----- Original Message -----
From: "Harold B. Mandel" <ka1xo@juno.com>
To: <dpipes@earthlink.net>
Cc: <Amps@contesting.com>
Sent: Sunday, December 26, 2004 10:02 PM
Subject: [Amps] INRUSH
> The Inrush Protector product you mention in your previous post is
exactly
> the ticket.
>
> I just finished a commercial television transmitter repair job
> where the owners have replaced 300+ diodes in the last
> quarter and were becoming frantic. The 46KW UHF
> station had no inrush protection scheme for the Anode
> Supply (3-Phase, 480V, 15KV @ 12 amperes).
>
> It took a Crouzet Timer, a P&B 30-amp control relay
> and 2 Square-D 100 amp contactors with twelve 400 watt,
> 6.8 ohm resistors to solve. The resistors don't even
> get hot when she steps and no more blown diodes.
>
> By the way, the filter is 2 units of 194uF @ 30KV
> and weigh around 200 pounds each.
in my opinion the filter bank is too much oversized for a 3-phase
powersupply
even when no bridge rectifier is used and that caused the problem
with the diodes.
With a commercial tv transmitter I would expect it being on the air
around the clock with rare occasions were the power supply is being
switched
73
Peter
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