Joan Pierce on sat 30 aug 03
Hi Clayarters...
I have a situation that I don't see addressed in the archives, although it could just be that I don't know how to make my search specific enough. I was test firing my new L&L JD230 electric kiln today as I am supposed to according to the manual. I should mention that I purchased this kiln and had the wiring done (by a licensed electrician) over a year ago, but life interrupted and I'm just now getting the chance to use it.
Everything was going well, almost 12 hours into the firing the temperature was 1365 or thereabout and I was reading my clayart e-mail when all of a sudden the computer just shut off. The breaker boxes are in the basement near the kiln, on my way to them I noticed that some other lights/appliances had lost power too. When I got downstairs I discovered the kiln and vent powerless as well. All the breaker switches were in the ON position so I turned them all off and on again and the kiln started up. It lasted a few minutes then shut down again. This time I left the kiln breaker off and reset all the others, but again, none were thrown into the off position with the power loss.
My question...is it normal for breaker switches to remain in the ON position, even though the things they control have no power? I always thought that with a problem like this I'd find a switch or switches in the OFF position.
My other question...do I really need to re-do the test firing after I get the electrician to come fix this problem?
The strange part is that this house was built in the 50's with 100 amp service. An addition was done in the 80's and a 2nd breaker box was installed, 50 amp I believe. The lights/devices that went out in addition to the kiln were on a breaker switch in the 100 amp box, the kiln is on the 50 amp box.
Any advice?
Thanks in advance for any advice you have to offer...and thanks for just being part of this wonderful list!
Joan in PA where the greenware will have to wait a little longer to be bisqued.
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Earl Krueger on sat 30 aug 03
On Saturday, August 30, 2003, at 05:40 PM, Joan Pierce wrote:
> My question...is it normal for breaker switches to remain in the ON
> position, even though the things they control have no power? I always
> thought that with a problem like this I'd find a switch or switches in
> the OFF position.
>
On circuit breakers there is an intermediate position between ON and
OFF. When a breaker trips it goes to this intermediate position and
shuts off the power. To reset it you must turn the breaker to OFF and
then to ON. If you try just going to ON without going to OFF first, it
won't stay.
Something else to think about. Circuit breakers work by generating
heat based on the amount of electrical current flowing through them.
When the temperature inside the breaker gets to a certain point the
breaker trips. The exact amount of current that will trip a breaker
depends on how fast the heat generated inside the breaker dissipates.
If the heat cannot dissipate at the rate specified by the manufacturer
the breaker will trip at a lower current than it's rating. I have
seen breakers that tripped under normal loads, but only when the
afternoon sun was shining on the wall the panel was mounted in. If
your kiln is too near the breaker panel the air temperature may be high
enough that the breaker is tripping early.
> My other question...do I really need to re-do the test firing after I
> get the electrician to come fix this problem?
What is the purpose of the "test firing"? If it's to make sure the
kiln and controller are working and set properly it doesn't sound like
you've proved that out yet. So, yes I would do the test again.
Besides, it's a good way to get to know your kiln better.
> The lights/devices that went out in addition to the kiln were on a
> breaker switch in the 100 amp box, the kiln is on the 50 amp box.
According to the L&L website the JD230 consumes 43.98 amps of
electrical current. This is very close to the 50 amp rating of your
sub-panel. Since you mentioned that circuits other than the kiln also
went out I assume that the main breaker in the sub-panel is the one
that tripped. If you subtract the kiln current from the panel rating
(50 - 43.98 = 6.02) you only have a margin of 6 amps capacity. That's
not much ! Any other appliances that were on would probably put you
over the limit.
(This may get a little too technical now.) I'm assuming that you have
240 volt service. At 50 amps and 240 volts your sub-panel can supply
240 X 50= 12,000 watts of power. You're kiln consumes 10,554 watts.
The difference 12,000 - 10,554 = 1,446. That's about 14 100 watt
light bulbs worth. Or a combination of light bulbs and a toaster or
clothes iron or hair dryer, etc.
In the L&L manual (page 11) you will see 'The National Electrical
(Code) says that you should fuse a resistance circuit (kilns are a
resistive load...) for 125% of their rated full load amps. The full
load amps is listed on the data nameplate of the kiln.' If you
multiply the 43.98 amps by 125% you get 54.975 amps. This exceeds the
capacity of your 50 amp sub-panel.
I would definitely get a good (underlined) electrician to look at your
situation. Upgrading your sub-panel service could be expensive but
what value do you put on your and your family and friends safety?
Hope this helps.
Earl...
Pamela Watkins on sun 31 aug 03
Hi Joan,
In regards to your question on breakers seemingly "on" switch when no power.... Yes, the switch will kick back a bit, but not to off. I know this because my compressor for spray glaze has wacked out my switch box and the same switch question occurred. Your answer? Get the electrician out again... you need more power/isolated breaker for the kiln. You can't have your kiln kicking off!!! I would re-fire the bisque and I would inquire with the electrician as, if a pro- should have know what amps you needed and hooked you up accordingly.
Joan Pierce wrote:
Hi Clayarters...
I have a situation that I don't see addressed in the archives, although it could just be that I don't know how to make my search specific enough. I was test firing my new L&L JD230 electric kiln today as I am supposed to according to the manual. I should mention that I purchased this kiln and had the wiring done (by a licensed electrician) over a year ago, but life interrupted and I'm just now getting the chance to use it.
Everything was going well, almost 12 hours into the firing the temperature was 1365 or thereabout and I was reading my clayart e-mail when all of a sudden the computer just shut off. The breaker boxes are in the basement near the kiln, on my way to them I noticed that some other lights/appliances had lost power too. When I got downstairs I discovered the kiln and vent powerless as well. All the breaker switches were in the ON position so I turned them all off and on again and the kiln started up. It lasted a few minutes then shut down again. This time I left the kiln breaker off and reset all the others, but again, none were thrown into the off position with the power loss.
My question...is it normal for breaker switches to remain in the ON position, even though the things they control have no power? I always thought that with a problem like this I'd find a switch or switches in the OFF position.
My other question...do I really need to re-do the test firing after I get the electrician to come fix this problem?
The strange part is that this house was built in the 50's with 100 amp service. An addition was done in the 80's and a 2nd breaker box was installed, 50 amp I believe. The lights/devices that went out in addition to the kiln were on a breaker switch in the 100 amp box, the kiln is on the 50 amp box.
Any advice?
Thanks in advance for any advice you have to offer...and thanks for just being part of this wonderful list!
Joan in PA where the greenware will have to wait a little longer to be bisqued.
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Kenneth D. Westfall on tue 2 sep 03
Sound like you may need to look into up grading your hole house to a 200
amp service. If you have much in the way of electric appliances ie Air
Conditioning, water heater, stove,cloths dryer, and furnace then 100 amp
service is already being run close to the max. It sound like also is the
info others have said about your L and L kiln it should have never been on
a 50 amp circuit to start with.
At 05:40 PM 08/30/2003 -0700, you wrote:
>Hi Clayarters...
>
>I have a situation that I don't see addressed in the archives, although it
>could just be that I don't know how to make my search specific enough. I
>was test firing my new L&L JD230 electric kiln today as I am supposed to
>according to the manual. I should mention that I purchased this kiln and
>had the wiring done (by a licensed electrician) over a year ago, but life
>interrupted and I'm just now getting the chance to use it.
>
>Everything was going well, almost 12 hours into the firing the temperature
>was 1365 or thereabout and I was reading my clayart e-mail when all of a
>sudden the computer just shut off. The breaker boxes are in the basement
>near the kiln, on my way to them I noticed that some other
>lights/appliances had lost power too. When I got downstairs I discovered
>the kiln and vent powerless as well. All the breaker switches were in the
>ON position so I turned them all off and on again and the kiln started
>up. It lasted a few minutes then shut down again. This time I left the
>kiln breaker off and reset all the others, but again, none were thrown
>into the off position with the power loss.
>
>My question...is it normal for breaker switches to remain in the ON
>position, even though the things they control have no power? I always
>thought that with a problem like this I'd find a switch or switches in the
>OFF position.
>
>My other question...do I really need to re-do the test firing after I get
>the electrician to come fix this problem?
>
>The strange part is that this house was built in the 50's with 100 amp
>service. An addition was done in the 80's and a 2nd breaker box was
>installed, 50 amp I believe. The lights/devices that went out in addition
>to the kiln were on a breaker switch in the 100 amp box, the kiln is on
>the 50 amp box.
>
>Any advice?
>
>Thanks in advance for any advice you have to offer...and thanks for just
>being part of this wonderful list!
>
>Joan in PA where the greenware will have to wait a little longer to be
>bisqued.
>
>
>
>
>---------------------------------
>Do you Yahoo!?
>Yahoo! SiteBuilder - Free, easy-to-use web site design software
>
>______________________________________________________________________________
>Send postings to clayart@lsv.ceramics.org
>
>You may look at the archives for the list or change your subscription
>settings from http://www.ceramics.org/clayart/
>
>Moderator of the list is Mel Jacobson who may be reached at
>melpots@pclink.com.
Kenneth D. Westfall
Pine Hill Pottery
R.D. #2 Box 6AA
Harrisville, WV 26362
kenneth@pinehillpottery.com
http://www.pinehillpottery.com
Arnold Howard on tue 2 sep 03
Joan, this has happened to me, too. A breaker can shut off yet still
appear to be in the On position. I would replace the breaker.
Secondly, it sounds like other appliances are on the same circuit as
your kiln. That may be why the breaker shut off.
The purpose of the test firing is to dry out the kiln and to make sure
it is functioning properly before firing ware. It would't hurt to do the
test firing again.
Sincerely,
Arnold Howard
Paragon Industries, L.P.
arnoldhoward@att.net
From: Joan Pierce
The breaker boxes are in the basement near the kiln, on my way to them I
noticed that some other lights/appliances had lost power too. When I
got downstairs I discovered the kiln and vent powerless as well. All
the breaker switches were in the ON position so I turned them all off
and on again and the kiln started up. It lasted a few minutes then shut
down again. This time I left the kiln breaker off and reset all the
others, but again, none were thrown into the off position with the power
loss.
>
> My question...is it normal for breaker switches to remain in the ON
position, even though the things they control have no power?
>
> My other question...do I really need to re-do the test firing after I
get the electrician to come fix this problem?
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