Schneider ATV320 Inverter Installation and Debugging Guide

The control terminal is located below the front of the frequency converter (compact type) or on a detachable control module. The key terminals are as follows:

AI1, AI2, AI3: Analog inputs (0~10 V or 0~20 mA)

AQ1: Analog output (0~10 V or 0~20 mA)

DI1~DI6: Digital input, can be configured as source type (PNP) or drain type (NPN) through the SW1 switch

R1A/R1C, R2A/R2C: Relay output (R1:3A/250Vac; R2:5A/250Vac)

STO: Safe torque shutdown input (dual channel)

P24,+24:24 Vdc power input/output

Wiring points:

It is recommended to use shielded twisted pair for digital input, with the shielding layer grounded at one end (on the frequency converter side)

The analog input cable and power line should be routed separately, with a minimum distance of 20 cm between them

The STO terminal must be connected to 24 Vdc in order to function properly; If the external power supply is disconnected, the STO function is triggered and the motor cannot start

3.3 Grounding and EMC

The grounding terminal (PE) of the frequency converter must be directly connected to the cabinet grounding busbar using a separate wire, and series grounding is prohibited. The shielding layer of shielded cables should use metal clamps to extensively contact the grounding plate.

For situations that require compliance with IEC 61800-3 category C2 or C3, shielded motor cables must be used and EMC filters (some low-power models have built-in filters) must be installed on the incoming side. If operating on IT systems (ungrounded or high impedance grounded) or corner grounded systems, the Y capacitor with built-in EMC filter must be disconnected (by removing or moving IT jumpers/screws), otherwise it may cause overvoltage or overheating damage.

Selection of upstream protection devices: circuit breakers and fuses

ATV320 must be equipped with appropriate short-circuit protection devices (SCPD) to ensure the safety of upstream lines in the event of internal faults in the frequency converter. The manual provides a detailed selection table for IEC and UL/CSA.

4.1 Selection of Circuit Breakers (IEC)

Taking a 240V single-phase power supply and ATV320U07M2B (0.75 kW) as an example:

PowerPacT series, model H, can be selected ▪ L36020， Set current 20 A, SCCR 5 kA

Or choose the TeSys GV2 series, model GV2L161703, SCCR 5 kA

Minimum shell volume requirement is 55 liters (3323 cubic inches)

For 415V three-phase ATV320U55N4B（5.5 kW）：

Choose PowerPacT H ▪ L36020（20 A），SCCR 22 kA

Or TeSys GV2L223276, SCCR 22 kA

Engineering Tip: When selecting, it is also necessary to calculate the expected short-circuit current (Isc) at the installation point. The manual provides Isc estimation formulas and tables based on transformer capacity, cable length, and cross-sectional area. For example, when a 100 kVA transformer (usc=4%), 400 Vac, cable 10 m, 10 mm ² (AWG 8), Isc ≈ 6.6 kA。 The maximum breaking capacity of the selected SCPD must be greater than this value, and its minimum allowable Isc should be less than the actual Isc.

4.2 Selection of fuses (IEC)

For single-phase 240V input, it is recommended to use gG or gR/gS/aR type fuses. For example, ATV320U04M2B requires the use of a 12 A fuse (gG type) or a 10 A fuse (gR type), with an SCCR of up to 100 kA. In high short-circuit capacity situations, fuses often provide higher breaking capacity.

4.3 UL Certification Selection

For the North American market, please refer to Appendix NVE21777 of the ATV320 Quick Start Guide. Typical configurations such as ATV320U15N4C can be paired with PowerPacT H ▪ L36015 circuit breaker or class J fuse (15A).

IT system operation disconnected from EMC filter

In ungrounded (IT) or corner grounded systems, the built-in EMC filter (Y capacitor) in the frequency converter can cause an increase in ground leakage current, which may lead to false alarms or damage to the insulation monitoring device. Therefore, the filter must be disconnected.

The operational steps vary depending on the framework:

Frame 1B/2B: Find the IT jumper under the installation screw of the top GV2 circuit breaker adapter and turn it to the "disconnected" position

Frame 4B/5B/4C/5C: Remove the power terminal protection cover, find the dip switch or screw on the left side, and move it to the disconnected position

Frame 1C/2C/3C: Remove terminal cover, move jumper or remove/reinstall screws (note: screws cannot be lost and cannot be operated without screws)

High protection W/WS: Remove the front cover, find and operate the switch/screw inside

After completing this setting, the frequency converter will no longer meet the EMC requirements of IEC 61800-3 and other measures need to be taken at the system level (such as installing external filters).

Control terminal source/drain configuration (Sink/Source)

The digital input of ATV320 can be configured as source type (PNP, factory default) or drain type (NPN) through a micro switch (SW1). The switch is located below the control terminal and can only be accessed by removing the control module cover plate.

Source type (SRC): The common terminal is connected to 0V, and the input terminal receives a+24V signal. Suitable for PNP output of most PLCs.

Leakage type (SINK or EXT): The common terminal is connected to+24V, and the input terminal receives a 0V signal. Suitable for NPN output.