Installation - Operation Manual
SMO14-2 SMO28-2 SMO28G-2
SMO FORCED AIR OVENS 230 Voltage
These ovens require permanent connect wiring (also known as a hardwiring) to a power source
Pictured on Cover: Left to right SMO14-2 and SMO28-2
2 | Page
SMO Forced Air Ovens 230 Voltage
Part Number (Manual): 4861581
Revision: January 30, 2018
Note: The SMO28G-2 ships with two wire shelves typically used in curing applications. The
SMO28G-2 is identical to the SMO28-2 in all other respects.
SHEL LAB is a brand of Sheldon Manufacturing, INC.
Safety Certifications
These units are CUE listed by TÜV SÜD as forced air ovens for professional, industrial, or
educational use where the preparation or testing of materials is done at an ambient air pressure
range of 22.14 – 31.3 inHg (75 – 106 kPa) and no flammable, volatile, or combustible materials are
being heated.
These units have been tested to the following requirements:
CAN/CSA C22.2 No. 61010-1:2012
CAN/CSA C22.2 No. 61010-2-010 + R:2009
UL 61010A-2-010:2002
UL 61010-1:2012
EN 61010-1:2010
EN 61010-2-010:2003
3 | Page
TABLE OF CONTENTS
INTRODUCTION ........................................................................................................................................................ 5
Read this Manual .................................................................................................................................................................... 5
Safety Considerations and Requirements ...................................................................................................................... 5
Contacting Assistance .......................................................................................................................................................... 6
Temperature Reference Sensor Device .......................................................................................................................... 6
Engineering Improvements.................................................................................................................................................. 6
RECEIVING YOUR UNIT ............................................................................................................................................ 7
Inspect the Shipment ............................................................................................................................................................. 7
Orientation................................................................................................................................................................................ 8
Recording Data Plate Information .................................................................................................................................... 11
INSTALLATION ......................................................................................................................................................... 13
Hardwire Requirement ........................................................................................................................................................ 13
Installation Checklist ........................................................................................................................................................... 13
Required Ambient Conditions ........................................................................................................................................... 14
Required Clearances ........................................................................................................................................................... 14
Environmental Disruption Sources .................................................................................................................................. 14
Power Source Requirements ............................................................................................................................................ 15
Power Feed Wiring ............................................................................................................................................................... 15
Lifting and Handling ............................................................................................................................................................ 16
Leveling ................................................................................................................................................................................... 16
Install the Oven ...................................................................................................................................................................... 17
Installation Cleaning ............................................................................................................................................................. 17
Install the Shelving ................................................................................................................................................................ 17
GRAPHIC SYMBOLS ................................................................................................................................................ 19
CONTROL PANEL OVERVIEW ............................................................................................................................... 21
OPERATION.............................................................................................................................................................. 23
Operating Precautions ....................................................................................................................................................... 23
Theory of Operation ........................................................................................................................................................... 24
Put the Oven into Operation ............................................................................................................................................ 26
Set the Temperature Set Point .........................................................................................................................................27
Set the Over Temperature Limit ...................................................................................................................................... 28
Setting the Timer ................................................................................................................................................................. 29
Launch a Heating Profile.................................................................................................................................................... 31
Drying Racks and other Accessories ............................................................................................................................. 32
USER MAINTENANCE ............................................................................................................................................. 33
Cleaning and Disinfecting ................................................................................................................................................. 33
Door Components ............................................................................................................................................................... 34
Electrical Components ....................................................................................................................................................... 34
Calibrating the Temperature Display ............................................................................................................................ 35
UNIT SPECIFICATIONS .......................................................................................................................................... 39
Weight ..................................................................................................................................................................................... 39
Dimensions ............................................................................................................................................................................ 39
Capacity ................................................................................................................................................................................. 39
Shelf Capacity by Weight .................................................................................................................................................. 40
Air Flow Performance ......................................................................................................................................................... 40
Temperature .......................................................................................................................................................................... 41
Power ....................................................................................................................................................................................... 41
PARTS LIST ............................................................................................................................................................... 43
4 | Page
INTRODUCTION
Thank you for purchasing a SHEL LAB oven. We know you have many choices in today’s competitive
marketplace when it comes to constant temperature equipment. We appreciate you choosing ours. We
stand behind our products and will be here if you need us.
READ THIS MANUAL
Failure to follow the guidelines and instructions in this user manual may create a protection
impairment by disabling or interfering with the unit safety features. This can result in injury or death.
Before using the unit, read the manual in its entirety to understand how to install, operate, and
maintain the unit in a safe manner. Keep this manual available for use by all operators. Ensure all
operators are given appropriate training before the unit begins service.
SAFETY CONSIDERATIONS AND REQUIREMENTS
Follow basic safety precautions, including all national laws, regulations, and local ordinances in your
area regarding the use of this unit. If you have any questions about local requirements, please
contact the appropriate agencies.
SOPs
Because of the range of potential applications this unit can be used for, the operator or their
supervisors must draw up a site-specific standard operating procedure (SOP) covering each
application and associated safety guidelines. This SOP must be written and available to all operators
in a language they understand.
Locations and Intended Applications Range
SMO forced-air ovens are engineered for constant temperature forced-air drying, curing, and baking
applications in professional, industrial, and educational environments. The ovens are not intended
for use at hazardous or household locations.
Power
Your unit and its recommended accessories are designed and tested to meet strict safety
requirements.
• Always hardwire the unit power feed to a protective earth-grounded electrical source that
conforms to national and local electrical codes. If the unit is not grounded, parts such as
knobs and controls may conduct electricity and cause serious injury.
• Position the unit so the end-user can quickly and easily disconnect or uncouple the power
feed in the event of an emergency.
• Avoid damaging the power feed. Do not bend it excessively, step on it, place heavy objects
on it. A damaged power feed can easily become a shock or fire hazard. Never use a power
feed after it has been damaged.
• Use only approved accessories. Do not modify system components. Any alterations or
modifications to your oven may be dangerous and will void your warranty.
5 | Page
INTRODUCTION
CONTACTING ASSISTANCE
Phone hours for Sheldon Technical Support are 6 am – 4:30 pm Pacific Coast Time (west coast of
the United States, UTC -8). Please have the following information ready when calling or emailing
Technical Support: the model number and the serial number (see page 11).
EMAIL: support@sheldonmfg.com
PHONE: 1-800-322-4897 extension 4, or (503) 640-3000
FAX: (503) 640-1366
Sheldon Manufacturing, INC.
P.O. Box 627
Cornelius, OR 97113
TEMPERATURE REFERENCE SENSOR DEVICE
The oven does not come with a temperature reference device. A reference
device must be purchased separately for performing in-house accuracy
validations or calibration adjustments of the oven temperature display.
The device must be accurate to at least 0.1°C and should be regularly
calibrated by a third party. For best results, use a digital device with one or
more thermocouple probes. Remote readings eliminate chamber door openings and avoid
subsequent waits for the chamber temperature to re-stabilize. Select probes suitable for the
application temperature you will validate or correct the display accuracy at.
Alcohol thermometers are insufficient for conducting accurate validations and calibrations. Do not
use a mercury thermometer. Never place a mercury thermometer in the oven chamber. Always use
thermocouple probes.
ENGINEERING IMPROVEMENTS
Sheldon Manufacturing continually improves all of its products. As a result, engineering changes and
improvements are made from time to time. Therefore, some changes, modifications, and
improvements may not be covered in this manual. If your unit’s operating characteristics or
appearance differs from those described in this manual, please contact your SHEL LAB dealer or
customer service representative for assistance.
6 | Page
SMO28-2
6
24
4
SMO28G-2
2 8 4
RECEIVING YOUR UNIT
INSPECT THE SHIPMENT
• When a unit leaves the factory, safe delivery becomes the responsibility of the carrier.
• Damage sustained during transit is not covered by the manufacturing defect warranty.
• Save the shipping carton until you are certain that the unit and its accessories function
properly
When you receive your unit, inspect it for concealed loss or damage to its interior and exterior. If you
find any damage to the unit, follow the carrier’s procedure for claiming damage or loss.
1. Carefully inspect the shipping carton for damage.
2. Report any damage to the carrier service that delivered the unit.
3. If the carton is not damaged, open the carton and remove the contents.
4. The unit should come with an Installation and Operation Manual.
5. Verify that the correct number of accessory items have been included.
Included Components:
Model
SMO14-2 3 12 4
Model
Shelves
Shelves
Shelf Clips Leveling Feet
Shelf Clips Leveling Feet
6. Carefully check all packaging for accessories before discarding.
7 | Page
Figure
Power Panel (Back)
Permanent Connect Wire Braid
Control Panel
Vent Port with Sliding Dampener
Vent Port with Sliding Dampener
Main Temperature
and OTL Sensor
Door Latch
Door Latch
Shelf Standard Rail
Oven Chamber
Chamber Door
Chamber Liner Gasket
Door Liner
RECEIVING YOUR UNIT
ORIENTATION
1: SMO28-2
10 gauge, 6 inches (15 cm)
Gasket
Handle
8 | Page
Figure
Power Panel (Back)
Permanent Connect Wire Braid
Control Panel
Vent Port with Sliding Dampener
Vent port with Sliding Dampener
Main Temperature and
Door Latch
Shelf Standard Rail
Oven Chamber
Chamber Door
Chamber
Liner
Door Liner
RECEIVING YOUR UNIT
2: SMO28G-2
10 gauge, 6 inches (15 cm)
Gasket
OTL Sensor Probes
Handle
9 | Page
Figure
Control Panel
Main Temperature and
Shelf Standard Rail
Chamber Door
Vent Port with Sliding Dampener
Vent Port with Sliding Dampener
Oven Chamber
Power Panel (Back)
Permanent Connect
Door Liner
Chamber Liner Gasket
RECEIVING YOUR UNIT
3: SMO14-2
Wire Braid 14 gauge, 6
inches (15 cm)
OTL Sensor Probes
Gasket
Handle
10 | Page
RECEIVING YOUR UNIT
RECORDING DATA PLATE INFORMATION
Locate the data plate on the back of the oven below the power braid inlet. The data plate contains
the oven model number and serial number. Technical support and your distributor will need these
numbers in order to assist you in the future.
Date Plate Information
Model Number
Serial Number
11 | Page
RECEIVING YOUR UNIT
12 | Page
INSTALLATION
HARDWIRE REQUIREMENT
The oven requires permanent connect wiring (commonly known as hardwiring). Wiring to the power
source must be performed by a qualified electrical technician. All other Installation steps may be
performed by the end user.
INSTALLATION CHECKLIST
Carry out the procedures and steps listed below to install the oven in a new workspace location and
prepare it for use. All procedures are found in the Installation section of this manual.
Pre-Installation
Check that the required ambient condition for the oven are met, page 14
Check that the spacing clearance requirements are met, page 14
• Unit dimensions may be found on page 39
Check for performance-disrupting heat and cold sources in the environment, page 14
Check that a suitable permanent connect electrical power supply is present, page 15
Install the Oven in its Workspace Location
Review the lifting and handling instructions, page 16
Make sure the oven is level, page 16
Install the oven in its workspace location, page 17
Set up the Oven for Use
Clean the oven chamber and shelving if needed, page 17
Install the shelving in the oven chamber, page 17
13 | Page
6” (152mm)
6” (152mm)
12” (305mm)
24” (610mm)
24” (610mm)
Door Swing
37.9” (962mm)
INSTALLATION
REQUIRED AMBIENT CONDITIONS
This oven is intended for use indoors, at room temperatures between 15°C and 40°C (59°F and
°F), at no greater than 80% Relative Humidity (at 25°C / 77°F).
104
Operating the unit outside of these conditions may adversely affect its temperature range and
stability. For conditions outside of those listed above, please contact your distributor to explore
other oven options suited to your laboratory or production environment.
REQUIRED CLEARANCES
All Units
These clearances are required for the oven to operate safely and meet its stated temperature
specifications
• 24 inches (610 mm) of vertical headspace clearance.
• Do not place objects on top of the oven.
• Allow at least 6 inches (152 mm) from the access port and fan vent on the back of the oven
to the nearest wall or partition. Keep the fan unobstructed at all times.
ENVIRONMENTAL DISRUPTION SOURCES
When selecting a location to install the unit, consider all environmental conditions that can affect its
temperature performance. For example:
• Proximity to other ovens, autoclaves, and any device that produces significant radiant heat
• Heating and cooling ducts, or other sources of fast-moving air currents
• High-traffic areas
• Direct sunlight
14 | Page
INSTALLATION
POWER SOURCE REQUIREMENTS
When selecting a location for the oven, check that each of the following requirements is satisfied:
Power supply: The power supply must meet the power requirements listed on the oven data plate
(located on the back of the unit, beneath the power feed inlet.
• These ovens are intended for a 230 volt, 50/60 Hz applications at the following amperages:
Model Amperage Model Amperage
SMO14-2
• The power source must be single (1) phase and protective earth grounded.
• The power source must conform to all national and local electrical codes.
• Supplied voltage must not vary more than 10% from the data plate rating. Damage to the oven
may result if the supplied voltage varies more than 10%.
• Use a separate circuit to prevent loss of the unit due to overloading or circuit failure. The circuit
must meet or exceed the amperage requirements listed on the oven data plate.
12
SMO28-2
20
Switch or circuit-breaker: A switch or circuit-breaker must be used in the building installation to protect
against overcurrent conditions.
• The required circuit-breakers are, SMO14-2 15A and SMO28-2 SMO28G-2 30A.
Power feed disconnect: The oven must be positioned so that all operators have access to the power feed
disconnect in case of emergencies.
• The Disconnect must be in close proximity to the equipment and within easy reach of the
operator.
• The Disconnect must be marked as the disconnecting device for the equipment.
POWER FEED WIRING
The oven comes provided with an integral 6 inch (15 cm) wire braid of:
• SMO14-2 – Two 14-gauge high-temperature (300°C) hot wires and a 14-gauge earth ground.
• SMO28-2 SMO28G-2 -- Two 10-gauge high-temperature (300°C) hot wires and a 10-gauge
earth ground.
The wires for power source connection should be in accordance with the following:
• SMO14-2: Green/Yellow – Earth; Red – Hot; Black – Hot.
• SMO28-2 SMO28G-2: Green/Yellow – Earth; Black – Hot; Black – Hot.
The oven must be grounded using the protective conductor terminal (green with yellow stripe wire). Do
not remove the protective conductor (earth connection). Removing the protective conductor will negate the
oven protections against potentially dangerous electric shocks and create a possible fire hazard.
15 | Page
INSTALLATION
LIFTING AND HANDLING
The oven is heavy. Use appropriate lifting devices that are sufficiently rated for these loads. Follow these
guidelines when lifting the oven:
• Lift the oven only from its bottom surface.
• Doors, handles, and knobs are not adequate for lifting or stabilization.
• Restrain the oven completely while lifting or transporting so it cannot tip.
• Remove all moving parts, such as shelves and trays, and lock doors in the closed position
during transfers to prevent shifting and damage.
LEVELING
Install the 4 leveling feet with the 4 corner holes on the bottom of the oven.
The oven must be level and stable for safe operation.
Note: To prevent damage when moving the unit, turn all four leveling feet so that the leg of each
foot sits inside the unit.
16 | Page
Figure
Figure
Rocking Motion
INSTALLATION
INSTALL THE OVEN
Place the unit in a workspace location that meets the criteria discussed in the previous entries of the
Installation section.
• Verify that the oven stands level and does not rock. Adjust the leveling feet as needed.
• Power: The oven may now be hardwired to its power source
INSTALLATION CLEANING
The unit was cleaned at the factory, but not sterilized. It may have been exposed to contaminants en route
during shipping.
• Remove all wrappings and coverings from shelving prior to cleaning and installation.
• Do not clean with deionized water.
• See the Cleaning and Disinfecting topic in the User Maintenance section (see page 33) for
more information on how to clean the oven chamber prior to putting the unit into operation.
INSTALL THE SHELVING
Space the shelves evenly in the oven chamber to ensure the best possible air circulation and temperature
uniformity.
1. Install 4 shelf clips in 4 slots on the shelf standard rails on the left and right walls and the rear
wall of the chamber interior.
a. Squeeze each clip.
b. Insert the top tab first, then the bottom tab using a rocking motion.
c. The slots must all be at equal height from the oven chamber floor.
2. Set the shelf on the clips.
5: Installing Shelf Clip
4: Shelf Set on Clips
17 | Page
INSTALLATION
18 | Page
GRAPHIC SYMBOLS
The oven is provided with multiple graphic symbols on its exterior. The symbols identify hazards and
the functions of the adjustable components, as well as important notes in the user manual.
Symbol Definition
Consult the user manual.
Consulter le manuel d'utilisation
Indicates Temperature
Repère température
Indicates the Over Temperature Limit system
Indique le système de dépassement de temperature
AC Power
Repère le courant alternatif
I/ON O/OFF
I indique que l'interrupteur est en position marche.
O indique que le commutateur est en position d'arrêt.
Protective earth ground
Terre électrique
Indicates UP and DOWN respectively
Touches d e déplacements respectifs vers le HAUT et le BA
Indicates a Manually Adjustable control
Indique un bouton réglable manuellement
Potential shock hazard
Risque de choc électrique
Recycle the unit. Do not dispose of in a landfill.
Recycler l'unité. Ne jetez pas dans une décharge.
19 | Page
GRAPHIC SYMBOLS
Symbol Definition
Indicates the timer
Indique le minuterie
Start or Stop the Timer
Lancer ou arrêter le minuteur
Reset the Timer
Réinitialisation de la Minuterie
Caution hot surface
Attention surface chaude
20 | Page
CONTROL PANEL OVERVIEW
Figure 6: Control Panel
Power Switch
The green Power Switch controls overall power to the oven. When in the ON ( I ) position the switch
illuminates and the oven will heat to and maintain the currently programmed temperature set point.
Timer Switch
The black Timer Switch controls power to the timer system. When this switch is in the ON position
the SET TIMER display will illuminate, and the oven can run a timed steady-state heating profile at
the current temperature set point. The oven will not heat while the Timer system is on unless a
profile is running.
Over Temperature Limit Control (OTL)
This graduated dial sets the temperature limit for the Over Temperature Limit system. The OTL is an
independent mechanical heating cutoff that prevents unchecked heating of the oven in the event of
a failure of the main temperature controller system. For more details, please see the explanation of
the Over Temperature Limit System on page 25 in the Theory of Operation entry.
OTL Light
Marked OVER TEMP ACTIVATED, this light illuminates whenever the OTL System is routing power
away from the heating elements. Under normal operating conditions this light should never
illuminate.
Timer Display and Control Pad
The SET TIMER display can show the duration of the currently programmed heating profile, or a
flashing duration adjustment mode, or the countdown of a running profile to 0.
The “//” RESET button is used to place the Timer display in its adjustable duration mode, and then to
scroll through the duration time parameters.
The black SET TIMER arrow buttons adjust the heating profile duration time parameters when the
display is in its blinking adjustment mode.
The “T” START/STOP timer button launches a heating profile or pauses a running profile.
21 | Page
CONTROL PANEL
Main Temperature Display and Control
Marked SET TEMPERATURE, this display shows the current oven chamber air temperature accurate
to 1°C. The display can also show an adjustable temperature set point in the display’s set point
mode, as well as an adjustable offset while in calibration mode.
The arrow buttons can be used to adjust the temperature set point or place the unit in its calibration
mode, and then enter a calibration offset value.
Heating Activated Light
The green pilot light located beneath the label HEATING ACTIVATED illuminates whenever the
workspace oven heating elements are powered and warming the oven. The oven uses measured
pulses to achieve and maintain the temperature set point.
22 | Page
OPERATION
Safe operation of the oven is dependent on the actions and behavior of the oven operators.
Operating personnel must read and understand the Operating Precautions in this section prior to
operating the oven. The operators must follow these instructions to prevent injuries and to
safeguard their health, environment, and the materials being treated in the oven, as well as to
prevent damage to the oven. Failure to adhere to Operating Precautions, deliberately or through
error, is a hazardous behavior on the part of the operator.
Le fonctionnement sûr du four dépend des actions et du comportement des opérateurs du four. Le
personnel d'exploitation doit lire et comprendre les consignes de sécurité et les précautions
d'utilisation de cette section avant d'utiliser le four. Les opérateurs doivent suivre ces instructions
pour prévenir les blessures et protéger leur santé, leur environnement et les matériaux traités dans
le four, ainsi que pour éviter d'endommager le four. Le non-respect des consignes de sécurité et des
précautions d'utilisation, délibérément ou par erreur, est un comportement dangereux de la part de
l'opérateur.
OPERATING PRECAUTIONS
• Do not use this oven in unsafe improper applications that produce flammable or combustible
gasses, vapors, liquids, or fuel-air mixtures in quantities that can become potentially
explosive.
• Outgassed byproducts may be hazardous to or noxious for operating personnel. Exhaust
should be vented to a location outside the workspace in a safe manner in accordance with
all applicable laws, ordinances, and regulations. Do not operate the oven in an unsafe area
with noxious fumes.
• Do not use this oven for applications heating hazardous fibers or dust. These items can
become airborne and come into contact with hot surfaces.
• Individual ovens are not rated to be explosion proof. Follow all building certification
requirements and laws for Class I, II, or III locations as defined by the US National Electric
Code.
• The bottom surface of the chamber should not be used as a work surface. It runs hotter than
the shelf temperatures. Never place samples or product on the oven chamber floor.
• Do not place sealed or filled containers in the oven. These may burst open when heated.
• Do not place alcohol or mercury thermometers in the oven. These devices may rupture
under heat or other improper uses.
• Do not move the oven until it has finished cooling.
Warning: The vent dampers may be hot to the touch. These areas are marked with Hot Surface labels.
Proper PPE should be employed to minimize risk to burn.
Avertissement: Les clapets d'aération peuvent être chauds au toucher. Ces zones sont marqués avec des
étiquettes de Surface chaude. Les EPI approprié devraient être employée pour réduire au minimum le
risque de brûler.
23 | Page
OPERATION
THEORY OF OPERATION
Heating
When powered, the SMO oven chamber heats to and then maintains the currently programmed
temperature set point. The set point may be adjusted by the end-user using the Set Temperature controls.
Heating is controlled by a microprocessor controller board that stores the temperature set point. The
microprocessor senses the chamber air temperature via a solid-state probe located in the airstream on the
back wall of the chamber. When the processor detects that the chamber temperature has dropped below
the temperature set point, it pulses power to a heating element in a recirculation air duct space located
above the oven chamber.
The processor employs proportional-integral-derivative analytical feedback-loop functions when measuring
and controlling the chamber air temperature levels. PID-controlled heating pulse intensities and lengths are
proportional to the difference between the measured chamber temperature and the current set point. The
frequency of pulses is derived from the rate of change in the difference. The integral function slows the
rate of pulses when the temperature nears the set point to avoid overshooting.
SMO ovens rely on natural heat radiation for cooling.
When the oven is powered the chamber air temperature cannot go below the ambient room temperature
plus the internal waste heat of the oven. Waste heat is generated primarily by the operation of the blower
fan motor and the resulting air compression in the duct spaces. In practice, the temperature floor is
ambient +15°C.
The oven depends on the operation of the blower fan to maintain temperature uniformity and stability in
the chamber.
Air Circulation
The oven continually circulates air internally while powered. Air is forced through vent holes at the back of
the chamber, blows across the shelf space to the front, and is then pulled upward into a heating and
recirculation air duct by the action of the blower fan.
The oven is provided with two vents that may be opened or closed using dampener slides located on the
oven exterior. SMO forced air ovens must be run with the dampeners closed in order to achieve the
stated chamber temperature uniformity and stability.
The dampeners are intended to speed drying or evaporation rates after the heated portion of an
application is complete. Opening the dampener vents while the oven is running may speed the rate of
material drying, dependent on the nature of your application. However, running the oven with the
dampeners open introduces cool air into the chamber while allowing heated air to exit. This may impact the
temperature uniformity and stability of the chamber, and lower the operational temperature ceiling.
24 | Page
OPERATION
Timed Heating Profile
The oven is provided with a Timer subsystem that can run the oven in a steady-state heating profile at the
current temperature set point from 1 minute up to 99 hours, 59 minutes. Allow the oven to heat to
temperature prior to launching the profile. Launching a profile with the temperature set point set to 150°C
immediately after turning on the oven will result in the first 24 minutes of the profile being spent with the
chamber rising from room temperature to 150°C.
When the Timer system is on, the oven will not heat unless a profile is running.
The Over Temperature Limit System (OTL)
When set, the OTL heating cutoff system prevents runaway heating in the event of a failure of the
microprocessor controller or its thermometer probe. The OTL operates independently of the
microprocessor and is provided with a separate, hydrostatic temperature sensor probe located in the oven
chamber. In the event the temperature of the chamber exceeds the current OTL setting, the OTL routes
power away from the heating elements. The Over Temperature Limit is set by the end-user, typically at
approximately 5°C above the application temperature set point. Because of its nature as a mechanical
cutoff system and its lack of PID analytics, the OTL cannot deliver the same degree of temperature stability
and measurement precision as the digital display and microprocessor.
25 | Page
OPERATION
Note: Performing a temperature accuracy verification requires a suitable temperature reference
device. Please see the Temperature Reference Device entry on page 6 for the device
requirements.
PUT THE OVEN INTO OPERATION
Carry out the following steps and procedures to put the oven into operation after installing it in a new
workspace environment.
1. Turn on the oven by placing the green main power switch in the ( I ) ON position.
2. Perform the following procedures:
• Set the Oven Temperature Set Point page 27
• Set the Over Temperature Limit page 31
• Optional: Set the oven timer to run the oven for a set duration. Please see page 29.
26 | Page
1. Set OTL control to its maximum setting, if not already set to max.
2. Jump to the Temperature Set Point Adjustment mode
3.
4. Wait for 5 seconds after entering the Set Point
HEATIN G AC T I VATED
Set Temperature
Initial Set Poiint
OPERATION
SET THE TEMPERATURE SET POINT
Adjust the oven temperature set point to that of your application.
• Turning the OTL all the way to the right (clockwise) prevents the heating
cutoff system from interfering with this procedure.
Set Temperature
Press and
hold either
Set Point Adjustment Mode
Note: The display will automatically exit the adjustment mode after 5 seconds of
inactivity on the arrow keys, saving the last shown set point value.
Set the Temperature Set Point
New Set Point
Adjust
Set Temperature
• The display will stop flashing. The set point is now saved in the controller.
• The display will revert to showing the current chamber air temperature,
heating or passively cooling to match the new set point.
End of Procedure
27 | Page
2. Turn the dial counterclockwise until the red Over Temperature Limit Light illuminates.
3.
4. Leave the OTL dial set just above the activation point.
Optional: Turn the dial slightly to the left.
•
OPERATION
SET THE OVER TEMPERATURE LIMIT
This procedure sets the Over Temperature Limit heating cutoff to approximately 5˚C above the
current temperature set point. Perform the steps below once the oven has been stabilized at your
application temperature set point for at least a 30 minutes.
1. Set OTL control to its maximum setting, if not already set to max.
Slowly turn the dial clockwise until the OTL Activated light turns off.
• The Over Temperature Limit is now set approximately 1˚C
above the current chamber temperature.
If the OTL is sporadically activating, you may turn the dial very slightly to the right (clockwise).
If the OTL continues activating, check for ambient sources of heat or cold that may be adversely impacting
the unit temperature stability. If you can find no sources of external or internal temperature fluctuations,
contact Tech Support or your distributor for assistance.
28 | Page
This sets the OTL cutoff threshold nearer to the current
chamber temperature.
End of Procedure
1.
2.
3. Set the Hour parameter
4. Advanced to Tens-of-Minutes parameter
OPERATION
SETTING THE TIMER
This procedure enters a heating profile duration in the Timer system. When launched, the profile
runs the oven for the duration at the present temperature set point.
Turn on the Timer System
Push to On
Place the Timer Display in its adjustable Set Timer mode
Press and
Hold RESET
Set Timer
1 Minute Profile
Set Timer
Hours Selected
Set Timer
• The Timer Display will illuminate, showing
the previously programmed profile duration.
• The oven will cease heating
• After approximately 3 seconds a flashing
decimal point will appear after the hours
parameter.
Note: If 5 seconds elapse with no activity on the
Arrow Pad buttons, the Timer Display will exit the
adjustment mode with the last entered time values
saved.
1 Hour, 1 Minute
Adjust
Set Timer
Push
Tens of Minutes Selected
Note: Advancing saves the adjusted hour
parameter.
Continued next page
29 | Page
5.
6.
7. Set the Minutes parameter
8. Wait for 5 seconds after entering the Minutes parameter
OPERATION
Setting the Timer Continued
Set the Tens-of-Minute parameter
Set Timer
1 Hour, 51 Minutes
Adjust
Advance to the Minutes parameter
Push
Adjust
Set Timer
Minutes Selected
Set Timer
1 Hour, 55 Minutes
• The flashing decimal point will advance to
between the third and fourth numbers, saving
the new Tens-of-Minutes parameter setting
Set Timer
End of procedure
30 | Page
• The display will exit adjustment mode.
• The Minutes parameter is now saved.
1. Turn on the Timer System
2.
Optional: Pausing a running profile
3. The oven ceases heating upon reaching “00:00”
OPERATION
LAUNCH A HEATING PROFILE
The oven can be run in a timed steady-state heating profile at the current temperature set point.
Allow the oven to come up to temperature prior to launching a profile. See the Setting the Timer
procedure on page 29 for how to set the length of the profile.
Note: While the Timer system is on, the oven will not heat unless a profile is running.
Push to On (I)
Launch the current profile
Press and Hold
Push
Set Timer
1 Hour, 55 Minute Profile
Set Timer
• The oven will cease heating until the profile is restarted, reset, or the
Timer system is turned off.
To restart the profile where it left off, press the Start/Stop “T” button
•
again.
• The Timer Display will illuminate, showing
the previously programmed profile duration.
• The oven will cease heating
• The Timer Activated light illuminates and the
Display will start counting down.
• The oven will resume heating.
Set Timer
Profile Complete
• To resume manual heating place the Timer Switch
in the OFF ( O ) position.
• To launch another profile, press the “//”
End of procedure
Reset button and enter a new profile, or
allow the previous profile to reset
automatically after 5 seconds.
31 | Page
OPERATION
DRYING RACKS AND OTHER ACCESSORIES
Make sure that any accessories used inside the oven chamber, such as drying racks, are suitable for your
application and will not suffer damage when brought to temperature. Always set the OTL cutoff system to
approximately 5°C above your application temperature set point in order to safeguard accessories against
over temperature events. The manufacturing defect warranty does not cover damage caused by melted
or otherwise overheated accessory items.
32 | Page
USER MAINTENANCE
Warning: Prior to maintenance or service on this unit, disconnect the power feed from the power supply.
Avertissement: Avant d'effectuer toute maintenance ou entretien de cet appareil, débrancher le cordon
secteur de la source d'alimentation.
CLEANING AND DISINFECTING
If a hazardous material or substance has spilled in the oven, immediately initiate your site Hazardous
Material Spill Containment protocol. Contact your local Site Safety Officer and follow instructions per
the site policy and procedures.
• Periodic cleaning is required.
• Do not use spray on cleaners or disinfectants. These can leak through openings and coat
electrical components.
• Consult with the manufacturer or their agent if you have any doubts about the
compatibility of decontamination or cleaning agents with the parts of the equipment or
with the material contained in it.
• Do not use cleaners or disinfectants that contain solvents capable of harming paint
coatings or stainless steel surfaces. Do not use chlorine-based bleaches or abrasives;
these will damage the chamber liner.
Warning: Exercise caution if cleaning the unit with alcohol or flammable cleaners. Always allow the
unit to cool down to room temperature prior to cleaning and make sure all cleaning agents have
evaporated or otherwise been completely removed prior to putting the unit back into service.
Avertissement: Soyez prudent lorsque vous nettoyez l'appareil avec de l'alcool ou des produits de
nettoyage inflammables. Laissez toujours refroidir l'appareil à la température ambiante avant le
nettoyage et assurez-vous que tous les produits de nettoyage se sont évaporés ou ont été
complètement enlevés avant de remettre l'appareil en service.
Cleaning
1. Disconnect the unit from its power supply.
2. Remove all removable interior components such as shelving and accessories.
3. Clean the unit with a mild soap and water solution, including all corners.
o Do not use an abrasive cleaner, these will damage metal surfaces.
o Do not use deionized water to rinse or clean with!
o Take special care when cleaning around the temperature sensor probes in the
chamber to prevent damage. Do not clean the probes.
4. Rinse with distilled water and wipe dry with a soft cloth.
33 | Page
USER MAINTENANCE
Disinfecting
Disinfect the oven if algae, mold, bacteria, or other biological contaminants are an issue. For
maximum effectiveness, disinfection procedures are typically performed after cleaning.
Keep the following points in mind when disinfecting the oven:
• Turn off and disconnect the unit to safeguard against electrical hazards.
• Disinfect the oven chamber using commercially available disinfectants that are non-
corrosive, non-abrasive, and suitable for use on stainless steel and glass surfaces. Contact
your local Site Safety Officer for detailed information on which disinfectants are compatible
with your applications.
• If permitted by your protocol, remove all removable interior accessories (shelving and other
non-attached items) from the chamber when disinfecting.
• Disinfect all surfaces in the chamber, making sure to thoroughly disinfect the corners.
Exercise care to avoid damaging the sensor probes.
When disinfecting external surfaces, use disinfectants that will not damage painted metal, glass, and
plastic
DOOR COMPONENTS
Periodically, inspect the door latch, trim, and catch for alignment. Check the two silicon rubber gaskets
located on the door and on the doorframe of the oven body for signs of drying, brittleness or cracking.
Failure to maintain the integrity of the door system shortens the lifespan of the oven and may adversely
impact chamber temperature uniformity and stability.
Replacement of the door liner and chamber liner gaskets is a service-level procedure.
ELECTRICAL COMPONENTS
Electrical components do not require maintenance. If the unit electrical systems fail to operate as
specified, please contact your distributor or Technical Support for assistance.
34 | Page
4 ) Close all the way the vent port
3 ) The oven chamber door must
2 ) Place the sesnor probes in the oven with the probe
Heat-resistant
1 ) Introduce the reference device
USER MAINTENANCE
CALIBRATING THE TEMPERATURE DISPLAY
Note: Please see the Reference Sensor Device entry on page 6 for the minimum device
requirements.
Temperature calibrations match the temperature display to the actual air temperature inside the
oven chamber. The actual air temperature is supplied by a reference sensor device. Calibrations
compensate for software drifts in the controller as well as deviations caused by the natural material
evolution of the sensor probe in the heated chamber space. Calibrate as often as required by your
laboratory or production protocol, or regulatory compliance schedule. Always calibrate to the
industry or regulatory standards required for your application.
A Suggested Calibration Set Up
non-stick tape
recommended
be closed and latched.
heads at least at least 2 inches (5cm) from the surface
of the shelving or walls to prevent heatsinking. Secure
with non-stick, heat-resistant tape.
not being used.
thermocouple sensor probes into the
oven chamber through the rear access
port. There should be at least 12 inches
(30.5cm) of probe wire in the oven to
prevent heatskinking the outside
temperature.
2 ) Carefully the close port slider.
Leaving a ¼ inch gap (6mm) is
acceptable when wire probes are in the
port and should not interfere with the
calibration accuracy. The chamber air
pressure is close to neutral while the
oven is in operation, limiting the
exchange with cooler external
atmosphere.
If performing a single point calibration, place the sensor
probe head as close to the geometric center of the
oven chamber as possible.
35 | Page
Begin Calibration
Suggested Calibration Procedure
1
2
150°C
Start
30 Minute Minimum
Heat Up to 150°C:
USER MAINTENANCE
5 ) Heat up and stabilization period.
• The oven chamber must be stable at temperature in order to perform an accurate
calibration.
• The temperature is considered stabilized when the oven chamber has operated at your
calibration temperature for at least 30 minutes with no fluctuations of ±0.2°C or greater.
~ 24 Minutes
Fluctuations
(Exaggerated)
Stability Period
Figure 7: Oven Chamber Heat Up and Stabilization Phases
Once the chamber has stabilized with no fluctuations, compare the
reference temperature device and chamber temperature display
readings.
a. If the readings are the same, or the difference between the two
falls within the acceptable range of your protocol, the display is
accurately showing the chamber temperature. The Temperature
Calibration procedure is now complete.
- Or -
b. See Step 2 if a difference falls outside the acceptable range of
your protocol.
The display requires calibration. Advance to Step 3.
• If the door was opened to check a reference
device temperature inside the chamber wait 15
minutes after the reference device reading
stops fluctuating before proceeding.
Reference Device
Set Temperature
Reference Device
Set Temperature
36 | Page
Continued next page
3
4
6
USER MAINTENANCE
Calibration continued
Place the oven in temperature calibration mode.
a. Press and hold both the UP and DOWN arrow buttons
simultaneously.
• The Temperature Display will show the letters “C O”,
then begin flashing the current temperature value.
Note: If an arrow key is not pressed for five seconds, the Temperature
Display will cease flashing, and store the last displayed value as the new
current chamber temperature value.
Set Temperature
Set Temperature
Current Temp. Value
Set Temperature
5
Adjust the current temperature value to match the
reference device.
a. Use the UP and DOWN arrow buttons.
After entering the correction adjustment, wait 5
seconds.
• The temperature display will cease flashing and
store the correction as an offset.
• The oven will now begin heating or allow itself
to cool to reach your set point with the
corrected display value.
Wait for the oven to achieve the new set point with
the corrected display value.
Corrected
Reference Device
Set Temperature
Heating with Corrected
Value
Set Temperature
Procedure continued on next page
37 | Page
7
8
9
USER MAINTENANCE
Calibration continued
After the oven has achieved the set point, wait for
the oven chamber temperature to stabilize.
• The chamber temperature is stabilized when
no fluctuations of 1°C or greater have been
detected with the reference device for a
minimum of 30 minutes.
• Failure to wait for stabilization will result in an
inaccurate calibration.
Reference Device
Once the temperature has stabilized, compare the reference
device and the oven display temperature readings.
a. If the readings are the same, or the difference between
the two falls within the acceptable range of your
protocol, the oven is calibrated for temperature.
-Or-
b. Advance to step 9.
If the two readings still fall outside the acceptable range of your
protocol, repeat steps 3 – 8 up to two more times.
• Three calibrations attempts may be required to
successfully calibrate ovens more than ± 2⁰C out of
calibration.
If the temperature readings of the oven and the reference device fall outside your
protocol after three calibration attempts, contact Technical Support or your distributor
for assistance.
Reference Device
Set Temperature
Reference Device
Set Temperature
38 | Page
End of procedure
UNIT SPECIFICATIONS
These ovens are 230 voltage units. Please refer to the oven data plate for individual electrical
specifications.
Technical data specified applies to units with standard equipment at an ambient temperature of 25°C
and at nominal voltage. The temperatures specified are determined in accordance to factory
standard following DIN 12880 respecting the recommended wall clearances of 10% of the height,
width, and depth of the inner chamber. All indications are average values, typical for units produced
in the series. We reserve the right to alter technical specifications at all times.
WEIGHT
Model Shipping Net Weight
SMO14-2 361 lbs. / 164 kgs 280.0 lbs. / 127.3 kgs
SMO28-2 513 lbs. / 233 kgs 390.0 lbs. / 177.3 kgs
SMO28G-2 513 lbs. / 233 kgs 390.0 lbs. / 177.3 kgs
DIMENSIONS
By Inches
Model Exterior W × D × H Interior W × D × H
SMO14-2 37.5 x 34.0 x 48.0 in 30.8 x 24.8 x 31.0 in
SMO28-2 37.5 x 35.0 x 78.3 in 30.8 x 25.0 x 61.0 in
SMO28G-2 37.5 x 35.0 x 78.3 in 30.8 x 25.0 x 61.0 in
By Millimeters
Model Exterior W × D × H Interior W × D × H
SMO14-2 953 x 864 x 1219 mm 782 x 630 x 788 mm
SMO28-2 953 x 889 x 1989 mm 782 x 635 x 1575 mm
SMO28G-2 953 x 889 x 1989 mm 782 x 635 x 1575 mm
CAPACITY
Model Cubic Feet Liters
SMO14-2
13.7 388
SMO28-2
SMO28G-2
27.6 781
27.6 781
39 | Page
Linear Feet per Minute
5
1.5
UNIT SPECIFICATIONS
SHELF CAPACITY BY WEIGHT
Model Per Shelf Total
SMO14-2 75.0 lbs / 34.0 kg 225.0 lbs / 102.0 kg
SMO28-2
SMO28G-2 30.0 lbs* / 13.6 kg 60.0 lbs / 27.2 kg
*30lbs with the weight evenly distributed across the shelf.
75.0 lbs / 34.0 kg 450.0 lbs / 204.0 kg
AIR FLOW PERFORMANCE
Ventilation Rates
Model Cubic Feet per Minute @80°C Liters per Minute @80°C
SMO14-2 42 1189
SMO28-2 39.4 1116
SMO28G-2 39.4 1116
Air Changes per Hour
Model @80°C
SMO14-2 175
SMO28-2 85
SMO28G-2 85
Air Velocity Across Shelf Space
Model
SMO14-2
SMO28-2
SMO28G-2
40 | Page
Meters per Minute
5 1.5
5 1.5
230
20
50/60 Hz
UNIT SPECIFICATIONS
TEMPERATURE
Model Range Uniformity Stability
SMO14-2
SMO28-2
SMO28G-2
Ambient +15 to 260°C + 3.0° @ 150°C ± 0.4°C
Ambient +15 to 260°C + 3.5° @ 150°C
Ambient +15 to 260°C + 3.5° @ 150°C ± 0.2°C
Model Heat Up Time to 150° Recovery at 150°C*
SMO14-2 35 minutes 7 minutes
SMO28-2 29 minutes
SMO28G-2 29 minutes 7 minutes
*From a 30-second door opening.
POWER
Model AC Voltage Amperage Frequency
SMO14-2
SMO28-2
± 0.2°C
7 minutes
230 12 50/60 Hz
230 20 50/60 Hz
SMO28G-2
41 | Page
UNIT SPECIFICATIONS
42 | Page
PARTS LIST
Description Parts Number
Adjustable Feet
2700506
Shelf Clip
1250512
Shelf, Stainless Steel, SMO14-2 SMO28-2
995-00006
Shelf, Wire, SMO28G-2
6800537NCF
Ordering
If you have the Part Number for an item, you may order it directly from Sheldon Manufacturing by
calling 1-800-322-4897 extension 3. If you are uncertain that you have the correct Part Number, or if
you need that specific item, please contact Sheldon Technical Support for help at 1-800-322-4897
extension 4 or (503) 640-3000. Please have the model number and serial number of the unit ready,
as Tech Support will need this information to match your unit to its correct part.
43 | Page
P.O. Box 627
Cornelius, OR 97113
USA
support@sheldonmfg.com
sheldonmanufacturing.com
1-800-322-4897
(503) 640-3000
FAX: 503 640-1366
Loading...