[TowerTalk] Relay lightening protection

[jimlux]

Kipton Moravec wrote:
> On Fri, 2009-01-30 at 06:53 -0800, jimlux wrote:
>> donovanf at starpower.net wrote:
>>> This discussion of relay reliability and switching speed is
>>> irrelevant for a relays in a phased array that should never be hot
>>> switched.
>> The reliability issues in the Tyco ap note aren't tied to whether the 
>> contacts are carrying current.
>>
> 
> Carrying current IS the whole issue. If they were not carrying current
> then it does not matter how fast the contacts close or open.
> 
> The goal of the applications note was to minimize the contact arcing,
> which increases contact life or reliability. It is described in the
> second paragraph of the second column of the first page. 
> 
> http://relays.tycoelectronics.com/appnotes/app_pdfs/13c3311.pdf
> 
> You do not have arcing if there is no current. So if there is no current
> then contact speed is not an issue.
> 
> 

I think they're talking about the "control contacts", while the life 
issue is the "controlled relay".  i.e. the residual flux making the 
relay sticky, etc.