The Lenze SMD inverter, commonly identified by model numbers beginning with ESMD, was widely used in industrial motor control applications. Although the range has been obsolete for some time, many machines fitted with these drives remain in service across manufacturing and industry.
For businesses still operating equipment with an SMD inverter, the main question is what happens when the drive fails or needs replacing.
The good news is that an obsolete inverter does not necessarily mean the machine itself needs replacing. For many straightforward applications, the Lenze i510 provides a potential modern replacement route, subject to checking the original drive specification and the requirements of the application.
Modern Drives & Controls supplies Lenze inverter drives and provides technical support for replacement applications.
What was the Lenze SMD inverter?
The Lenze SMD was a compact frequency inverter designed to control the speed of AC motors. Drives from this range were used in a variety of applications where straightforward, reliable variable-speed control was required.
Typical applications included conveyors, pumps, fans and other industrial machinery.
The drives offered basic motor speed control alongside functions such as acceleration and deceleration ramps, fixed frequencies, motor monitoring and configurable inputs and outputs.
Many of these machines were designed around the original SMD drive. As a result, replacing the inverter involves more than simply choosing another drive with the same kilowatt rating.
What does obsolescence mean for existing SMD drives?
Although the Lenze SMD range is obsolete, drives already installed in machinery can continue to operate for years, provided the equipment remains in good condition.
The difficulty arises when a drive develops a fault, replacement stock becomes harder to source, or a machine needs to be returned to service quickly.
Depending on the specific model, it may still be possible to locate an existing unit or investigate a repair. However, availability should be checked rather than assumed, and relying on an increasingly difficult-to-source drive can create problems for future maintenance.
For equipment that remains important to production, it may be worth identifying a suitable modern replacement before a failure occurs.
What replaces the Lenze SMD / ESMD inverter?
For many straightforward applications previously using an SMD inverter, the Lenze i510 is a sensible starting point when assessing a replacement.
The i510 is part of the modern Lenze i500 inverter family and is designed for a range of standard industrial motor-control applications.
However, the correct replacement depends on the original ESMD model, the motor being controlled and how the drive is integrated into the machine. A replacement should be selected against the actual electrical and functional requirements rather than by matching the power rating alone.
What needs checking before replacing an ESMD drive?
Before selecting a replacement, the following information should be checked:
-
Original model number: The full ESMD type number helps establish the original drive specification.
-
Supply voltage and phase: Confirm the incoming electrical supply and the drive's input requirements.
-
Motor rating: Check the motor's rated voltage, current, power and operating requirements.
-
Control method: Establish whether the drive receives start/stop commands and a speed reference from switches, a potentiometer, a PLC or another control system.
-
Inputs and outputs: Check which digital and analogue signals are used, including any interlocks or status signals.
-
Braking and stopping requirements: Confirm whether the application relies on particular deceleration times, braking functions or external braking components.
-
Physical installation: Check the available space, mounting arrangement, cable connections and enclosure requirements.
-
Parameters and commissioning: Record the existing settings where possible and establish how the replacement will be configured and tested.
These checks help avoid choosing a drive that appears suitable on paper but does not meet the needs of the existing machine.
Can a Lenze i510 be fitted directly in place of an ESMD?
Not necessarily. Although the i510 is a potential replacement for many basic SMD applications, a direct, drop-in replacement should not be assumed.
The mounting arrangement, power connections, control terminals and parameter settings may differ. The replacement may therefore require wiring changes, configuration work or modifications to the existing installation.
It is also important to establish whether the original application uses any functions or interfaces that need to be retained.
By checking these details before ordering, it is possible to plan the changeover properly and reduce the risk of unexpected problems during installation and commissioning.
For further information, see our guide to selecting the right Lenze i500 inverter for your application.
Should you replace an obsolete SMD drive before it fails?
There is no need to replace every working SMD inverter simply because the range is obsolete. If the machine is operating reliably, a replacement may not be immediately necessary.
However, there are good reasons to plan ahead, particularly where a machine is critical to production or where a drive failure could cause significant downtime.
Identifying the original model, checking replacement options and understanding any required wiring or configuration changes can make a future replacement much easier to manage.
Where several machines use the same drive, planning ahead can also help maintenance teams establish a consistent replacement approach.
Lenze SMD / ESMD inverter replacements from Modern Drives & Controls
Modern Drives & Controls supplies Lenze inverter drives and supports customers looking to replace older or obsolete equipment.
For an SMD / ESMD replacement, we can help assess the original drive specification and identify a suitable modern alternative, with the Lenze i510 being a potential option for straightforward applications.
To help us identify the correct replacement, provide the full model number from the existing drive's nameplate, together with the motor rating and a brief description of the machine or application.
You can find out more about our Lenze drives and technical support or contact Modern Drives & Controls to discuss your requirements.
Still running a Lenze SMD / ESMD inverter? Contact our team before your existing drive becomes a problem, and we can help you assess the available replacement options.
