How to Choose the Right ABB ACS355 VFD for OEM Machinery

Choosing an ABB ACS355 for OEM machinery should begin with the motor's rated current and load profile, not simply the motor's kW rating. For typical 400 V three-phase machinery, the ABB ACS355-03E-05A6-4 is a natural candidate for 2.2 kW applications, while the ACS355-03E-08A8-4 targets 4.0 kW output and 8.8 A nominal output current.

The correct variable frequency drive (VFD) is the one whose continuous and overload current capability matches the actual machine load while also satisfying voltage, braking, control, enclosure and environmental requirements. ABB identifies the ACS355-03E-05A6-4 as 2.2 kW, 5.6 A and IP20, and the ACS355-03E-08A8-4 as 4.0 kW, 8.8 A and IP20.

Why VFD Sizing Goes Wrong on OEM Machines

Most VFD sizing mistakes happen because engineers select a drive from motor horsepower or kW alone instead of matching the drive to the machine's actual load and operating cycle.

A motor may have the expected power rating yet still cause drive trips when a conveyor starts with a loaded belt or when machinery demands high starting torque. Selecting a drive too close to its nominal rating can leave insufficient margin for the real operating cycle.

Oversizing creates the opposite problem. A larger VFD can increase purchase cost and cabinet footprint without solving the actual engineering constraint. A drive may also perform correctly during commissioning but fail intermittently in production because the production cycle introduces more frequent acceleration and deceleration, higher thermal stress or a higher ambient temperature.

Correcting these problems requires three checks: motor current, load behavior and machine control requirements.

Three Checks Before Choosing an ABB ACS355

A reliable ACS355 selection starts with the motor nameplate and then moves outward to the mechanical load and machine control architecture.

1. Check Motor Voltage, Power and Rated Current

Record the motor's rated voltage, rated current, rated power, frequency, speed, connection and, where applicable, service factor. The motor rated current should be treated as the primary electrical sizing reference rather than kW alone.

For example, the ABB ACS355-03E-05A6-4 is specified by ABB at 2.2 kW, 5.6 A and IP20. It can therefore be evaluated for a 2.2 kW motor on a relevant 400 V three-phase supply, subject to verification of the motor nameplate and load profile.

The ABB ACS355-03E-08A8-4 is specified at 4.0 kW and 8.8 A nominal output current. It is appropriate to evaluate where the motor and application require that higher power/current capability. It should not, however, be selected merely because it is a larger model.

2. Match the Drive to the Mechanical Load

Motor power tells you how large the motor is, but the mechanical load determines how hard the VFD actually has to work.

A conveyor may require substantial torque during startup, while a fan has a substantially different load characteristic. A high-inertia machine may also need careful consideration of acceleration and braking even when its steady-state motor power appears acceptable.

3. Check Control and Installation Requirements

Before final selection, verify the required speed range, acceleration and deceleration times, braking requirements, digital and analog I/O, communication protocols, EMC requirements, IP rating, cabinet cooling and ambient temperature.

The ACS355 is best positioned as a compact, machine-oriented drive rather than a universal solution for every motor-control application. The installation environment matters as much as the electrical rating: an IP20 drive normally requires suitable cabinet protection and thermal management for the complete installation.

ABB ACS355 vs Other Compact VFD Approaches

The best VFD depends on the machine architecture, so an ABB ACS355 should be compared by application fit rather than brand reputation alone.

Pricing should be treated as indicative rather than a fixed technical specification. Prices vary by region, supplier, stock status, accessories and configuration. Schneider Electric, for example, lists different ATV320 configurations and availability, while ABB's product pages provide technical specifications rather than a universal retail price.

ABB ACS355 product documentation | Schneider Electric Altivar ATV320

Example: Retrofitting a Conveyor on an OEM Packaging Machine

In a typical packaging-machine retrofit, we start with the motor nameplate rather than the failed drive's model number.

Step 1 — Record the motor data. We capture the 400 V rating, motor kW, rated current, frequency and RPM. This establishes the electrical baseline for drive selection.

Step 2 — Observe the machine. We check empty-conveyor startup, loaded startup, normal running speed, required acceleration time and stopping behavior. These observations reveal whether the application behaves like a conventional constant-torque load or presents additional inertia and braking demands.

Step 3 — Select the drive. If the motor is 2.2 kW and its rated current and load requirements are compatible, we evaluate the ACS355-03E-05A6-4. If the application requires higher drive capacity and the motor/load data supports it, we evaluate the ACS355-03E-08A8-4. We also review the broader ABB Drives / VFD range at ChipsGate where another rating may be more appropriate.

Step 4 — Commission. We enter the motor nameplate data, verify acceleration and deceleration, confirm direction, check current under normal load and test the worst-case production cycle. The production test is important because a drive that passes an unloaded commissioning test has not necessarily been validated for the machine's real duty cycle.

Four ACS355 Selection Mistakes to Avoid

1. Selecting by kW alone. The motor's kW rating may match while its rated current or overload requirement does not. Workaround: compare the motor nameplate current with the drive's applicable current rating.
2. Ignoring acceleration requirements. High inertia can produce overcurrent during acceleration. Workaround: review acceleration time, load inertia and braking requirements.
3. Treating IP20 as a complete installation solution. The drive's enclosure rating does not automatically make the complete cabinet suitable for dust, humidity or temperature conditions. Workaround: evaluate cabinet cooling and the complete installation environment.
4. Assuming a larger VFD is always safer. Oversizing can increase cost without resolving the actual engineering constraint. Workaround: size around actual current, load profile and required overload capacity.

Why VFD Selection Is Also an Energy Decision

VFD selection affects more than machine control because motor-driven systems represent a major share of industrial electricity consumption. The International Energy Agency reports that electric motors and the systems they drive account for more than 40% of global electricity consumption and identifies efficiency improvements in these systems as a significant opportunity.

A VFD does not automatically guarantee energy savings. The benefit depends on the load and operating profile. Variable-speed applications such as fans and centrifugal pumps generally offer stronger savings opportunities when output demand varies, whereas a constant-torque machine may have a different economic case.

The regulatory context also matters. EU Regulation 2019/1781 establishes ecodesign requirements for covered electric motors and variable speed drives. For covered VSDs, the regulation specifies power-loss requirements corresponding to the IE2 efficiency class from July 2021.

The Practical ABB ACS355 Selection Rule

For OEM machinery, the right ABB ACS355 is the model that matches the motor's rated current, mechanical load, overload requirements and installation environment—not simply the closest kW number.

• Start with the motor nameplate.
• Match the drive to the mechanical load.
• Validate acceleration, braking, environment and control requirements.

Need help selecting an ABB ACS355 for your machine? Review the available ABB drives at ChipsGate and compare the model specifications against your motor nameplate before ordering.

FAQ

Can I choose the ACS355 only by motor horsepower?

No. Motor rated current and the actual load profile also need to match the drive. kW is an important starting point, but it does not fully describe overload requirements or application behavior.

Is the ACS355-03E-05A6-4 suitable for a 2.2 kW motor?

It depends. The motor voltage, rated current, load type and operating conditions must also be compatible. ABB identifies this model as 2.2 kW, 5.6 A and IP20.

Can I use the ACS355-03E-08A8-4 for a smaller motor?

It depends on the application. Oversizing does not automatically make a VFD a better choice. Current matching, control behavior, cost and the machine's operating requirements should all be considered.

Are VFDs always more energy efficient than fixed-speed operation?

No. The energy benefit depends on the load and operating profile. Variable-speed control is particularly valuable where the required mechanical output varies substantially.

Is the ACS355 a good choice for OEM machinery?

Yes, when its electrical ratings, control requirements and environmental requirements match the machine. It should not be treated as universally the best VFD; application fit remains the deciding factor.