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My Raku Kiln


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#21 Cass

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Posted 21 October 2012 - 01:15 AM

i'll take your word!...rare that if forget to kill it these days, maybe once a year

#22 Benzine

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Posted 21 October 2012 - 11:06 AM



I wonder how well some good insulated gloves would protect a person from 220 volts?


i use the thick kevlar gloves, like hockey mitts, i doubt it could arc right thru those, i don't want to test it though!


it absolutely will arc through those, I say this having received a nice 240v jolt from an annealer with a faulty door switch while wearing those kevlar beasts.


Whoa! How did that feel, and what did it do to you?

I've been shocked by lower voltage on a couple occasions, and it was unpleasant. One time, i was trying to fix a digital camera, and kept getting zapped, because the flash capacitor would automatically recharge after each picture. So there was no way to discharge it permanently.
"Anything worth believing, is worth questioning"

#23 JBaymore

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Posted 21 October 2012 - 12:50 PM

One time, i was trying to fix a digital camera, and kept getting zapped, because the flash capacitor would automatically recharge after each picture. So there was no way to discharge it permanently.


That was low amperage and high voltage. Annoying. The kiln is high voltage and high amperage. Can be lethal if your body is grounded well away from the contact point on you body.

Damp, sweaty insides of such gloves are good conductors.

best,

.............john
John Baymore
Immediate Past President; Potters Council
Professor of Ceramics; New Hampshire Insitute of Art

http://www.JohnBaymore.com

#24 Benzine

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Posted 21 October 2012 - 12:58 PM

One time, i was trying to fix a digital camera, and kept getting zapped, because the flash capacitor would automatically recharge after each picture. So there was no way to discharge it permanently.


That was low amperage and high voltage. Annoying. The kiln is high voltage and high amperage. Can be lethal if your body is grounded well away from the contact point on you body.

Damp, sweaty insides of such gloves are good conductors.

best,

.............john


Yeah, like I said, it was just unpleasant. It went up my arm a bit, and left some small burn blisters on the tips of my fingers. I don't think high amperage would be unpleasant at all, because I don't think I'd have a chance to feel it.

How many amps is the standard electric kiln? I tell my students to use caution, not only because of the heat the kiln creates, but also because of the electrical risk. But I just tell them about the high volts, because most of them don't understand what the amp amount would mean.
"Anything worth believing, is worth questioning"

#25 Chantay

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Posted 21 October 2012 - 01:28 PM

I'm wondering why an electric kiln doesn't shut off when you open the lid more than an inch. Could you imagine your dryer running after you opened the door?


- chantay

#26 Cass

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Posted 21 October 2012 - 02:56 PM

(they probably assume no one would be silly enough to open it while running!Posted Image)

#27 Benzine

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Posted 21 October 2012 - 03:21 PM

I'm wondering why an electric kiln doesn't shut off when you open the lid more than an inch. Could you imagine your dryer running after you opened the door?



I will actually keep the dryer running, if I need to snag something out of it. I just quickly press the switch, as I open the door.
"Anything worth believing, is worth questioning"

#28 JBaymore

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Posted 21 October 2012 - 04:46 PM

How many amps is the standard electric kiln?


For a continuous load... whatever amperage the breaker it is on is rated at. SO for a largetr electric kiln ...... maybe 30 to 50 amps.

I am not precissely sure what an instantaneous peak current load would be on such a household breaker though. Meaning if for a nanosecond or a millisecond it'd pass a far higher current level until it actually activated. I'm guessing it would. But that is pure guesswork.

208 or 220 Volts at 30 Amps through your body would NOT be a good thing. :blink:

http://engineering.d...talCurrent.html

best,

...............john
John Baymore
Immediate Past President; Potters Council
Professor of Ceramics; New Hampshire Insitute of Art

http://www.JohnBaymore.com

#29 Benzine

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Posted 21 October 2012 - 04:50 PM


How many amps is the standard electric kiln?


For a continuous load... whatever amperage the breaker it is on is rated at. SO for a largetr electric kiln ...... maybe 30 to 50 amps.

I am not precissely sure what an instantaneous peak current load would be on such a household breaker though. Meaning if for a nanosecond or a millisecond it'd pass a far higher current level until it actually activated. I'm guessing it would. But that is pure guesswork.

208 or 220 Volts at 30 Amps through your body would NOT be a good thing. :blink:

http://engineering.d...talCurrent.html

best,

...............john



I wouldn't say so, considering, that what, .6 milliamps across the heart will kill a person?
"Anything worth believing, is worth questioning"

#30 ayjay

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Posted 22 October 2012 - 04:19 AM

I'm wondering why an electric kiln doesn't shut off when you open the lid more than an inch. Could you imagine your dryer running after you opened the door?



Both of my electric kilns shut off when you open the lid, the older one can't be opened without turning off the supply and the newer one has a switch at the hinge which will shut it down when opened.

I know nothing of dryers. :D

#31 Benzine

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Posted 22 October 2012 - 08:21 PM


I'm wondering why an electric kiln doesn't shut off when you open the lid more than an inch. Could you imagine your dryer running after you opened the door?



Both of my electric kilns shut off when you open the lid, the older one can't be opened without turning off the supply and the newer one has a switch at the hinge which will shut it down when opened.

I know nothing of dryers. :D


Dryers are like kilns, but take waaaaaaaaay longer to dry clothes.
"Anything worth believing, is worth questioning"

#32 justanassembler

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Posted 22 October 2012 - 11:13 PM

Whoa! How did that feel, and what did it do to you?

I've been shocked by lower voltage on a couple occasions, and it was unpleasant. One time, i was trying to fix a digital camera, and kept getting zapped, because the flash capacitor would automatically recharge after each picture. So there was no way to discharge it permanently.



it knocked me on my butt, luckily. The alternative is that it would have seized my muscles not allowing me to release the punty and my partner would have had to knock me off of it with a 2x4. I got really, really lucky.




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