Are 4-125A's used much anymore? I've accumulated several and a couple of
sockets. Two appear to be brand new one a JAN, both Eimac and one that
appears used.
Jim
N7FCF
----- Original Message -----
From: "Carl" <km1h@jeremy.mv.com>
To: "James R Carr" <n7fcf@hctc.com>; "Roger (K8RI)"
<sub1@rogerhalstead.com>; <amps@contesting.com>
Sent: Saturday, January 08, 2011 7:00 PM
Subject: Re: [Amps] Fuses
> Never mind the blessings, just send money or your first born.
>
>
> ----- Original Message -----
> From: "James R Carr" <n7fcf@hctc.com>
> To: "Carl" <km1h@jeremy.mv.com>; "Roger (K8RI)" <sub1@rogerhalstead.com>;
> <amps@contesting.com>
> Sent: Saturday, January 08, 2011 9:32 PM
> Subject: Re: [Amps] Fuses
>
>
>> Oh bless you your worthiness
>> ----- Original Message -----
>> From: "Carl" <km1h@jeremy.mv.com>
>> To: "James R Carr" <n7fcf@hctc.com>; "Roger (K8RI)"
>> <sub1@rogerhalstead.com>; <amps@contesting.com>
>> Sent: Saturday, January 08, 2011 5:46 PM
>> Subject: Re: [Amps] Fuses
>>
>>
>>>I like it when the commoners react fast.
>>>
>>> You may carry on.
>>>
>>>
>>> ----- Original Message -----
>>> From: "James R Carr" <n7fcf@hctc.com>
>>> To: "Carl" <km1h@jeremy.mv.com>; "Roger (K8RI)"
>>> <sub1@rogerhalstead.com>; <amps@contesting.com>
>>> Sent: Saturday, January 08, 2011 8:09 PM
>>> Subject: Re: [Amps] Fuses
>>>
>>>
>>>> Excuse us your royal highness
>>>> ----- Original Message -----
>>>> From: "Carl" <km1h@jeremy.mv.com>
>>>> To: "James R Carr" <n7fcf@hctc.com>; "Roger (K8RI)"
>>>> <sub1@rogerhalstead.com>; <amps@contesting.com>
>>>> Sent: Saturday, January 08, 2011 4:36 PM
>>>> Subject: Re: [Amps] Fuses
>>>>
>>>>
>>>>> Can you two get back to earth and keep it somewhat relative to ham
>>>>> amps in the under 20KW range (-;
>>>>>
>>>>> Carl
>>>>> KM1H
>>>>>
>>>>>
>>>>> ----- Original Message -----
>>>>> From: "James R Carr" <n7fcf@hctc.com>
>>>>> To: "Roger (K8RI)" <sub1@rogerhalstead.com>; <amps@contesting.com>
>>>>> Sent: Saturday, January 08, 2011 7:21 PM
>>>>> Subject: Re: [Amps] Fuses
>>>>>
>>>>>
>>>>>> Down in prosser, WA about 30 years ago they had a problem with a
>>>>>> pottato
>>>>>> processing plant and a mechanic came running into the panel room and
>>>>>> before
>>>>>> anyone could stop him threw the main 480v 3 phase breaker. The plant
>>>>>> was
>>>>>> under full load with motors up the cazoo. When the back emf hit it
>>>>>> blew the
>>>>>> breaker out of the panel. The guy was lucky he wasn't hurt.
>>>>>> I retired in 2000 and there is a whole raft of devices that have come
>>>>>> on
>>>>>> line since.
>>>>>> Jim
>>>>>> N7FCF
>>>>>> ----- Original Message -----
>>>>>> From: "Roger (K8RI)" <sub1@rogerhalstead.com>
>>>>>> To: <amps@contesting.com>
>>>>>> Sent: Saturday, January 08, 2011 2:38 PM
>>>>>> Subject: Re: [Amps] Fuses
>>>>>>
>>>>>>
>>>>>>>
>>>>>>>
>>>>>>> On 1/8/2011 5:22 PM, James R Carr wrote:
>>>>>>>> Agreed, The first instant in time you have the full output of
>>>>>>>> Bonnyville
>>>>>>>> Dam
>>>>>>>> on the fault. But then the impedance of the system kicks in and
>>>>>>>> limits
>>>>>>>> it.
>>>>>>>> But still depending on the size of the utility transformer, it's
>>>>>>>> eficiency,
>>>>>>>> the length and size of the service conductors, you can still have
>>>>>>>> several
>>>>>>>> thousand amps at the main panel and down the line. About 20 25
>>>>>>>> years ago
>>>>>>>> they had to increase the fault clearing ability all the breakers in
>>>>>>>> the
>>>>>>>> panels from 5000 amps to 20000 amps due to the increased use of low
>>>>>>>> loss
>>>>>>> Our mains weren't quite that large, but they were big...It's been
>>>>>>> too
>>>>>>> long for me to remember the actual size.
>>>>>>> They used magnetic quenching in arc chutes. They could open under
>>>>>>> full
>>>>>>> load without self destruction, BUT with big transformers down stream
>>>>>>> (Inductive loads) the "kick back" was so bad that reverse EMF would
>>>>>>> take
>>>>>>> out almost any thing attached to the line. So, if you blew one of
>>>>>>> the
>>>>>>> mains you knew it was going to be an expensive day.
>>>>>>>
>>>>>>> 73
>>>>>>>
>>>>>>> Roger (K8RI)
>>>>>>>> transformers by the utilities. basically the breaker can clear it
>>>>>>>> without
>>>>>>>> exploding. It probably will be terminally damaged though. I have
>>>>>>>> seen
>>>>>>>> buss
>>>>>>>> bars twisted into pretsels by a dead short and a breaker that
>>>>>>>> didn't
>>>>>>>> clear
>>>>>>>> quick enough.
>>>>>>>> Jim
>>>>>>>> N7FCF
>>>>>>>> ----- Original Message -----
>>>>>>>> From: "Jim Thomson"<jim.thom@telus.net>
>>>>>>>> To:<amps@contesting.com>
>>>>>>>> Sent: Saturday, January 08, 2011 2:18 AM
>>>>>>>> Subject: [Amps] Fuses
>>>>>>>>
>>>>>>>>
>>>>>>>>> Date: Sat, 8 Jan 2011 08:34:30 +0000
>>>>>>>>> From: Ian White GM3SEK<gm3sek@ifwtech.co.uk>
>>>>>>>>> Subject: Re: [Amps] Fuses
>>>>>>>>>
>>>>>>>>> James R Carr wrote:
>>>>>>>>>> Where pray tell do you get a hydraulic breaker? I have installed
>>>>>>>>>> several thousand over the years but have yet to see one filled
>>>>>>>>>> with
>>>>>>>>>> oil. As for current limiting devices, the fastest breaker will
>>>>>>>>>> hold in
>>>>>>>>>> for three to seven full cycles. To be current limiting, a fuse
>>>>>>>>>> has to
>>>>>>>>>> clear in less
>>>>>>>>>> than 1/2 cycle.
>>>>>>>>> A fuse provides NO current limiting until it blows; and a breaker
>>>>>>>>> provides NO current limiting until it breaks.
>>>>>>>>>
>>>>>>>>> A lot of damage can be done in those first few milliseconds, which
>>>>>>>>> is
>>>>>>>>> why the fuse/breaker is only PART of the solution.
>>>>>>>>>
>>>>>>>>> We always need a surge limiting resistor in the B+ as well, to
>>>>>>>>> provide
>>>>>>>>> instantaneous current limiting until the fuse/breaker takes over
>>>>>>>>> and
>>>>>>>>> finally breaks the circuit.
>>>>>>>>>
>>>>>>>>>
>>>>>>>>> --
>>>>>>>>>
>>>>>>>>> 73 from Ian GM3SEK
>>>>>>>>> http://www.ifwtech.co.uk/g3sek
>>>>>>>>>
>>>>>>>>> ## Agreed. The purpose of the mag-hydraulic breaker is [A] handy
>>>>>>>>> dandy
>>>>>>>>> way of opening off the 240 v line, without having to kill the
>>>>>>>>> dedicated
>>>>>>>>> breaker in the
>>>>>>>>> main 200A panel. [B] eliminate any follow on current.
>>>>>>>>>
>>>>>>>>> ## On my latest 7700 vdc supply, I use a Buss HVU series, sand
>>>>>>>>> filled
>>>>>>>>> HV fuse..rated at 3A..in series
>>>>>>>>> with the B+ lead. The HV fuse gets inserted just prior to the
>>>>>>>>> kw
>>>>>>>>> rated
>>>>>>>>> glitch R, which consists of 4 x
>>>>>>>>> parallel globar type AS energy absorbing type resistor's, 1.5"
>>>>>>>>> diam x
>>>>>>>>> 18' long. [ 4 x 200 ohm in parallel= 50 ohms]
>>>>>>>>> 7700/50 ohms = 154A. max fault current. Now 154 A of fault
>>>>>>>>> current,
>>>>>>>>> flowing through a 3 A rated
>>>>>>>>> fuse, will open VERY fast. [ the fuse is running at 5100% of
>>>>>>>>> it's
>>>>>>>>> rating]. I use a 50 ohm glitch R on the
>>>>>>>>> smaller supplies as well... with the provisio that a smaller rated
>>>>>>>>> HV
>>>>>>>>> fuse
>>>>>>>>> is used..like 1A, etc.
>>>>>>>>>
>>>>>>>>> ## I also use a 2nd Buss HV fuse, in the sec of the plate xfmr,
>>>>>>>>> [one
>>>>>>>>> leg
>>>>>>>>> only], between sec and input to
>>>>>>>>> FWB. In normal operation, with any B+ to chassis fault, the B+
>>>>>>>>> HV fuse
>>>>>>>>> alway's blows open 1st..so the
>>>>>>>>> breaker used in the 240 v line is sorta a moot point. That B+
>>>>>>>>> fuse
>>>>>>>>> concept has been tested 34 x times
>>>>>>>>> now, and nothing ever happens..except a blown HV fuse. Once,
>>>>>>>>> some of
>>>>>>>>> the
>>>>>>>>> blown HV fuses were
>>>>>>>>> 'refurbished' with a single strand, soldered on the outside..and
>>>>>>>>> wrapped
>>>>>>>>> with 88 tape. In one case, the
>>>>>>>>> wire ga of the single strand refurbished job was too big.. and
>>>>>>>>> the end
>>>>>>>>> result was the parallel pair of 100
>>>>>>>>> ohm, 225 W- WW's were literally incinerated, burnt to a crisp.
>>>>>>>>> That
>>>>>>>>> was
>>>>>>>>> with a 165 uf filter cap..and a 253 lb
>>>>>>>>> dahl hypersil xfmr. That particular glitch R was replaced with 4
>>>>>>>>> parallel 200 ohm, 225 W, wirewounds
>>>>>>>>> [ $12.00 each, from mouser],and the correct size HV fuse. Zero
>>>>>>>>> problems
>>>>>>>>> since then, and you can literally
>>>>>>>>> cro-bar it all day long. I would not trust any of these glitch
>>>>>>>>> R's,
>>>>>>>>> even
>>>>>>>>> big ones..without a prior series HV fuse,
>>>>>>>>> not with big uf caps, huge amount's of joules involved, and then
>>>>>>>>> trying
>>>>>>>>> to
>>>>>>>>> rely on a breaker [ or even the
>>>>>>>>> 2nd HV AC fuse].
>>>>>>>>>
>>>>>>>>> ## In one instance, one of the hv lytics [ 3900 uf @ 450 vdc]
>>>>>>>>> towards
>>>>>>>>> the hot end of the string, arced through a
>>>>>>>>> crack in the plywood, and launched itself. Since the fault was
>>>>>>>>> before
>>>>>>>>> the B+ fuse.... the 2nd HV fuse blew.
>>>>>>>>> [ the one located between sec of xfmr and FWB]. The 96 x 6A10's
>>>>>>>>> in
>>>>>>>>> the
>>>>>>>>> FWB were not damaged. In 2 x instances the
>>>>>>>>> 240 vac breaker popped open. Once when a screw removed from a 6"
>>>>>>>>> fan..and
>>>>>>>>> the AL fan swung down like a pendulum
>>>>>>>>> and hit one side of the 240 vac buss. [ and blew a chunk out of
>>>>>>>>> the fan
>>>>>>>>> casing]. The 2nd time was a B+ fault.
>>>>>>>>>
>>>>>>>>> ## I use a simple 50 ohm-50W WW on my L4B's..with the stock
>>>>>>>>> drake HV
>>>>>>>>> B+ fuse. [ consist of a .82 ohm, 1 watt carbon R ].
>>>>>>>>> The stock .82 Ohm R always blows cleanly in 1/2. I have only
>>>>>>>>> had 2
>>>>>>>>> x
>>>>>>>>> ever blow open since 1977.
>>>>>>>>>
>>>>>>>>> later... Jim VE7RF
>>>>>>>>> _______________________________________________
>>>>>>>>> Amps mailing list
>>>>>>>>> Amps@contesting.com
>>>>>>>>> http://lists.contesting.com/mailman/listinfo/amps
>>>>>>>> _______________________________________________
>>>>>>>> Amps mailing list
>>>>>>>> Amps@contesting.com
>>>>>>>> http://lists.contesting.com/mailman/listinfo/amps
>>>>>>>>
>>>>>>>
>>>>>>> _______________________________________________
>>>>>>> Amps mailing list
>>>>>>> Amps@contesting.com
>>>>>>> http://lists.contesting.com/mailman/listinfo/amps
>>>>>>
>>>>>> _______________________________________________
>>>>>> Amps mailing list
>>>>>> Amps@contesting.com
>>>>>> http://lists.contesting.com/mailman/listinfo/amps
>>>>>
>>>>
>>>
>>
>
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