Battery Bank Earth Fault

Recently we had a really unusual fault with one of the UPSs that we maintain. The UPS is a 200kVA Delphys Green Power model from Socomec. It is about 4 years old and has been very reliable and easy to maintain to date. We had performed a...

Solid State Relay Redesign

A solid state relay was sent in to us for repair recently. From viewing the board it was clear that a couple of tracks had been blown off the board. Running some external wires to replace the blown tracks would have been a quick fix however...

Fibre Side lay sensors

The input end of a Komori printing press includes a system for ensuring that either side of the paper is butted up against a known edge. The way it does this is that there is a paper detector setup in line with the edge that detects if the...

OpenBSD in a wire bender

The last couple of days have been spent repairing a servo motor drive from a Macsoft 3D wire bender. Some capacitors had failed, damaging the circuit board and causing two of the IGBT's to fail. We were able to get the machine going again f...

How to pick the power rating of a new UPS

One of the most important decisions when choosing a new UPS is selecting what power rating you need. The power rating limits how much load you can draw from the UPS e.g. how many computers you can use it to protect. It also has an effect o...