So, you don't use current transformers or clamp on AC ammeters?
It should be clear the discussion is about high available fault
current - the current you get when the source is short circuited. This
is a really basic concept in design and protection of high current AC
power circuits. (But it may not be something you have run across.)
High available fault current can result in arc flash. Arc flash can
result in major injury and death in addition to major equipment
destruction. Arc-flash is estimated to kill 200-300 people a year.
OSHA has made arc-flash an issue. Safety protection may require
wearing an arc-flash suit.
One of the smartest electricians I know was seriously injured by arc
flash. And it was through an equipment failure - he made no mistake.
If you are working in dangerous locations without the proper training
you are likely to die. If you are properly trained, the company
supplies the proper equipment needed to do the work.
<snip>
The issue I raised is appropriate meters. As I wrote above, the IEC
has measurement Categories I-IV. If working in high energy locations,
like panel boards and services, the appropriate meters are Cat III and
IV. These meters are designed for the riskier environment and have
better transient withstand and fusing.
My analog Triplett 310 has a glass fuse. I have a Beckman digital that
has a similar fuse. They might be safe in Cat I. My Fluke is rated Cat
III and IV. That includes transient withstand well above the nominal
voltage rating and high interrupt capacity fuses.
OSHA might be real displeased if the wrong meter was used. And when
OSHA is unhappy you might be unhappy.
If you didn’t assume everyone else was an idiot you might actually
learn something. (But probably not Archimedes.)