Stafford Instruments ST535C User manual
ST535C Handbook Page 1
Temperature Programmer Handbook
Issue: 6.002
Date: 10 May 2021
www.staffordinstruments.co.uk
© Copyright 2021 Stafford Instruments Ltd.
TAFFOR
S
D
ST535C
Page ST535C Handbook
2
At a Glance
ZONE 1 ICON
ZONE 2 ICON
ZONE 3 ICON
START/STOP KEY
KILN HEATING
INDICATOR
FIRING INDICATOR
CONTROL KEYS
MIMIC DISPLAY
MAIN
DISPLAY
SEGMENT
DISPLAY
RADIO ICON
PAUSED INDICATOR
MAINS SWITCH
FUSE
ST535C
EVENT INDICATORS
FUNCTION KEY
ST535C Handbook Page 3
Quick Start Guide
Switch on & wait for kiln temperature display
To run a firing program set up previously press
the ► key
To stop the firing at any time press the ► key
again
To review firing data press the ► key to enter the
programming mode
To change firing data press the ▲ & ▼ keys to
change the displayed value
Use the ► key again as necessary to step to the
next firing value or segment to be reviewed or
changed
To mark the end of a program set a ramp rate to
END with the ▼ key
To exit the programming mode either wait 20
seconds or press the ► key to start firing
If the keyboard is locked then press and hold
down the function key for 5 seconds to unlock
Page ST535C Handbook
4
Contents
At a Glance ......................................................2
Quick Start Guide.............................................3
Contents...........................................................4
Features ...........................................................5
Turning On .......................................................6
Programming....................................................7
Temperature Display........................................9
Control Relays..................................................9
Firing ..............................................................12
Cooling ...........................................................13
Operating Notes .............................................14
Adjusting While Firing.....................................15
Error Messages.............................................. 16
Other Features ...............................................18
Sample Glass Programs ................................19
Sample Ceramics Programs ..........................20
WiFi & USB Datalogging Option..................... 21
Installation ......................................................26
Characteristics ...............................................36
ST535C Handbook Page 5
Multi-zone (1,2 or 3 zones)
32 programs each with 32 segments
1 controlled heating / cooling ramp + soak per segment
Soak periods up to 99 hours 59 mins
Ramp rates from 0.1 to 999°/hour + FULL
Ideal for glass or ceramics use
Programs can be altered while firing
Program pause and advance facilities
Keyboard lockable
Delayed start facility - up to 99 hours 59 mins
Power failure recovery
Energy used display
Setpoint display
Alarm buzzer & alarm relay output
2 Programmable control relay outputs
WiFi + USB datalogger option
°C/°F operation
Features
Page ST535C Handbook
6
Turning On
When turned on the ST535C performs a dis-
play test by lighting all of the display segments
and illuminating all of the front panel indicator
lamps.
The version number of the software embedded
within the ST535C is now displayed. If you
need technical support you might be asked for
this code together with the serial number.
Next displayed is the thermocouple type set-
ting. This should match the type of thermocou-
ple fitted to the kiln and can be R, S, K or N
type (R,S,K,N).
The final display will show the kiln temperature.
All other lamps (except the zone indicator lamp
for multi-zone kilns) should be off.
If pressing any key causes LOCKED to appear
then the keyboard has been locked. This is an
anti-tamper feature. Press the function key &
hold down for 5 seconds to unlock.
During firing the star icon will light to show
when heating power is being applied to the
kiln.
This now shows that the keyboard is UN-
LOCKED. To re-lock the keyboard press the
function key & hold down for 5 seconds.
If any mimic panel lamps are on then the ST535C is firing. To stop the firing
press the ► key.
Note: During power up the SEGMENT display shows
the operating units (°C/°F) of the ST535C (Installer
adjustable).
ST535C
F6.00
T/C:R
20oC
LOCKED
UNLOCKED
32oC
ST535C Handbook Page 7
Programming
A firing segment
An ST535C firing segment comprises a ramp followed by a soak period. Two
segments can be used for simple firing (biscuit firing for example) or several seg-
ments can be used per program for complex firing (crystal glazing or glass-
making for example).
The ST535C ramps the kiln temperature at the required ramp rate until the kiln
reaches the soak / target temperature. It then soaks (dwells) at the soak temper-
ature for the soak period. It then runs the next segment until the end of the pro-
gram is reached.
The ST535C is capable of both positive (heating) ramps and negative (cooling)
ramps - as used in glassmaking for annealing. The type of ramp is clearly shown
on the mimic display during firing.
The ramp rate is settable in the range 0.1 to 9.9°/hour then 10 to 999°/hour or
FULL (full power) or END (end of program).
The soak / target temperature is settable over the range 0 to 1550°C (2822°F).
The soak period is settable over the range 00.00 (no soak) to 99 hours 59 mins.
Note: during soaking the ST535C display alternates every 15 seconds
between kiln temperature and soak period remaining.
Cooling Ramp
Heating Ramp
Soak Period
Soak Temperature
(target temperature)
Page ST535C Handbook
8
When not firing there are no indicators lit on
the mimic panel, the run indicator is off and
the display shows the current kiln
temperature.
Altering a program
The controller settings can be reviewed by pressing the ► key.
The first push of the ► key flashes the
program number display. The required firing
program can now be selected with the ▲ & ▼
keys.
Note: holding down the ▲ or ▼ keys causes rapid change of the displayed value.
The next push of the ► key displays the ramp
rate in the range END, 0.1-9.9°/HR, 10-999°/HR
or FULL. This can be altered with the ▲ & ▼
keys. The heating ramp or the cooling ramp
indicator on the mimic panel will flash. END marks the end of the program. FULL
heats or cools as fast as possible.
The next push of the ► key displays the soak
temperature. This can be altered with the ▲
& ▼ keys. The soak temperature indicator
on the mimic panel will flash.
The next push of the ► key displays the soak
period in hours:minutes. This can be altered
in the range 00:00 to 99:59 with the ▲ & ▼
keys. The soak period indicator on the mimic
panel will flash.
The next push of the ► key increments the segment number digit and
firing data for the next segment can be entered.
Program data entry is terminated if END is
selected for a ramp rate with the ▼ key. Pro-
gram data entry is also automatically terminat-
ed if the maximum number of segments have
been entered.
Note 2: to exit programming without cycling through all of the above steps wait 20 seconds without pressing any
keys - the ST535C will revert to the idle display. Alternatively press the ► key to exit programming and to begin
firing immediately.
Note 3: the ◄ key can be used to reverse through the programming steps to correct errors or to exit programming
mode.
Note 1: available ramp rate displays are: END, 0.1 … 999 & FULL. If END is shown but another segment is
required then push the ▲ key to obtain the required ramp rate (in the range 0.1°/hr to 999°/hr). If maximum
heating/cooling is required then push the ▲ key until FULL is displayed. To mark the end of the program push
the▼ key until END is displayed.
20oC
PROG: 1
150oC/HR
600oC
00:15
END
ST535C Handbook Page 9
Temperature Display
To change the displayed zone press either the
▲ or ▼ keys. The zone number icons will
change to show which zone temperature is being
displayed.
This section only applies to multi-zone (2 or 3 zones) kilns. A single zone
kiln will always show the temperature of zone 1 only.
For a single zone kiln the zone icons are not
used and the temperature of zone 1 is always
displayed.
For multi-zone kilns the temperature of each
zone can be displayed. Zone 1 is displayed by
default when the ST325 is powered on.
Control Relay Configuration
While displaying a ramp rate an event output can be
switched on or off by holding in the function key then
pressing either the 1 key or the 2 key. The event
output will be ON when the event icon is on.
The ST535C has 2 control relay outputs.
Control relay 1 can be configured as an event output, a damper control output or a fan
control output.
Control relay 2 can be configured as an event output only.
See the Installation section for details about configuring the control relays.
While displaying a soak period the event output can
be switched on or off by holding in the function key
then pressing either the 1 key. The event output
will be ON when the event icon is on.
Control Relays
Event Outputs
The control relays when configured as event outputs can be programmed to change
state at the start of a ramp and also at the start of a soak period. Thus both ramp and
soak events are possible. The event output is ON (relay contacts are closed) when
the relevant event icon is lit. Prior to running a program both event outputs are OFF
(relay contacts are open). The status of the event outputs is stored within the firing
program.
1020oC
1020oC
1018oC
150oC/HR
00:15
Page ST535C Handbook
10
To enter the damper temperature configuration menu press the ► key and
the key down together while the controller is not running a program (firing
indicator not lit).
Note: in the sequence below if no key presses are detected within 30
seconds the ST535C will exit the menu and damper temperature chang-
es will not be saved.
The damper close temperature prompt is
shown. Release the & keys.
Press the key.
The damper close temperature is now
shown. Adjust with the & keys (hold
down for acceleration).
Press the key.
The damper open temperature prompt is
now shown.
Press the key.
The damper open temperature is now
shown. Adjust with the & keys (hold
down for acceleration)
Press the key.
The instrument will now reset and the new damper control temperatures will
be stored.
Note: in the sequence above it is important that the key is pressed a
total of 4 times else changes will not be saved.
Damper Output
Damper Operation
Prior to firing the damper will be open. During firing, when the kiln reaches
the damper close temperature, the damper will close. The event indicator 1
will be on.
At the end of the firing and when the kiln has cooled naturally to the damper
open temperature, the damper will open. The event indicator 1 will be off.
DAMPER:C
150oC
DAMPER:O
300oC
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