Amps
[Top] [All Lists]

[AMPS] circuit breaker recommendation

To: <amps@contesting.com>
Subject: [AMPS] circuit breaker recommendation
From: jtml@lanl.gov (John Lyles)
Date: Mon, 8 Oct 2001 07:25:05 -0600
For years I have used panel mounted breakers like the Airpax, ETA, 
Potter Brumfield W91X series, Seimens, etc. I think a number of 
manufacturers have consolidated a bit, but most make similar packages 
that can be uses as a second source for each other. The instantaneous 
MH is fine, it really isn't instantaneous but closer than a thermal 
breaker I would guess. Just rate it to be above the RMS current you 
plan on drawing (also the inrush if you don't have step start should 
be considered, and either the delay curve for the breaker chosen for 
this, or a slightly larger breaker chosen. Breakers are rated for 
line to ground voltage, for a 2 pole breaker. It is very difficult to 
find a 480 VAC panel mounted breaker, for instance. However one 
realizes that 277 volts is all that is present with respect to ground.

High speed electronic crowbar or overcurrent sensing can be used to 
open the primary power and the breaker protects your wiring and iron 
from burning up in a direct short. Some breakers can be obtained with 
separate trip coils which can be triggered from an overcurrent 
circuit to remove AC power that way. Only thing is that you might 
drop cooling, filaments and all this way and perhaps you want to keep 
a little cooling going until your tube cools down (depends on if 
bottle or with handles, etc.).

These breakers are sold at Allied and Newark among other 
distributors. Good choices...

73
John
K5PRO

To: <amps@contesting.com>
>Date: Sun, 7 Oct 2001 12:52:48 EDT
>From: ToddRoberts2001@aol.com
>Subject: [AMPS] CIRCUIT BREAKER FOR TRANSFORMER PRIMARY CIRCUIT
>
>Can anyone recommend a suitable panel-mount 2-pole circuit breaker for the
>240V primary circuit of a high-voltage transformer power supply? There are so
>many different types of circuit breakers available : Magnetic -Hydraulic,
>Thermal - Magnetic, medium-delay etc. the choice can be confusing. I would
>assume an instantaneous acting Magnetic-Hydraulic would be the best but even
>those seem to have different time-delay settings in catalogs I have looked
>at. Grainger seems to have a good selection but the catalog listings are
>confusing. I would guess a 20-25 amp rating would be good for a last line of
>defense and compatible with the ratings of my house wiring. Thanks for any
>suggestions. 73 Todd Roberts WD4NGG .

-- 

--
FAQ on WWW:               http://www.contesting.com/FAQ/amps
Submissions:              amps@contesting.com
Administrative requests:  amps-REQUEST@contesting.com
Problems:                 owner-amps@contesting.com


<Prev in Thread] Current Thread [Next in Thread>