This past week I had a local customer visit our facility looking to test the effectiveness of our Super Ion Air Knife on their 6″ wide x 10′ long epoxy coated, copper bus bar. A bus bar is a metal strip or bar (typically copper) that is used to conduct electricity for high voltage equipment in lieu of traditional wiring. With this particular customer they were applying a protective epoxy coating to the strip then used a high voltage tester with a metal brush to check the epoxy for any exposed copper.
They would put an electrical charge on to the brush and rub it across the epoxy. If any charge from the brush is able to reach the grounded copper, the test brush shuts down immediately due to the detection of an electrical path through a defect in the epoxy. The problem they came to EXAIR to solve was related to the static charge built up on the epoxy from rubbing the test brush on it. This static charge was shocking the personnel responsible for grabbing and removing the bus bars from the test area, so they called and visited EXAIR for assistance.
The customer brought (2) 5′ lengths samples of the strip and a portable test machine to run the test at our facility. After they rubbed the brush across the the strip and created a static charge, our Digital Static Meter detected anywhere from 6500V to 15,000V at different points on the epoxy coating. We tested our 6″ Super Ion Air Knife, operating at 60 PSIG at a distance of about 40″ away and were able to lower the reading to around 1400 V in a matter of seconds. While this was acceptable to the customer, they mentioned they had additional time available in the process for removing static. Keeping this in mind we decided to keep the same operating parameters but would treat the sample for 1 minute. The additional treatment time was able to lower the voltage on the epoxy to around 200V. Pleased with this result, the customer placed an order for (2) 60″ Super Ion Air Knives to cover the length of the 10′ strip.