Make sure you ground static wrist straps to grounded equipment.

We’ve been having some issues with hardware damaged by static during on-site commissioning – it seems as though it is easier than ever before to fry circuit boards. Do you think modern devices are more susceptible than they have been in the past or is it something we are doing wrong?

If you’re working with equipment onsite or offsite there needs to be thought given to static protection. ESD voltages can be massive – up to 30kV – and a person doesn’t need to do much moving around to generate such a high voltage, which comes along with damaging current waveforms that can corrupt firmware and pop circuits.

Part of the issue is that the tiny electrical paths in modern boards are more vulnerable to ESD. Even if they are protected by fuses, your techs may touch a component up-stream of the board’s defences.

There are things you can do. Rubber soled shoes, rubber mats in front of work benches, leaving systems plugged into AC with mains switched off so the cabinet retains a ground path, combined with the use of anti-static wrist straps. And if you’re moving boards around, make sure they are positioned inside or on top of anti-static bags or foam.