Janet H Walker on thu 23 oct 97
... the 50amp to the kiln receptacle...
?? I got a Skutt, 48 amp rated. It came with instructions to install
it on a 60 amp breaker, not a 50 amp breaker. Could that be the heart
of the issue I wonder?
Jan Walker
Cambridge MA, USA
Kenneth D. Westfall on fri 24 oct 97
Dear Jan
That is deafanitly your problem. Breakers are not rated to handle
resistance load such as a kiln. They are rated for electric motor which put
a monentary load on them. A heating elemants put a constant load and
breaker are I believe only rated for 95 or 90 % of the marked amps. So a 50
amp breaker can only handle a 45 amp resistance load. Have you breaker
change and besure the wiring is sized large enough to handle the larger
breaker. A over sized breaker on light wirer spells disaster.
Kenneth D. Westfall
Pine Hill Pottery
RD#2 Box 6AA
Harrisville, WV 26362
pinehill@ruralnet.org
DON'T GET STUCK IN THE MUDPIES--K & T
Margaret Arial on sat 25 oct 97
Jan,
Yes that is at least part of your problem the amp is too high for 50 you need
10% bigger amp wise breaker so 60 is next choice since i've not seen 55 in
this market.It will not be needed.Direct wiring into a breaker with a cutoff
, away from the main box, as close as is possible to the kiln,but accessible
to cut off without contacting a hot kiln in an emergency.IIf the building has
only 100 amps you'd bettered check all the major draws on the system and
turn off any that will cut on to bring usage near capacity i.e. stoves, water
heaters, furnaces and similar energy consumers.IF YOU WERE TO BE A LONG TERM
TENANT WITH THIS SYSTEM YOU MIGHT PRICE A SEPERATE 200 AMP SERVICE.IT WOULD
BE SAFER.
Margaret originally from Mass.
Bill Hall on sat 25 oct 97
> ... the 50amp to the kiln receptacle...
>
>?? I got a Skutt, 48 amp rated. It came with instructions to install
>it on a 60 amp breaker, not a 50 amp breaker. Could that be the >heart
>of the issue I wonder?
Sorry, I missed the first part of this thread. I just had a new Paragon TNF
wired at my house. It can draw up to 51 amps, and is on a 70-amp breaker.
The rating for the breaker is the amperage at which it will trip, not the
maximum normal load. It should be rated so that the maximum normal load is
80% of its rating. So, a 48 amp load should be on a 60 amp breaker. (60 X .8
= 48)
And, a comment on another message in this thread: breakers are not designed
to be tripped regularly. If you have a breaker that trips regularly, either
the breaker is worn out or faulty, there is a problem with the circuit or
load (the kiln), or the load is too big for the circuit.
Bill Hall
Dallas, where the fall rainy weather has arrived.
bill@applink.net http://www.applink.net/bill
Ron Wright on sat 25 oct 97
I just can't keep quiet anymore after reading this thread. A household
circuit breaker IS rated for a resistance load Not a motor (inductive)
load. Transient voltage spikes from a motor will not trip a breaker. A
breaker has a bimetal spring in it that works on the heat generated by
current flowing through the circuit. A prolonged period of current draw
close to the maximum rating will trip a breaker as well as a large
momentary current draw. Sort of like a cone in a kiln. Watts (P) over
current (I) x voltage (E). Also, a new breaker will trip at it's rated
current, not at a percentage of that rating. It would not get a U.L.
approval if didn't. Although a breaker subjected to many heavy loads
will trip at lower current draw as it ages. There, I got that off my
chest so I can go back to my pots.
Ron Wright
Formally an electronics tech, now a cop, working on being a potter.
In Chicago where the weather sucks.
Kenneth D. Westfall wrote:
>
> ----------------------------Original message----------------------------
> Dear Jan
> That is deafanitly your problem. Breakers are not rated to handle
> resistance load such as a kiln. They are rated for electric motor which put
> a monentary load on them. A heating elemants put a constant load and
> breaker are I believe only rated for 95 or 90 % of the marked amps. So a 50
> amp breaker can only handle a 45 amp resistance load. Have you breaker
> change and besure the wiring is sized large enough to handle the larger
> breaker. A over sized breaker on light wirer spells disaster.
>
> Kenneth D. Westfall
> Pine Hill Pottery
> RD#2 Box 6AA
> Harrisville, WV 26362
> pinehill@ruralnet.org
>
> DON'T GET STUCK IN THE MUDPIES--K & T
Paul Monaghan on sun 26 oct 97
Kenneth D. Westfall wrote:
>
> ----------------------------Original message----------------------------
> Dear Jan
> That is deafanitly your problem. Breakers are not rated to handle
> resistance load such as a kiln. They are rated for electric motor which put
> a monentary load on them. A heating elemants put a constant load and
> breaker are I believe only rated for 95 or 90 % of the marked amps. So a 50
> amp breaker can only handle a 45 amp resistance load. Have you breaker
> change and besure the wiring is sized large enough to handle the larger
> breaker. A over sized breaker on light wirer spells disaster.
>
> Kenneth D. Westfall
> Pine Hill Pottery
> RD#2 Box 6AA
> Harrisville, WV 26362
> pinehill@ruralnet.org
>
> DON'T GET STUCK IN THE MUDPIES--K & T
Hi Ken,
The breakers are rated for the stated load in AMPS. Just opposite to
what you are saying. Actually you must also consider the speed at which
the breaker trips - usually not important in a household setting. the
motor loads will momentarily draw 7 times the steady state current on
start-up. In these situations being discussed the breakers will usually
handle this. if, however, someone has instsalled a very high speed
breaker - which is unlikely - it will trip very fast on a relatively
small overload. Resistance loads such as kilns DO NOT create surges as
do motors (Inductive loads).
Ciao,
Paul :-))
--
Paul J. Monaghan email: paul@web2u.com
WEB2U Productions --- http://www.web2u.com
The "COOLEST" Site on the WEB
"The Computer Secrets are hidden at http://www.web2u.com/secret"
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Tom Morris on mon 27 oct 97
In my many years of being an electrician's apprentice, I have learned that
any load, whether inductive (such as a motor) or resistive (such as a kiln)
draws more energy before reaching full speed OR full temperature. My
advice, get the 60 amp breaker, but then a 50 amp set of fuses. The fuses
will blow after a sustained overload, such as an element drawing too much
power, and the breaker will pop if you get a dead short.
Tom Morris
Where the summer is so hot, I don't even need a kiln ;o>
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