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Controller Front Panel |
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The Keypad
The controller is easy to master once you understand that the keys have two functions:
The controller is used to control temperature, it is not a safety device.
Do not operate the controller in temperatures above 125 °F.
Never leave your kiln unattended at the end of a firing.
The controller contains electronic components which are sensitive to static electricity. Before handling the controller dissipate any static charge you may have by touching metal or a screw on the controller panel, the electrical box, the kiln lid, or some other grounded object.
Always check the position of the thermocouple probe before starting a firing. The current temperature displayed on the controller is measured at the end of the thermocouple.
Always review the current program before firing to ensure the correct profile is programmed.
You enter a program that tells the controller what temperature you want to fire to and at what rate you want the temperature to rise. The controller uses a thermocouple (t/c) to sense the temperature in the kiln. The temperature is measured at the tip of the t/c so it is important that the tip be 1½" to 2" inside the kiln wall. When START is pressed, the controller reads the kiln temperature and uses that temperature as a starting point for a traveling set-point. The controller then calculates how much power is needed to keep the temperature equal to the traveling set-point and cycles the electricity to the elements so the correct amount of power is applied. As the firing progresses, the controller moves the traveling set-point according to the programmed firing rate and recalculates how much power is needed to keep the temperature at the new traveling set-point.
You can enter a program in two different ways. The cone fire method is the easiest and is designed for firing ceramics to ensure correct heat-work for each cone number and firing rate. With as few as six key presses, you can have a firing programmed and started. The vary-fire method allows more complicated profiles and more freedom but is slightly more difficult to program. Vary-fire programs are used for firing such things as glass, jewelry, and crystalline glazes.
Do NOT fire your kiln or furnace until you have read this section and Cone-Fire Basics or Ramp-Hold Basics. TO use your controller to its fullest capacity, read the advanced sections and Additional Features.
Testing and Recording
You will learn much by testing. How slowly should clay be heated through quartz inversion? How slowly must you cool glass through the annealing range? Find out for yourself by testing. The RTC 1000 can precisely control every stage of firing, so you can easily experiment and test.
Keep a notebook of firing records. When you fire similar projects weeks later, after you have forgotten the details of your previous firing, you will be grateful for your records.
Room Temperature and Humidity
It is okay to store the RTC 1000 at subzero temperatures. But before operating, raise the room temperature to at least 0°F/-18°C.
The circuit board is rated for 155°F/68°C maximum operating temperature. However, maximum temperature for rated accuracy is 125°F/52°C. If the board gets hotter, open windows and exhaust hot air from the room. (See instructions for checking circuit board temperatures.)
High humidity will not adversely affect the RTC 1000 unless water condenses on the circuit board. If this happens, do not fire the kiln until the moisture has evaporated from the board.
IdLE and CPL Messages
The controller displays 'ErrP' when you first apply power. Press ENTER. 'ErrP' will change to 'IdLE' and a flashing temperature. Operations being from 'IdLE'.
If the display shows 'FAIL' instead of 'IdLE', the thermocouple is either disconnected or burned out.
'CPL' means "completed". The controller will display 'CPL', then 'IdLE', after it performs such actions as changing from °F to °C display. 'CPL' may remain after a while before 'IdLE' appears. Please be patient ---the controller is processing data.
Which Instructions to Use
The RTC 1000 fires in two modes
FAST, MEDIUM, SLOW, CONE-FIRE, AND Cone #s printed on the controller faceplate apply to Cone-Fire Mode.
How to Tell if You Have Cone-Fire
Care of the Thermocouple
The small metal rod protruding into the firing chamber is the temperature sensor, or thermocouple. This could affect the temperature reading.
Bumping the thermocouple during loading can damage it or push it out of the firing chamber. It should protrude into the firing chamber at least 1/2 " - 5/8". (Do not be concerned if your thermocouple extends even farther.)
Avoid firing clay with a high sulfur content. The sulfur erodes the thermocouple making it brittle and easy to break.
Display Dots
Single Center Dot: Time
A lower center dot appears during time display. It separates hours from minutes (i.e. 1 hour, 30 minutes displays as 1.30). During temperature display, the dot disappears.
Single Right-Hand Dot: °C
When a temperature is displayed in °C, a lighted dot appears in the lower right. In °F it disappears.
Three Dot Display: Power Monitoring
To adjust temperature, the RTC 1000 sends power to the relay(s) intermittently. The relays, in turn, power the heating elements. To monitor when the relays are turned on, press 8 during firing. When three dots appear along the bottom display, relays are receiving power.
To turn off Power Monitoring, press 8 again. This feature is used mostly for diagnostics.
Correcting Entries
If you enter the wrong temperature, cone, time, etc., while programming, enter 0000. Then enter the correct numbers before pressing ENTER.
The Stop Key
You can stop a firing at any time by pressing the STOP button.
If you inadvertently enter Ramp-Hold, you do not have to go through all the prompts to get back out. Press STOP when 'USEr' appears. That will take you back to 'IdLE'.
If you inadvertently enter Cone-Fire, STOP will NOT take you back to 'IdLE'. Press ENTER after each Cone-Fire prompt until 'CPL', then 'IdLE' appears.
If you inadvertently press MENU, you can get back to 'IdLE' by pressing STOP.
Cool-Down Temperature Display
When the firing is finished 'CPLt' will display alternating with the total firing time in hours and minutes. To view the current kiln temperature as the kiln cools, press ENTER. 'CPLt' will disappear. Then temperature will display.
Repeat Firings
To repeat the previous firing, press ENTER twice from 'IdLE'. The kiln will begin firing. This works in both Cone-Fire and Ramp-Hold. But first, make sure you are repeating the correct firing by using "Program Review" below.
Program Review
When you select a firing program in Cone-Fire or Ramp0Hold and go back to 'IdLE', you have called a program from storage. It is then ready to fire. "Program Review" shows you the values for that program.
To start "Program Review" from 'IdLE', press ENTER, then 6. Values for the program selected for firing will display one after the other. You can also use "Program Review" during firing simply by pressing 6.
TIP: In Program Review, values for a program display about one per second. You can speed up this display by pressing 1 repeatedly. If you hold down the key values will speed by. This works from both 'IdLE' and during firing.
Pyrometric Witness Cones in Ceramic Firings
Though the RTC 1000 fires electronically, every ceramic firing should include shelf or witness cones. They measure heat work accurately and give a history of the firing.
If you fire the same sized load and type of ware regularly, the shelf cones let you compare one firing to the next and alert you when something is wrong. For example, if the shelf cone bends farther and farther with each consecutive firing, this may indicate thermocouple temperature drift.
Keep cones 3 " from the peephole to avoid cool air drafts. Wear firing safety glasses when viewing the cones at high temperature. Your dealer can tell you which cone number to use for each clay and glaze.
When Kiln Shuts Off Too Soon
If the kiln shuts off below maturity, you can turn it back on and keep firing. Simply program a higher temperature or hotter cone. Then from 'IdLE', press START twice. The kiln will begin firing, taking up where it left off.
Ceramic firings: if the kiln shuts off within 100°F/50°C of maturity, and the temperature drops 50°F/28°C or more after the kiln shuts off, do not depend on the pyrometric witness cones in the kiln. Once the cones cool 50°F/28°C after they have been heated within 100°F/50°C or maturity they will not bend properly. This is due to the formation of a hard shell.
Cone-Fire Basics
Firing Speeds
Cone-Fire operates in Fast, Medium, or Slow speed. The instructions that follow will show you how to select speed.
To view the firing segment of a cone-fire, press 5 during firing (See Present Status). The segment number will appear (see left column in the following charts), informing you of how far the firing has progressed.
Fast (1)
Consider Fast for overglazes, decals, china paint, or small, thin-walled ceramic greenware.
Cone-Fire Fast Firing Schedule
| Segment in "Present Status" | Actual Segment | Rate of Firing Schedule |
| 5 | - | Pre-Heat (if any) |
| 6 | 1 | 570° F/hour until the last 250° F |
| 7 | 2 | 200° F/hour during the last 250° F |
Cone-Fire Medium Firing Schedule
| Segment in "Present Status" | Actual Segment | Rate of Firing Schedule |
| 4 | - | Pre-Heat (if any) |
| 5 | 1 | 110° F/hour 250° F |
| 6 | 2 | 400° F/hour until the last 250° F |
| 7 | 3 | 120° F/hour during the last 250° F |
Cone-Fire Slow Firing Schedule
| Segment in "Present Status" | Actual Segment | Rate of Firing Schedule |
| 2 | - | Pre-Heat (if any) |
| 3 | 1 | 80° F/hour to 250° F |
| 4 | 2 | 250° F/hour until the temperature reaches 950° F |
| 5 | 3 | 110° F/hour until the temperature reaches 1100° F |
| 6 | 4 | 225° F/hour until the last 200° F |
| 7 | 5 | 90° F/hour until the last 250° F |
| 8 | 6 | 150° F/hour, cooling down to 1000° F |
Example: to fire to cone 05½, program Cone-Fire for 05 and add 30 minutes of hold time.
Pre-Heating the Ware
Moist greenware can explode during firing. This happens when the moisture in the clay turns to steam rapidly and cannot easily escape. The RTC 1000 "Pre-Heat" feature dries the ware at low temperature before the moisture can turn to steam.
Pre-Heat is necessary when firing thick greenware, such as stoneware. It may also be necessary in humid weather, which inhibits drying. If possible, however, avoid using Pre-Heat to dry greenware. If the greenware feels damp or cool when you touch it to your cheek, dry it longer before firing. Use a dehumidifier in humid weather. Drying greenware in the kiln tends to rust the kiln.
TIP: During Pre-Heat, vent the lid. Otherwise the firebricks will absorb moisture, leading to rust behind the stainless steel case. Moisture in the firebrick will also slow the kiln to a crawl when firing begins.
AOP
The optional "AOP" (Auxiliary Output) is an electrical outlet, usually mounted in the kiln's switch box. The AOP outlet can power a kiln vent or other appliance. If your kiln is equipped with AOP, 'AOP' will appear in Cone-Fire after 'HoLD'. (If 'AOP' does not appear in the display, your kiln is not equipped with AOP.)
When set to OFF, the AOP outlet receives power during the Cone-Fire firing. At the end of the firing, the AOP shuts off.
When set to ON, the AOP remains powered during both Cone-Fire firing and cooling. It shuts off after the kiln cools to 150°F/66°C.
TIP: For slow cooling in Cone-Fire, select AOP OFF.
Adjusting AOP in Cone-Fire
Advanced Cone-Fire
Built-in Cone Table
For your convenience, the controller can look up a pyrometric cone temperature. Do not be concerned, however, if your kiln's cone shut-off temperature of a cone varies depending on firing speed.
Cone temperatures displayed are for self-supporting cones fired at a rate of 108°F during the last hour.
TIP: Before using Cone Offset, check that the thermocouple is protruding into the firing chamber by at least 1/2" - 5/8". Sometimes bumping a shelf against a thermocouple pushes t out of the firing chamber, thereby preventing accurate temperature readings.
Cone Offset Examples, °F
| 0001 | Kiln will fire 1°F Hotter |
| 0030 | Kiln will fire 30°F Hotter |
| 0049 | Kiln will fire 49°F Hotter |
| 0000 or 9000 | No Adjustment |
| 9005 | Kiln will fire 5°F Cooler |
| 9040 | Kiln will fire 40°F Cooler |
| 9049 | Kiln will fire 49°F Cooler |
* Cone Offset works in °C the same as in °F. In the above examples, replace °F with equivalent °C.
Once you enter a Cone Offset number, Cone-Fire will remain adjusted to that number for that cone until you change it again. Keep a written record of Cone Offset Adjustments.
Ramp-Hold Basics
User Programs
When you enter Ramp-Hold mode, the first prompt to appear is 'USEr', meaning, "Select a User Program". A user program is a firing schedule stored in memory.
It includes:
AOP
The optional "AOP" (Auxiliary Output) is an electrical outlet, usually mounted to the kiln's switch box. The AOP outlet can power a kiln vent or other appliance. If your kiln is equipped with AOP, 'AOP' will appear in Ramp-Hold after 'SEG'. (If 'AOP' does not appear in the display, your kiln is not equipped with AOP.) In Ramp-Hold, AOP can be turned on or off for each segment.
Adjusting AOP in Ramp-Hold
Advanced Ramp-Hold
Segments for Controlled Cooling
For controlled cooling, program a segment to a lower temperature than that of the receding segment.
Skip Segment
You may need to skip a segment in Ramp-Hold. For instance, you are firing to cone 05 for the first time. You program the last segment to soak for 30 minutes at 1850°F. (This is a few degrees below cone 05.) You are not sure at what temperature the cone will bend during this firing.
At 1850°F, the alarm beeps, alerting you to check the witness cone on the shelf. You look into peephole every few minutes to check the cone. After a 10-minute hold, the shelf cone 05 bends to maturity. Using "Skip Segment", the controller begins a cool-down segment. Skip Segment stops the current segment and starts the next segment.
Skip Segment works only during firing and only in Ramp-Hold, not Cone-Fire. To skip a segment, press 9. 'SStP' will appear. If you change your mind and don't want to skip that segment, do nothing and the firing will continue as it was. If you still want to skip the segment, press ENTER. 'rA' will appear along with the segment number you just skipped to.
Press 5 ("Present Status") if you are not sure which segment the firing has reached. Then skip the segment.
'16-S' appears under MENU only after user program 5 has been selected in Ramp-Hold.
When you use Program Review for a 16 segment firing, user program 5 will appear. Then '16-S', 'On', to confirm that your program is the 16 segment. However, the values for user program 6 will not appear in Program Review.
Selecting °F or °C (CHG°)
The controller operates in your choice of °F or °C temperature. In °C display, a lighted dot appears in the lower right. In °F, it disappears. To switch from °F to °C or vice versa:
°F/°C Temperature Conversion Formula
Below are formulas for converting temperature between °F and °C. Converting a firing rate requires a different formula than firing temperature:
Firing Temperature
(i.e. "Fire to 1600°F." 1600°F = 871°C)
(°C x 1.8) + 32 = °F
(°F - 32) divided by 1.8 = °C
Firing Rate and Temperature Change
(i.e. "Fire at 200°F per hour" or "Fire 200°F hotter" 200°F = 111°C)
°C x 1.8 = °F
°F divided by 1.8 = °C
Delay Fire
The Delay Fire programs the kiln to begin firing later. Use it to adjust the firing to suit your schedule or to take advantage of lower electric rates at night.
It zeroes out after each completed firing. To set the Delay, follow earlier instructions for entering the Cone-Fire or Ramp-Hold firing program. Then press ENTER, then 3. Enter the delay time in hours/minutes. (i.e. 12 hours and 30 minutes = 12.30). To begin firing, press ENTER twice.
WARNING: Never leave your kiln unattended near the end of a firing. We cannot guarantee your kiln against overfiring even though the controller is automatic. The operator assumes full responsibility for shutting the kiln off at the proper time.
The alarm beeps when a preset temperature is reached. Use the alarm to alert you to:
Setting the Alarm From Idle
Setting Alarm During Firing
Present Status: Current Segment and Traveling Set-Point Temperature
"Present Status" displays the current segment of a firing and temperature of the circuit board.
Knowing which segment you are in is especially useful for firings with both heating-up and cooling-down segments. Present Status works with both Cone-Fire and Ramp-Hold. (See Cone-Fire firing schedules)
To use present Status, press 5 during a firing. The following information will display momentarily. Then normal temperature display will return:
Checking Circuit Board Temperature from IdLE
Power Failures
The RTC 1000 handles a power failure in two ways:
The following three situations cause ErrP messages:
When the ErrP power failure message appears, press ENTER. The hours fired and temperature reached, before the power failed, will appear followed by IdLE. To resume firing, press ENTER twice. The kiln will begin firing again from its present temperature. For example, the kiln reached 1000°F/538°C before power failed. When you turn the kiln back on, the temperature is 700°F/371°C. Firing will resume from 700°F/538°C. You do not need to cool the kiln to room temperature before starting over unless you use witness cones (See next section). When you resume firing by pressing ENTER twice, the controller begins firing again from segment one. If the temperature is already higher than that of segment one, the controller skips to the next segment. When it finds a segment with a higher target temperature, it begins firing in that segment. For this reason, a power failure during a ramping down (cooling) segment can confuse the controller. When you resume firing, the controller will begin firing from a ramping up (heating) segment rather than the ramping down segment.
Firing Ceramics After an Extended Power Failure
Thermocouple Offset (tCOS)
The thermocouple is the 1/8" diameter rod protruding into the firing chamber. It measures temperature. Thermocouples can " drift" as they age, causing inaccurate temperature readings. (This may be so slight that you won't notice it.) To calibrate the controller to compensate for drift, use "Thermocouple Offset". TIP: Before using Thermocouple Offset, check that the thermocouple is protruding into the firing chamber by at least 1/2" - 5/8". Sometimes bumping a shelf against a thermocouple pushes t out of the firing chamber, thereby preventing accurate temperature readings.
Thermocouple Offset for Ceramic Firings
In ceramics, Cone Offset (see page 4) adjusts each pyrometric cone without affecting the other cones. Thermocouple Offset, on the other hand, affects all cones equally, and all Ramp-Hold firings. A 5°F hotter setting in Thermocouple Offset fires everything 5°F hotter. If you find that all of your cones are consistently under- or over- firing, adjust Thermocouple Offset. If you need to adjust only a particular cone, use Cone Offset.
Calibrating Thermocouple Offset with a Thermocouple Standard or Pyrometer.
A thermocouple standard is a device that calibrates pyrometers and controllers. If you do not have a thermocouple standard, you can calibrate Thermocouple Offset using a calibrated digital pyrometer. One way to calibrate your digital pyrometer is to take it to a heat treater or other location that has a calibrated controller you can trust. Take a reading with your pyrometer. Either zero it out to match the other heat source, or write down the temperature difference between your pyrometer and the reliable source. Store your pyrometer. Use it only for calibrating controllers. Thus, it remains a reliable calibration standard. Adjust Thermocouple Offset to compensate for any temperature difference between the controller and the calibrated pyrometer or thermocouple standard.
Setting Thermocouple Offset
You can raise or lower firing chamber temperature from 1-50°F/1-28°C. If the kiln is firing too hot, place 90 and 01-50°F/1-28°C. If the kiln is too cool, place 00 before 01-50°F/1-28°C. The following chart contains seven examples of Thermocouple Offsets. Program any temperature in the 01-50°F/1-28°C range, hotter or cooler, using these examples as a guide.
| Thermocouple Offset Examples, °F | |
| 0001 | Kiln will fire 1°F Cooler |
| 0030 | Kiln will fire 30°F Cooler |
| 0049 | Kiln will fire 49°F Cooler |
| 0000 or 9000 | No Adjustment |
| 9005 | Kiln will fire 5°F Hotter |
| 9040 | Kiln will fire 40°F Hotter |
| 9049 | Kiln will fire 49°F Hotter |
| * Thermocouple Offset works in °C the same as in °F. In the above examples, replace °F with equivalent °C. | |
Directions for Thermocouple Offsets:
To reset Thermocouple Offset back to 0000, press ENTER then 0. RSEt will appear, then press ENTER.
Turning Off Error Codes (ErCd)
The RTC 1000 uses error codes to alert you to firing problems. In certain applications, it may be desirable to turn off some of the error codes. For instance, error code Err1 appears when temperature rises slower than 12°F/12°C per hour. (In Ramp-Hold, the temperature is also below the programmed temperature.) Err1 may interfere when the door of the kiln is opened to remove certain materials, such as enameled pieces or heat-treated steel. "Error Codes" ErCd, when set to OFF, turns off error codes Err1, Err2, Err3, and Err4. During the last 250°F/139°C of a Cone-Fire program, the Err1,code will become active again even when ErCd is turned off.
Setting Error Codes ON or OFF
The RTC 1000 is able to track the cost of firing based on the cost of electricity and the wattage rating of the kiln. Both of these numbers need to be entered into the RTC 1000 kiln controller. The cost of firing can be viewed at any time by pressing the Program Review key. If the Program Review key is pressed while the controller is in idle the controller will display the total cost of the last firing. If the Program Review button is pressed while a firing is in progress the controller will display the cost of the current firing up to that point in time. The cost of firing will be displayed immediately after the message
Press ENTER key. The display will alternate between the messages "COST" and a four-digit number. Enter the price per kilowatt-hour of electricity in your area.
EXAMPLE: If price per kilowatt-hour is $0.071, enter 0071 into the controller.
Press ENTER key. The display will alternate between the messages "WATT" and a four-digit number. Enter the wattage rating of your kiln divided by 10.
EXAMPLE: If the rating of your kiln is 11650 Watts, enter 1165. If the rating of your kiln is 1450, enter 145.
Press ENTER key. The controller will return to idle.
FIRING COUNTER – The firing counter will help the user keep track of the number of firings on their kiln and help plan routine kiln maintenance. It is incremented five minutes into each firing. The number of firings can be viewed during a program review after the word FIRE.