Key points
Modern AC drives need very little routine attention, but they’re not quite fit-and-forget devices. However, a well-planned program of preventive maintenance can help users to consistently get the best from their drives.
After they’re installed and commissioned, AC drives generally get on with the job they’re intended to do. As a result, there’s an understandable tendency to leave them to it, especially when the drive user’s maintenance team more often than not has more pressing matters to deal with.
It may even seem as if leaving the AC drives to their own devices has no serious consequences but in reality this is much like driving a car without ever having it serviced. Everything seems fine for a while, but sooner or later, there will inevitably be a price to pay.
What problems can happen to AC drives with no maintenance?
So, what is at risk when an AC drive receives no routine maintenance? The simple answer is quite a lot! Terminals could work loose leading to overheating and ultimately failure. Air filters could clog reducing the cooling air flow and pushing up the operating temperature of the AC drive, resulting in a shorter working life. Firmware may not get updated, depriving the AC drive user of the latest enhancements to the product.
The list goes on, but we can summarise by saying that the major consequences of neglecting routine maintenance is degradation in AC drive performance over time accompanied by reduced reliability and shortened working life. All of these issues can have a big impact on the user’s business; reduced reliability, for example, means more unplanned downtime, and downtime is both costly and disruptive.
How to implement an AC drive maintenance plan
Clearly, routine maintenance for AC drives brings important benefits. However, maintenance resources and budgets at many sites today are under extreme pressure, so how can an effective yet affordable AC drive maintenance program be planned and implemented? Below we discuss a simple and convenient example a preventive maintenance service:
The foundation is a comprehensive audit of the AC drive installation, which not only considers the AC drive but also the way it’s being used and the conditions in which it operates. This is vital, because it’s no surprise that an AC drive with a tough duty cycle operating in a challenging environment – hot or dusty for example – will need attention more regularly than a similar drive that’s lightly loaded and working in a less challenging environment.
After the audit has been completed, the service provider will draw up a recommended maintenance program. The program aims to provide all of the routine maintenance needed to keep the AC drives in excellent condition. That way, you avoid prescribing excessive maintenance work that would simply increase costs while yielding little in the way of extra benefits. This is where the experience and expertise of the company providing the maintenance service come into play to set an appropriate service level.
Certified AC drive audit
When the program and the fee for implementing the service have been agreed with the AC drive user, the program will start. This means that a certified engineer from the service provider will visit the AC drive user’s site at regular intervals to carry out routine maintenance. The work carried out will vary according to the type of AC drive, the operating conditions, the age of the AC drive and other factors, and will be specified in the program agreement.
Typically, however, it will involve basic inspection and checks for tightness of connections, condition of cooling system and firmware versions. The engineer will also consult the drive fault log and any other available records for events that might require further investigation.
If necessary, the engineer will update the firmware and carry out routine tasks like cleaning the cooling channels and replacing door filters. While performing these tasks, the engineer will look particularly carefully for issues that, while not yet significant, could lead to future problems.
AC drive maintenance report
After each maintenance visit, the AC drive user will receive a report that not only gives full details of the work carried out and the items replaced. The report also includes recommendations for any further work needed to optimise the performance and reliability of the AC drive. It is worth noting, however, that in the majority of cases there is no need for such additional work, as all routine attention is already included in the preventive maintenance service.
We’ve already discussed most of the benefits of this service, but there’s one that may be less apparent but equally important: The engineer carries out the maintenance work with only minimal involvement of the service user’s own maintenance team. This means that the work definitely gets done as scheduled even if the maintenance team is busy, and that the team’s availability to deal with urgent issues elsewhere is not compromised.
There remains, however, one issue that we haven’t yet touched on: the cost of the service. It’s impossible, of course, to quote a figure as this will depend on several factors such as the number of AC drives to be covered, their age and working environment.
The distance the engineer has to travel to get to the service user’s site or sites also plays a part. A good service provider will, however, provide a fixed price to aid budgeting along with comprehensive details of what’s included, so there are no unwelcome extras.
AC drive preventive maintenance
It’s worth taking the savings the service will provide into account. If it prevents one breakdown, the resulting savings may well outweigh many years of service fees. And even if breakdown prevention is ignored, the service will still be worth while in terms of consistently high AC drive performance and efficiency. Having efficient drives will help minimise energy usage and extend the life of the AC drive, which means replacements are few and far between.
As we’ve seen, all AC drives benefit from regular preventive maintenance and AC drive users now have access to a service that will provide such maintenance reliably and affordably. Most of us would consider regular servicing essential for our cars and there is no doubt that it’s just as important for our AC drives.
So, if you haven’t already done so, why not contact your AC drive manufacturer and enquire about the preventive maintenance services they have on offer? By helping you to keep your drives performing perfectly, those services could save you a lot of time, trouble and money.
