The Lenze SSN range of small geared motors has been used in industrial machinery and equipment for many years. Models including the SSN25, SSN31 and SSN40 can still be found operating on older machinery, despite the range now being obsolete.
When one of these geared motors eventually needs replacing, identifying a suitable alternative can be more complicated than simply matching the motor power or gearbox size.
Modern Drives & Controls can help identify older Lenze SSN geared motors and source a suitable replacement for the existing machine.
Is the Lenze SSN geared motor range obsolete?
Yes. The Lenze SSN range is no longer part of Lenze's current geared-motor range.
This means that if an SSN25, SSN31 or SSN40 geared motor fails, the original unit may no longer be available as a new Lenze replacement.
However, the fact that the original geared motor is obsolete does not necessarily mean that the machinery needs to be redesigned.
The first step is to identify exactly what is fitted to the machine and establish the requirements for its replacement.
Which Lenze SSN geared motors are affected?
The SSN range included a number of small geared-motor configurations, including:
- SSN25
- SSN31
- SSN40
Different motor powers, gearbox ratios, output speeds, mounting arrangements and other options were available.
The original Lenze catalogue shows, for example, a range of SSN31 configurations with different reduction ratios and output speeds.
This is why the type number alone should not always be treated as a complete specification.
How do you identify an old Lenze SSN geared motor?
The best starting point is the motor or gearbox nameplate.
If you have an SSN geared motor on existing machinery, take a clear photograph of the nameplate and send it to us.
Where possible, we are looking for:
- Complete Lenze type number
- Lenze material number
- Motor power
- Motor voltage
- Motor speed
- Gear ratio
- Output speed
- Output torque
- Mounting arrangement
- Shaft or bore dimensions
- Any brake or other options
The Lenze material number is particularly useful when identifying older equipment, as the same basic SSN type can be available in different configurations.
If you can provide a photograph of the complete geared motor as well as the nameplate, this can also help us understand the mechanical arrangement.
Why isn't matching the motor power enough?
An old geared motor cannot necessarily be replaced simply by finding another motor with the same kilowatt rating.
For example, two geared motors could have the same motor power but different:
- Reduction ratios
- Output speeds
- Output torque
- Shaft or bore dimensions
- Mounting arrangements
- Motor speeds
- Electrical specifications
The replacement therefore needs to be considered in relation to the machine, not just the motor rating.
This is particularly important when replacing an obsolete geared motor that has been installed in an existing machine for many years.
What if the nameplate is missing?
A missing or unreadable nameplate does not necessarily mean that the geared motor cannot be identified.
We may be able to work from information such as:
- Photographs of the motor and gearbox
- Motor power
- Supply voltage
- Motor speed
- Output speed
- Gearbox ratio
- Shaft or bore dimensions
- Mounting dimensions
- Available space
- Description of the machine
- Required machine speed
- Information about the driven load
The more information available, the easier it is to determine what the original geared motor was doing and what the replacement needs to achieve.
Example: identifying an SSN31 geared motor
One example of an older Lenze SSN31 geared motor is:
Type: SSN31-1UHAR-056C21
Lenze material number: 13473385
The original Lenze specification for this particular unit includes:
| Specification | Original unit |
|---|---|
| Motor type | 13.751.55.3.2.0 |
| Motor | AC asynchronous |
| Rated power | 0.150 kW |
| Motor speed | 2700 rpm |
| Rated voltage | 230/400 V AC |
| Frequency | 50 Hz |
| Gear ratio | 10:1 |
| Output speed | 270 rpm |
| Motor rated torque | 0.530 Nm |
| Output torque | 4.09 Nm |
| Protection | IP55 |
| Insulation class | F |
| Thermal protection | NC thermal contact |
| Hollow shaft | 15 mm |
| Mounting | Foot mounted with centring |
| Output | Without flange |
This example demonstrates why identifying the complete specification matters.
The motor speed, gearbox ratio and output speed are different values, and the mechanical arrangement is also an important part of the replacement specification.
Replacing an obsolete Lenze SSN geared motor
There is not necessarily a single modern replacement that can simply be selected from the old SSN type number.
Instead, the replacement needs to be selected around the requirements of the existing machine.
Depending on the application, this can include checking:
- Required output speed
- Required output torque
- Motor power
- Supply voltage
- Gearbox ratio
- Shaft or bore dimensions
- Mounting arrangement
- Available installation space
- Duty cycle
- Starting and stopping requirements
- The characteristics of the driven machine
Our aim is to identify a practical replacement that provides the required performance while being suitable for the existing installation.
Need to replace an old Lenze SSN motor?
If you have an obsolete Lenze SSN25, SSN31 or SSN40 geared motor, send us a photograph of the nameplate.
If you have the Lenze material number, complete type code or any original documentation, include that as well.
Even if the nameplate is damaged or some of the information is missing, we may be able to work from photographs and the details of the existing machine.
Modern Drives & Controls has extensive experience identifying older Lenze equipment and helping customers find practical replacement solutions for obsolete products. Our wider Lenze replacement work also includes older GKR, GSS, GKS, GST, GFL and GPA geared motors.
Have an obsolete Lenze SSN geared motor that needs replacing?
Contact Modern Drives & Controls with the details or a photograph of the existing unit and our technical team can help establish the replacement requirements.