[R-390] C553

[David Wise]

Thank you for your testing, Charles, I wondered about that.  It's great to have it nailed down.  That narrows it to pure film/foil or C0G ceramic.

C553 REPLACEMENTS IN STOCK AT MOUSER, AUGUST 2014
 
PURE FILM/FOIL
 CDE
  715P10356KD3 600V $2.34 
  715P103516LD3 1.6KV $4.04
  DMT6S1K 630V $1.55
  WMF6S1K-F 630V $2.24 >>> AXIAL

C0G CERAMIC
 AVX
  SV13CA103JAR 630V $4.16
  SV14AA103KAR 1KV $6.69
 TDK
  FK22C0G2J103J 630V $1.26

-----Original Message-----
From: R-390 [mailto:r-390-bounces at mailman.qth.net] On Behalf Of Charles Steinmetz
Sent: Wednesday, August 06, 2014 10:54 AM
To: 390 list
Subject: Re: [R-390] C553

David wrote:

Honestly, I see no need for a rating > 600v if you use a quality 
film-and-foil.  I have never observed a failure (or even heard of 
one) of a 600v Orange Drop 225P or 715P in the C553 position (or even 
a 400v 225P or 715P, which many folks use).  I've personally 
installed well over 100 of them, and lots of other people use them, 
so there is a large information base.

>or settle for metalized and run up the voltage to reduce the odds of 
>a self-heal event.

Unfortunately, testing I did some years ago does not support the 
proposition that self-healing events in metallized film caps go down 
as the voltage rating increases, once the circuit voltage is greater 
than about 200v.  I suspect the catastrophic failure rate does go 
down with increasing voltage rating, but the self-healing kills 
filters and it does not seem to.  (Note that manufacturers do not 
consider self-healing events to be faults or failures -- they are 
part of the normal operation of metallized film caps.)

Best regards,

Charles