Sentry Xpress 5.0 Instructions For Use Manual

Sentry Xpress 5.0

Digital Temperature Controller

Cone-Fire and Ramp-Hold Instructions

°C Display Dot

Temperature Display

No Display Dot: Tempera ture display is in °F.

Right-Hand Display Dot:

Temperature display is in °C. Seepage19forinstructions

on selecting °F and °C.

Time Display

Center Display Dot:

Separates hours from minutes. Example: Display shown above is 1 hour and 30 minutes.

To stop a firing, press Start/Stop key at any time. ABRT will appear, and the heating ele ments will turn off. Press Start/Stop again to re turn to IDLE.

IM-222/3-19

°F

°C

Start/Stop Key

1) On/Off: Starts and stops a firing.

2) Enter Data: Press after each pro-

gramming step. It works like the Enter key on a computer.

Up Arrow Key

1) Raise Numbers

2) Select a Firing Mode: From

[IDLE] press Start/Stop.PressUp

Arrow to select Cone-Fire or

Ramp-Hold.

3) Edit a Program While the Kiln is Firing p16:

[SKIP ]Skip a segment [HLDT] Change hold time [CHGT] Change end temperature

4) All Other Options: [DELA]Select how Delay works.17

[TC ]Select thermocouple type.

p18

[ALAR] Set temperature alarm. p18 [DIAG ] Check amps. p19 [F/C ]Select °F or °C display p19 [LIM ]Set max temperature. p19 [COST] Look up cost of a firing. 19 [EXIT ]Press Start/Stop to return

to IDLE. [OPT2 ] Press Start/Stop to see

level 2 options.

[OFST ] Adj. cone temperature. p16 [TCOS] Adjust thermocouple. p20

[TEDE ] Change sensitivity of

the FTH, FTC and LTDE warning alarms. p20

[HTDE] Change sensitivity of the HTDE shut down alarm. p21

[LOCK] Lock programs. p21 [AOP1] For kilns with the optional

AOP switch box electrical outlet.p22 [ELEC ] Check circuit board tem

perature, useful in hot weather. p22

[EXIT ]Press Start/Stop to return to IDLE.

[OPT3 ] Press Start/Stop to see level 3 options.

[COOL] Select Slow Cooling so it appears during Cone-Fire program ming. p17

[RATE ] Select your preferred type of rate. p22

[CENT] Enter cost of electricity. 23 [KW ]Enter kiln’s wattage. p23 [SFTY] See kiln’s max tempera

ture. p24

[SOFT ] See software version. p24 [CFG ]Shows controller model.24 [RST ]Reset the controller to its

factory default settings. p24

Indicator Lights

Top: Light is on dur ing programming.

Middle: Light is on dur ing program review.

Bottom: Light turns on only when the elements are on during a firing.

Down Arrow Key

1) Lower Numbers

2) Repeat the Last Fir ing: From Down Arrow.Thepro-

gram you have selected will appear one step at a time. When pears, press Start/Stop. Page 5

4) Review a Program: During firing, press Down Arrow. The program you

entered will appear one step at a time. Page 5

[IDLE] press

[STRT] ap-

Quick Cone-Fire programming . . . page 10

Ramp-Hold programming for the power user . . . page 13

Error messages . . . pages 25 - 27

Confused about display messages? ... pages28-29

Sentry Xpress 5 Cone-Fire / Ramp-Hold

Before You Begin

Thank you for purchasing the Sentry Xpress temperature controller. As you read the manual, pull up a chair and sit in front of your kiln so you can try out the keys.

Thecontrollerdisplaymessagesarelimitedtofourcharac ters. If at any time you are confused by these messages, turn to Display Messages on pages 28 - 29.

The back cover is a shorthand guide to programming, to be used after you have read the programming instructions on pages 10 and 13.

You can customize the programming (pages 10 and 13) by adding or removing these steps:

Delay: Schedule a firing for later. This works in all firings. Page 17 Fan: If your kiln is set up with a vent and switch box outlet, or, socket, you can turn the fan on or

off for Ramp-Hold segments. Page 22.

Lock: Passcode-protect individual Ramp-Hold programs. Page 21 Slow Cooling: Enhance certain glazes in Cone-Fire mode. Page 17.

If you don’t need these features, streamline programming by removing their display prompts. Turn to the pages shown above for instructions.

Do not worry if you hear a clicking noise during operation. Mechanical relays click as they turn the heating elements on and off. This is normal. It is also normal for the temperature to fluctuate up and down as the kiln heats up. Please don’t be concerned.

The warranty on your Sentry controller does not cover damage from overfiring, regardless of the circumstances. It is the operator’s responsibility to make sure the kiln turns off at the end of the firing.

We are constantly trying to find better ways to make kilns, and your kiln is extremely reliable. Nevertheless, it containsmechanical partsthat eventuallywear out.In some cases, a parts failure can lead to akiln overfire. Thereforeit isimportant that youoccasionally check onthe kilnduring operation. Although the kiln does not require constant attention, it should never be left unat tended. Please check the kiln especially during the later stages of firing.

Write notes on the controller features that you use. Then if you are away from your kiln for a period, you can review your notes to refresh your memory. The cover shows the controller op tions at a glance. Use the cover as a quick index.

Use Program Review (page 5) every time you fire the kiln. This is your assurance that you are firing the correct program. Check the program in the display against a written copy.

2 Do not leave your kiln unattended during operation.

Contents

Before You Begin .............2

Safety Rules .................4

Safety first. Quick habits for trou ble-free firing.

Chapter 1 Basic Pointers .......5

A quick read of this chapter will save you time later.

Time and Temperature Displays ....5

Operation Begins from

the IDLE Display ................5

Thermocouple Inspection .........5

How to Scroll Numbers Rapidly ....5

Program Review & Repeat Firing . . . 5

Delay .........................6

The LID Message................6

Power Failures ..................6

CPLT Message: Firing Completed . . 6 Hot and Cold Weather;

Storage Sheds..................6

Thunder Storms and Power Surges . 7

Canceling a New Program ........7

Two Firing Modes:

Cone-Fire and Ramp-Hold ........7

Preventing an Overfire............7

How to Disable the Audible Alarm . . 7

Chapter 2 Cone-Fire ...........8

Learn quick ceramic firing.

Pyrometric Cones ...............8

Firing Schedules ................9

How to Interpret the Bending

of a Pyrometric Cone.............9

How to Correct for

Under- or Over-Fired Cones .......9

Cone-Fire Programming

Instructions ..................10

Firing Speed [SPD] .............10

Hold at Cone Temperature [HOLD] 10

Slow Cooling [COOL] ...........11

How to Customize Cone-Fire .....11

For Kilns with the AOP Outlet .....11

Chapter 3 Ramp-Hold .........12

Read this section for non-ceramic firings and customized ceramic firings.

Theory of Ramp-Hold Operation. . . 12

How to Store Programs..........12

Ramp-Hold Rate: 3 Types

Rate as Degrees Per Hour . . . . . . 13

Rate as Degrees Per Minute. . . . . 14

Rate as Time Needed to Reach

the Target Temperature . . . . . . . . 14

Ramp-Hold Programming

Instructions ..................13

Hold (HD ) ....................14

Temperature Overshoot .........14

AOP: Turn on a Fan or Alarm .....14

Programming a Cooling Segment . 14

A Ramp-Hold Practice Program . . . 15

Chapter 4 Customize Your

Controller with Options .......15

Become a power user. The infor mation is here if you ever need it.

How to Edit a Program

During a Firing .................15

Skip to the Next Segment . . . . . . 16

Change Hold Time . . . . . . . . . . . . 16

Change Target Temperature . . . . 16

Cone-Fire Options

OFST / Cone Offset ............16

Interpreting Cone Bending to

Set a Cone Offset . . . . . . . . . . . . . 17

When Cone Temperature

Is Off More Than 20°F/11°C . . . . . 17

COOL / Slow Cooling for Glazes . . 17 General Options DELA / Delay the Firing for Later . . 17 TC / Choose Thermocouple Type . 18

ALAR / Temperature Alarm.......18

Setting the Alarm From IDLE . . . . 18

Setting the Alarm During a Firing. 18

DIAG (Diagnostics) .............19

Check the Amperage Test the Relays and AOP1 Outlet

F/C / Select °F or °C

Temperature Display ............19

°F/°C Temperature Conversion Formulas

LIM / Set a Maximum

Temperature for Your Kiln ........19

COST / View the Electrical

Cost of a Firing ................19

TCOS / Thermocouple Offset .....20

TEDE / Temperature Deviation ....20

HTDE / Adjust High

Temperature Deviation ..........21

LOCK / Program Lock ..........21

How to Activate the Lock Option . 21 How to Lock Individual Programs 22

AOP1 / Auxiliary Output .........22

ELEC / Electronics Temperature . . 22 RATE / Select Preferred

Type of Ramp-Hold Rate.........22

CENT / Enter Cost Per Kilowatt-Hour from Your Electric Bill

(for Firing Cost) ................23

KW / Kilowatts of Your Kiln (Needed to Calculate Firing Cost). . 23

SFTY / Maximum Temperature....24

SOFT / Software Version.........24

CFG / Configuration Code .......24

RST / Reset ...................24

Chapter 5 Error Messages.....25

Error messages are like the heart rate monitor on a digital watch. They let you know when some thing is wrong.

Non-Interrupting Error Messages

FTC / Failed to Cool ............25

FTH / Failed to Heat ............25

LTDE / Low Temperature Deviation 25

PF / Power Failure..............25

Terminating Error Messages

- - - - / No Thermocouple ........25

BADP / Bad Programming .......25

ETH / Electronics Too Hot .......25

FAIL / Thermocouple Failure .....25

FE 1 / Failed to Read/Write

To Memory ...................26

FE 4 / Unstable Analog-to-Digital Con version; Errors Detecting

Thermocouple Signal ...........26

FTL / Firing Too Long ...........26

HTDE / High Temperature

Deviation .....................26

LAG / Thermocouple Lag ........26

LID / Safety Switch .............26

OTL / Over Temperature Limit ....27

PF1 / Power Failure.............27

PF 2 / Power Failure ............27

PF 3 / Power Failure ............27

TC 2 / Thermocouple Failure .....27

TCR / Thermocouple Leads

Reversed .....................27

Basic Power Failure Principles ....27

Using Ceramic Witness Cones After an Extended

Power Failure . . . . . . . . . . . . . . . . 27

Display Messages............28

Preset Cone-Fire Programs ....30

Orton Cone Temperature Chart . 31

Ramp-Hold Firing Records ....33

Make copies. Keep a log book of your firings. Build a knowledge base.

Glossary ...................34

Ramp-Hold

Shorthand Instructions .......35

Cone-Fire

Shorthand Instructions .......36

Keep the kiln lid or door closed when the kiln is not in use. 3

Sentry Xpress 5 Cone-Fire / Ramp-Hold

Safety Rules

The warranty on your Sentry Xpress controller does not cover damage from overfiring, regardless of the circum stances. It is the operator’s responsibility to make sure the kiln turns off at the end of the firing.

Follow these safety rules in addition to the ones in your kiln manual:

When the kiln is not in use, disconnect the

power and keep the lid or door closed. (For

larger kilns with heavy cordsets, werecommend

a power disconnect box near the kiln.)

Large studio kilns should have a power disconnect box for the kiln. Place the box in the kiln room.

Do not leave the kiln unattended, especially

near the expected shut-off time. Do not leave a

kiln turned on at your studio while you are at

home sleeping.

Wear green #3 firing safety glasses when look

ing into the peephole of a hot kiln.

Do not touch hot sides of kiln. Keep unsuper

vised children away.

Install your kiln at least 12 - 18 inches from any

wall or combustible surface. (See manufac

turer’s recommendation for your model.)

Do not open lid or door until kiln has cooled and

all switches are off.

Fire only in a well-ventilated, covered and pro

tected area away from flammable materials.

Keep cordset away from hot sides of kiln.

DANGEROUS VOLTAGE! Do not touch

heating elements with anything. Disconnect

kiln before servicing.

Do not operate if the controller itself is hotter than 158°F / 70°C. (See instructions on page 22 for checking circuit board temperature.) Never allow the firing room temperature to exceed

110°F / 43°C. (Measure room temperature three feet from the kiln.)

Stop a firing by pressing the Start/Stop button, not by only disconnecting the power. In certain conditions, the controller will interpret a power interruption as a power failure and turn the kiln back on when you reconnect the power.

Place the kiln onthe stand recommended by the manufacturer. When a kiln is safety tested, the lab fires the kiln on the stand designed for the kiln. Cinder blocks or brickscan inhibit theflow of air under the kiln. They can also change the kiln’s heating characteristics.

Place the kiln on a non-combustible surface.

Keep the kiln lid or door closed when the kiln is not in use. This keeps dust out of the kiln. Also, should someone turn on the kiln while you are away, the closed lid will keep the heat safely inside the firing chamber.

Never place anything on top of the kiln, even when the kiln is idle. If people become accustomed to placing papers and other objects on the kiln, they may forget and do that while the kiln is firing.

Remove tripping hazards from around the kiln. Keep the kiln’s supply cord out of traffic areas.

Avoid using extension cords.

Never fire tempered glass inside a kiln. It could explode.

Greenware, which is unfired clay, must be bone dry before firing. Moist greenware can explode

inside the kiln, damaging the ware and the kiln. Place a piece of greenware against the inside of your wrist. If it feels cool, it is too wet to fire.

Store kiln shelves in a dry area. Moist shelves can explode inside a kiln.

If you smell burning plastic, turn the kiln off. Examine the wall outlet (socket) and supply cord for signs of burning.

Never place extra insulation around the kiln in an attempt to conserve energy. The extra insu

lation can cause the wiring and the steel case to over-heat.

Do not leave your kiln unattended during operation.

Chapter 1

Basic Pointers

In This Chapter you will learn to . . .

Choose between Cone-Fire and Ramp-Hold

Use the controller in freezing or hot weather

Understand the display window layout

Easily repeat the last firing

Make a quick visual check of your thermocouple

Avoid overfiring your kiln

Disable the audible alarm

Time and Temperature Displays

Center Dot: Time

A center dot appears during time display. It separates hours from minutes. (Example: 1 hour, 30 minutes displays as 01.30.) During temperature display, the dot disappears.

Right-Hand Dot: °C

When temperature is displayed in °C, a dot appears in the lower right. In °F display, it disappears. You can choose between Fahrenheit and Celsius display. See page 19.

Operation Begins from the IDLE Display

[IDLE] must appear before you

can fire the kiln.

If [CPLT], [PF3], or other message appears instead of

[IDLE] when the kiln is first turned on, press the

Start/Stop key (the key with the circular arrow).

[IDLE] will appear.

If youpress Start/Stopduring afiring, [ABRT]will ap pear. To get back to

If the display shows an error message such as [FAIL] in stead of

[CPLT] (firing completed) appears at the end ofa firing.

To make

[IDLE], see pages 25-27.

[IDLE] appear, press Start/Stop.

[IDLE], press Start/Stop again.

Thermocouple Inspection

The small rod protruding into the firing chamber is the temperature sensor, or thermocouple.

CAUTION: Bumping the thermocouple can push it out of the firing chamber. This could cause an overfire! The controller does not contain an alarm to detect this type of failure. Bumping the thermo couple could also cause inaccurate readings.

Thermocouples come in different widths. The wider the thermocouple, the farther it should extend into the firing

Time

°C

chamber. A ¼” - ½” diameter thermocouple should extend into the kiln about ¾” - 1”. (Do not be concerned if yourthermo couple extends into the firing chamber even farther.)

Note: Keep shelves, posts and ware 1” - 1 ½” away from the thermocouple. Keep an extra thermocou ple on hand, especially if you fire hotter than 2000°F / 1093°C.

If you are using a separate portable controller, you will need to install the thermocouple on the kiln. See the sepa rate TnF 2 installation instructions.

Pointer: Keep shelves, posts and ware1” - 1 ½”away from the thermocouple.

How to Scroll Numbers Rapidly

During programming, hold an arrow key down several seconds, and numbers will begin to scroll rapidly. Ordi narily, you would press the Up Arrow to raise a number and the Down Arrow to lowerit. Butsometimes itis faster to press theopposite key. Thisis because thenumbers scroll below 0000 to the highest number, and vice versa. Examples:

To program a 99.59 hour Hold when the display shows

[00.00], press the Down Arrow once.

To program a FULL rate when the display shows

[0000], press the Down Arrow once.

To program a temperature of 200°F when the display

[1800], press the Up Arrow. That is faster than

shows pressing the Down Arrow and scrolling from 1800 to

200.

Program Review & Repeat Firing

Program Review lets you check that the program in the controller is accurate. Use Program Review before every firing. It takesonly seconds. ProgramReview shows the val ues for the program in active memory. Use Program Re

view from

program in active memory is 1) the program that you fired last, or 2) the program that you entered or selected since

the last firing.

Using Program Review during firing: Press the Down Arrow key. The rate, temperature, hold, etc. will dis

play one after the other. The firing will continue.

To repeat a firing, use Program Review from [IDLE]: Press the Down Arrow key. After rate, temperature, hold, etc.,

[DELA] will appear unless it has been removed in Op

tions. Enter thedelay time, or press theStart/Stopkey.

[-ON-] will appear, and the kiln will begin firing the pro

gram just reviewed.

[IDLE] to repeat the last program you fired. The

[STRT] will appear. Press Start/Stop.

Pointer: When can end the firing before it begins. Do nothing for 60 seconds. The display will return to

[DELA] flashes after [STRT], you

[IDLE].

Keep the kiln lid or door closed when the kiln is not in use. 5

Sentry Xpress 5 Cone-Fire / Ramp-Hold

Note: In Program Review, Cone-Fire speed is dis played as the RA (ramp) part of each segment. Cone-Fire Review shows the segments and ramp rates listed in the charts on pages 30-31.

Delay

Delay is a count-down timer. The kiln begins firing when the timer runs out of time. Use delay to fit a firing into your schedule. See also page 17.

CAUTION: For safety, do not leave the kiln alone during a delay or a firing. We cannot guarantee your kiln against overfiring even though the con troller is automatic.

1 After you have selected aprogram and thecontrol

ler is ready to begin firing,

[STRT] will appear.

2 Press the Start/Stop key once. [DELA] will ap

pear, alternating with

[00.00].

3 Use the arrow keys to enter delay time. (The deci

mal separates hours and minutes. Example: 1 hour and 10 minutes = 01.10) Then press Start/Stop.

[-ON-] will appear, then [DELA] alternating with

time left until the firing begins.

Note: Press Start/Stop during delay to end the delay and begin the firing. The maximum delay is 99 hours and 59 minutes.

[PF 3] The power failed during afiring and the tempera

ture dropped more than 72°F / 40°C by the time the power came back on.

CPLT Message: Firing Completed

When the firing has successfully completed, the Sentry Xpress will beep for 60 seconds and shut off the elements. Then four messages will cycle one after the other:

1 [CPLT] (complete)

2 Firing time in hours and minutes

3 The temperature reached during the last segment

that you programmed

4 The current kiln temperature

Note: After the kiln fires to completion, discon nect the power. It is okay to turn off the power to the controller while the kiln cools to room temperature.

Hot and Cold Weather; Storage Sheds

It is okay to store the Sentry Xpressat sub-zero tempera tures. But before operating, raise the room temperature to at least 32°F / 0°C.

CAUTION: For safety, do not leave the kiln alone during a delay or 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 LID Message

This indicates that your kiln is equipped with a lid or door safety switch, and the lid ordoor is open. This will turn off the elements.

If your kiln does not have a safety switch, or the kiln is closed, please see page 26.

Power Failures

After a power failure, the controller will continue firing provided–

The kiln temperature is above 212°F / 100°C when the power comes back on.

The temperature dropped no more than 180°F / 100°C while the power was off.

Power Failure Messages

[PF 1] The power failed during a cooling segment, and

the kiln cooled past the target temperature while the power was off.

[PF 2] The power failed during a firing and thekiln tem

perature was below 212°F / 100°C when the power came back on.

Hot weather pointer: Blow a gentle stream of air through the control panel of the kilnto reduce the temperature of thecontroller circuitboard.

The Sentry Xpress will registersub-zero °F / °C tempera tures. However, 32°F / 0°C is the lowest recommended op erating temperature.

Pointer: Raise the room temperature with a space heater before firing the kiln.Place the spaceheater within a coupleof feet ofthe control paneland let it run for an hour or so. Or even hang a shop light near the kiln to raise the temperature above freezing.

The circuit board is rated for 176°F / 80°C maximum op erating temperature. However, the maximum recom mended temperature is 158°F / 70°C, measured at the con troller inside the kiln switchbox. Tolower the temperature, open windows andblow air across the kiln’s switch box with a fan. Place several fans in the room during hot weather. (See ELEC, page22, to checkcircuit board temperature.)

High humidity will not adversely affect the Sentry Xpress unless water condenses on the circuit board. In this case, do not fire the kiln until the moisture has evaporated from the board.

6 Do not leave your kiln unattended during operation.

Thunder Storms and Power Surges

Unplug the kiln when not in use, especially during thun der storms and in areas that have frequent power surges. If the kiln is part way through a firing when a storm begins, it may be okay to continue the firing. When the kiln shuts off, disconnect the power.

Preventing an Overfire

Even though a digital controller turns off the kiln auto matically, you should monitor the kiln during firing. This is to prevent a possible overfire.

1 Remain nearby while the kiln is firing. Check the

kiln occasionally.

2 Set the temperature

alarm (page 18) to re mind yourself to check the kiln. Ifyou are toofar away to hear the alarm, you might try using a baby monitor.

Try to avoid firing your kiln during thunderstorms. Keep the kiln discon nected from the power when not in use. (Lake Grapevine, Texas. Photoby Jared Davidson.)

CAUTION: When firing the kiln during a storm, do not leave the kiln unattended.

Canceling a New Program

It’s okay if you pause while entering a program. There is no time out. If you change your mind and want to cancel a new program, turn off the power to the controller. Or continue enteringa program.When

[STRT] appears, press the

Down Arrow key. The controller will cancel the firing and go back to

[IDLE].

Cone-Fire and Ramp-Hold

To give you greater flexibility, your controller has two firing modes: Cone-Fire and Ramp-Hold.

Cone-Fire Mode (see pages 8-11)

Cone-Fire mode fires the ware to a pyrometric cone number using the Orton cone tables on page 32. This mode is for ceramics, pottery, stoneware, and glazes. Your sup plier can tell you which cone number to program.

Ramp-Hold Mode (see pages 12-15)

Use Ramp-Hold mode to create custom firings. Select your own firing speed, temperature, and hold time in up to 20 steps, or segments.

The chart shows the recommended firing mode for sev eral types of ware:

Type of Firing Suggested Firing Mode

China Painting Cone-Fire Ceramic Decals Cone-Fire Ceramic Glaze Cone-Fire Ceramic Greenware Cone-Fire Glass Bead Annealing Ramp-Hold Glass Fusing Ramp-Hold Glass Slumping Ramp-Hold Lost Wax Ramp-Hold

3 After the kiln fires to

completion, disconnect the power. It is okay to turn off the power to the controller while the kiln cools to room tempera

Pointer: Set a wristwatch alarm, cell phone, or even an alarm clock to remind youself to check on your kiln.

ture.

How to Disable the Audible Alarm

The Sentry Xpressmakes a beepingnoise when it firesto completion and whenit displays error messages. Some people prefer not to have an audible alarm. You can disable the alarm by removing a jumper on the back of the controller. Replace the jumper when you want the alarm again.

1 Disconnect the kiln

from the power.

2 Remove the four

corner screws that

hold the controller to the switch box. Lift out the con

troller.

3 Find the 2-pin

jumper plug for the alarm on the back of the controller. It is on the connec tion pins labeled BUZZ ENABLE. Remove and save the jumper plug.

4 Reinstall the con

troller being careful not to tug on the wires.

Remove the 2-pin jumper plug from the connectors labeled BUZZ ENABLE to si lence the beeping alarm.You will find the connectors on theback of the controller.

Keep the kiln lid or door closed when the kiln is not in use. 7

Sentry Xpress 5 Cone-Fire / Ramp-Hold

Chapter 2

Cone-Fire

In this chapter you will learn to . . .

See witness cones at high temperatures

Program a Cone-Fire program in minutes

Pre-heat the ware so it doesn’t explode

Bend a cone by adding extra hold time

Cool slowly (called down fire) to alter glazes

Cone-Fire mode is based on Orton pyro metric cones. It is not designed for heat treating, glass fusing and enameling. For these firings, see “Ramp-Hold,” pages 12-15. Use Ramp-Hold to fire ceramic pieces that require a custom firing schedule, such as some types of stone ware sculpture or crystalline glaze.

Note: If the bending of the witness cone does not match the Cone-Fire shut-off, you may want to ad just Cone Offset (page 16) or Thermocouple Off set (page 20). If the witness cones bend inconsis tently from one firing to another, see “Sentry Troubleshooter,” a separate publication.

How to Position Cones on the Shelf (for Ceramic Kilns)

Position the witness cones so you can see them through a peephole during firing. If the kiln takes longer than usual to fire, you may wonder if some thing has gone wrong and the

kiln is over-firing. But by seeing the cones,you will know how the firing is actually progressing.

If you follow these guidelines, you should be able to see the cones even at cone 10:

1 Place the cones 8” - 12”

away from a peephole. Positioning them closer makes them difficult to see.

Use self-supporting witness cones on theshelf. Theystand upright without cone holders.

Before using Cone-Fire mode, read all of this chapter. Have your controller in front of you so you can try out the keys as youread.Formoredetailsonpyrometric cones, please see your kiln manual.

Pyrometric Witness Cones

Question A cone 5 firing was 7°F below the target listed in your manual, and a cone 6 firing was 22°F below the target.Is this typicaland okay? Is the dig ital controller on my kiln operating normally even though it did not achieve the controller tempera tures that were programmed at cone 5 and 6?

Answer This is normalfor Cone-Fire operation. If the kiln fires slower than the normal rate, it will shut off at a lower temperature. If the kiln fires faster than a normal rate, it will shut off at a higher temperature, sometimes by only a few degrees.

The Sentry Xpress controller shuts off automatically without cones. Nevertheless, every ceramic firing should include at least one witness cone (also called the shelf cone). The witness cone is placed inside the kiln. The wit ness cone isthe most accuratemeasurement of heat workin a ceramic firing.

If you fire the same size load and type of ware regularly, the witness cones let you compare one firing tothe next and alert you when something is wrong. For example, if the wit ness cone bends farther and farther with each consecutive firing, this may indicate thermocouple temperature drift.

The heating element in the background should be lined up with the lower part of the witness cones. If the element is too high, the tips of the cones will disappear from view when they bend.

2 Have enough space

around the cones to keep them from touch ing a piece of ware when they bend.

3 Position cones so that

when viewed from the peephole, they are sil houetted by a glowing

heating element on the opposite kiln wall. (Keep cones at least 2” from an element.)

Silhouette the lower part of the cone against an element. Keep the cone 8” - 12” away from the peephole.

4 The element that silhouettes the cones should be

level with the lower partof the cone. If the element is in line with the upper part of the cone, you won’t be able to see the cone when it bends.

8 Do not leave your kiln unattended during operation.

5 If you use the three cone system, always have the

higher temperature cone on the same side in every firing. Otherwise you can lose track of which cone is which.

6 Wear green #3 kiln firing safety glasses when view

ing the cones through the peephole.

See your dealer if in doubt about which cone number to use with each clay and glaze.

1. Correct Bend

When the self-supporting cone bends so that the tip is approxi mately even with the top of the

base, the cone has beenexposed to the correct amount of heat work for that cone number. This is calleda6o’clock bend.

Firing Schedules

Cone-Fire uses three ranges of firing schedules:

Low fire cones 022 - 011

Medium fire cones 010 - 01

High fire cones1-10

The firing schedules programmed into Cone-Fire mode are listed on pages 30-31. Should you ever want to custom ize a Cone-Fire program, make the desired changes to a fir ing schedule and program it in Ramp-Hold (page 11).

CAUTION: Cone numbers beginning with 0 are lower in temperature than those without the 0. When programing a Cone-Fire, be sure you know the difference betweenan 05 and5. See “Temperature Equivalents Chart for Orton Self-Supporting Pyrometric Cones,” page 32.

Low Fire Cones 022 - 011

This range includes decals, over-decorations, lusters, and golds. You can usually fire fast. Good venting is important because of the oils and otherorganics. Donot close the lid from thevented position until all odorhas disappeared.

Middle Fire Cones 010 - 01

Glazes fired on bisque ware (ware that has already been fired) can be fired faster than greenware.

High Fire Cones 1 -10

This is the firing range for porcelain and stoneware. These bodies fire nearly to vitrification andcan shrink up to 16%. Water, carbon and sulfur burn out during the early stages and must be vented. The amount of oxygen in the kiln affects the color of the fired clay. The high fire sched ules programmedinto Cone-Fire slow down during the last 216°F/120°C (two hours) to produce better density in the ware.

How to Interpret the Bending of a Pyrometric Cone

The cones illustrated here are called self-supporting cones. They are the easiest type of witness cone to use.

2. Under-Fired Cone

The cone in this photo has not bent far enough. It indicates that the kiln did not firelong enough or hot enough.

3. Over-Fired Cone

When a cone collapses or pud dles, it indicates that the kiln over-fired the ware rated to that cone number.

Note: Do not be overly concerned with achieving an exact 6 o’clock bend. The difference between a 3 o’clockand a 6 o’clock bend is only a few degrees of temperature.

How to Correct for Under- or Over-Fired Cones

Before changing a firing because of an under- or over-fired cone, make sure the correct cone was in the kiln. For instance, if you fired to cone 05, make sure the cone in the kiln wasnot a cone5 instead. (Seethe cone temperature chart on page 32.) Try the following ideas, one at a time:

Compensating for an Under-Fired Cone

Fire to the same cone number next time, but add hold time. How much to add is a matter of experimentation. A general guideline would be 10-30 minutes.

If the kiln still does not fire hot enough, then fire to the next hotter cone number, without hold time.

Adjust the Thermocouple Offset. See page 20.

Customize the firing in Ramp-Hold. See page 11.

Compensating for an Over-Fired Cone

Fire to the next cooler cone number.

If firing to the next cooler cone number results in un der-firing, add hold time.

Adjust the Thermocouple Offset. See page 20.

Customize the firing in Ramp-Hold. See page 11.

Keep the kiln lid or door closed when the kiln is not in use. 9

Sentry Xpress 5 Cone-Fire / Ramp-Hold

Cone-Fire Programming

Instructions

Lock, Slow Cooling, and Delay can each be turned on or off as programming steps. Ignore the steps below that you have deactivated. See LOCK, page 21; COOL, page 17; and DELA, page 17.

1 From [IDLE], press Start/Stop (left button). 2 Using the Up Arrow key (not the Down Ar

row), skip past Then press Start/Stop.

[USER] and select [CONE].

3 The last pyrometric cone you fired will appear.

Use the arrow keys to change the cone number. Then press Start/Stop.

4 If the program is locked, [UNLO] (Unlock) will

appear alternating with change the program, enter your passcode. Oth erwise press Start/Stop, which will take you to Step 9.

[0000]. If you want to

5 [SPD] alternating with [SLOW], [STD] (stan

dard) or to change speed. Then press Start/Stop.

[FAST] will appear.Use the arrow keys

6 [HOLD] and the hold time from the last firing

will appear. (Example:1 hour and 10 minutes =

01.10) Use the arrow keys to change the hold time. Then press Start/Stop.

7 [COOL] will appear. Enter a slow cooling rate

as degrees per hour. (180°F/82°C is the maximum cooling rate. Enter 0 to turn Slow Cooling off.) Then press Start/Stop.

8 [LOCK] alternating with [0000] will appear.

Enter your passcode to lock the program, or press Start/Stop to leave it unlocked.

9 [STRT] will appear. Press Start/Stop. [DELA]

will appear. Seta delay time.If you don’tneed to delay the firing, leave the time at press Start/Stop. indicator light will begin blinking, and the kiln will begin firing. If Delay was programmed,

[DELA] will appear, then time remaining until

start.

To stop a firing before completion, press Start/Stop.

[ABRT] (abort), the firing time, final firingtemperature,

and current temperature will appear.

When the kiln fires to completion, it will beep for 30 seconds. final firing temperature, and current temperature will appear.

view & Repeat Firing,” page 5.

[CPLT] (fired to completion), the firing time,

To return to

To fire the same program again, see “Program Re

[IDLE], press Start/Stop.

[-ON-] will appear, the Run

[00.00]. Then

Entering a Cone-Fire Program

Firing Speed [SPD]

When you select Medium speed in a Cone-Fire pro gram, the kiln uses the standard firing schedules listed on pages 30-31. When you select Fast, the standard schedules fire 20% faster. On Slow, they fire 20% slower.

Pointer: The Medium speed appears in thedisplay as

[STD] (Standard).

Note: The final segment heating rate will not change. It will always be108°F/60°C perhour. Slow and Fast speeds affect only the earlier ramp seg ments of theCone-Fire schedules onpages 30-31.

Hold at Cone Temperature [HOLD]

Cone-Fire Hold heat-soaks the ware at the conetemper ature. Without Hold, the kiln shuts off after it reaches the cone temperature or Slow Cooling begins. Hold maintains the cone temperature for the length of time you specify.

Hold is not needed in every firing. Experience will help you decide when to use Hold. Some of the reasons you might consider using it:

To even out the temperature throughout the kiln.

To allow heat to penetrate more completely into the clay. (Rapid firing is like cooking: the turkey will be done on the outside but not on the inside.)

To help glaze absorb china paint.

To heal glaze defects such as bubbles.

CAUTION: Too much hold time canoverfire your ware and burn out colors. Be sure to experiment with hold before firing a full load of ware with it.

One wayto add hold time without over-firing is to fire to one cone cooler than needed. Then add enough hold time to bend the nexthotter cone. Holdtime neededto bendthe next cone willvary. As arule of thumb,20 minutes ofhold = one cone of heat work.

Example: to fire to cone 05, program Cone-Fire for 06

and add 20 minutes of hold time.

If your kiln has apeephole, watch thepyrometric witness cones during firing. Press Stop/Startwhen the correct wit ness cone bends. Note how much Hold time was needed. Program that much Hold time the next time you fire the same type of ware.

Note: During Hold, the display temperature will alternate with time left in Hold. To figure hold time for the next firing, subtract time left in Hold

from the total hold time entered.

10 Do not leave your kiln unattended during operation.

When Hold is set to 99.59 hours, the Sentry Xpress will

remain at that temperature indefinitely, until the Start/Stop key is pressed.

Slow Cooling [COOL]

Slow cooling, alsocalled downfiring, enhances the qual ity of some ceramic glazesand may healglaze bubbles. Slow cooling encourages crystal develoment, deeper gloss, and sometimes startling color shifts. Iron red glazes seem to re spond well to slow cooling.

The [COOL] promptdoes not appear in thedisplay dur ing programming until you activate the Slow Cooling Option. See page 17.

The Sentry’s Slow Cooling begins after the cone firing and ends at 800°F / 426°C.

When [COOL] appears in Cone-Fire programming, en ter a cooling rate between 1°F - 180°F / 1°C - 82°C per hour. A good starting point is a rate of 90°F / 50°C.

Enter a rate of 0 to turn Slow Cooling off.

Pointer: If the kiln seems to take forever to shut off, press the Down Arrow for Present Status. Check the Slow Cooling rate. The firing time can extend for many hours if the cooling rate is too slow. This also adds to element wear.

Answer 9 ½ hours is the firing time programmed into the Cone-Fire mode at fast speed. The easiest way to go faster is to use Ramp-Hold mode, where you can program the exact speed you want. Note, however, that the firing speed is limited to the

kiln’s heating capacity.

For Kilns with the AOP Outlet

The AOP(auxiliary output) is an optional receptacle, or socket, mounted on the kiln. Plug a kiln vent into the recep tacle, and use your controller to turn on the vent automati cally. You must select

[VFAN] (Vent Fan) in the [AOP1]

option. See page 22.

How to Customize Cone-Fire

You can customize a Cone-Fire program using Ramp-Hold. (See the next section.) On pages 30-31, tables show the segments used to program each cone number in Cone-Fire. For instance, a cone 016 firing at medium speed

[STD] uses these two segments:

Rate Temp.

Segment °F/°C °F/°C Hold

1 396 / 220 1314 / 712 00.00

2 108 / 60 1422 / 772 00.00

Suppose your 016 witness cone, at a medium speed fir ing, only barely started to bend. To fire 25° hotter, raise the target temperature of segment 2 by 25°:

1422 + 25 = 1447

This is the program you would enter in Ramp-Hold:

Rate Temp.

Segment °F/°C °F/°C Hold

1 396 / 220 1314 / 712 00.00

2 108 / 60 1447 / 786 00.00

You could also easily add a slow cooling segment:

Rate Temp.

Segment °F/°C °F/°C Hold

1 396 / 220 1314 / 712 00.00

2 108 / 60 1447 / 786 00.00

3 100 / 55 1000 / 537 00.00

Question My kiln is taking too long to fire: 9 ½ hours to cone 6. I want the kiln to fire in 4 hours.

TheOrtonVentMastercanbeturnedonoroff throughout the firing through the controller.

When the Kiln Shuts Off Too Soon

Ceramic Firings

If the kiln fires to completion before the pyrometric witness conebends, you can turnthe kiln back on and keep firing. Program for a hotter cone following the instructions in the red box, page 10. The kiln will begin firing, taking up where it left off.

Note: By seeing the witness cones through a peep hole, you will know if the kiln shuts off too soon.

If the kiln shuts off within 100°F/55°C of maturity, and the temperature drops 50°F/28°C or more after the kiln shuts off, do not depend on the witness cones. Once they cool 50°F/28°C after they have been heated to within 100°F/55°C of maturity, they will not bend properly. This is because they form a hard shell.

Wrong Thermocouple Type

If a K-Type thermocouple is installed on your kiln, but S-Type is selected in Options, the kiln will continually underfire by a wide margin. (The kiln will overfire if S-Type is installed and K-Type is selected.) See the TC option, page 18, to check the thermocouple type selected.

Starting a Firing in a Hot Kiln

If youever need to begin a firing when the kiln is already hot, begin the program as you normally would. The Sentry Xpress will automatically begin firing from the first seg ment that matches the current kiln temperature.

Keep the kiln lid or door closed when the kiln is not in use. 11

+ 25 hidden pages

Sentry Xpress 5.0 Instructions For Use Manual

Specifications and Main Features

Frequently Asked Questions

User Manual

Before You Begin

Safety Rules

Basic Pointers

Cone-Fire