martymoose
Hero member
- Location
- Sydney, Australia
Love the auto alert
Correct Fuse amperage.
- Thread starter philw
- Start date
130A might be a bit ambitious for a ring pull
The electrical company I work for used to have a HV test facility where they could set up fault conditions and put 12kV onto it. They'd make a big day of it with industry big wigs attending a luncheon culminating in a viewing behind bullet proof glass of a very large switchboard in which one of many possible faults had been set up. The one time I was witness to the event a ring spanner had been placed across two phases of 120mm x 12mm copper bus rail. A remote switch was closed and an almighty kaboombah followed with panels and doors blowing across the room, bouncing off ceiling/walls/viewing window and flames all over. The relief vents on the board itself were totally overwhelmed. In the real world anyone in the switchroom would have been toasted. Was a great eye opener for this apprentice.
Managed to take out a whole industrial estate, dead short on the 11KV/415V kiosk sub, was standing in front of the cabinet, though did put the very heavy rear panels on the 700KVA UPS. The boom comes later, what you get first is a hissing rush, sort of like pfffft then the boom, was showered with hot metal though mostly unharmed, the factory manager though i was dead... shock wave was also well prevalent. We used mine trailing cable to hook onto the sub direct feed, input current was static at 2KA on a six pulse rectifier, should have been a 12 pulse Star Delta transformer input. Drew up to 4KA on battery charge and load support... Poms built the machine and we commissioned it... there were even bigger multi units... 500VDC DC link voltage and better part of 20 ton of batteries... spanners actually have finite resistance, go red and then white while fused on the copper bus bar... noticed it when the trades assist dropped the uninsulated spanner across the DC link... did tell him to run if anything goes wrong, that he did...run .. real quick. Pity he did not pay attention when i told him to wrap his tools, then he retrieved a different spanner when i was out of the room... excitement is where you find it... or run when it arrives.. j
helicopterjim
Hero member
- Location
- near Lone Butte, BC, Canada
When I was a teenager I was working for a neighbour farmer who seemed rather boring with no sense of humour. He told me about when he was 18 years old and working in a factory at the end of WW2. His job was welding heavy duty bracketry onto the chassis of military trucks. He and another fellow on night shift decided it would be fun to put two of their heavy duty welders in series and see if they could weld using a crowbar as an electrode. Needless to say ...... the "welding rod" stuck to the truck frame they were welding and a few seconds later ........ rather than trip the welders breaker ....... a rather large transformer exploded and one corner of the factory caught fire. The lights were out ....... and I believe he said the lights were out for a large portion of town ..... and in the dark they managed to chisel the crowbar off the truck frame and disguise the evidence. They never found out what "caused" the transformer explosion.
Jim
Jim