Inverter Maintenance

We are able to provide specialist attention to the inverter section of the plant.

By carrying out an inverter maintenance and management service, we are able to provide that specialist attention to the inverter section of the plant, by ensuring that the inverters are serviceable, ready for use 24 hours per day.

Utilising a database if necessary, we are able to keep customers informed and up to date on all drives, in operation, in stores and in repair.

By increasing the reliability of the inverters used in a manufacturing environment, we are able to reduce the downtime due to a reduction of inverter failures, therefore helping the customer increase their productivity, with the aim of zero breakdowns.

System Approach Summary

RJW divides the inverter maintenance function into four distinct areas in order to maximise performance and delivery the best possible results. Each area can be tailored around each customer’s specific requirements. These sections are:-


By carrying out careful planning (including asset registration) and setting out the project in clear areas we will ensure all requirements are covered. This includes ensuring, where required by the customer, the inverter maintenance program incorporating an asset register, repair history and condition monitoring reports, is used and is delivering the outputs required. The planning stage will also ensure the inverter stock is correctly stored and the correct stock coverage is also in place.

Site Maintenance

We aim to carry out the most suitable form of condition monitoring (most likely thermography) or preventive maintenance technique to every available unit in order to generate a complete database of information on the state of each item to prevent the occurrence of unknown failures.


We carry out best practice techniques in all aspects of repair designed to maximise the life of the components involved to provide greater reliability and prevent downtime and unwanted failures.


Working within the parameters allowed by the customer, we aim to monitor all aspects of the activity on site in order to create the best possible return on the work carried out and to learn from failure modes.

Inverter Maintenance – Planning

The planning element of the inverter maintenance program has a number of aspects that can be added or removed subject to maintenance requirements and regimes on site:

Inverter Maintenance Program – Online Asset Register

An online asset register can be used in the inverter maintenance contract and be maintained as part of the contract.

This system has been written directly for inverter maintenance applications and has had a number of modifications to assist in the smooth running of the management program:

Features of the system include:

  • Online internet based access
  • Password protected security system
  • Full nameplate register listing all nameplate details
  • Inspection details
  • Repair history
  • Maintenance inspection details

As mentioned earlier, the inverter maintenance software has been written exclusively for inverter maintenance contracts, as a result further features you may require can be added by our IT personnel.

As part of the audit, a full listing is made of inverters where there is a lack of stock coverage.

Inverter Parameters

As part of this system, inverter parameters will also be taken and stored for reprogramming new drives, or following repair.

Inverter Maintenance – On site prevention and inspection

Preventive maintenance on site can significantly improve the reliability and mean time to failure of inverters on site, giving greater reliability and productivity.

The preventive maintenance inspections and procedures are designed to provide a detailed view to the condition of the plant enabling downtime to be minimised by identifying faults prior to failure.

By carrying out these activities we aim to:

  • reduce downtime
  • reduce costs
  • enable a continuous improvement approach to the inverter maintenance

We carry out the following work as part of the site preventive maintenance activity:

  • Visual inspection of the drive and it’s surrounding area.
  • Thermographic inspection of connections and terminals.
  • Inspection of connecting ribbons and fibre optic cables (if present).
  • Functional inspection of the fan and cooling system.
  • ESD protected cleaning of the drive.
  • Inspection of the emergency stop circuit.
  • Inspection and storage of the parameters.
  • Function testing of the drive under normal conditions
  • Basic measurements with supply voltage
  • Inspection of the drive spare part inventory

A report detailing any findings and also any recommendations for remedial action, would be provided following each visit.

Where additional work comes to light as a result, this will be carried out or arrangements made for a second visit.

Inverter Repairs

RJW has over 20 years experience in the repair of inverters, soft starts, servo drives and other forms of electronic speed control used within industrial manufacturing and commercial environments. We have extensive data gathered over this time to support our repair activities from a wide range of manufacturers including but not limited to:

  • ABB
  • Lenze
  • Allen Bradley
  • Leroy Somer
  • Bosch
  • Mitsubishi
  • Control Techniques
  • Moog
  • Danfoss
  • Omron
  • Emerson
  • Parker
  • Eurotherm
  • Rexroth
  • Fanuc
  • Schneider
  • IMO
  • SEW
  • Indramat
  • Siemens

Together with the manufacturers data and experience in repairing drives, RJW also has comprehensive parts stock to support the repairs in-house.

All inverters are tested using an equivalent sized motor for the drive unit as part of the repair and test procedures.

Emergency Service Repairs

RJW are one of the few electronics repair companies who offer a round the clock repair service, meaning that drives can be returned within 24 hours (subject to parts).

Repair Analysis

As part of the inverter maintenance program, a full report can be provided detailing the repair involved and, where possible, giving a root cause for the failure so that future failures can be prevented.

Inverter Maintenance – Review

RJW would aim to carry out a regular review of the program in order to measure the effectiveness of the activities involved and in order to ensure continuous improvement is being achieved.

Typically every quarter we would look to analyse the fault codes from the repair reports and, combined with the findings from our inspections, make recommendations for further actions to improve reliability further.

Benefits of the Inverter Maintenance Program

  1. By taking a proactive approach to the inverters on site, we would aim to reduce the downtime due to inverters to zero.
  2. We are able to offer a one stop shop for all makes of drives on site.
  3. We are able to combine all three major functions (planning, repair and maintenance) in one ‘package’ enabling us to easily make recommendations from our knowledge of each aspect of the programme.
  4. We are an approved representative for Control Techniques and our sales and repair staff are trained by CT.

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