Carl Finch on fri 30 dec 05
replace factory cord?
At 07:02 AM 12/30/2005, Leland Hall wrote:
> It appears to me that one can not merely cut off the plug, as the cord is
>too short. The disconnect needs to be a minimum 18" off the floor to meet
>code, and besides, logic indicates that a safety switch should be at or
>around eye or waist level.
>
>I see that these cords utilize an unusual copper wire. The structure of the
>copper itself is very much like a common household lamp cord, though much
>heavier. Very fine strands wound together to equal a #6 gauge, and very
>heavily sheathed for protection. I assume the fine stranded #6 wire is
>chosen for it's ability to withstand the years of twisting and movement it
>is likely to subjected to during the life of the appliance.
I would think so, too.
>For example,
>where the cord enters the control panel, the cord clamp is made so as to
>swivel, or rotate within the body of the panel.
Are you sure? Usually a cord is to clamped TIGHT where it enters an
appliance. That's the way it is on the cord attached to the control box of
my Skutt KM1027 kiln. There is a cable clamp at the entry point.
The clamp looks like this, only
larger:
Looking halfway down the page you'll see that there's a locknut on one end
and the screw-down clamp on the other, intended to prevent any cable
swiveling. If the cable were allowed to swivel it could cause big problems
inside the case--rotating the cable on the outside would cause strain on
the connections inside.
Of course if the locknut loosens up it *will* allow the cable to swivel. I
just checked on my own kiln, and sure enough, that locknut wasn't even
finger-tight! Mr. Skutt really ought to use an entry hole with a "flat"
and a clamp with a matching flat to prevent rotation of a loose
clamp. This type of cable clamp is appropriate for wiring that doesn't
'move' (e.g., hidden in a wall), but I think it's inappropriate for this
sort of strain relief because of its tendency to loosen after being pulled
around a bit.
> This makes sense to me as
>when a kiln is relocated the cord is likely to be pulled to some other
>angle to accommodate various outlet locations, so the swivel feature,
>combined with the very flexible nature of the wire itself both seem to
>work in conjunction so as to avoid the wire breaking from repeated stresses.
>
>Also, I note the wire ends inside the panel have round hole terminals,
>which are attached with compression crimping.
>
>With all this said, (and I realize this is much conjecture) I don't see how
>to extend the length of the cord to reach the safety/disconnect, which will
>be up on the wall.
>
>It occurs to me that one could just purchase the appropriate length of #4
>or #6 copper wire, run it through flexible metal conduit, (you know, that
>spiral-ee stuff) and call it good. But I don't think it would be.
MC armoured (the "spiral-ee stuff") is OK as long as your kiln is
indoors. But it is not 'code' for outdoors.
>The commonly availiable #4 or #6 copper wire is fewer strands, stiff, and
>I think would not hold up at the terminal ends at the ceramic block in the
>control box. And what to use for the terminals and how to attach them?
Dunno. I noticed that when I took apart my kiln plug a few months ago to
see what it would take to hardwire it. I'm wondering if the stranded wire
could simply be tinned with solder, and whether that would be code and
suitable.
My cord seems long enough to move the kiln at least a little bit. Are you
planning big moves?!
But now after thinking a bit, I'm wondering if a flexible cord should even
be used at all for hardwiring. The only hardwired kilns I've seen were
done entirely with armoured cable (they were indoors). Their original
flexible cords had been removed completely.
>Does Skutt offer longer cords? (I'll be calling them today)
I'm curious to know, too. Once I figure out exactly where I want my kiln I
expect to hardwire it, too.
--Carl
in Muddy Medford, Oregon
Leland Hall on fri 30 dec 05
replace factory cord?
Greetings.
While attempting to figure out how to hardwire a kiln to a
disconnect/safety switch I am running into more questions than solutions.
It appears to me that one can not merely cut off the plug, as the cord is
too short. The disconnect needs to be a minimum 18=94 off the floor to meet=
code, and besides, logic indicates that a safety switch should be at or
around eye or waist level.
I see that these cords utilize an unusual copper wire. The structure of the
copper itself is very much like a common household lamp cord, though much
heavier. Very fine strands wound together to equal a #6 gauge, and very
heavily sheathed for protection. I assume the fine stranded #6 wire is
chosen for it=92s ability to withstand the years of twisting and movement it=
is likely to subjected to during the life of the appliance. For example,
where the cord enters the control panel, the cord clamp is made so as to
swivel, or rotate within the body of the panel. This makes sense to me as
when a kiln is relocated the cord is likely to be pulled to some other
angle to accommodate various outlet locations, so the swivel feature,
combined with the very flexible nature of the wire itself both seem to
work in conjunction so as to avoid the wire breaking from repeated stresses.=
Also, I note the wire ends inside the panel have round hole terminals,
which are attached with compression crimping.
With all this said, (and I realize this is much conjecture) I don=92t see ho=
w
to extend the length of the cord to reach the safety/disconnect, which will
be up on the wall.
It occurs to me that one could just purchase the appropriate length of #4
or #6 copper wire, run it through flexible metal conduit, (you know, that
spiral-ee stuff) and call it good. But I don=92t think it would be. The
commonly availiable #4 or #6 copper wire is fewer strands, stiff, and I
think would not hold up at the terminal ends at the ceramic block in the
control box. And what to use for the terminals and how to attach them?
Does Skutt offer longer cords? (I=92ll be calling them today) I tried to
search the archives here for information, but the =93search=94 function is n=
ot
working for me today.
I am working with an electriction who seems excellent with residential
applications. However, he is not experienced with doings like this
whatsoever. I=92m happy to see that he has a keen eye for safety and code,
but this =93kiln=94 stuff is all new to him. He=92s on vacation at the time=
anyway, so I need to proceed with caution, and then he will peruse what I
have come up with (if anything) when he returns. Then of course, (in the
end) the county has their say too.
My apologies for the disjointed writing, (now and past) I do the best I
can with what I have, and appreciate those of you who have shown patients.
Thank you for any ideas, suggestions, whatever.
Best
Leland Hall
Before The Wheel
La Pine, OR USA
William & Susan Schran User on fri 30 dec 05
replace factory cord?
On 12/30/05 10:02 AM, "Leland Hall" wrote:
> It occurs to me that one could just purchase the appropriate length of #4
> or #6 copper wire, run it through flexible metal conduit, (you know, that
> spiral-ee stuff) and call it good. But I don=B9t think it would be. The
> commonly availiable #4 or #6 copper wire is fewer strands, stiff, and I
> think would not hold up at the terminal ends at the ceramic block in the
> control box.
Two larger L&L's (80 amp breakers) at school that required hardwire hook-up=
,
came with just a hole in the control panel. Electrician used flexible metal
conduit with solid copper, not stranded, wiring through it. Think it was #2
or #4 wire.
-- William "Bill" Schran
Fredericksburg, Virginia
wschran@cox.net
wschran@nvcc.edu
Taylor, in Rockport TX on fri 30 dec 05
replace factory cord?
Hey Leland:
I can only tell you what I did with my kiln, but I think your situation
can't be too different.
I removed the plug cord from my old Paragon. (I took pictures this last
time I hard wired it and will try to put them on Flickr if I can remember
tonight) The connections happened to be very large wire nuts and I used
similar nuts to connect the number 6 (stranded always as far as I know)
wire from the box. Yes, I also placed my #6 in flexible armor and used the
appropriate connector at the switch box on the kiln. I can't tell if your
supply connects are wire to wire or wire to some kind of terminal block. I
would think the electrician could use some kind of connector with
compression screw to do the job. I had to do that for my subpannel feed.
The neutral wire was way too big for the neutral bus, but a simple
connector screwed into the bus allowed the #whater I had to connect.
Your electrician will know what wire will carry what load for the run. I
know that cable numbering and wire numbering can be very confusing to
blokes like us. Call it Freddie as long as it will carry the juice. I'm
going to suggest that you NOT order another plug cord. Hard wire for sure--=
new, fresh cable to your disconnect boxes. Don't scrimp on this stuff.
You da man.
Yepper Leland, once a wire gets to a certain size, it really needs to be
made of bundled smaller wires. Could you imagine trying to fish a solid
copper #6 cable through 7 feet of wall, up, down, and into the boxes? Oh
brother!
Taylor, in Rockport TX
On Fri, 30 Dec 2005 10:02:57 -0500, Leland Hall
wrote:
>Greetings.
>
>While attempting to figure out how to hardwire a kiln to a
>disconnect/safety switch I am running into more questions than solutions.
>
> It appears to me that one can not merely cut off the plug, as the cord is
>too short. The disconnect needs to be a minimum 18=94 off the floor to mee=
t
>code, and besides, logic indicates that a safety switch should be at or
>around eye or waist level.
>
>I see that these cords utilize an unusual copper wire. The structure of the=
>copper itself is very much like a common household lamp cord, though much
>heavier. Very fine strands wound together to equal a #6 gauge, and very
>heavily sheathed for protection. I assume the fine stranded #6 wire is
>chosen for it=92s ability to withstand the years of twisting and movement i=
t
>is likely to subjected to during the life of the appliance. For example,
>where the cord enters the control panel, the cord clamp is made so as to
>swivel, or rotate within the body of the panel. This makes sense to me as
>when a kiln is relocated the cord is likely to be pulled to some other
>angle to accommodate various outlet locations, so the swivel feature,
>combined with the very flexible nature of the wire itself both seem to
>work in conjunction so as to avoid the wire breaking from repeated
stresses.
>
>Also, I note the wire ends inside the panel have round hole terminals,
>which are attached with compression crimping.
>
>With all this said, (and I realize this is much conjecture) I don=92t see h=
ow
>to extend the length of the cord to reach the safety/disconnect, which will=
>be up on the wall.
>
>It occurs to me that one could just purchase the appropriate length of #4
>or #6 copper wire, run it through flexible metal conduit, (you know, that
>spiral-ee stuff) and call it good. But I don=92t think it would be. The
>commonly availiable #4 or #6 copper wire is fewer strands, stiff, and I
>think would not hold up at the terminal ends at the ceramic block in the
>control box. And what to use for the terminals and how to attach them?
...
Leland Hall on sat 31 dec 05
replace factory cord?
Taylor, and others, thanks for your input here. Means a lot.
And the pics are nice.
Quote from Taylor: "The connections happened to be very large wire nuts
and I used
similar nuts to connect the number 6 (stranded always as far as I know)
wire from the box."
I didn't like seeing those wire nuts inside your kiln, but as you might
understand, I may have become parinoid. I'm remembering something I heard
years ago that made me laugh. "Just because your not paranoid, doesn't
mean their not after you!" Not that that has anything to do with
anything. What I'm getting at is that those wire nuts look to me like a
possible source of trouble. (from what I've heard) Hope I'm wrong.
Any way, I talked to Skutt, Great customer support. A feller talked to me
for 45 minutes, and on their dime too. I would prefer to take option "A",
and do one run from kiln to dissconect, but I'm not gonna come up with a
crimper tool for those big round hole terminals, So---what with wire nuts
being out of the question, (Taylor, did I mention those wire nuts your
using scare me?) I'll be using option "B", which is utilise factory cord, a
water proof box low on the wall behind the kiln, and splice inside the box
using those little copper splicer clamps with hex nuts on them. I was
shown this neat stuff, you wrap the clamps/splice with. It's an eighth
inch thick, 4"x4" sheet of tar looking stuff, probably vinyl or whatever.
Kind of a black putty like substance, cut it into strips, wrap the splice
inside the box with this stuff, (it adhears to itself amazingly, welds sort
of), then wrap the whole thing with electrical tape), screw on the lid,
good to go.
That's a poor discription I know. But the Ace hardware fellow says that
this stuff is what is used do do splices on submersed pumps. Wish I knew
what it's called.
Regarding the factory cord. Those wires are of Very fine strands, almost
hair like. Typical #6 copper for house wireing, say, your furnace or
something, is much courser strands. I was postulating that Skutt used the
finely stranded stuff for the sake of flexibility, since the cords are
exposed to traffic, and the kilns are semi portable. The tech guy
confirmed this.
One last thing, apparently, according to the tech dude, a "fusible" saftey
disconnect, is not the most appropriate unit for this application, though
is ok. A non fused, simple "knife switch", of appropriate amp rating, is
best. Apparently those "shotgun shell" fuses, where the brass (copper)
cap/end snaps into the fuse holder, is a possible source of resistance.
Occasional removal of the fuses and light sanding/cleaning is in order.
I'm wondering if a spot of that antioxident grease smeared around the ends
of those might be good?
I'm done. Shoot, I'm writing to Clayart again at 6AM with only 1/2 a cup
of coffee in me. Hope I'm making sense.
Peace
Leland Hall
Closer To The Wheel
La Pine
Leland Hall on thu 5 jan 06
replace factory cord?
Carl, and whoever may be following this,
Thanks for the on list and off list replies. Very usefull.
I was mistaken about the clamp inside the control box. It is not designed
to "swivel", but it DID swivel, as the nut had come loose. I'm glad you
pointed that out. This looseness and swiveling allows stress on the
terminals if the cord is moved. Not good.
So what about soldering those terminals? Too much heat? How to
determine? I suppose a hammer and "dull" chisel could be used to crimp new
terminals onto the wire. Don't know if that would suffice. Ther's a tool
for this yes? A spot of "anti-oxidant" grease would seem to me to be in
order on all connections, but it does not appear that Skutt uses any in the
control box.
There is a flexable vinyl conduit, very tuff stuff. I think it's made for
wet locations, even under conduit. With it comes a "system" of connectors
and fittings, all "water proof".
Yes, would prefer to use an appropriatly "armored" cable of approprite
length, with "appropriate round hole terminals for inside the control box.
My local supplier does not carry cable of such a nature, and still the
terminal question.
Carl, Big moves with the kilns? Well--not exactly. It's just that no
longer having a kiln shed, I have to now live with them in what's left of
the studio. Rather cramped. I am fabricating kiln stands on wheels, so
that they may be rolled out of the way when not in use. Also, as this
building is classified as a "detatched garage", all electrical "outlets",
fixtures and such must be 18 inches up off the floor. The factory cord
just isn't long enough to pull that off.
So I think the best question I have at this point, is this: Consider that
the "terminal" issue were solved, then what "armoured" cable would best
suit this application, and comes bulK? (by the foot)
some one suggested looking into eight foot dryer cords. cut the plug off.
good idea, just havn't had time yet.
Thanks again folks. Keep it coming please, wer'e not there yet.
Leland Hall
Before The Wheel Enterprises
La Pine, OR, USA
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
>For example,
>where the cord enters the control panel, the cord clamp is made so as to
>swivel, or rotate within the body of the panel.
Are you sure? Usually a cord is to clamped TIGHT where it enters an
appliance. That's the way it is on the cord attached to the control box of
my Skutt KM1027 kiln. There is a cable clamp at the entry point.
The clamp looks like this, only
larger:
Looking halfway down the page you'll see that there's a locknut on one end
and the screw-down clamp on the other, intended to prevent any cable
swiveling. If the cable were allowed to swivel it could cause big problems
inside the case--rotating the cable on the outside would cause strain on
the connections inside.
Of course if the locknut loosens up it *will* allow the cable to swivel. I
just checked on my own kiln, and sure enough, that locknut wasn't even
finger-tight! Mr. Skutt really ought to use an entry hole with a "flat"
and a clamp with a matching flat to prevent rotation of a loose
clamp. This type of cable clamp is appropriate for wiring that doesn't
'move' (e.g., hidden in a wall), but I think it's inappropriate for this
sort of strain relief because of its tendency to loosen after being pulled
around a bit.
> This makes sense to me as
>when a kiln is relocated the cord is likely to be pulled to some other
>angle to accommodate various outlet locations, so the swivel feature,
>combined with the very flexible nature of the wire itself both seem to
>work in conjunction so as to avoid the wire breaking from repeated
stresses.
>
>Also, I note the wire ends inside the panel have round hole terminals,
>which are attached with compression crimping.
>
>With all this said, (and I realize this is much conjecture) I don't see how
>to extend the length of the cord to reach the safety/disconnect, which will
>be up on the wall.
>
>It occurs to me that one could just purchase the appropriate length of #4
>or #6 copper wire, run it through flexible metal conduit, (you know, that
>spiral-ee stuff) and call it good. But I don't think it would be.
MC armoured (the "spiral-ee stuff") is OK as long as your kiln is
indoors. But it is not 'code' for outdoors.
>The commonly availiable #4 or #6 copper wire is fewer strands, stiff, and
>I think would not hold up at the terminal ends at the ceramic block in the
>control box. And what to use for the terminals and how to attach them?
Dunno. I noticed that when I took apart my kiln plug a few months ago to
see what it would take to hardwire it. I'm wondering if the stranded wire
could simply be tinned with solder, and whether that would be code and
suitable.
My cord seems long enough to move the kiln at least a little bit. Are you
planning big moves?!
But now after thinking a bit, I'm wondering if a flexible cord should even
be used at all for hardwiring. The only hardwired kilns I've seen were
done entirely with armoured cable (they were indoors). Their original
flexible cords had been removed completely.
>Does Skutt offer longer cords? (I'll be calling them today)
I'm curious to know, too. Once I figure out exactly where I want my kiln I
expect to hardwire it, too.
--Carl
in Muddy Medford, Oregon
| |
|
