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new electric kiln and breaker size

updated sat 23 jun 12

 

James Freeman on thu 21 jun 12


On Thu, Jun 21, 2012 at 9:58 AM, J Motzkin wrote:

I want to replace this kiln with a 60 amp kiln that can go to ^10 but will
likely only be used to ^6 or bisque.
The Skutt KM1227-PK is a 60 amp kiln, specs say it needs an 80 amp breaker.

Must we change the breaker or can I wait and see if it trips on the way to
^6 ? What are the issues, dangers?

Also, any opinions about this skutt or other choices?




Judy...

Assuming your existing kiln wiring is sized for a 60 amp circuit, you
CANNOT install an 80 amp breaker or you will potentially overload the
wire. If the wire is indeed big enough to handle an 80 amp load, then
replacing the breaker is a simple and inexpensive job that you can probably
do yourself. There are tons of online videos and tutorials demonstrating
how to do this.

The required wire gauge is based on the voltage, the maximum current load
(amps), and the length of the circuit. Think of the wire like a pipe: If
you were already running at your pipe's maximum throughput, but you want to
start drawing more water (amps), you need either a larger pipe (wire gauge)
or a higher pressure (voltage). Since you are already at 240 volts, your
only option would be a bigger pipe. Depending on where and how your wiring
is run, this could run from very reasonable to very expensive. There are
various online wire gauge tables and calculators, or better yet you can
consult your electrician.

As to whether the kiln will fire on a 60 amp circuit, I am guessing that
will be a function of how rapidly you attempt to heat it. At a reasonable
pace, and with good elements, you will probably be just fine, though others
will certainly be more knowledgeable in this regard than I.

On the choice of kiln, everyone will have their own opinion. It's kind of
like the Ford versus Chevy truck debate, or the 9mm versus .45 debate, or
the Mary Ann versus Ginger debate (Mary Ann!). There is no "right" answer,
because everyone's needs, budget, and priorities are different. Having
said that, I purchased a big Skutt kiln for the college, having found a
great deal from a downsizing ceramics manufactory that was selling three
never fired ones out of storage. I hated that kiln. It seemed to cool way
too quickly, and the off-brand controller was a PITA to use, at least for
my needs. Having fired half a dozen brands at my own studio and at the
college, my own preference is for Evenheat and Cone Art. Both are really
well made (I assume Tucker is doing as good a job building the Cone Art
kilns as did Shimpo), well insulated, and come with Bartlett controllers.
I have not had the pleasure of firing one of Arnold's Paragon kilns, but I
have been told that they too are rock solid.

Congrats on the new kiln!

...James

James Freeman

"Talk sense to a fool, and he calls you foolish."
-Euripides

http://www.jamesfreemanstudio.com
http://www.flickr.com/photos/jamesfreemanstudio/
http://www.jamesfreemanstudio.com/resources

J Motzkin on thu 21 jun 12


My old electric kiln is 240, single phase, marked 60/75 amps, KW 14.4/18
I have it hard wired to a shutoff box with fuses and on a 60 amp breaker. I
use it almost exclusively for bisque as it is old and tired.

I want to replace this kiln with a 60 amp kiln that can go to ^10 but will
likely only be used to ^6 or bisque.
The Skutt KM1227-PK is a 60 amp kiln, specs say it needs an 80 amp breaker.

Must we change the breaker or can I wait and see if it trips on the way to
^6 ? What are the issues, dangers?

Also, any opinions about this skutt or other choices?
Thanks,
Judy

cer*ram*ics (se-ram'iks), *n*. 1. Just an excuse to start a FIRE

motzkin/studio
jmotzkin@motzkin.com
7 tufts street
cambridge MA 02139
617.547.5513
BreadPots.com
www.motzkin.com
projects
judith, judy, zhudi, jude, =3DD6=3DF2=3DB5=3DD8, =3DC3=3DFE=3DCB=3DBC=3DE2=
=3DF9

dmcarts2u@AOL.COM on thu 21 jun 12


KM1227-PK

I would verify the size and wiring type you have and call Skutt to verify w=
=3D
hat size conductor's they recommend for your wiring type. A typical 60 amp =
=3D
circuit is wired with #6 copper and it looks like Skutt is spec'g #4 copper=
=3D
for this kiln. I just went through this on my new studio project.


Michael

http://www.dmcarts.com


-----Original Message-----
From: J Motzkin
To: Clayart
Sent: Thu, Jun 21, 2012 1:41 pm
Subject: new electric kiln and breaker size


My old electric kiln is 240, single phase, marked 60/75 amps, KW 14.4/18
I have it hard wired to a shutoff box with fuses and on a 60 amp breaker. I
use it almost exclusively for bisque as it is old and tired.

I want to replace this kiln with a 60 amp kiln that can go to ^10 but will
likely only be used to ^6 or bisque.
The Skutt KM1227-PK is a 60 amp kiln, specs say it needs an 80 amp breaker.

Must we change the breaker or can I wait and see if it trips on the way to
^6 ? What are the issues, dangers?

Also, any opinions about this skutt or other choices?
Thanks,
Judy

cer*ram*ics (se-ram'iks), *n*. 1. Just an excuse to start a FIRE

motzkin/studio
jmotzkin@motzkin.com
7 tufts street
cambridge MA 02139
617.547.5513
BreadPots.com
www.motzkin.com
projects
judith, judy, zhudi, jude, =3DE7=3D83=3D9B=3DE5=3D9C=3DB0, =3DE6=3D91=3DB8=
=3DE6=3D80=3D9D=3DE6=3D80=3DA1

=3D20

Arnold Howard on thu 21 jun 12


On 6/21/2012 8:58 AM, J Motzkin wrote:
> My old electric kiln is 240, single phase, marked 60/75 amps, KW 14.4/18
> I have it hard wired to a shutoff box with fuses and on a 60 amp breaker.=
I
> use it almost exclusively for bisque as it is old and tired.
>
> I want to replace this kiln with a 60 amp kiln that can go to ^10 but wil=
l
> likely only be used to ^6 or bisque.
> The Skutt KM1227-PK is a 60 amp kiln, specs say it needs an 80 amp breake=
r.

Judy, your circuit needs 4 gauge copper wire for a 60 amp kiln. The wire
gauge is probably stamped on the insulation.

Sincerely,

Arnold Howard
Paragon Industries, L.P., Mesquite, Texas USA
ahoward@paragonweb.com / www.paragonweb.com

William & Susan Schran User on fri 22 jun 12


On 6/21/12 9:58 AM, "J Motzkin" wrote:

>I want to replace this kiln with a 60 amp kiln that can go to ^10 but will
>likely only be used to ^6 or bisque.
>The Skutt KM1227-PK is a 60 amp kiln, specs say it needs an 80 amp
>breaker.
>
>Must we change the breaker or can I wait and see if it trips on the way to
>^6 ? What are the issues, dangers?

Don't wait, it will trip the breaker. You need the 80 amp breaker and you
may need to increase the size of your wiring depending on what you have
currently installed.
I imagine you may have 6ga. wire now, and the specs for the KM1227-PK,
240V, 1ph., require a 4 ga. copper wire.

Bill
--
William "Bill" Schran
wschran@cox.net
wschran@nvcc.edu
http://www.creativecreekartisans.com

Rimas VisGirda on fri 22 jun 12


Why screw around? Just switch out an 80 amp breaker... Cost, about $50... N=
o worries... -PRICELESS! -Rimas

David Woof on fri 22 jun 12


Hi Judy.
=3D20
The 80 amp specs give a margin so that the breaker won't trip when you reac=
=3D
h the full amp demand rated for those particular elements=3D2C but will sti=
ll=3D
trip off if there is a higher demand fault in the system. =3D20
=3D20
Repeated heating and subsequent tripping off of a breaker rated too small f=
=3D
or the load causes wear and tear to the breaker and so weakens it=3D2C caus=
in=3D
g it to trip from increasingly less amperage.
=3D20
Contrary to a rather common misunderstanding=3D2C the controls for typical =
po=3D
tter's kilns do not increase the amperage to the elements but simply leave =
=3D
them on for longer durations as the firing progresses and the temperature r=
=3D
ises. Thus to reach cone 6 your kiln has already been drawing full amperag=
=3D
e at constant duty for some time. To go on to reach cone 10 is then a matte=
=3D
r of the elements continuing to draw their full rated amperage for a longer=
=3D
duration.
=3D20
David Woof
______________________________________________________________
=3D20
Date: Thu=3D2C 21 Jun 2012 09:58:27 -0400
From: J Motzkin jmotzkin@GMAIL.COM
Subject:new electric kiln and breaker size
=3D20
My old electric kiln is 240=3D2C single phase=3D2C marked 60/75 amps=3D2C =
KW 14.=3D
4/18I have it hard wired to a shutoff box with fuses and on a 60 amp breake=
=3D
r. Iuse it almost exclusively for bisque as it is old and tired. I want to =
=3D
replace this kiln with a 60 amp kiln that can go to ^10 but willlikely only=
=3D
be used to ^6 or bisque.The Skutt KM1227-PK is a 60 amp kiln=3D2C specs sa=
y =3D
it needs an 80 amp breaker. Must we change the breaker or can I wait and se=
=3D
e if it trips on the way to^6 ? What are the issues=3D2C dangers? Also=3D2C=
any=3D
opinions about this skutt or other choices?
=3D20
Thanks=3D2C
=3D20
Judy =3D