rpoet
Member
After a kamikaze all night session trying to prep a piece of theatrical automation for air shipment from the greater Chicago area to a nightclub in Singapore, I managed t knock out all the lights and other power in our shop.
We were using a step-up transformer to get 460v 3P for testing, as that's the voltage in Singapore. Our shop only had 208v available. We'd wrapped up testing and my co-worker had gone to get the box truck we were going to load this thing onto. I was SURE I'd shut off the disconnect to the testing transformer, and I proceeded to pull the temp power leads off the main breaker's lugs in the shiny new panel.
I hadn't shut off the disconnect.
The three phase conductors slapped together and knocked out power to the entire shop in a large blue ball of fire. To this day, there's still a blot of vaporized copper on the side of the cabinet that's now in Singapore.
To make it worse, it tripped the main breaker instead of the branch breaker (gotta love old buildings), so we couldn't use the shop's chain hoist to get the thing off the build table (about 900#) and onto the waiting pallet. It was 5 in the morning, and I had to call the landlord to come in and reset the main breaker in the electrical vault for our shop space.
Lesson learned - sleep deprivation makes people STOOPUD. I'm lucky I wasn't hurt.
-rpoet
We were using a step-up transformer to get 460v 3P for testing, as that's the voltage in Singapore. Our shop only had 208v available. We'd wrapped up testing and my co-worker had gone to get the box truck we were going to load this thing onto. I was SURE I'd shut off the disconnect to the testing transformer, and I proceeded to pull the temp power leads off the main breaker's lugs in the shiny new panel.
I hadn't shut off the disconnect.
The three phase conductors slapped together and knocked out power to the entire shop in a large blue ball of fire. To this day, there's still a blot of vaporized copper on the side of the cabinet that's now in Singapore.
To make it worse, it tripped the main breaker instead of the branch breaker (gotta love old buildings), so we couldn't use the shop's chain hoist to get the thing off the build table (about 900#) and onto the waiting pallet. It was 5 in the morning, and I had to call the landlord to come in and reset the main breaker in the electrical vault for our shop space.
Lesson learned - sleep deprivation makes people STOOPUD. I'm lucky I wasn't hurt.
-rpoet