Repairing automation equipment has a valid place in obsolescence management

I was fortunate enough to introduce my company to some of Norway’s major oil producers recently. I was there to present ‘The benefits of repairing equipment over replacements’. Now what I found was not really surprising, generally when they had a failure on electronic control equipment the usual response was to buy new from the manufacturer. All good really but the problems arose when the equipment was obsolete. The manufacturer would then offer their upgrade solution. Now there’s nothing wrong with that at all, in my opinion it’s good to have a program in place to cover upgrades of equipment.

I was there to offer an alternative, probably at the right time too with the oil price down to around $30 a barrel as opposed to the high of around $100 a barrel. My alternative option would save money too.

From discussions in the presentations to the procurement and technical teams, it was evident that power supply units (PSUs) were a main area of equipment failure. That again is not surprising as rack-mounted PSUs do a great deal of work in an electronic control system, they wear out. Just to add to the failures, the PSUs they use had been made obsolete by the manufacturer. This lead to urgent pooling of spare units with no option other than to upgrade when the last spare had been used.

Now here’s where the repair comes in as a valuable option. Soon after I’d arrived back in the UK I was contacted to say a number of power supplies had been shipped to my company, all faulty and all obsolete. They were ABB (Powec/Power one) units from the PMP model range. The shipment consisted of 12, 24 and 48 volt units.

Before I discuss the repair/refurbishment process I should add that I believe a repair carried out to our standards and specifications will bring the unit ‘back to new condition’. This gives a guarantee the unit will function like a new unit and increase the lifespan. hence a valid option in obsolescence management.

Repairing automation equipment has a valid place in obsolescence management

Now here’s a picture of one of the PSUs with the covers removed. We found the majority of the shipment had similar faults, those were failing bus capacitors. Now the function of these capacitors is to ‘hold’ the charge, when they start to fail the PSU cannot deliver the specified current or the voltage will drop. Two things that aren’t good for a PSU. Our repair process is documented and strictly adhered to, so we deliver a consistent repair. We remove and replace every component that we know from our experience, degrades with age. All electrolytic capacitors are removed and replace with an upgraded 105 Degree C type. (better specification than from new), all relays are replaced, all fuses are replaced, all opts-isolators are replaced, all fans are replaced, all transformers are checked. all power devices are checked and retaining clips replaced, all solder joints and connections are checked, all rework is carried out to IPC7711/21 rework specification. To ensure the PSU operated correctly it is fitted to our active load rig for an extended burn in test. We also carry out a thermal check of the unit to ensure to components are operating within their temperature specifications.

Here is a video of a power supply going through the diagnosis process on our active load rig.

So in summary, repairs and refurbishments in my opinion have a valid place in managing obsolescence. What we’ve done for many customers is to provide a repair item to the same specification when it was when first manufactured.

For the oil companies we are currently working for, we’ve provided a long awaited solution by replenishing their useable stocks of PSUs. One headache removed for their obsolescence team and a huge cost saving too.

Fletcher Moorland Ltd.
Elenora Street

T: 01782 411021