The Good, the Bad and the Ugly
The Good, the Bad and the Ugly
Very well stated, Zog
There are a lot of stories out there regarding T-shooting, repair, PM and testing of electrical equipment and the integrety of companies performing this work. Which brings me to this story.
I was hired by a large transfer switch (ATS) manufacturer to rewire one of their 1600A bypass isolation type (ZBTS160FC-7) ATSs that had recently burnt up at a hospital. The chief engineer reported that when they were performing their weekly generator test, they heard a loud
BOOM when this ATS was transferring to emergency. The ATS was immediately isolated and LOTO (not a problem since it was a redundant chiller circuit.) This was one of the nastiest blowups that I have ever had to deal with. The main emergency solenoid as well as 80% of the wiring harnesses on the ATS power panel and in the bypass switch area were burnt and melted (by code, ATS wiring is not protected by fuses.) In performing the damage assesment inspection, I asked the chief where the platform was to roll out the ATS power panel (this model racks out horizontally.) He looked at me confused and said "
we don't have a platform!" I looked at him and pointed to the inspection sticker on the door of the unit. The sticker was from another large ATS manufacturer (if not the largest, that we will call CO. X) and was dated the year before. I asked the chief how CO. X was performing the preventive maintenance PM) each year and he answered
"they don't rack them out." I looked him in the eye and said
" when I rack this out I will show you why it burnt up!" With the ATS racked out on a makeshift platform, I had the chief try to manually transfer the ATS with the handle (very hard to operate) and showed him the hard, dried grease in the mechanism gears at the back of the unit and said
"this lack of cleaning and proper lubrication caused the unit to burn up." He looked at me with terror in his eyes and said
"Oh my God, I have 6 more like this, can you give me a quote to PM them?"We repaired the unit, performed a complete PM and tested it to bring it up to proper operating condition.
We got the contract to PM and test the other 6 units successfully and, needless to say, left the site with a very happy customer.:grin:
Morals of the Story:
All switchgear companies are not created equal.
Just because it has a PM inspection sticker from a manufacturer doesn't mean the work was done correctly.
Tony