI and setting operational parameters.
Overview of option menus and a critical warning about unexpected motor starts.