ABB ACS380 Inverter Complete Guide

Safety features: STO, SS1-t, and PROFIsafe

4.1 Built in Safety Torque Shutdown (STO)

All ACS380 come standard with STO and comply with IEC 61800-5-2, ISO 13849-1 PL e/Cat.3, and SIL3. STO cuts off the drive signal of the inverter output stage, causing the motor to enter a torque free state and stop sliding freely. Typical application: To prevent accidental start-up (compliant with EN ISO 14118) or emergency stop (Class 0 stop).

Wiring points: The STO terminals (X1:5 and X1:6) are dual channel safety inputs. During normal operation, both channels require 24V DC. Any loss of 24V or inconsistency of two signals for more than 1 second will trigger a safety stop. A common mistake made on site is that only one channel was connected, resulting in the inability to close the safety circuit. The two normally open contacts of the safety relay or safety PLC must be connected to the STO input terminal separately.

4.2 Safety Stop Time Control (SS1-t)

SS1-t first decelerates according to the set slope, and automatically activates STO when the speed drops to zero. If the deceleration does not reach zero within the specified time, STO will be triggered directly. Compliant with Class 1 stop (EN/IEC 60204-1). SS1-t can be triggered by the safety PLC through PROFIsafe safety communication (using FSPS-21 module), or directly triggered through hardware terminals (parameters need to be set).

4.3 PROFIsafe module FSPS-21

Option+Q986 provides FSPS-21 module, supporting both PROFINET IO and PROFIsafe. This module is directly installed on the side of the frequency converter (without occupying the I/O option slot), and the safety PLC sends STO or SS1-t commands through PROFIsafe, without the need for hard wired safety circuits. Attention: FSPS-21 is not compatible with other fieldbus modules (such as FPNO-21) and can only choose one of the two.

Troubleshooting: Unable to reset after triggering the safety function. Check the status word of the safety PLC and confirm that the safety request has been revoked. Then check if the frequency converter parameter 31.22 (STO status) is "OK". If the parameter displays' Channel mismatch ', check if the flat cable between FSPS-21 and the frequency converter is loose. Power off and restart can clear temporary faults, but hardware issues require module replacement.

Communication and I/O Expansion: Standard vs Configuration

5.1 Built in interface of standard type (S)

4 DI+2 DI/DO (configurable)+2 AI+1 AO+1 relay output+STO.

Built in Modbus RTU (EIA-485 terminal).

Side options include BREL-01 (with 4 additional relay outputs), BAPO-01 (external 24V power supply), and BTAC-02 (HTL/TTL encoder+external 24V).

5.2 Flexible selection of configuration type (C)

The configuration type substrate only retains 2 DI+1 RO+STO, and all other I/O and communication are implemented through options:

Front end I/O options: BIO-01 provides 3 DI+1 DO+1 AI (used in conjunction with fieldbus).

Side options (one out of three): BTAC-02 (encoder+external 24V supply), BREL-01 (4 relays), BAPO-01 (external 24V supply).

Fieldbus options (one must be selected): see the table below.

Option code protocol module model

+K451 DeviceNet FDNA-01

+K454 PROFIBUS DP FPBA-01

+K457 CANopen FCAN-01

+K469 EtherCAT FECA-01

+K470 Ethernet POWERLINK FEPL-02

+K490 EtherNet/IP FEIP-21

+K491 Modbus/TCP FMBT-21

+K492 PROFINET IO FPNO-21

Engineering Tip: When selecting, if PROFIsafe safety communication is required, the combination of+K492 (PROFINET IO) and+Q986 (FSPS-21) must be selected, and other buses cannot be used. In addition, all fieldbus modules will automatically configure upon the first power on, and the PLC can remotely complete the variable frequency drive parameter settings, greatly reducing debugging time.

Common communication failure: PLC cannot establish a connection with the frequency converter. Firstly, check if the LINK indicator light on the bus module is constantly on. For PROFINET, use the "Device Topology" feature of TIA Portal to confirm that the device name is consistent with the frequency converter settings (default is empty at the factory and needs to be written using Drive Composer). For EtherNet/IP, check if the IP address matches the one configured in the PLC and confirm that the EDS file has been imported correctly.

Selection and Application of Braking Resistors

ACS380 comes standard with a built-in brake chopper (available on all models except for the minimum power model). The braking resistor needs to be externally connected.

6.1 Key Parameters

Rmin: The minimum allowable resistance value. Below this value will cause overcurrent damage to the chopper.

Rmax: The maximum resistance value that ensures continuous braking power (PBRcont). The larger the resistance, the smaller the braking power.

PBRcont: Continuous braking capability (can withstand unlimited time).

PBRmax: Maximum braking capacity (1.5 times PBRcont within a 1-minute/10 minute cycle).

For example, three-phase 400V model ACS380-04xx-07A2-4 (R1 chassis):

Rmin=53Ω，Rmax=139Ω， PBRcont=2.2kW，PBRmax=3.3kW。

6.2 Selection Example

If a braking power of 2.5kW is required for 5 seconds, every 10 seconds, the average braking power=2.5kW × 5/10=1.25kW, which is less than PBRcont=2.2kW and meets the requirement. The peak power of 2.5kW is less than PBRmax=3.3kW, which also meets the requirement. We recommend using Danohm resistors provided by ABB (such as CBR-V 330 D T 406 78R UL). If a third-party resistor is used, it must be ensured that the resistance value is ≥ Rmin and ≤ Rmax, and the heat capacity (Joule integral) of the resistor must be calculated.