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Kiln Pointers
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Troubleshooting a Blank Digital Kiln Display |
Sometimes cherished memories are made from the smallest incidents. Below the Kiln Pointer, you will find such a story from a high school pottery teacher. Q. What causes a digital kiln to shut off and the display to go blank right after you press the Start button? A. The answer applies to any brand of digital kiln. There are two situations: The kiln shuts off because the circuit breaker trips, or the controller’s display goes blank but the circuit breaker does not trip. CIRCUIT BREAKER TRIPS To turn on the heating elements, the controller sends a signal to one or more relays. They, in turn, send power to the elements. When the circuit breaker trips right after you press the Start button, unplug the kiln and remove the kiln’s switch box. Look for an electrical short on the element side of the relay: 1) A relay-to-element lead wire is touching the heat shield. Find the two element connectors for each element. You will see wires attached to the connectors. Look for a wire with frayed insulation that is touching the kiln case. Also, check the wire terminals. If one is tilted far enough to touch the heat shield, it can shut off the breaker. Look for a small burn mark on the heat shield. It is a sign of electrical arcing between the wire terminal and the heat shield. 2) Place an ohmmeter probe on an element connector and the other probe on the kiln case. The ohmmeter should show no continuity. 3) Look for a disconnected element-to-relay wire that is touching the kiln case. 4) It is possible for element pins from two adjacent elements to touch each other inside the firebrick wall. This causes the elements to short out between each other. This will cause an ohmmeter reading that is much lower than normal for those elements. DISPLAY GOES BLANK BUT CIRCUIT BREAKER DOES NOT TRIP 1) A defective relay is drawing too much current from the controller, making the display go blank. Unplug the kiln. Disconnect the two controller-to-relay wires from each relay, one at a time. (In Paragon kilns, they are the red and black wires.) Position the disconnected wires so that the wire terminals cannot touch each other or anything else inside the switch box. After you disconnect each relay, turn the kiln on again and press the Start button. Do this until you find the relay that is draining the controller. Replace that relay. 2) The transformer that powers the controller is wired incorrectly or is going bad. Study your kiln’s wiring diagram to make sure the transformer is wired properly. BAKED CLAY COOKIES A story appeared on the Clayart email forum recently that I wanted to share. Mel Jacobson of Minnetonka, Minnesota related an experience from the days when he taught a high school pottery class: “Kids would bring baked goodies to the clay room. We always had a few bites around. Often, uninvited guests would sneak into the room and snitch a few cookies...most often the faculty. ‘He he, they won't miss a couple of cookies.’ “We made soft clay cookies--nice and brown, fresh clay, and sprinkled bits of china clay on the tops. Or we would use a fork and make those wonderful peanut butter cookie patterns. Kids would mess with iron for days to get the color right. We added a touch of foil or Saran wrap. Remember, always keep an old brownie pan around your art room just for clay brownies. Soft, elegant, yummy. “We set them out on the attendance table. Never had a complaint. But we counted cookies every hour. There were always one or two missing. “At the end of the year we would fire up a few cookies and give them to deserving kids--you know, those kids who always gave back more than they got. On the back was just a simple ‘Above and beyond.’ They would cry. A 40-year-old woman stopped me at the mall one day. She said, ‘Mel, I still have my clay cookie on my dresser after all these years. My husband is very careful with it.’” To read more about Mel, visit www.paragonweb.com and scroll down toward the bottom of the page. A QUIKFIRE KILN POINTER Ted Ricchiuti of Seaside Park, New Jersey uses a wind-up timer on his Paragon QuikFire kilns. (You can use this idea on any type of kiln.) He wrote, “Fifteen minutes is just about enough for a full fuse. I have not burned out the elements of my QuikFire kilns since I installed these timers. Before using the timers, there had been times when I walked away from the QuikFire during a busy day and forgot that I was firing something. The timers make a nice clicking sound as they wind down, which helps to remind me that the kiln is turned on.” A RECENT Q&A Q. Any suggestions on photographing glass jewelry? A. There are many ways to photograph glass. To bring out the color of your piece, place it on a sheet of white translucent Plexiglas. Then shine a light from behind. To bring out the surface texture of the glass, also position a light in front. Collect excellent photos of glass and jewelry. You can find them in catalogs and magazine ads. Then try the same lighting techniques that were used in the photos. The light source sometimes appears in a reflective surface of the jewelry. With best wishes, Arnold Howard Paragon Industries, L.P. – Better Designed Kilns 2011 South Town East Blvd. Mesquite, TX 75149-1122 Voice: 972-288-7557 & 800-876-4328 / Fax: 972-222-0646 ahoward@paragonweb.com / www.paragonweb.com |
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