Just a few days before Christmas, a rain storm blew through Calipatria, CA and took a critical generator offline at a power plant. After some troubleshooting, the onsite crew identified the generator current transformers (there were three Combustion Turbines (CTs) stacked per phase and encapsulated in a can) as suspect and asked Southwest Energy Systems (SES) to investigate. The tests showed the CTs were good but it was apparent that some damage had occurred in one or more phases. SES then arranged for, the very capable, Arizona Electrical Apparatus (AEA) to remove the CTs and take them to their workshop for further testing and repair. Dennis Barnes of AEA reports, “They were bad, the minute we put current to them we blew a hole right in the side”. Apparently, it was a good call to pull them out and not take additional risk.

With only a few days to get the unit back online, the middle of the holiday season upon us, and the manufacturer quoting six months to deliver CT’s; it was time to get creative.

AEA pulled twelve CT’s out of their massive inventory, tested them and began to engineer and build CT stacks to replace the originals. Between Friday, December 29th and Sunday, January 1st AEA worked around the clock to build what you see in the above photograph (middle item is the original factor CT). The new CT stacks were installed on January 2nd and SES technicians reprogrammed the relays accordingly, verified everything was installed properly and the plant started up the next day.

You may be asking yourself “What do snowflakes have to do with this story?” Like the snowflake, the CT Stacks are one of a kind. Another one like this cannot be found anywhere on the planet.

Southwest Energy Systems and Arizona Electrical Apparatus have joined forces as partners on a myriad of projects similar to this one.