Thursday, 4 February 2016

Andy Preston, UK Drives Product Manager, ABB writes: Variable-speed drives (VSDs) are now more efficient, productive and easy to use than ever before, but did you know that those efficiency levels promised at the start can easily drift unless your drive is well looked after?

What can you, as an end user, do to prevent efficiency declining and ensure that in years to come your drive is still performing as it was on the day it was first commissioned?

Before we begin, I’d just like to get some important public service announcements out the way first:
  • ABB drives must only be installed and maintained by a qualified electrician
  • ABB drives are only field repairable by authorized service personnel. In the event of a failure never attempt to repair a drive yourself
  • In the event of a failure or if you have any questions, contact your local ABB Authorised Value Provider (AVP) or ABB representative for more information
Now we’ve got that out the way, let’s talk about what you can do. Whilst most maintenance tasks are best left to a qualified engineer, there are still preventive maintenance duties you can perform to keep your drive healthy and prolong its useful life.

Set up a preventive maintenance plan – The single most important piece of advice I can give is to set up a preventive maintenance plan from day one; preferably before day one. The simplest way to do this is to register the drive with ABB, and our installed base tool will then remind you what to do and when.  This will underpin all drive maintenance for its entire lifespan. Drives have very few parts that need maintenance, but components eventually wear out and so need to be regularly checked, repaired and/or replaced. Being on top of what’s likely to go and when means that you can pre-empt and avoid almost any failure. Check the drive’s user manual to see ABB’s recommendations as to when individual components, such as cooling fans or capacitors, need to be replaced, and see to it that these maintenance duties are carried out, or register it with us, and let us remind you.

Keep your drive clean – Dust on VSD hardware can lead to poor airflow which is detrimental to its performance. Dust also carries moisture, which can damage circuit boards and cause failures. Use a vacuum cleaner with antistatic hose and nozzle to clear the heat sinks and circulating fans. Why antistatic? Because an ordinary vacuum cleaner can create static discharges which can damage circuit boards. Blow compressed air from bottom to top and simultaneously use a vacuum cleaner at the air outlet to trap dust. The compressed air must be a non-static generating spray or a reverse operated electrostatic discharge (ESD) vacuum, as ordinary compressed air contains oil and water, which are not substances you want in your drive.

Keep it dry – Moisture on a circuit board will short circuit the boards causing all sorts of problems, and eventually it causes corrosion, which can lead to drive failure at any time. Even a drive situated in a dry area can attract moisture from unexpected sources. It only takes the ingress of one drop to start doing damage, so ensure that the drive is properly enclosed and situated, and check that there is no way for moisture to get in. Some drives are specified to withstand water exposure, but as a general rule drives and water do not mix, so keep them apart if at all possible. This goes for spare VSDs too.
Speaking of which, idle VSDs require maintenance. For instance, the DC capacitors, which are filled with electrolyte, need to be powered up periodically to “reform” them. Powering up a poorly formed capacitor can cause it to explode, so ABB recommends powering up once every six months to a year.

Keep connections tight – We’re erring towards “leave it to the professionals” territory here, but as long as the drive is powered down and disconnected, you can check that external connections are tight. This can help avoid arcing, which is best avoided as it can cause damage to the drive terminals, overvoltage faults, clearing of input fuses, or damage to protective components. Re-torquing screws is not a good idea, and further tightening an already tight connection can cause further damage.

I can’t emphasise enough that all drive maintenance should be carried out by a qualified electrician. ABB and its AVPs offer a range of maintenance services to suit your needs, from annual inspections all the way up to remote monitoring services that can tell ABB that something’s amiss in your drive long before it displays any signs of wear.

If you have any questions about drives or drive maintenance, talk to the ABB Drives team on 07000 DRIVES (that’s 07000 374837).

Keep up to date - fill in the form below to join our mailing list


Post a Comment