the UL standard is 50 mA not 50A for a dangerous current
50mA will not trip any fuse or circuit breaker I ever saw.
Ground bond test has to pass several tens of amps with low single digit voltage drop.
The first commercial ground bond tester I found on google provides 10A to 30A test current.
Ground Bond
A ground bond test verifies integrity of the
ground path by applying a high current, low
voltage source to the ground path circuit,
typically a 25 or 30 A current.
This test is similar to the ground continuity
test with the additional benefit of verifying
how a product will perform under actual fault
conditions.
When a ground fault occurs, current starts
to flow through the ground circuit. If the
current-carrying capacity is high enough
and the circuit resistance low enough, the
system operates properly and the user is
protected from shock.
If, however, the ground circuit cannot carry
enough current or has too high an electrical
resistance, the circuit breaker may not trip
or the fuse may not blow. If this occurs,
voltage can build up to a point where current
will flow through the user’s body instead
of the ground circuit.
I try not to be too pedantic but ground safety is important.
JR