Sheldon Shel lab SMO28HP-2 User manual

Installation - Operation Manual
SMO28HP-2, SMO10HP-2
SMO28HP-2 formerly designated SMO34HP-2
HIGH-PERFORMANCE OVENS
220 – 240 Voltage

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These ovens require permanent connect wiring (also known as hardwiring) to a power supply.
Pictured on the front cover, left to right: SMO28HP-2, SMO10HP-2
The SMO28HP-2 was previously designated SMO34HP-2
Warning:This product contains chemicals, including triglycidyl isocyanurate, known to the State of
California to cause cancer as well as birth defects or other reproductive harm. For more information,
go to www.P65Warnings.ca.gov.
¡Advertencia! Este producto contiene sustancias químicas, incluido el triglicidil isocianurato, que el
estado de California sabe que causa cáncer, así como defectos de nacimiento u otros daños
reproductivos. Para obtener más información, visite www.P65Warnings.ca.gov.
Avertissement!Ce produit peut vous exposer à des produits chimiques, dont l'isocyanurate de
triglycidyle, reconnu par l'État de Californie pour provoquer le cancer, des anomalies congénitales
ou d'autres problèmes de reproduction. Pour plus d'informations, visitez le site
www.P65Warnings.ca.gov.

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SMO High-Performance Ovens
220 – 240 Voltage
Part Number (Manual): 4861777
Revision: June 22, 2020
Sheldon Part ID Numbers:
Model SMO10HP-2 SMO28HP-2
Part ID SLFHP1022-H SLFHP2822-H
The Part ID denotes the specific build version of the model.
SHEL LAB is a brand of Sheldon Manufacturing, INC, an ISO 9001
certified manufacturer.
Safety Certifications
These units are CUE listed by TÜV SÜD America 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.
The units have been tested to the following requirements:
CAN/CSA-22.2 No. 61010-1:2012
CAN/CSA-C22.2 No. 61010-2-010:2015
UL 61010-1:2012
UL 61010-2-010:2015
EN 61010-1:2010
EN 61010-2-010:2014

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TABLE OF CONTENTS
INTRODUCTION .................................................................................................................................................5
Read this Manual....................................................................................................................................................................5
Safety Considerations and Requirements ......................................................................................................................5
Contacting Assistance ..........................................................................................................................................................6
Manufacturing Warranty ......................................................................................................................................................6
Engineering Improvements .................................................................................................................................................6
Reference Sensor Device .................................................................................................................................................... 7
RECEIVING YOUR UNIT.....................................................................................................................................9
Inspect the Shipment.............................................................................................................................................................9
Orientation Images .............................................................................................................................................................. 10
Record the Data Plate Information.................................................................................................................................. 12
INSTALLATION ................................................................................................................................................. 13
Hardwire Requirement........................................................................................................................................................ 13
Installation Procedure Checklist ...................................................................................................................................... 13
Required Ambient Conditions........................................................................................................................................... 14
Required Clearances........................................................................................................................................................... 14
Power Source Requirements ............................................................................................................................................ 15
Power Feed Wiring............................................................................................................................................................... 16
Lifting and Handling ............................................................................................................................................................ 16
Leveling....................................................................................................................................................................................17
Install the Oven ......................................................................................................................................................................17
Installation Cleaning and Disinfecting ............................................................................................................................17
Shelving Installation............................................................................................................................................................. 18
GRAPHIC SYMBOLS......................................................................................................................................... 19
CONTROL OVERVIEW ..................................................................................................................................... 21
OPERATION ..................................................................................................................................................... 23
Operating Precautions....................................................................................................................................................... 23
Theory of Operations ......................................................................................................................................................... 24
Put the Oven into Operation ............................................................................................................................................ 26
Set the High Temperature Limit.......................................................................................................................................27
Setting the Constant Temperature Setpoint ............................................................................................................... 28
Temperature Programs ..................................................................................................................................................... 28
High Temperature Limit Activated ................................................................................................................................. 29
Venting the Exhaust Port................................................................................................................................................... 30
Power Exhaust Blower........................................................................................................................................................ 31
Data Port................................................................................................................................................................................ 33
Changing the Unit of Measurement............................................................................................................................... 33
USER MAINTENANCE..................................................................................................................................... 35
Cleaning and Disinfecting................................................................................................................................................. 35
Door Gaskets and Chamber Integrity ........................................................................................................................... 36
Electrical Components....................................................................................................................................................... 36
Calibrating the Temperature Display .............................................................................................................................37
Unlocking the Temperature Controller .......................................................................................................................... 41
Heating Issues — Diagnostic Questionnaire............................................................................................................... 44
UNIT SPECIFICATIONS................................................................................................................................... 49
Weight..................................................................................................................................................................................... 49
Dimensions............................................................................................................................................................................ 49
Capacity ................................................................................................................................................................................. 50
Air Flow Performance......................................................................................................................................................... 50
Temperature Performance ................................................................................................................................................ 51
Power...................................................................................................................................................................................... 52
PARTS LIST ...................................................................................................................................................... 53

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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. Ensure all end-users are given appropriate training before the unit
begins service.
Keep this manual available for use by all end-users.
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 end-user 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 end-users
in a language they understand.
Intended Applications and Locations
SMOHP forced-air ovens are engineered for constant temperature forced-air drying, curing, and
baking applications in professional, industrial, and educational environments. The units 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 the power feed excessively, step on it, or
place heavy objects on it. A damaged power feed can be a shock or fire hazard. Never use a
power feed if it is damaged or altered in any way.
•Use only approved accessories. Do not modify system components. Any alterations or
modifications to your unit not explicitly authorized by the manufacturer can be dangerous
and will void your warranty.

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INTRODUCTION
CONTACTING ASSISTANCE
Phone hours for Sheldon Customer Support are 6 am – 4:30 pm Pacific Coast Time (west coast of
the United States, UTC -8) Monday – Friday. Please have the following information ready when
calling or emailing Customer Support: the model, serial, and part numbersand Part ID (see page
12).
[email protected]
1-800-322-4897 extension 4
[phone] extension 4
FAX: [phone]
Sheldon Manufacturing, INC.
P.O. Box 627
Cornelius, OR 97113
USA
MANUFACTURING WARRANTY
For information on your warranty and online warranty registration please visit:
•sheldonmanufacturing.com/warranty
ENGINEERING IMPROVEMENTS
Sheldon Manufacturing, Inc. 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.

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INTRODUCTION
REFERENCE SENSOR DEVICE
Must be purchased separately
A reference sensor device is required for calibrating the oven temperature display.
Reference devices must meet the following standards:
•Accurate to at least 0.1°C
The device should be regularly calibrated, preferably by a third party.
Temperature Probes
Use a digital device with a wire thermocouple probe that can be introduced into the unit chamber
through the unit access port. Select a thermocouple suitable for the application temperature you will be
calibrating at.
Why a Probe?
Reference readings taken outside the chamber using wire temperature probes avoid chamber door
openings. Openings disrupt the chamber temperature. Each disruption requires a minimum 1-hour wait
to allow the atmosphere to re-stabilize before continuing.
No Alcohol or Mercury Thermometers
Alcohol thermometers do not have sufficient accuracy to conduct accurate temperature calibrations.
Never place a mercury thermometer in the unit chamber. Always use thermocouple probes.
Temperature
Reference

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INTRODUCTION

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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. Inspect the unit for signs of damage. See the orientation depictions on the next pages as a
reference.
5. The unit should come with an Installation and Operation Manual and a Programming Guide.
6. Verify that the correct number of accessory items has been included.
7. Carefully check all packaging for accessory items before discarding.
Included Accessories
Model Shelves Shelf Clips Leveling Feet
SMO10HP-2
3
12 Clips
4
SMO28HP-2
6
24 Clips
4
Shelves
SMO10HP-2 SMO28HP-2

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SMO28HP-2
RECEIVING
ORIENTATION IMAGES
Permanent Connect Wire Braid
6 gauge, 6 inches (150 mm)
Exhaust Vent
Intake Vent
Power Panel
(Back)
Accessory
Outlet 6-20R
Fuse Holders for
Accessory Outlet
(2 amps each)
Control Panel
Chamber Ceiling Liner
Temperature Sensor Probes
Door
Gasket
Power Supply
Feed
Shelf Standard Mounting Rail
Access Port – Back of Oven

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RECEIVING
Intake Vent
Exhaust Vent
Control Panel
Chamber Ceiling Liner
Shelf Standard Mounting Rail
Temperature Sensor Probes
SMO10HP-2
Access Port – Back of Oven
Permanent Connect Wire Braid
6 gauge, 6 inches (150 mm)
Power Panel
(Back)
Accessory
Outlet 6-20R
Fuse Holders for
Accessory Outlet
(2 amps each)
Power Supply
Feed
Door Gasket

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RECEIVING
RECORD THE DATA PLATE INFORMATION
The data plate contains the unit model number, serial number, part number, and part ID. Customer
Support will need this information during any support call. Record it below for future reference.
•The data plate is located on the back of the oven, next to the power inlet.
Plate Information
MODEL NO:
SERIAL NO:
PART NO:
PART ID:

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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 PROCEDURE CHECKLIST
For installing the unit in a new workspace location.
Pre-Installation
Check that the required ambient conditions for the unit are met, page 14.
Check that the spacing clearance requirements are met, page 14.
•Unit dimensions may be found on page 49.
Check that a suitable permanent connect electrical power supply is present, page 15.
Install the oven in a suitable workspace location
Review the lifting and handling instructions, page 16.
Install the unit leveling feet, page 17.
Install the oven in its workspace location, page 17.
•The oven may be connected to its power supply after this procedure.
Set up the oven for use
Clean the unit and shelving (recommended), page 17.
Install the shelving, page 18.

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12” (305 mm)
INSTALLATION
REQUIRED AMBIENT CONDITIONS
These units are intended for use indoors, at room temperatures between 15°C and 40°C (59°F and
104°F), at no greater than 80% Relative Humidity (at 25°C / 77°F). Operating outside these conditions may
adversely affect the unit temperature performance.
When selecting a location to install the unit, consider all environmental conditions that can affect its
temperature performance. These include:
•Proximity to other ovens, autoclaves, and any device producing significant radiant heat
•Heating and cooling vents or other sources of fast-moving air currents
•High-traffic areas
•Direct sunlight
REQUIRED CLEARANCES
These clearances are required to provide airflows for ventilation and cooling.
6 inches (152 mm) of clearance is required on the sides of the unit.
12 inches (305 mm) of clearance is required on the back of the unit.
24 inches (620 mm) of headspace clearance is required between the exhaust vent and any
overhead cover or partition if no exhaust venting is connected.
•12 inches (305 mm) of headspace clearance will suffice if the oven exhaust is vented from
the workspace through a duct or other channeling.
Do not place objects on top of the oven. Exception: A power exhaust blower may be mounted on the
top exhaust vent.
The chamber access port is located on the back of the oven. Leave sufficient clearance for end-
users to safely access this port.
24” (610 mm)
12” (305mm)
6” (152 mm) Fan
Access Port
6” (152
)
6” (152 mm)
Door Swing
Venting Duct Attached
6” (152 mm)
6” (152 mm)
Hot Exhaust

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INSTALLATION
POWER SOURCE REQUIREMENTS
When selecting a location for the oven, verify that each of the following requirements is satisfied:
Power Supply: The power supply must meet the power requirements listed on the unit data plate.
•These units are intended for 220 – 240 volt, 50/60 Hz applications at the following
amperages:
Model Amperage Model Amperage
SMO10-HP-2 26 SMO28-HP-2 50
•The power source must be single phase and protective earth grounded.
•The power source must conform to all national and local electrical codes.
•The unit may be damaged if the supplied voltage varies by more than 10% from the data
plate rating.
•Use a separate circuit to prevent loss of the unit due to overloading or circuit failure.
Switch or circuit breaker: A switch or circuit-breaker must be used in the building installation to
protect against overcurrent conditions. The recommended circuit-breakers are:
oSMO10HP-2 30 amps
oSMO28HP-2 60 amps
Power Feed Disconnect: The oven must be positioned so all end-users 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
end-user.
•The disconnect must be marked as the disconnecting device for the equipment.
Accessory Outlet Fuses: The oven is provided with a pair of 2-amp fuses installed adjacent to the
external power receptacle used to power accessory blower fans.
•The fuses protect against overcurrent conditions related to the operation of any attached
exhaust blower.
•If one fuse blows, the outlet will depower. The cause of a blown fuse should be determined
prior to replacing it.
These fuses do not provide protection against overcurrent events associated with major components
of the oven. Overcurrent protection for the oven must be set up in the location power supply external to
the unit. See the circuit breaker requirements.

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INSTALLATION
POWER FEED WIRING
The oven comes provided with an integral 6-inch (150 mm) wire braid consisting of:
•SMO10HP-2 – two 6-gauge hot wires and a 6-gauge earth ground.
•SMO28HP-2 – two 6-gauge hot wires and a 6-gauge earth ground.
The wires for power source connection should be in accordance with the following for all units:
Green/Yellow – Earth; Black – Hot; Black – Hot.
The oven must be earth 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.
LIFTING AND HANDLING
The unit is heavy. Use appropriate lifting devices that are sufficiently rated for these loads. Follow these
guidelines when lifting the unit.
•Lift the unit only from its bottom surface.
•Doors, handles, and knobs are not adequate for lifting or stabilization.
•Restrain the unit 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.

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INSTALLATION
LEVELING
Install the 4 leveling feet in the 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 4 leveling feet so that the leg of each foot
sits inside the unit.
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.
•A qualified technician may now connect the oven to its power source.
INSTALLATION CLEANING AND DISINFECTING
The manufacturer recommends cleaning and disinfecting the shelving and oven chamber prior to
installing the shelving in the chamber. The unit was cleaned at the factory but may have been
exposed to contaminants during shipping.
•Remove all wrappings and coverings from shelving prior to cleaning and installation.
•See the Cleaning and Disinfecting topic in the User Maintenance chapter (page 35) for
more information on how to clean the oven chamber and shelving.
•Do not clean with deionized water.

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INSTALLATION
SHELVING INSTALLATION
Airflow: The horizontal airflow in the chamber moves from the small duct holes in the chamber right
wall, across the shelf space, and into the large holes in the left wall. To maximize airflow, avoid
obstructing the duct holes on either side as much as possible when placing shelves.
Spacing: Space the shelves evenly in the oven chamber to ensure the best possible temperature
uniformity.
1. Install the shelf clips in the slots of the shelf standard mounting rails located on the sides of the
chamber interior, 4 clips per shelf.
a. Squeeze each clip, insert the top tab first, and then the bottom tab using a
rocking motion.
2. Set the shelves on the clips.
a. Verify the shelves are level.
Rocking Motion
Install 4 Shelf Clips
Place the Shelf

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GRAPHIC SYMBOLS
The unit is provided with graphic symbols on its exterior. These identify hazards and adjustable
components as well as important notes in the user manual.
Symbol Definition
Consult the user manual
Consulter le manuel d'utilisation
Indicates adjustable temperature
Indique température réglable
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
Potential shock hazard
Risque de choc électrique
Caution hot surface
Attention surface chaude
Recycle the unit. Do not dispose of in a landfill.
Recycler l'unité. Ne jetez pas dans une décharge.

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SYMBOLS