[Amps] MOVs

[Michael Tope]

Jim,

This is probably a dumb question, but why not put the MOV between hot 
and neutral? If the spike is differential mode, that would kill it 
without spiking current into the safety ground.

73 Mike W4EF......

On 1/22/2014 10:45 PM, Jim Brown wrote:
> Because MOV's conduct surge currents onto ground, and the IR (and IZ) 
> drop raises the potential of the chassis. When the "protected" 
> equipment has a low voltage connection to other equipment powered 
> and/or grounded at another point, the difference between one chassis 
> and the other often fries the interface circuitry.
>
> I've seen many well-documented examples of this with audio systems, 
> and with computers connected by wired Ethernet, no radios anywhere 
> around.  The sharp guys in pro audio stopped using MOVs at least 20 
> years ago.
>
> 73, Jim K9YC
>
> On 1/22/2014 10:11 PM, Jim W7RY wrote:
>> Why?
>>
>> On 1/22/2014 9:59 PM, Jim Brown wrote:
>>> On 1/22/2014 8:40 PM, Gary "Joe" Mayfield wrote:
>>>> What are folks thoughts
>>>> about MOVs on the primary side of the transformer?
>>>
>>> Bad idea. ANY MOV on branch circuits is a bad idea.