Question: My Elox Astra Power Supply continues to have electronics failures. My maintenance department is blaming conductive dust. We change the air filters regularly, what else can we do?
Answer: The Astra Power Supply requires a high volume of air to cool the components inside. Unfortunately, the air filters on top do not do a very good job of removing dust from the incoming air. In addition, the side doors, control drawer and front panel are not sealed, so dust can enter from multiple places. With the advent of high-speed electrode milling, many EDM departments have environments that are far from conducive to Power Supply longevity.
There are some steps that can be taken to mitigate the problem. One of the most helpful steps is to conformal coat the circuit boards. Chemtronics manufactures an aerosol product called Konform, It is spayed on from an aerosol can like spray paint. It is clear and dries almost transparent. When cured, it provides an electrically insulating barrier that will prevent conductive dust from damaging circuits. It has an added benefit of being very thermally conductive and can actually help eliminate hot spots on the circuit boards. The only down-side to coating the boards is that the coating makes it difficult to troubleshoot the board for service. However, as long as the repair tech knows the coating is there, it can be easily scraped off in the spots where checks need to be made.
Additionally, adding some sealing tape around the door and panel edges can help to prevent unfiltered air from entering through the cracks. A change in air filter to a dust reduction style can also be a help. However this comes with some caveats. The pleated dust reduction filters will reduce the overall airflow. This will require the filters to be changed more often and may lead to high internal temperatures when operating at high-power on hot summer days.
Perhaps the best practice in keeping Power Supplies operational is to do all of the steps above and include an annual deep-cleaning where the units are thoroughly cleaned. This should give you the best chance for long-term operation with minimum down-time.