Introduction - Orton AutoFire Plus User Manual

AutoFire® Kiln Controller User's Guide

INTRODUCTION

Congratulations on purchasing Orton's AutoFire controller. You now have the finest controller available for
®
use in firing glass and ceramics. It will provide more precise control and many valuable features not available
with other controllers. It can even be programmed and the firing monitored from a personal computer, using
software available from Orton. Contact your kiln manufacturer or Orton for more information on this feature.
This User's Guide will explain the features, benefits, options and operation of your new Orton AutoFire® Kiln
Controller. Use the "Quick start reference card" for normal operation of the controller and this Guide for more
detailed descriptions of controller features. Before making your first firing, take the time to become familiar
with the features of this product. With proper use and installation, you will be assured many years of superior
performance and service. If you have any comments or questions, feel free to contact the Orton Ceramic
Foundation or your Orton Distributor or Reseller. We would enjoy hearing from you. Again, thanks for
choosing an Orton product.
For simplicity, AutoFire® has only 8 keys. The main keys allow firing programs to be selected and the delay
start feature to be used with a limited number of keystrokes. The OPTIONS key provides you with access to
many other features. Take the time to learn the features you want to regularly use. All models of the AutoFire®
controller use the same basic programming, but not all features are available on every model.
AutoFire® controllers use proprietary PID Plus control software that eliminates the excessive cycling
associated with control schemes found with most other controllers. Cycling occurs when the controller turns the
kiln on or off and the temperature does not closely follow the program selected. PID Plus minimizes the effect of
cycling by anticipating how the kiln temperature will respond when power is turned on and off.
AutoFire® controllers store programs and calibration data in memory even when powered off. If during a
firing, the power goes out, it remembers how far the firing has progressed to determine whether it can be
successfully resumed when power is reapplied (see page 23).
Thermocouples
All controllers depend on thermocouples placed in the kiln to measure temperature. With time, the output of
most thermocouples will change, this is called drift. When drift occurs, the thermocouple no longer measures the
same temperature as it did when it was new. Typically, drift causes the kiln temperature to be higher than the
temperature displayed by the controller. Type K thermocouples drift more than Type S and these need to be
replaced after 50-100 firings, or when damaged.
Orton recommends that Type K thermocouples normally not be used at higher temperatures (above 2100°F,
unless they are made of 8 gage wire or enclosed in a protective sheath. Smaller diameter (14 gage) wire are not
advisable for repeat firings above 2100°F. Type S can be used when firings regularly exceed 2100°F.
Pyrometric Cones
Orton recommends using witness cones in each firing to help determine if the kiln and controller are firing
properly. These also give a permanent record of your firing. Orton cones bend when a specific amount of
heatwork has been received. Bending temperatures will be different when the heating rate is changed. During the
last 60 to 90 minutes, the AutoFire® controller always heats the kiln at 108°F/hr (60°C/hr), during a selected
Conefire firing.
If the kiln cannot maintain this heating rate, then a lower shut-off temperature is calculated to minimize
overheating of the ware. The overall firing time of the program will be longer. This occurs when the final firing
temperature at the time of completion is lower then the anticipated temperature.
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