Fredrick Paget on wed 14 nov 01
Jonathan,
You could get a set of elements from Euclids that will run on the
available voltage.
You want to check the voltage both with the kiln on and kiln off. If there
is a big differince you have a problem such as a too small wire or bad
connection somewhere.
There are several ways to boost the voltage. We used to make a boost
/buck transformer at Sylvania Ipswich, Mass. but the factory was sold to
Advance in Chicago and the building torn down 30 years ago.
If there is a controller on your kiln it may run on half the line
voltage of 240 so you need to hook up the boost so that it gets the proper
voltage. Usually a boost is wired in series with the line being a
transformer with about a 20 volt secondary and a primary that runs on 120
or 240. If you add that to one side of the line it will unbalance the
voltage to neutral. The voltage to neutral could be either 108 or 132
depending on which side of the line was hooked to. The neutral would not be
in the middle voltage wise any more. You could check this with a voltmeter.
This is important if there is a controller on the kiln as it is usually
wired to one side of the line and neutral to get 120 volts. Ideally you
should use two buck windings - one on each side of the line. However this
gets hard to implement and expensive . The controller will probably run on
108 and I would try it on that side of the line.
The boost transformer has to put out the full current rating of the kiln,
That is you want a 25volt 40 amp transformer if the kiln uses 40 amps. and
so forth. You can make the voltage adjustable by running the primary of the
boost transformer with a Variac or Powerstat adjustable voltage
autotransformer of about one fifth the current rating of the kiln.
Another way is to use a transformer with taps and connect to the proper
one.That is it might have a tap at the center of the 20 volt winding which
would give 10 volts .
Good luck
Fred
From Fred Paget, Marin County, California, USA
Jonathan Kirkendall on wed 14 nov 01
Hi all,
This is long and a bit complicated, and not at all as fun as the electric
boogie woogie, for those of you who remember that.
I have been renting studio space in an old carriage house (garage) in
downtown DC for about four years now. I rent from a wonderful woman named
Gay, who is very excited about having me there. Before I moved in, the
garage was empty for a few years, and before that it was a Harley Davidson
repair shop.
When I moved in, I called PEPCO, our local electric company, to have the
electric put in my name. When they asked me to read off the meter number, I
was told that that meter is not in the system. When I inquired about
putting the meter on the system, the nice woman at the other end said "Sir,
do you understand that we can't bill you if we don't know the meter exists?"
She actually had to repeat that a few times before the light came on in my
head.
So, dear friends, I do admit to having a wonderful situation in that I could
fire my electric kiln without ever being charged. A wonderful thing
until...last February, when the alley (where my studio is located)
experienced a man-hole cover explosion and fire of its very own (these have
been happening all around DC for a year or so and are fairly alarming).
Seventy two hours later, the electricity was back on...but my new Skutt KM
1027 electronic controlled kiln would no longer reach cone 6 (I got the
message "ERROR 1"). Called the electrician who took a voltage reading and
said "Sorry, you're only getting 215 volts, not 240, from the street."
So, I called PEPCO...but my meter is unregistered! (insert here that saying
about the fiddler collecting his dues, or something like that...I can't ever
remember that one). There was nothing they could do.
However, necessity being the mother of invention, I discovered that if I
fired to cone 5, held it for 45 minutes, I got a great cone 6 firing (yea
for heat work!). So, I've been doing that since last February, until a few
weeks ago when again, I started getting the message Error 1. I changed the
thermocouple, and no difference. I tested the resistance of the coils, and
they were all right on target. I called the electrician, and the same
story: only 215 volts coming into the studio, and for some reason, my trick
of firing to cone 5 and holding is no longer working.
I desperately need advice. I have orders due and holiday sales approaching.
You should know that my kiln is plugged in a foot away from the box, using
#6 copper wiring. Here are my options and obstacles as I see them:
1) Bite the bullet, register the meter, then complain about the voltage.
This puts my landlady in the unfortunate position of perhaps being charged
for years of electricity, and she doesn't want to keep me THAT badly. Also,
PEPCO can take months to repair things like this; this isn't something that
could happen by the end of the week, or even by the end of the year.
2) Replace the electric box and the wiring. The breaker box is very old (I
can't remember the brand, but it's not made anymore, and before I came, as
my landlady says, there was lots of jerryrigging of wires). The idea is,
that while this won't solve the problem of turning 215 volts into 240, it
may increase it just enough to enable me to go back to my cone 5 firings
with the 45 minute hold. The landlady is ready to do this, and pay for it.
3) Try firing to 2100 (where the kiln shuts off) and hold for an hour or so.
4) add a voltage booster. My dear friend, savior, and studio mate (3 in
1!!!) Anji has discovered a booster that will take 218 and boost it to 240.
Costs under $200. Does anyone have any experience with something like this?
Maybe we should do the new box then try this?
I really do need help - this gives me a sinking feeling in the pit of my
stomach, and kept me awake last night. Any ideas? Suppotive comments about
hanging in there would also do.
Grateful for this list,
Jonathan in DC
Cindy Strnad on wed 14 nov 01
Hi, Jonathan.
Hmm, well, you could set up a windmill . . . .
But, aside from that, you may want to try changing
out the elements anyway. They do lose their oomph
after a while. I know you checked and the
resistance readings were okay, but based on the
symptoms you're experiencing, I'll bet new
elements would make a difference. With the
under-powered power you're receiving, every little
bit helps. I would also highly recommend changing
out the switch box since that option is available.
From your description, it may be a dangerous
situation, leaving it as it is, and possibly it
would give you a few more electrons--I don't know
about that part. But seriously, change that
breaker box, whatever else you may do. Also, you
mention your kiln is "plugged in". It sounds as if
you're using the term metaphorically, but if it's
not hardwired into the wiring system, I'd do that
as well.
Good luck,
Cindy Strnad
Earthen Vessels Pottery
RR 1, Box 51
Custer, SD 57730
USA
cindy@earthen-vessels-pottery.com
http://www.earthen-vessels-pottery.com
william schran on wed 14 nov 01
Jonathan - Seems the simple solution is to change your elements to 208v.
Bill in Northern Va.
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