David Hendley on sat 12 may 01
I'm not an electrician, and I don't play one on TV, but an
electrician wanting $150-200 for twisting a few wires
together blows my mind.
Installing a plug and a receptacle is what should be expensive.
Hardwiring is simply skipping that step.
To switch your kiln to hardwired, all that needs to be done
is remove the plug, remove the receptacle, and join the
appropriate wires with wire nuts inside the outlet box.
A different cover for the box, with a stress relief clamp might
be needed, but total materials cost would be a few dollars,
at most.
As for whether the change-over is needed, I say no, as long
as you monitor the plug. Check to make sure it is not getting
hot, and remove it after every few firings for a visual inspection.
As long as its unplugged, shine up the blades with fine sandpaper
to make sure you will continue to have good electrical contact.
--
David Hendley
Maydelle, Texas
hendley@tyler.net
http://www.farmpots.com/
----- Original Message -----
From: Susan
To:
Sent: Friday, May 11, 2001 10:12 AM
Subject: Re: kiln/electrical/smoke
| Okay, another hardwire/plug question for you all. I bought a used Baile=
y
| electric 2327-1 kiln a few months ago & am finally setting it up. It's =
7
| cu. ft., 240v, and I believe its jacket plate says it's rated to cone 8=
.. I
| can't tell if it says 43 or 48 amps. I'll be firing to max of cone 6.
|
| When I bought it (from a decent supplier), their kiln repair guy
| said, "gee, it doesn't have a plug on it... I'll put one on." At the ti=
me,
| it didn't occur to me that maybe it didn't have a plug because it neede=
d
to
| be hardwired. He didn't bring it up, and so I didn't even think of it.
|
| Several months down the road, I'm setting it up and it suddenly strikes
| me... maybe this needed to be hardwired? I called Bailey, & they
| said, "definitely hardwire it." I talked to two friends--a ceramics pro=
f
| and an electrical engineer--& they both said I should just feel the plu=
g
| periodically and see if it gets hot. If it doesn't get hot, they said I
| should be fine.
|
| My electrician says hardwiring it will run me $150-200. I just spend a
| bushel of money getting him to wire my studio; he knew at the time what=
my
| kiln draws, & I'm sure he used a receptacle that's beefy enough to hand=
le
| what my kiln needs. When I called to ask him for a quote, his first
| response was that he didn't see why it needed to be hardwired, but when=
I
| told him it would be on for 8-10 hours, he said that might be why.
|
| Any thoughts? experiences? I can't personally imagine that every studio
| potter with a kiln like mine has it hardwired. I don't want to do
something
| stupid, but I also would rather not spend an unnecessary $200. I won't =
be
| in this studio for more than 5 years, so if I can safely stick with the
| plug, I'd sure like to.
|
| Thanks,
| Susan
|
mudlark on sun 13 may 01
To add to this. I've had very few problems with electric kilns. But, I can
remember a couple times in which the plug failed. When this happens it is
dangerous and can create further problems down the line.
Now, that said. Instead of wire nuts you should use , I can't remember what their
called but they are a bolt-clamp specificly for large guage wire. Then you wrap
them with elecrical tape. And you must use a stress relief clamp on your cord.
All this stuff can be bought at your local True Value or what ever you have there.
David Hendley wrote:
> I'm not an electrician, and I don't play one on TV, but an
> electrician wanting $150-200 for twisting a few wires
> together blows my mind.
> Installing a plug and a receptacle is what should be expensive.
> Hardwiring is simply skipping that step.
>
> To switch your kiln to hardwired, all that needs to be done
> is remove the plug, remove the receptacle, and join the
> appropriate wires with wire nuts inside the outlet box.
> A different cover for the box, with a stress relief clamp might
> be needed, but total materials cost would be a few dollars,
> at most.
>
> As for whether the change-over is needed, I say no, as long
> as you monitor the plug. Check to make sure it is not getting
> hot, and remove it after every few firings for a visual inspection.
> As long as its unplugged, shine up the blades with fine sandpaper
> to make sure you will continue to have good electrical contact.
> --
> David Hendley
> Maydelle, Texas
> hendley@tyler.net
> http://www.farmpots.com/
>
> ----- Original Message -----
> From: Susan
> To:
> Sent: Friday, May 11, 2001 10:12 AM
> Subject: Re: kiln/electrical/smoke
>
> | Okay, another hardwire/plug question for you all. I bought a used Bailey
> | electric 2327-1 kiln a few months ago & am finally setting it up. It's 7
> | cu. ft., 240v, and I believe its jacket plate says it's rated to cone 8. I
> | can't tell if it says 43 or 48 amps. I'll be firing to max of cone 6.
> |
> | When I bought it (from a decent supplier), their kiln repair guy
> | said, "gee, it doesn't have a plug on it... I'll put one on." At the time,
> | it didn't occur to me that maybe it didn't have a plug because it needed
> to
> | be hardwired. He didn't bring it up, and so I didn't even think of it.
> |
> | Several months down the road, I'm setting it up and it suddenly strikes
> | me... maybe this needed to be hardwired? I called Bailey, & they
> | said, "definitely hardwire it." I talked to two friends--a ceramics prof
> | and an electrical engineer--& they both said I should just feel the plug
> | periodically and see if it gets hot. If it doesn't get hot, they said I
> | should be fine.
> |
> | My electrician says hardwiring it will run me $150-200. I just spend a
> | bushel of money getting him to wire my studio; he knew at the time what my
> | kiln draws, & I'm sure he used a receptacle that's beefy enough to handle
> | what my kiln needs. When I called to ask him for a quote, his first
> | response was that he didn't see why it needed to be hardwired, but when I
> | told him it would be on for 8-10 hours, he said that might be why.
> |
> | Any thoughts? experiences? I can't personally imagine that every studio
> | potter with a kiln like mine has it hardwired. I don't want to do
> something
> | stupid, but I also would rather not spend an unnecessary $200. I won't be
> | in this studio for more than 5 years, so if I can safely stick with the
> | plug, I'd sure like to.
> |
> | Thanks,
> | Susan
> |
>
> ______________________________________________________________________________
> 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.
--
Clyde Tullis
Mudlark Pottery
320 G Street
Salida, CO 81201
719-539-1299
mudlark@chaffee.net
http://www.mudlarkpottery.com
Craig Martell on mon 14 may 01
Dear Afficianados of electricity:
The name for the gadgets that one uses to hardwire a kiln circuit with #6
or larger wire is: "split bolt connectors". I think that's probably what
David H. was talking about, not wire nuts. I've read enough of his posts
to know that he is mechanically saavy and then some.
The deal with electric kilns is large amp draw. If you have 200 amp
service to your shop, a 7cu ft. electric is going to draw almost 25% of the
service on high. What makes the elements heat is resistance and that's
where you want high resistance and lots of heat, not in your plugs or
external wiring. Split bolts apply enough pressure to the connected wires
to significantly drop the resistance and heat. Everything from the
connection at the circut breaker in the power panel to the element/feedwire
connection should be very tight and clean.
Two other weak points in the circuit are the nichrome butt connectors used
to connect the element feed wires to the elements. At the factory, these
crimped connections are done with crimpers that look like bolt
cutters. Big tools with long handles that can apply a lot of force. When
we change elements in our studios we use crimping tools that are the size
of pliers and apply a lot less force. I've switched to small split bolts
on two of my electrics that I use for bisque. This lowers resistance and
allows elements to be changed easier and faster. It's really tough to
remove butt connectors and you usually lose some wire doing this. The
other problem point is the "interbox connectors", which are basically just
plugs. Since the kiln rings are going to move a bit during expansion and
contraction, these plugs will eventually burn. My wife has a large oval
electric for fusing and slumping glass. The lid is really heavy because
it's fitted with elements and this causes the top ring to flex when you
open and close the lid. After about 50 firings her kiln started blowing
the breaker so I too the electrical boxes apart and, sure enough, the
interbox connector was totally fried. I hard wired the connection and
didn't install a new plug. A-OK now.
My point? I think that the electronics in most studio electrics could be
upgraded a bit to eliminate some burnout/resistance problems. Why are the
not? Increased labor and expense, would be my guess. It takes a worker
much less time to crimp a circuit together than it does to apply and
tighten a split bolt. Hard wiring the electrical boxes would mean
redesinging and refitting the boxes so the rings could be separated when
the kiln needed to be moved or repaired.
later, Craig Martell in Oregon
Isao & Don on tue 15 may 01
At 12:12 5/14/01 -0700, you wrote:
>Dear Afficianados of electricity:
>
>The name for the gadgets that one uses to hardwire a kiln circuit with #=
6
>or larger wire is: "split bolt connectors". I think that's probably wha=
t
>David H. was talking about, not wire nuts. I've read enough of his post=
s
>to know that he is mechanically saavy and then some.
>
>The deal with electric kilns is large amp draw. If you have 200 amp
>service to your shop, a 7cu ft. electric is going to draw almost 25% of =
the
>service on high. What makes the elements heat is resistance and that's
>where you want high resistance and lots of heat, not in your plugs or
>external wiring. Split bolts apply enough pressure to the connected wir=
es
>to significantly drop the resistance and heat. Everything from the
>connection at the circut breaker in the power panel to the element/feedw=
ire
>connection should be very tight and clean.
>
>Two other weak points in the circuit are the nichrome butt connectors us=
ed
>to connect the element feed wires to the elements. At the factory, thes=
e
>crimped connections are done with crimpers that look like bolt
>cutters. Big tools with long handles that can apply a lot of force. Wh=
en
>we change elements in our studios we use crimping tools that are the siz=
e
>of pliers and apply a lot less force. I've switched to small split bolt=
s
>on two of my electrics that I use for bisque. This lowers resistance an=
d
>allows elements to be changed easier and faster. It's really tough to
>remove butt connectors and you usually lose some wire doing this. The
>other problem point is the "interbox connectors", which are basically ju=
st
>plugs. Since the kiln rings are going to move a bit during expansion an=
d
>contraction, these plugs will eventually burn. My wife has a large oval
>electric for fusing and slumping glass. The lid is really heavy because
>it's fitted with elements and this causes the top ring to flex when you
>open and close the lid. After about 50 firings her kiln started blowing
>the breaker so I too the electrical boxes apart and, sure enough, the
>interbox connector was totally fried. I hard wired the connection and
>didn't install a new plug. A-OK now.
>
>My point? I think that the electronics in most studio electrics could b=
e
>upgraded a bit to eliminate some burnout/resistance problems. Why are t=
he
>not? Increased labor and expense, would be my guess. It takes a worker
>much less time to crimp a circuit together than it does to apply and
>tighten a split bolt. Hard wiring the electrical boxes would mean
>redesinging and refitting the boxes so the rings could be separated when
>the kiln needed to be moved or repaired.
>
>later, Craig Martell in Oregon, L'd be abit careful "hardwiring" althoug=
h
it is certainly superior to 'plugs'. Whether one is owning property or
renting, kilns may be classed as "Appliances". Hardwiring implies that th=
e
appliance becomes a part of the real estate and is not removable when the
householder sells or moves except by prior agreement. (just knitpicking.)
Don M.
>
>________________________________________________________________________=
___
___
>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.
>
Don & Isao Sanami Morrill
e-Mail:
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