Thermo Scientific 3950 Operating instructions

Model 3950 and 3951
Forma 29 cu. ft. Reach-In Incubator
Operating and Maintenance Manual 7003950 Rev. 21
Visit us online to register your warranty
www.thermoscientific.com/labwarranty

Thermo Scientific
Manual Number 7003950
21 29318//IN-4272 12/14/12 Clarified usage on exploded drawing 3950-08-4 list ccs
20 28773/IN-4231 10/8/12 Updated Figure 1-6 to current ccs
19 28267 2/20/12 Added cautions for running high RH or temps ccs
18 24921/IN-3939 2/16/12 Removed accessory list - pg 7-2 ccs
17 27292/IN-4073 9/29/11 Updated component mount assy drawing - spacers (pg 8-7 & 8-8) ccs
16 27398/IN-4107 9/13/11 Updated float sw 360171 to 1900471 assy with pins 370397 - pg 8-1 ccs
15 25421/IN-3917 3/25/09 Corrected Mode Menu list pg 1-3 ccs
14 24975 10/31/08 Updated water specs on page 1-6 ccs
Preface
Reach-In Incubator i
* T/C is a thermal conductivity sensor.
** All units are 50/60 Hz.
Covered
Models CO2Sensor* Voltage**
3950 T/C 100-120
3951 T/C 200-230

Thermo Scientificii Reach-In Incubator
Preface
Important Read this instruction manual. Failure to read, understand and follow the instructions in this manual
may result in damage to the unit, injury to operating personnel, and poor equipment performance. s
Caution All internal adjustments and maintenance must be performed by qualified service personnel. s
Warning If the incubator is not used in the manner specified in this operating manual, the protection provided
by the equipment design may be impaired. s
Caution When operating this unit under high temperatures and/or relative humidity (RH), caution must be
observed when the unit is shut down, unexpectedly or by choice. Condensate can form on the interior of the
chamber as it cools. This includes the heating element surfaces. Heavy condensate can bridge the ceramic
insulators and cause a temporary electrical short to ground. This electrical circuit is protected by a circuit breaker.
However, to avoid this contingency if these conditions occur, open the door of the unit and allow it to stand
open until the water vapor disperses. s
Material in this manual is for information purposes only. The contents and the product it describes are subject to
change without notice. Thermo Fisher Scientific makes no representations or warranties with respect to this
manual. In no event shall Thermo be held liable for any damages, direct or incidental, arising out of or related to
the use of this manual.
©2000 Thermo Fisher Scientific. All rights reserved.

Thermo Scientific Reach-In Incubator iii
Preface
Important operating and/or maintenance instructions. Read the accompanying text carefully.
Potential electrical hazards. Only qualified persons should perform procedures associated with this
symbol.
Equipment being maintained or serviced must be turned off and locked off to prevent possible injury.
Hot surface(s) present which may cause burns to unprotected skin, or to materials which may be
damaged by elevated temperatures.
Marking of electrical and electronic equipment, which applies to electrical and electronic equipment
falling under the Directive 2002/96/EC (WEEE) and the equipment that has been put on the market
after 13 August 2005.
This product is required to comply with the European Union’s Waste Electrical & Electronic
Equipment (WEEE) Directive 2002/96/EC. It is marked with the WEEE symbol. Thermo Fisher
Scientific has contracted with one or more recycling/disposal companies in each EU Member State
European Country, and this product should be disposed of or recycled through them. Further
information on Thermo’s compliance with this directive, the recyclers in your country and information
on Thermo Scientific products will be available at www.thermofisher .com.
4Always use the proper protective equipment (clothing, gloves, goggles, etc.)
4Always dissipate extreme cold or heat and wear protective clothing.
4Always follow good hygiene practices.
4Each individual is responsible for his or her own safety.

Thermo Scientificiv Reach-In Incubator
Preface
Do You Need Information or Assistance on
Thermo Scientific Products?
If you do, please contact us 8:00 a.m. to 6:00 p.m. (Eastern Time) at:
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Our staff can provide information on pricing and give you quotations. We can
take your order and provide delivery information on major equipment items or make
arrangements to have your local sales representative contact you. Our products are listed on the
Internet and we can be contacted through our Internet home page.
Our staff can supply technical information about proper setup, operation or
troubleshooting of your equipment. We can fill your needs for spare or replacement parts or
provide you with on-site service. We can also provide you with a quotation on our Extended
Warranty for your Thermo Scientific products.
Whatever Thermo Scientific products you need or use, we will be happy to discuss your
applications. If you are experiencing technical problems, working together, we will help you
locate the problem and, chances are, correct it yourself...over the telephone without a service
call.
When more extensive service is necessary, we will assist you with direct factory trained
technicians or a qualified service organization for on-the-spot repair. If your service need is
covered by the warranty, we will arrange for the unit to be repaired at our expense and to your
satisfaction.
Regardless of your needs, our professional telephone technicians are available to assist you
Monday through Friday from 8:00 a.m. to 6:00 p.m. Eastern Time. Please contact us by
telephone or fax. If you wish to write, our mailing address is:
International customers, please contact your local Thermo Scientific distributor.
Sales Support
Service Support
www.unitylabservices.com

Thermo Scientific Reach-In Incubator v
Preface
Warranty Notes
Information You Should Know Before Requesting Warranty Service
•Locate the model and serial numbers. Aserial tag is located on the unit itself.
•For equipment service or maintenance, or with technical or special application inquiries, contact Technical
Services at 1-800-438-4851 or 1-740-373-4763 (USA and Canada). Outside the USA, contact your local
distributor.
Repairs NOT Covered Under Warranty
•Calibration of control parameters. Nominal calibrations are performed at the factory; typically ±1°Cfor
temperature, ±1% for gases, and ±5% for humidity. Our service personnel can provide precise calibrations as
abillable service at your location. Calibration after awarranty repair is covered under the warranty.
•Damage resulting from use of improper quality water, chemicals or cleaning agents detrimental to
equipment materials.
•Service calls for improper installation or operating instructions. Corrections to any of the following
are billable services:
1) electrical service connection
2) tubing connections
3) gas regulators
4) gas tanks
5) unit leveling
6) room ventilation
7) adverse ambient temperature fluctuations
8) any repair external to the unit
•Damage resulting from accident, alteration, misuse, abuse, fire, flood, acts of God, or improper
installation.
•Repairs to parts or systems resulting from unauthorized unit modifications.
•Any labor costs other than that specified during the parts and labor warranty period, which may
include additional warranty on CO2sensors, blower motors, water jackets, etc.

Reach-In Incubator viThermo Scientific
Table of Contents
Installation and Start-Up . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-1
Control Panel Keys, Displays, & Indicators . . . . . . . . . . . . . . . . . . . .1-2
Keypad Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-3
Unit Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-4
Preliminary Cleaning and Disinfecting . . . . . . . . . . . . . . . . . . . . . .1-4
Installing the Shelves . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-5
Leveling the Unit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-5
Attaching the Drain Lines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-5
The Water Supply . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-6
Filling the Humidity Reservoir . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-6
Connecting the Unit to Electrical Power . . . . . . . . . . . . . . . . . . . . .1-7
Connecting the CO2Gas Supply . . . . . . . . . . . . . . . . . . . . . . . . . .1-8
Incubator Start-Up . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-9
Setting the Operating Temperature . . . . . . . . . . . . . . . . . . . . . . . . .1-9
Setting the Overtemp Setpoint . . . . . . . . . . . . . . . . . . . . . . . . . . .1-10
Setting the CO2Setpoint . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-10
Calibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-1
Calibrating the Temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-1
Calibrating the CO2System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-2
Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-1
Disable the ADD WATER Alarm . . . . . . . . . . . . . . . . . . . . . . . . . . .3-1
Turn All Audible Alarms ON/OFF . . . . . . . . . . . . . . . . . . . . . . . . . .3-1
Set an Access Code . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-2
Set a Low Temp Alarm Limit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-2
Enable Temp Alarms to Trip Relay Contacts . . . . . . . . . . . . . . . . . . .3-3
Set Low CO2Alarm Limit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-3
Set High CO2Alarm Limit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-4
Enable CO2Alarms to Trip Relay Contacts . . . . . . . . . . . . . . . . . . . .3-4
Set New Zero No. for New CO2Sensors . . . . . . . . . . . . . . . . . . . . . .3-5
Set New Span No. for CO2Sensors . . . . . . . . . . . . . . . . . . . . . . . . . .3-5
Enable the High Humidity Feature . . . . . . . . . . . . . . . . . . . . . . . . . .3-6
Select a Primary Tank w/ Gas Guard Option . . . . . . . . . . . . . . . . . . .3-6
Disable the Gas Guard System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-7
Set RS485 Address . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-7
Section 1
Section 2
Section 3

vii Reach-In Incubator Thermo Scientific
Alarms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-1
Sensor Fault Alarms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-2
Preventive Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-3
Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5-1
Cleaning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5-1
Cleaning the Glass Doors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5-1
Cleaning the Humidity Reservoir . . . . . . . . . . . . . . . . . . . . . . . . . . . .5-2
Replacing the Power Fuses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5-3
Discarding/Removing Incubator from Service . . . . . . . . . . . . . . . . . .5-3
FactoryOptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6-1
Connect the Remote Alarm Contacts . . . . . . . . . . . . . . . . . . . . . . . . .6-1
Connect the RS485 Interface (P/N 190523) . . . . . . . . . . . . . . . . . . .6-2
Connect Analog Output Boards (P/N 190512, 190543, & 190544) .6-3
CO2Gas Guard (P/N 1900000) . . . . . . . . . . . . . . . . . . . . . . . . . . . .6-4
Connect CO2Gas Supplies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6-5
De-activate Gas Guard . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6-5
Operation of CO2Gas Guard . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6-5
Inner Doors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6-6
Shaker Support Shelves . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6-6
Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7-1
Spare Parts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8-1
Assembly Drawings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8-2
Exploded Parts Drawings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8-3
Electrical Schematics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9-1
Warranty. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10-1
Table of Contents
Section 4
Section 5
Section 6
Section 8
Section 7
Section 9
Section 10

Reach-In Incubator 1-1Thermo Scientific
Section 1 Installation and Start-Up
Figure 1-1. Front View Figure 1-2. Side View
Figure 1-3. BackView
Figure 1-4. Top View

1-2 Reach-In Incubator Thermo Scientific
Section 1
Installation and Start-Up
Figure 1-4. Control Panel Components
Silence - Silences the audible alarm.
Alarm Indicator - Light pulses on/off during an alarm condition in the
cabinet.
Mode Select Switch - Used to select Run, Setpoints, Calibration and
System Configuration Modes.
Message Center - Displays system status.
Mode Select Indicators -
• Run: Run Menu
• Set: Set Points Menu
• Cal: Calibrate Menu
• Config: Configuration Menu
Up and Down Arrows - Increases or decreases the number values, toggles
between choices.
Enter - Stores the value into computer memory.
Heat Indicator - Lights when power is applied to the heaters.
Temp Display – Displays temperature continuously
Scroll for Parameters Arrows - Moves the operator through the choices of
the selected mode.
CO2Inject Indicator - Lights when CO2is being injected into the incu-
bator.
% CO2 Display - Displays CO2percentage continuously.
Control Panel Keys,
Displays,& Indicators

Reach-In Incubator 1-3Thermo Scientific
Section 1
Installation and Start-Up
The Model 3950 Series Reach-In Incubator has four basic modes that
allow incubator setup: Run, Setpoints, Calibration and System
Configuration.
• Run is the default mode during normal operation.
• Set is used to enter system setpoints.
• Calibration is used to calibrate various system parameters.
• Configuration allows for custom setup of various options.
The chart below shows the selections under each of the modes.
Keypad Operation
RUNSETPOINTCALIBRATION CONFIGURATION
Default Mode Temperature Temp Offset Audible
Overtemp CO2 Cal Access Code
CO2 Temp Lo Alarm
Temp Relay
CO2 Lo Alarm
CO2 Hi Alarm
CO2 Relay
CO2 Z & S #'s
RH High On/Off
H20 Alarm On/Off
Tank Select
Gas Guard
RS485 Address
**Base Unit Displays
**Option Displays

Scroll for Parameters Arrows
Steps the operator through the parameters of SET, CAL and CONFIG
Modes. The right arrow goes to the next parameter, the left arrow
returns to the previous parameter.
Up Arrow
Increases or toggles the parameter values that have been selected in the
SET, CAL, and CONFIG Modes.
Enter
Must press Enter key to save to memory all changed values.
Down Arrow
Decreases or toggles the parameter values that have been selected in the
SET, CAL and CONFIG Modes.
Silence Key
Press to silence the audible alarm. See Section 4 for alarm ringback
times.
Caution Units must be installed against a wall or similar structure.
Maintain three-inch clearance behind the incubator for electrical, water
and gas hook-ups. s
Locate the unit on a firm level surface capable of supporting the unit
weight of approximately 500 lbs.
Locate the unit away from doors and windows and heating and air
conditioning ducts.
Warning This incubator weighs approximately 500 lbs. Have sufficient
personnel available when moving. s
Disinfect all interior surfaces with a general-use laboratory disinfectant.
Rinse thoroughly with sterile distilled water, then 70% ethanol. Dry with a
sterile cloth as needed. Disinfect the shelf channels and shelves, then rinse
with distilled water before installing.
Caution Before using any cleaning or decontamination method except
those recommended by the manufacturer, users should check with the
manufacturer that the proposed method will not damage the equipment.
Accidental spills of hazardous materials on or inside this unit are the
responsibility of the user. s
1-4 Reach-In Incubator Thermo Scientific
Section 1
Installation and Start-Up
PreliminaryCleaning and
Disinfecting
Unit Installation

Attaching the Drain Lines
The shelves may be installed at any
level in the incubator. Install a shelf
channel on each side. With the tabs
pointing up, attach the channel by
locating the rivet into a slotted hole,
far end first. Pull the channel toward
the front and slide the front rivet on
the channel into the slotted hole and
press down. Make sure that the
channels are opposite each other so
that the installed shelf will be level.
Place a bubble-type level on a shelf inside the incubator. Adjust the feet as
needed; counterclockwise to lengthen or clockwise to shorten. Level the
unit front-to-back and left-to-right.
Note Drain connections on the back of the unit are shipped capped. If
humidity is not required, the caps should be left on the drains. s
If manual or gravity feed method is used for humidity in the cabinet,
connecting the drains is optional.
If an in-house pure water supply is used to fill the reservoir, it is
recommended that the drains be connected to a floor drain.
Reach-In Incubator 1-5Thermo Scientific
Section 1
Installation and Start-Up
Leveling the Unit
Installing the Shelves
Figure 1-5. Shelf Channel
Back of Unit
1/4” Water Inlet fitting
to 1/4” ID tubing
to in-house water supply
shut-off valve (30 PSIG max.)
Chamber Drain (Overflow) -
3/8” elbow with 3/8” hose barb fitting.
Install with fitting sloping slightly downward.
Condensate Drain -
3/8” fitting
to 3/8” ID hose
Back View
Floor
Figure 1-6. Top View of Fitting Connections

In-house Pure Water Supply
Filling the Humidity
Reservoir
For best operation of the incubator, sterilized distilled, demineralized or de-
ionized water should be used in the humidity reservoir. Water purity
should be in the resistance range of 50K to 1M Ohm/cm, or a
conductivity range of 20.0 to 1.0 uS/cm. Refer to ASTM Standard D5391-
93 or D4195-88 for measuring water purity.
Distillation systems, as well as some types of reverse osmosis water purity
systems, can produce water in the quality range specified. Tap water is not
recommended as it may contain chlorine, which can deteriorate the
stainless steel. Tap water may also have a high mineral content, which
would produce a build-up of scale in the reservoir. High purity or ultra
pure water is not recommended as it is an extremely aggressive solvent and
will deteriorate the stainless steel. High purity water has a resistance of
above 1M to 18M Ohm. Even high purity water can contain bacteria and
organic contaminants. Water should always be sterilized or treated with a
decontaminant, safe for use with stainless steel as well as safe for the
product, prior to being introduced into the humidity reservoir.
Caution Distilled or de-ionized water used in the humidity reservoir must
be within a water quality resistance range of 50K to 1M Ohm/cm to
protect and prolong the life of the stainless steel. Use of water outside the
specified range will decrease the operating life of the unit and may void
warranty. s
The incubator is equipped with a liquid level float switch that detects low
water levels in the humidity reservoir and produces an alarm condition. As
all applications do not require humidity, this alarm can be disabled. To
disable the ADD WATER alarm, see Section 3. If humidity is required in
the current application, press the Silence key on the control panel to mute
the alarm while the humidity reservoir is being filled.
There are three methods for filling the humidity reservoir; an in-house
pure water supply, the manual and the gravity feed methods.
All incubators provide a connection for using an in-house water supply.
Connect a low pressure (not more than 30 PSI) water line, equipped with
a manual shut-off valve, to the inlet fitting on the float valve reservoir. The
1/4” hose connection is located on the rear of the incubator cabinet. With
the water turned on, a float valve inside the incubator regulates the water
level in the humidity reservoir. When the reservoir is full, a 10-second
audible tone is heard and the ADD WATER message no longer displays.
1-6 Reach-In Incubator Thermo Scientific
Section 1
Installation and Start-Up
The Water Supply

This fill system consists of a funnel attached to the side duct sheet and
tubing located inside the incubator. Disinfect the funnel and rinse with
sterile water before using. This funnel may be moved to a preferred
location by unscrewing the well nuts and disconnecting it from the
sidewall. Tighten the nuts after relocation. The holes allotted for funnel
use are slightly larger and in a centralized area. See Figure 1-6.
To fill the reservoir, pour sterile distilled water (approximately 2.5 gallons)
into the funnel. When the float switch trips, a 10-second audible tone
sounds and the ADD WATER message no longer displays. Add 1 gallon
after the 10-second tone is heard.
An optional carboy water fill system is also available. The carboy option kit
includes an instruction sheet that details the installation of the system.
See the serial tag on the side of the unit for electrical specifications or refer
to the electrical schematics at the end of this manual.
Warning Connect the incubator to a grounded, dedicated circuit. The
power cord connector is the mains disconnect device for the incubator.
Position the incubator so the unit can be easily disconnected. s
Plug the provided power cord into the power inlet connector on the back
of the cabinet, then into a grounded, dedicated electrical circuit.
Reach-In Incubator 1-7Thermo Scientific
Section 1
Installation and Start-Up
GravityFeed Method
Figure 1-6. Manual Feed Method with Funnel
Connecting the Unit to
Electrical Power
Manual Method

The Model 3950 Series also has an internal outlet located on the right side
of the interior back wall. The outlet is to provide power (230W maximum)
to accessory equipment. This outlet is not to be used when the temperature
is above 40°C and the RH more than 50%.
Warning High concentrations of CO2gas can cause asphyxiation.
OSHA Standards specify that employee exposure to carbon dioxide in any
8-hour shift of a 40-hour work week shall not exceed the 8-hour time
weighted average of 5000 PPM (0.5% CO2). The short-term exposure
limit for 15 minutes or less is 30,000 ppm (3% CO2). Carbon dioxide
monitors are recommended for confined areas where concentrations of
carbon dioxide gas can accumulate.
This incubator is designed for CO2gas only. Connecting a flammable or
toxic gas could result in a hazardous condition.
Gases other than CO2should not be connected to this equipment. CO2
gas cylinders have a UN1013 label on the cylinder and are equipped with a
CGA 320 outlet valve. Check the gas cylinder for the proper identification
labels. The CO2gas supply being connected to the incubator should be
industrial grade, 99.5% pure. Do not use CO2gas cylinders equipped with
siphon tubes. A siphon tube is used to extract liquid CO2from the
cylinder, which can damage the pressure regulator. Consult with your gas
supplier to ensure that the CO2cylinder does not contain a siphon tube.
Gas cylinders should also be secured to a wall or other stationary object to
prevent them from tipping.
A two-stage CO2pressure regulator is required to be installed on the outlet
valve of the gas cylinder. Input pressure to the incubator must be
maintained at 15 psig (103.4 kPa) for proper performance of the CO2
control system. A single stage CO2pressure regulator will not maintain 15
psig (103.4 kPa) to the incubator as the pressure in the CO2cylinder
decreases; therefore, a two-stage regulator is recommended.
If higher purity CO2is desired inside the incubator (greater than 99.5%
pure), the pressure regulator should be constructed with a stainless steel
diaphragm, along with specifying the purity of the CO2from the gas
supplier. Follow the manufacturer’s instructions to ensure proper and safe
installation of the pressure regulator on the gas cylinder.
Consult your facility safety officer to ensure that the equipment is installed
in accordance with the codes and regulations applicable in your area. s
1-8 Reach-In Incubator Thermo Scientific
Section 1
Installation and Start-Up
Connecting to Electrical
Power (continued)
Connecting the CO2Gas
Supply

Setting the Operating
Temperature
Incubator Start-Up
The CO2gas supply being connected should be industrial grade 99.5%
pure and should not contain siphon tubes. Install a two-stage pressure
regulator at the cylinder outlet. The high pressure gauge at the tank should
have 0-2000 psig range. The low pressure gauge, at the incubator inlet,
should have a 0-30 psig range. Input pressure to the incubator must be
maintained at 15 psig (103.4 kPa), ±5 psig.
Caution Each tank should be connected to one incubator only. s
The incubator has serrated fittings on the back of the cabinet to connect
the gas supply (Figure 1-2). The fitting is labeled CO2 Inlet #1 Tank.
Secure connections with clamps. Check all fittings for leaks.
For units having the CO2Gas Guard option, refer to Section 6.
With the incubator properly installed, connected to power, the humidity
reservoir filled and the unit connected to a gas supply, system setpoints can
be entered. The following setpoints can be entered in Set Mode:
Temperature, Overtemperature and CO2. To enter Set Mode, press the
Mode key until the Set indicator lights. Press the right and/or left arrow
keys until the proper parameter appears in the message display center. See
Chart 1-1 for more detail.
This incubator has an operating temperature setpoint range of 5.0°C above
ambient to 60.0°C. It is shipped from the factory with a temperature
setpoint of 10.0° C. At this setting, all heaters are turned off. To change
the operating temperature setpoint:
1. Press the Mode key until the Set indicator lights.
2. Press the right arrow until “Temp XX.X” is displayed in the message
center.
3. Press up/down until the desired temperature setpoint is displayed.
4. Press Enter to save the setpoint.
5. Press the Mode key until the Run indicator lights for Run mode or
press the right/left arrow keys to go to next/previous parameter.
Caution Any equipment placed inside chamber must be rated for unit
operating temperature and humidity. s
Reach-In Incubator 1-9Thermo Scientific
Section 1
Installation and Start-Up
Connecting CO2Gas
Supply(continued)

Warning The independent overtemp system is designed as a safety to
protect the incubator only. It is not intended to protect or limit the
maximum temperature of the cell cultures or customer’s equipment inside
the incubator if an overtemp condition occurs. s
All Model 3950 Series incubators are equipped with a secondary
temperature monitoring system to monitor the air temperature inside the
cabinet. This system is designed as a safety device to turn off all heaters in
the event of a temperature control failure. The temperature control point
in the incubator will be approximately ±1°C of the overtemp setpoint.
The overtemp setpoint is set by the factory (default) at 40°C. However, the
overtemp can be reset over a range from 0.5°C above the operating
temperature setpoint to 65°C.
If the incubator’s operating temperature setpoint is set above the overtemp
setpoint, the overtemp setpoint will automatically update to 1°C above the
temperature setpoint. It is recommended that the overtemp setpoint be
maintained at 1°C over the operating temperature setpoint.
To set the Overtemp setpoint:
1. Press the Mode key until the Set indicator lights.
2. Press the right arrow until Otemp XX.X is displayed in the message
center.
3. Press the up or down arrow until the desired Otemp setpoint is
displayed.
4. Press Enter to save the setting.
5. Press the Mode key until the Run indicator lights, or press the right or
left arrow to go to the next or previous parameter.
All CO2cells are calibrated at the factory at 37°C, medium humidity and
10% CO2. Therefore, if a temperature setpoint of 37°C has been entered,
the humidity reservoir has been filled and the CO2control is set to run
between 0-10%, the CO2setpoint may be entered immediately. Otherwise,
it is important to allow the unit 12 hours to stabilize at the temperature
setpoint before entering the CO2setpoint.
1-10 Reach-In Incubator Thermo Scientific
Section 1
Installation and Start-Up
Setting the Overtemp
Setpoint
Setting the CO2Setpoint

All models of the incubator have a CO2setpoint range of 0.0% to 20.0%.
The incubator is shipped from the factory with a CO2setpoint of 0.0%.
At this setting, all CO2control and alarms are turned off.
To change the CO2setpoint:
1. Press the Mode key until the Set indicator lights.
2. Press the right arrow until “CO2 XX.X” is displayed in the message
center.
3. Press the up/down arrow until the desired CO2setpoint is displayed.
4. Press Enter to save the setpoint.
5. Press the Mode key until the Run indicator lights to go to Run mode,
or press the right/left arrow keys to go to next/previous parameter.
Reach-In Incubator 1-11Thermo Scientific
Section 1
Installation and Start-Up
Setting the CO2Setpoint
(continued)