[Elecraft] KPA-1500 issue (power surge?

[Jim Brown]

On 7/10/2021 12:59 PM, Bob McGraw wrote:
> Sure, power strips are inexpensive.  But they really only protect 
> against one type of power surge.   If the voltage spikes, the breaker 
> should trip. However, this isn’t always instantaneous.  Delicate devices 
> can still be damaged, and many other types of surges will just pass 
> right through without tripping the  surge protector.  Not the best 
> solution. Despite being called a surge protector, this name doesn’t give 
> you the whole story.  These don’t even come close to the protection 
> whole house surge protectors offer you.

The problem with MOV protectors is FAR greater than what is outlined 
above. MOV "protectors" dump any spikes onto the equipment ground (green 
wire), and the resulting IR drop raises the potential of the equipment 
it is intended to protect. When that equipment is connected to other 
equipment plugged into a different outlet, the DIFFERENCE in potential 
between their their chassis can cause stuff to fry. The same thing can 
happen when one or more pieces of the interconnected equipment has a 
ground connection, but is not bonded to the other gear.

Properly bonding all equipment within a station minimizes the potential 
differences between the gear, AND if an MOV protector is used, must be 
bonded as well. N0AX and I finished working through this while finishing 
the latest revision of his ARRL book on Grounding and Bonding, and it's 
in both versions. I don't know if the new one is out yet.

At least 20 years ago, professional sound companies and designers of 
large sound systems learned all this the hard way. Luckily, a new type 
of protector had been invented -- a SERIES MODE protector that does not 
dump the surge on the Green Wire, but instead stores it in the magnetic 
field of a big inductor, then discharges it slowly after the surge 
event. These protectors are much more expensive, but cost a lot less 
than the gear they protect! When I was a consultant designing large 
systems, I specified them for every project. And I have used them in my 
home (for computers and home entertainment system), office (when I was 
still working), and in the shack.

SurgeX is the company that developed products for pro audio. I use the 
SA-20 (20A version of the SA15).

https://www.fullcompass.com/brand/sgx-surgex/

Years ago, I did some technical writing for them, producing this 
tutorial "White Paper." I was specifying them for the systems I designed 
LONG before writing it.

73, Jim K9YC