Shel lab SRI3, SRI3-2 Operation Manual

BOD INCUBATOR

110 – 120 Voltage / 220 – 240 Voltage

Installation - Operation Manual

SRI3 SRI3-2

WARNING: Never use this unit for the growth, cultivation, incubation or storage of fruit flies

(drosophila melanogaster). This unit is not designed for use with fruit flies. Improper use of this
unit, including use with fruit flies, will void any warranty. Other units are specifically manufactured

for fruit fly applications, and you should consult your dealer or the manufacturer in order to
identify another model suitable for your application.

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BOD INCUBATOR

SRI3 110 – 120 Voltage

SRI3-2 220 – 240 Voltage

Part Number (Manual): 4861574

Revision: February 12, 2018

These units are compliant with the following standards for use within an ambient air pressure range
of 22.14 – 31.3 inHg (75 – 106 kPa), with no flammable, volatile, or combustible materials being
heated.

CAN/CSA C22.2 No. 61010-1:2012
CAN/CSA C22.2 No. 61010-2-010:2004 Reaffirmed: 2014-07
UL 61010-1:2012-05
UL 61010A-2-010:2002-03
EN 61010-1:2010
EN 61010-2-010:2014
Supplemented by: UL 61010-2-010:2015

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TABLE OF CONTENTS

INTRODUCTION ........................................................................................................................................................ 5

Read this Manual .................................................................................................................................................................... 5

Safety Considerations and Requirements ...................................................................................................................... 5

Contacting Assistance .......................................................................................................................................................... 6

Engineering Improvements.................................................................................................................................................. 6

Reference Sensor Device .................................................................................................................................................... 7

RECEIVING YOUR UNIT ........................................................................................................................................... 9

Inspect the Shipment ............................................................................................................................................................. 9

Orientation Photo ................................................................................................................................................................. 10

Recording Data Plate Information .................................................................................................................................... 11

INSTALLATION ......................................................................................................................................................... 13

Installation Checklist ........................................................................................................................................................... 13

Required Ambient Conditions ........................................................................................................................................... 14

Required Clearances ........................................................................................................................................................... 14

Power Source Requirements ............................................................................................................................................ 15

Lifting and Handling ............................................................................................................................................................ 16

Leveling ................................................................................................................................................................................... 16

Install Incubator in Location .............................................................................................................................................. 16

Adjust Shelves ........................................................................................................................................................................ 17

Deionized and Distilled Water .......................................................................................................................................... 18

Installation Cleaning and Disinfection ........................................................................................................................... 18

GRAPHIC SYMBOLS ................................................................................................................................................ 19

CONTROL PANEL OVERVIEW ............................................................................................................................... 21

OPERATION.............................................................................................................................................................. 23

Theory of Operation ........................................................................................................................................................... 23

Put the Incubator into Operation .................................................................................................................................... 24

Set the Temperature Set Point ........................................................................................................................................ 25

Set the Over Temperature Limit ...................................................................................................................................... 26

Loading Samples ..................................................................................................................................................................27

Accessory Compatibility and Power Outlet ..................................................................................................................27

Condensation and the Dew Point .................................................................................................................................. 28

USER MAINTENANCE ............................................................................................................................................. 29

Cleaning and Disinfecting ................................................................................................................................................. 29

Minimizing Contamination Exposure ............................................................................................................................. 30

Electrical Components ....................................................................................................................................................... 30

Refrigeration and Defrosting............................................................................................................................................. 31

Calibrate the Temperature display ................................................................................................................................ 34

UNIT SPECIFICATIONS .......................................................................................................................................... 39

Weight ..................................................................................................................................................................................... 39

Dimensions ............................................................................................................................................................................ 39

Capacity ................................................................................................................................................................................. 39

Shelf Capacity by Weight .................................................................................................................................................. 40

Temperature ......................................................................................................................................................................... 40

Power ...................................................................................................................................................................................... 40

PARTS LIST ................................................................................................................................................................ 41

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INTRODUCTION

Thank you for purchasing a SHEL LAB product. 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 for you 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.

Intended Applications and Locations

These incubators are intended for professional, industrial, or educational BOD applications at a
constant temperature. The incubators are not designed for use in hazardous or household locations.

Power

Your unit and its recommended accessories are designed and tested to meet strict safety
requirements.

• The unit is designed to connect to a power source using the specific power cord type

shipped with the unit.

• Always plug the unit power cord into a protective earth grounded electrical outlet

conforming to national and local electrical codes. If the unit is not grounded properly, parts
such as knobs and controls can conduct electricity and cause serious injury.

• Do not bend the power cord excessively, step on it, or place heavy objects on it.

• A damaged cord can be a shock or fire hazard. Never use a power cord 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 Technical Support are 6 am – 4:30 pm Pacific Coast Time (west coast of
the United States, UTC -8), Monday through Friday. Please have the following information ready
when calling or emailing Technical Support: the model number and the serial number (see page 11).

EMAIL: [e-mail]
PHONE: [phone] extension 4, or [phone]
FAX: [phone]

Sheldon Manufacturing, INC.
P.O. Box 627
Cornelius, OR 97113

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.

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Temperature

INTRODUCTION

REFERENCE SENSOR DEVICE

Optional

Must be purchased separately

A reference sensor device is required for calibrating the unit 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 Probe

Use a digital device with a wire thermocouple probe that can be introduced into the unit chamber
through the door space. Select thermocouples suitable for the application temperature you will be
calibrating at.

Why Probes?

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.

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 depiction on the next page as a

reference.

5. The unit should come with an Installation and Operation Manual.

6. Verify that the correct number of accessory items has been included.

7. Carefully check all packaging for accessory items before discarding.

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Figure

Control Panel

Temperature Probe

Wire Shelf, 1 of 2

Chamber Door

Incubation
Door Gasket

RECEIVING YOUR UNIT

ORIENTATION PHOTO

1: SRI3/SRI3-2

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Chamber

RECEIVING YOUR UNIT

RECORDING DATA PLATE INFORMATION

The data plate contains the unit model number and serial number. Tech Support will need this
information during any support call. Record it below for future reference.

• The data plate is located near the power cord on the back of the unit.

Model Number

Serial Number

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RECEIVING YOUR UNIT

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INSTALLATION

INSTALLATION CHECKLIST

For installing the unit in a new workspace location.

Pre-Installation

 Check that the required ambient conditions and ventilation spacing for the incubator

are met, page

• Unit dimensions may be found on page 39.

 Check that a suitable electrical outlet and power supply is present, page 15.

14.

Install the Incubator in a suitable location

 Review the lifting and handling instructions, page 16.

 Install the incubator in its workspace location, page 16.

 Make sure the incubator is level, page 16.

Set up the Incubator for use

 Verify that all packaging has been removed from the incubator shelving and

incubation chamber. Adjust the shelving positions if need be, page

17.

 Clean and disinfect the incubator and shelving accessories that will be placed in

the incubation chamber, page

17.

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2.5” (60 mm)

4” (100 mm)

4” (100 mm)

Leave sufficient room in

INSTALLATION

REQUIRED AMBIENT CONDITIONS

When selecting a location to install the unit, consider all environmental conditions that can adversely
impact its temperature performance. These include:

• Proximity to ovens, autoclaves, and any device that produces significant radiant heat

• Heating and cooling vents or other sources of fast-moving air currents

• High-traffic areas

• Direct sunlight

These units are built for use indoors at room temperatures between 15°C and 30°C (59°F and 86°F), at
no greater than 80% Relative Humidity (at 25°C / 77°F). Operating outside these conditions may
adversely affect the unit temperature performance.

REQUIRED CLEARANCES

These clearances are required to provide air flows for ventilation and cooling.

4 inches (100 mm) of clearance is required on the sides and back.

2.5 inches (60 mm) of headspace clearance is required between the top of the unit and any

overhead partitions.

front of the unit for the
door to swing freely.

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INSTALLATION

POWER SOURCE REQUIREMENTS

When selecting a location for the unit, verify each of the following requirements is satisfied.

Power Source

The power source for the unit must match the voltage and the amperage requirements listed on the
unit data plate. These units are intended for 110 - 120V 50/60 Hz (SRI3) or 220 – 240V 50/60 Hz
(SRI3-2) applications at the following amperages:

SRI3 SRI3-2

5.0 Amps 3.5 Amps

• Supplied voltage must not vary more than 10% from the data plate rating. Damage to the

unit may result if the supplied voltage varies more than 10%.

• The wall power source must be protective earth grounded.

• Use a separate circuit to prevent loss of the unit due to overloading or circuit failure.

• The wall power source must conform to all national and local electrical codes.

Power Cord

The unit must be positioned so that all end-users can quickly unplug the power cord in the event of
an emergency.

• The SRI3 is provided with an integral 120V, 15 Amp, NEMA 5-15P, 8ft (2.5m) power cord.

• The SRI3-2 is provided with an integral 220V, 16 Amp, Euro CEE 7/7, 8ft (2.5m) power cord.

Circuit Breaker: The unit is provided with an integral circuit breaker to protect against overcurrent
conditions.

• Always determine the cause of an overcurrent event before resetting a tripped circuit

breaker.

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INSTALLATION

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.

LEVELING

The unit must be level and stable for safe operation.

INSTALL INCUBATOR IN LOCATION

Install the unit in a workspace location that meets the criteria discussed in the previous entries of the
Installation section.

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2. Install the right

3. Install the left side

1. Tilt the shelf at roughly

INSTALLATION

ADJUST SHELVES

Note: The form factor of the shelves may vary slightly by year of production.

The unit ships with its shelves installed in the incubation chamber. Tape, foam, and other packing
dunnage is used to secure the shelves during transit and prevent damage to the chamber interior.

1. Remove all shipping materials from the shelving.

Optional: Shelf Adjustment

Move the shelves as needed for your application.

60° up or down when
moving to avoid
scraping the chamber
walls.

side mounting
prongs first.

mounting prongs last.

Figure 2: Shelf Installed

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INSTALLATION

DEIONIZED AND DISTILLED WATER

Do not use deionized water to clean the chamber even if it is readily available in your laboratory

environment. Use of deionized water may corrode metal surfaces and voids the warranty. Sheldon
Manufacturing recommends the use of distilled water in the resistance range of 50K Ohm/cm to 1M
Ohm/cm, or a conductivity range of 20.0 uS/cm to 1.0 uS/cm, for cleaning applications.

INSTALLATION CLEANING AND DISINFECTION

The manufacturer recommends cleaning the shelving and unit chamber prior to installation of 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. Do not clean with deionized water.

Please see the Cleaning and Disinfection procedure on page 29 of the User Maintenance section
for information on how to clean and disinfect without damaging the unit and its components.

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GRAPHIC SYMBOLS

Your incubator comes provided with graphic symbols on its exterior surfaces. These identify hazards
and the function of the adjustable components, as well as important notes in the user manual.

Symbol Definition

Consult the user manual.
Consulter le manuel d'utilisation

Temperature display
Indique l'affichage de la température

Over Temperature Limit system
Thermostat température limite contrôle haute

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

Adjusts UP and DOWN
Ajuster le haut et vers le bas

Manually adjustable
Indique un réglage manuel

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

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GRAPHIC SYMBOLS

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CONTROL PANEL OVERVIEW

Power Switch

The power switch controls all power to the unit and its systems. Power is
supplied when the switch is illuminated and in the ( I ) ON position.

Heating Activated

The Heating indicator light illuminates when power is routed to the incubator
heating element. During normal operations, the green light will flicker on and
off almost continually.

Incubator Temperature Display

The temperature display shows the current incubator air temperature,
accurate to 0.1°C. The Up and Down buttons are used to navigate to the
temperature set point and calibration adjustment display modes. The display
blinks continually while in its set point or calibration adjustment modes,
preceded by an “SP” for Set Point or “C O” for calibration offset.

Over Temperature Limit

This graduated dial sets the heating cut off point for the OTL temperature limit system. The OTL
system prevents unchecked heating of the chamber in the event of a failure of the main digital
controller. For more details, please see the Over Temperature Limit System description in the
Theory of Operations (page 23).

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CONTROL PANEL OVERVIEW

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OPERATION

THEORY OF OPERATION

Refrigerated incubators are engineered to provide constant temperature incubation environments
suitable for BOD applications. The unit can obtain a stable, uniform temperature in its chamber,
ranging from 0°C up to 40°C.

Achieving and Maintaining the Temperature Set Point

When the unit is powered, its refrigeration compressor runs continuously. The chamber temperature
controller is wired to a solid-state temperature probe located in the chamber airstream on the chamber
back wall. When the controller detects that the chamber temperature has dropped below the set point,
it pulses power to a heating element. The element is located adjacent to the compressor chiller coil in
an air recirculation duct at the bottom of the unit.

The processor employs proportional-integral-derivative analytical feedback-loop functions when
measuring and controlling the chamber air temperature. 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 that difference. The
integral function slows the rate of pulses when the temperature nears the set point to avoid
overshooting.

A circulation fan provides even air distribution throughout the chamber and plays an important role in
maintaining temperature uniformity around the shelf space.

Temperature Low Limit Cutoff

The refrigeration system comes with a cut off limit set at 1°C. This helps prevent the chamber
temperature from dropping below freezing and endangering samples and fluid-filled sample containers
in the chamber.

The Over Temperature Limit System (OTL)

The OTL is a backup mechanical heating control system that operates independently of the
microprocessor controller. When set, the OTL prevents runaway heating in the event of a failure of
the main temperature control system or an external heat spike by rerouting power away from the
heating element.

The system consists of a mechanical thermostat control wired by a fluid capillary to an independent
hydrostatic temperature probe located on the back wall of the incubation chamber. The OTL is set
by the end-user at approximately 1°C above the current chamber temperature when operating
stabilized at your application temperature.

Because of its nature as a cutoff and its lack of PID analytics, the OTL cannot deliver the same
degree of temperature stability and measurement precision as the digital display and controls. The
OTL System should only be used as a means of heating regulation for the incubation chamber until
samples can be safely transferred to another incubator.

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OPERATION

PUT THE INCUBATOR INTO OPERATION

Putting the incubator into operation in a new workspace environment requires an 8-hour period for
the unit to come up to and stabilize at temperature prior to loading the incubation chamber with
samples. During this period the incubator must be powered with the chamber door closed. Allowing
time for stabilization helps protect samples. It is also necessary for the optional temperature display
accuracy verification procedures, as well as any resulting calibration.

Perform the following steps and procedures to prepare the incubator for use each time it is installed
in a new workspace environment:

1. Plug the power cord into the workspace supply outlet

2. Place the Power switch in the ON ( I ) position

3. Perform the following Operation procedures in order:

Optional: Set the Temperature Set Point, page 25.

• The incubator comes from the factory set to 20°C.

Required: Allow the incubator to thermally stabilize by operating sealed and
undisturbed for 8 hours before continuing.

Set the Over Temperature Limit, page 26

Load the Chamber, page 27

End of procedure

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Set Temperature Set Point

Initial Set Point

New Set Point

Point

OPERATION

SET THE TEMPERATURE SET POINT

The incubator comes from the factory with a set point of 20°C. Perform the steps below to change

the set point to your process or application temperature.

1

Turn the OTL dial clockwise to its max setting, if not already
set at max.

• This prevents the heating cutoff system from interfering

with this procedure.

2

Briefly push and release either of the temperature arrow
buttons to activate the temperature set point adjustment
mode.

• The display will briefly flash the letters “SP”, then show

the flashing, adjustable temperature set point.

Set Point

Adjustment Mode

Note: The display will automatically exit the adjustment mode
after 5 seconds of inactivity, with the last shown set point
value saved.

3

Adjust the set point to your application temperature using the
Up or the Down arrow keys.

4

Wait 5 seconds after entering the set point.

• The display will stop flashing, and the set point is

now saved in the controller.

• The chamber will now automatically heat or cool to

match your set point.

• The display will revert to showing the current

chamber air temperature.

Heating to New Set

5

See the Set the OTL procedure on page 26 for how to set the OTL
system once the incubation chamber has stabilized at your application
temperature set point and after you have performed any display
verifications or calibrations.

Note: When putting the unit into operation in a new location, allow the
incubator to run 8 hours prior to setting the OTL.

End of Procedure

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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

Note: Test the OTL system at least once per year for functionality.

SET THE OVER TEMPERATURE LIMIT

The incubator must be operating at your incubation application temperature and must be stable for at least
1 hour prior to setting the OTL. Allow the unit to operate for at least 8 hours prior to setting the OTL when
first placing it into operation.

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
incubator air 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. Check if any powered accessories in the incubation chamber are generating
heat. If you find no sources of external or internal temperature fluctuations, contact Technical Support or
your distributor for assistance.

• This sets the OTL cutoff threshold nearer

to the current incubator air temperature.

End of procedure

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OPERATION

L

OADING SAMPLES

The manufacturer strongly recommends waiting at least 8 hours after putting the incubator in
operation before loading samples in the chamber. This safeguards samples against temperature
instability. The samples should by placed at least 1 inch (25 mm) away from the chamber walls.
Proper spacing allows for maximum air circulation and a higher degree of temperature uniformity.

ACCESSORY COMPATIBILITY AND POWER OUTLET

Outlets

The SRI3 is provided with 2 power outlets inside the chamber. Do not attach powered equipment
drawing more than 1 amp from both outlets.

The SRI3-2 is provided with 1 power outlet inside the chamber. Do not attach powered equipment
drawing more than 1 amp from the outlet.

SRI3 SRI3-2

110 – 120 Volt 220 – 240 Volt

Accessories

Verify any powered accessory equipment used inside the chamber can safely and effectively
operate within your selected temperature range. Powered equipment, such as stirrers or shakers,
can generate heat sufficient to disrupt the thermal uniformity and stability of the chamber.

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OPERATION

CONDENSATION AND THE DEW POINT

Relative humidity inside the incubation chamber should never be allowed to exceed 80% at 25°C.

Exceeding this threshold will likely result in condensation, possible leaks around the incubator, and
may cause corrosion damage if allowed to continue for any significant length of time.

Condensation takes place whenever the humidity level in the incubation chamber reaches the dew
point. The dew point is the level of humidity at which the air cannot hold more water vapor. The
warmer the air, the more water vapor it can hold.

As the level of humidity rises in an incubation chamber, condensate will first appear on surfaces that
are cooler than the air temperature. Near the dew point, condensate forms on any item or exposed
surface even slightly cooler than the air. When the dew point is reached, condensate forms on nearly
all exposed surfaces.

Managing condensation primarily depends on either lowering the humidity level or increasing the air
temperature in the incubation chamber.

Note: Rising or falling air pressure from the weather will adjust the dew point up and down in small

increments. If the relative humidity in the incubation chamber is already near the dew point,
barometric fluctuations may push it across the dew point threshold.

Note: Thin air at higher altitudes holds less humidity than the denser air found at or near sea level.

If excessive condensate has appeared in the incubation chamber, dry the chamber interior and
check the following.

• Ensure samples on the shelves are evenly spaced to allow for good airflow.

• Ensure the chamber door is closing and latching properly.

• Are frequent or lengthy chamber door openings causing significant temperature disruptions

and chilling the chamber surfaces? If so, reduce the number of openings.

• Are there too many open or “breathable” containers of evaporating sample media in the

chamber? If so, reduce the number of open sample containers.

• Does the ambient humidity in the room exceed the stated operating range of 80% relative

environmental humidity? If so, lower the room humidity.

• Is the incubator exposed to an external flow of cold air such as an air-conditioning vent or a

door to a cooler hallway or adjacent room? Block or divert the air, or reposition the unit.

• Check the door gasket for damage, wear, or signs of brittleness or dryness. Arrange for

replacement of the gasket if damaged or excessively worn.

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USER MAINTENANCE

Warning: Disconnect the unit from its power supply prior to performing maintenance or services.

Avertissement: Débranchez cet appareil de son alimentation électrique avant d'effectuer la maintenance

ou les services.

CLEANING AND DISINFECTING

If a hazardous material or substance has spilled in the unit chamber, immediately initiate your site
Hazardous Material Spill Containment protocol. Contact your local Site Safety Officer and follow
instructions per the site policy and procedures.

• The unit chamber should be cleaned and disinfected prior to first use.

• Periodic cleaning and disinfection are 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.

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USER MAINTENANCE

Disinfecting

For maximum effectiveness, disinfection procedures are typically performed after cleaning. Keep the
following points in mind when disinfecting the unit.

• Turn off and disconnect the unit to safeguard against electrical hazards.

• Disinfect the unit 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.

• Gas concentrations from evaporating disinfecting agents can inhibit growth or cause

metabolic symptoms in microbiological sample populations. Make sure that chlorines,
quaternary ammonias, or any other overtly volatile disinfecting agents have been rinsed or
otherwise removed from the chamber surfaces, prior to placing samples in the chamber.

When disinfecting external surfaces, use disinfectants that will not damage painted metal, glass, and
plastic.

MINIMIZING CONTAMINATION EXPOSURE

The following are suggestions for minimizing exposure of the incubation chamber to potential
contaminants.

• Maintain a high air quality in the laboratory workspaces around the chamber.

• Avoid placing the unit near sources of air movement such as doors, air vents, or high traffic

routes in the workspace.

• Minimize the number of times the chamber door is opened during normal operations.

• Periodically, inspect the door latch, trim, catch, and gaskets for signs of deterioration.

ELECTRICAL COMPONENTS

Electrical components do not require maintenance. If the incubator fails to operate as specified,
please contact Technical Support or your distributor for assistance (please see page 6).

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Defrost Thermostat
Heating Element

Refrigeration Coil

USER MAINTENANCE

REFRIGERATION AND DEFROSTING

The refrigeration compressors of most home refrigerators run periodically in order to maintain an
average chamber temperature centered on the thermostat setting. This results in temperature
oscillations of up to 2° or 3°C and reflects the fact that affordable refrigeration compressors cannot
provide the high degree of temperature stability needed for laboratory applications — at least not
without assistance.

To counteract this instability, refrigeration compressors in the SRI family of incubators and plant
growth chambers run continually to provide constant chilling. At the same time, precise applications

of heat maintain thermal stability in the incubation or cultivation chamber to approximately ±0.5°C.

Freezing and Defrosting

Air is chilled in the chamber by blowing over a refrigeration coil. The surface temperature of the coil
may dip below freezing. This happens frequently when the unit is run toward the low end of its
performance range. At these temperatures, humidity in the air will condense and freeze on the coil.

Figure 3: Refrigeration Coil and Heating Element

To counteract this, a defrost thermostat checks the temperature of the coils for 20 minutes, once
every 12 hours. If the coil surface temperature is cool enough for ice to form during the 20-minute
interval, the defrost thermostat deactivates the compressor. This allows heat from the nearby heating
element to melt the ice on the coil without having to compete with the chilling flow of coolant fluid
through the coil. The defrost thermostat reactivates the compressor when the surface temperature
rises above the defrost trigger set point or when the 20-minute interval comes to an end.

If the incubator is running at the low end of its temperature range, defrosting can result in short-lived
but significant heat spikes in the unit incubator. This may preclude its use in biological oxygen
demand studies below 20°C.

31 | Page

USER MAINTENANCE

Factors in Ice Build Up

Incubators used for biologic oxygen demand studies and other closed-container applications will
generally require infrequent and very short defrost runtimes. However, runtimes may be prolonged
and occur more frequently if the incubator is used in a high humidity environment with the door
opened several times a day or left open for prolonged periods. Units with open media containers,
water pans, and other sources of evaporating water in the incubation chamber may also experience
significant ice buildup. This will necessitate long runs of the auto defrost cycle twice a day. If the
humidity is high enough and the temperature is set toward the low end of the unit performance
range, humidity can overwhelm the defrosting cycle, and significant ice accumulation may occur on
the coil.

Figure 4: Ice on the Cooling Coil

Loss of Efficiency

As ice accumulates, it insulates the heat-transporting coolant fluid within the coil, driving an
increasing loss of chilling efficiency. This may even cause false high temperature readings on the
defrost thermostat and prevent the system from recognizing that a defrost run is needed. When this
occurs, the first sign of trouble is often a rise in the chamber temperature, even though the main
control temperature set point has not been changed.

Units with heavy accumulations of ice on the cooling coil must be manually defrosted by shutting
down the unit for a 24-hour period. This provides sufficient time for the ice to melt. See the next
page for manually defrosting the chamber.

Forcing the Defrost Cycle

For units that are icing up from high humidity and low temperature settings, the manufacturer offers a
defrosting system retrofit kit that replaces the defrost thermostat installed at the factory. The retrofit
kit automatically turns off the compressor for 10 minutes every 12 hours, regardless of the
temperature on the coil surface. Please contact your distributor or Technical Support if you have any
questions.

32 | Page

Figure

Switch
the back of the incubator

USER MAINTENANCE

Turning Off the Automatic Defrost

Deactivating the defrost thermostat will result in ice accumulation and a
gradual loss of cooling efficiency. Incubators used for BOD and other
closed-container applications with the defrost thermostat turned off will
likely require manual defrosting every 6 months. Units with open sources
of water evaporation and the defrost thermostat shut off will require
manual defrosting every 2 to 3 months. The exact interval depends on
the environmental humidity, temperature setting, and the amount of
evaporation taking place inside the incubation chamber.

Manual Defrosting

5: Defrost Cycle

– Top left side on

Carry out the following steps to manually defrost the unit:

1. Unplug the incubator, open the chamber door, and allow the unit to stand undisturbed with

the door open for 24 hours.

2. Wipe up any condensate that forms in the chamber as well as any water around the

incubator after 24 hours have elapsed.

3. Close the chamber door, plug the incubator power cord into the wall power source, and

place the unit back into operation.

The Low Limit Dial (Prevents Freezing Temps)

The unit comes with a Low Limit Control System set at the factory to turn
off the refrigeration compressor when the incubator air temperature falls
to just above freezing (0°C). Freezing and sub-freezing temperatures risk
damaging plant samples as well as fluid-filled BOD sample containers.

If you wish to adjust the limit setting, please contact Technical Support
(page 6). The unit is not intended to be operated at freezing or sub­freezing temperatures. Setting the low set limit at or below 0°C voids the
manufacturing defect warranty.

Figure 6: Low Set Limit Dial

(Bottom Left of Unit, Back)

33 | Page

Non-stick tape

1. Introduce the reference device

DEFROST

2 inches (50 mm)

USER MAINTENANCE

CALIBRATE THE TEMPERATURE DISPLAY

Note: Performing a temperature display calibration requires a temperature reference device. Please

see the Reference Sensor Devices entry on page 7 for device requirements.

Temperature calibrations are performed to match the incubator temperature display to the actual air
temperature in the incubation chamber. The actual air temperature is supplied by a calibrated
reference device. Calibrations compensate for long-term drifts in the microprocessor controller as
well as those caused by the natural material evolution of the sensor probe in the heated and chilled
incubation space. Calibrate as often as required by your laboratory or production protocol, or
regulatory compliance schedule. Always calibrate to the standards and use the calibration setup
required by your industry requirements or laboratory protocol.

Suggested Single Point Offset Calibration Setup

thermocouple sensor probe
through the chamber door space.
The door must be able to close
and latch fully.

2. Place the probe inside the
cultivation chamber with the sensor
head as close to the geometric
center of the chamber as possible.
The probe head must be at least 2
inches (50 mm) from the surface of
the shelving and walls to prevent
heatsinking. Secure the probe
heads in position using the non-stick
tape.

3. The incubator chamber door must
be closed and latched. Use the tape
to seal any exterior gaps caused by
the probe wires.

4. Place the Defrost switch on the
back of the unit in the “O” Off
position for the duration of the
calibration procedure. The defrost
cycle can impact the chamber
temperature sufficiently to result in
an inaccurate calibration.

recommended

clearance

34 | Page

Begin Calibration

Suggested Temperature Calibration

Required temperature stability period operating undisturbed with the incubator door closed

Start

USER MAINTENANCE

5. Temperature Stabilization

The incubator air temperature must stabilize in order to perform an accurate calibration.

• Allow the incubator to operate undisturbed with the door shut for at least 8 hours when first

putting the unit into operation in a new environment.

• To be considered stabilized, the incubator chamber must operate at your calibration

temperature for at least 1 hour with no fluctuations of ±0.5°C or greater.

Fluctuations

(Exaggerated)

1

Once the incubator temperature has stabilized, compare the reference
device and incubator temperature display readings.

• 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 air
temperature. The Temperature Calibration procedure

is now complete.

-Or-

• If a difference falls outside of your protocol range, advance

to step 2.

2

A display calibration adjustment must be entered to match the display to
the reference device. See next step.

Reference Device



Reference Device

Continued on next page



35 | Page

Temperature Calibration Continued

Reference Device

USER MAINTENANCE

3

Place the display in temperature calibration mode.

a. Press and hold both the UP and DOWN temperature

buttons simultaneously for approximately 5 seconds.

b. Release the buttons when the temperature display

shows the letters “C O”. The display will begin flashing
the current temperature display value.

Note: If an arrow key is not pressed for 5 seconds, the display will
cease flashing, and store the last displayed number as the new
current chamber temperature value.

4

Use the Up and Down buttons to adjust the current
display temperature value until it matches the reference
device temperature reading.

5

6

After matching the display to the reference device, wait 5
seconds.

• The temperature display will cease flashing and

store the corrected chamber display value.

• The incubator will now begin heating or cooling in

order to reach the set point with the corrected
display value.

Allow the incubator to sit for at least 1 hour undisturbed to
stabilize after the incubator has achieved the corrected

temperature set point.

• Failure to wait until the incubator is fully stabilized

will result in an inaccurate reading.

Continued on next page

Cooling to Set Point

Set Point Achieved

36 | Page





DEFROST

USER MAINTENANCE

Temperature Calibration Continued

7

Compare the reference device reading with the chamber temperature
display again.

• If the reference device and the chamber temperature display

readings are the same or the difference falls within the range of
your protocol, the incubator is now calibrated for temperature.

-Or-

• See the next step if the readings fail to match or fall outside of

your protocol range.

8

If the two readings are not the same, and the difference still falls outside
the acceptable range of your protocol, repeat steps 3 – 7 up to two more
times.

• Three calibration attempts may be required to successfully

calibrate units that are more than ±2°C out of calibration.

Reference Device

Reference Device

9

If the temperature readings of the incubator temperature display and the
reference device still fall outside your protocol after 3 calibration
attempts, contact your distributor or technical support for assistance.

The manufacturer recommends turning the Defrost cycle back on after
completing the calibration.

End of procedure

37 | Page

USER MAINTENANCE

38 | Page

UNIT SPECIFICATIONS

The SRI3 Incubator is a 115 voltage unit; the SRI3-2 is a 230 voltage unit. Please refer to the unit
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 Unit Weight

SRI3 110 lb / 50 kg 93.0 lb / 43.0 kg

SRI3-2 125 lb / 57 kg 108.0 lb / 49.0 kg

DIMENSIONS

Inches

Model Exterior W × D × H Interior W × D × H

SRI3 24.0 x 21.0 x 33.8 in 16.0 x 14.0 x 22.5 in

SRI3-2 24.0 x 21.0 x 33.8 in 16.0 x 14.0 x 22.5 in

Millimeters

Model Exterior W × D × H Interior W × D × H

SRI3 610 x 534 x 858 mm 407 x 356 x 572 mm

SRI3-2 610 x 534 x 858 mm 407 x 356 x 572 mm

CAPACITY

Model Cubic Feet Liters

SRI3

SRI3-2

2.3 67.0

2.3 67.0

39 | Page

UNIT SPECIFICATIONS

SHELF CAPACITY BY WEIGHT

Model Per Shelf Total

SRI3 10.0 lb / 4.5 kg 20.0 lb / 9.0 kg

SRI3-2 10.0 lb / 4.5 kg 20.0 lb / 9.0 kg

TEMPERATURE

Model Range Uniformity Stability

SRI3

SRI3-2

Ambient 0°C to 45°C ± 0.5° ± 0.2°C
Ambient 0°C to 45°C ± 0.5° ± 0.2°C

POWER

Model AC Voltage Amperage Frequency

SRI3

SRI3-2

115 5.0 50/60 Hz

230 3.5 50/60 Hz

40 | Page

PARTS LIST

Ordering Parts and Consumables

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 [phone]. Please have the model number and serial number of the incubator
ready, as Tech Support will need this information to match your unit with its correct part.

41 | Page

P.O. Box 627

Cornelius, OR 97113

USA

[e-mail]

sheldonmanufacturing.com

1-800-322-4897

[phone]

FAX: [phone]