[Amps] Power Supply Turn Off Under Load

[TexasRF at aol.com]

There have been a couple of recent mentions of the bad effects of turning  
off a hv power supply that is under full load.
 
A google search didn't turn up useful information so I am wondering if a  
reader here might have some insight as to the problems associated with an 
under  full load shutdown?
 
This is the scenario where a 240vac primary breaker or fuse lets go during  
a transmission at full carrier level such as AM, RTTY or one of the current 
 Digital modes.
 
Thanks/73,
Gerald K5GW