I have dealt with many three phase and single phase dynamic braking
circuits, mostly in the 1-5 hp range and the number of phases on the motor
makes no difference, for braking ability.

The three phase braking circuits are more costly due to more contacts needed
to switch the load to the brake circuits. A simple SPDT switch will do for a
single phase saw.

The units I dealt with in 2000 ampere tapchangers typically used DC
injection (some were friction and some regenerative) and were set to time
out and allow the mechanism to coast onto a "top dead centre" position ready
for the next cycle. This could be made to stop "on the spot" if adjusted
this way but gave drift back to the brake initiating cam problems, at times
so the coast in was necessary. This would not be desirable to stop a machine
for a human usage.


wrote in message
...
Nah, there's nothing special about a three-phase motor that allows dynamic
braking.


It is totally cost prohibitive for a single phase motor.