Success Stories

EMI Troubleshooting

At a large laboratory/office building with three chiller plants, several control panels lost communication after a power outage. The on-staff mechanics put the system in hand and performed all the troubleshooting steps they knew without success. That’s when I got the call. Divide and conquer got us down to a single controller disconnected from everything but the comm link, still not working. We swapped the controller to see if the problem followed the device or the panel wiring, and that failed too. That really just left EMI, very unexpected on a system that had run for years unmodified. Waving an inductive amplifier around the panel found the culprit: the integral surge arrester had done its job when the transient hit, but it was now broadcasting EMI inside the panel and distorting every comm signal. We all learned something new that day. Check the LED on the surge arrester earlier in the process.

Cellular Network Nuances

A rural water system’s wells and stations uplinked by cellular modem, and they suffered repeated, seemingly random comm outages. The owner was frustrated and no one was admitting fault. The SCADA system provider called me in to determine whether it was hardware or the cellular network. I captured radio link traffic at the affected sites and at the central aggregator modem and proved the radio links were good and traffic was being generated on both sides, but packets were only arriving in one direction. Once I gave that proof to the tower provider’s engineering support team, the situation suddenly changed and comm was restored. They never had to admit that it was their network, but the desired result was achieved and everyone was happy.

Outside the Control Box

Controls themselves are rarely the first component to fail. It’s just the place where failures become noticeable first. On a small industrial process chiller, the flow switch had been tripping intermittently for some time. Previous technicians adjusted the switch, then replaced it, then modified it with a bigger paddle. Eventually someone connected gauges to the refrigeration side and saw that it just wasn’t flowing properly, and the switch was only a symptom. They opened the heat exchangers to clean them, but they weren’t fouled. That’s when I got the call. The pump was running near full amps and making good differential pressure, but the pipes didn’t sound like it was pushing much fluid. While I was looking for a way to bypass parts of the system, I spotted the root problem: an iron wye strainer installed in the copper line. Sure enough, when we opened it, it was 90% occluded by electrolytic deposition. Replacing the strainer put the system back in working order.

Radio Pathway Analysis

A SCADA customer’s data radio link to one of their wells worked fine all winter but dropped out in warmer weather, a little worse every year, until it wouldn’t communicate at all. That’s when I got the call. The root cause was simple: the Fresnel zone between the radios wasn’t clear, and it was worse when the trees had leaves. The remediation came in layers. The link was set for more bandwidth at lower speed, one antenna went up two more meters, alignment was checked and adjusted, and a few branches came off the worst offender. That got them a solid link year round.

Energy Savings Performance

I personally developed and implemented a staging management system for an industrial campus compressed air system, a variety of 50–300 horsepower fixed and variable speed compressors across dozens of aircraft depot maintenance facilities. By staging off idle compressors while maintaining 100% uptime for process availability, the system saved millions of dollars annually in energy costs, along with significant additional savings in maintenance costs.