On Sun, 21 Mar 2010 15:42:54 -0400, Paul Christensen wrote:
>BTW, the material that Jim Brown (K9YC) referenced from SurgeX is excellent.
>In thinking the secondary suppressor problem through, I thought that only a
>"single-mode" L-N bypass to neutral (rather than ground) would prevent a
>ground potential rise between branch circuits.
That's right. It's the MOV to ground that causes problems.
>Those devices exist, but apparently, they still do not provide as high
>degree of protection than the technology used by SurgeX.
That's the way I see it. The SurgeX stuff is expensive. When I'm specifying
sound systems, I put SurgeX boxes on the gear that is relatively expensive
and more likely to have issues with power line spikes. A 20A SurgeX unit that
costs about $500 can protect $100K worth of DSP gear, mixing equipment, EFX
boxes, etc. In terms of cost effectiveness and risk, that's a pretty good
ratio.l But I am less likely to specify them to protect power amps, where I
typically must put only 2-4 power amps on one SurgeX unit (because the
current draw of power amps often requires a circuit for every 2-4 power amps)
with a cost of only a few $K.
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