Thermo Scientific 3721 Operating instructions

Model 815 (3721 and 3722)
Microprocessor Controlled Low Temperature Incubator
Operating and Maintenance Manual 3177879 Rev. H

Thermo ScientificThermo Scientific
Manual Number 3177879
H24342/IN-3866 11/08 Added specs and additional info for CSA ccs
G 24342 10/08 1900381 rear comp cvr (from 316126, 1900390 int back wall plate (from 316135) ccs
F 24609 5/08 3185173 to 130630, 3164634 to 3164636 ccs
E -- 6/05 manual number, manufacture location (36100114 [34001729)
D -- 12/04 Update for base model FFU2064DW1 (pages 18-20)
C -- 9/01 Removed dual fans, updated parts list (pages 18-20)
B -- 8/99 Update parts list for new kit #s (page 19)
A -- 6/99 Initial release
Rev ECR/ECN Date Description By
Preface
Low Temp Incubator i
Covered
Models Volume (cu. ft.) Voltage
3721 20 120
3722 20 230

Thermo Scientificii Low Temp Incubator Thermo Scientific
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. ▲
Caution All internal adjustments and maintenance must be performed by qualified service personnel. ▲
Warning If the incubator is used in the manner specified in this operating manual, the protection provided by
the equipment design may be impaired. ▲
Material in this manual is for information purposes only. The contents and the product it describes are subject to
change without notice. Thermo 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.
©1999 Thermo Scientific. All rights reserved.

Thermo Scientific Low Temp Incubator iiiThermo Scientific
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 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
products will be available at www.thermo.com.
✔Always use the proper protective equipment (clothing, gloves, goggles, etc.)
✔Always dissipate extreme cold or heat and wear protective clothing.
✔Always follow good hygiene practices.
✔Each individual is responsible for his or her own safety.

Thermo Scientificiv Low Temp Incubator Thermo Scientific
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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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
[e-mail]

Thermo Scientific Low Temp Incubator vThermo Scientific
Preface
Warranty Notes
Information You Should Know Before Requesting Warranty Service
•Locate the model and serial numbers. A serial 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°C for
temperature, ±1% for gases, and ±5% for humidity. Our service personnel can provide precise calibrations as
a billable service at your location. Calibration after a warranty 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.

Section 4
Section 5
Section 6
Section 8
Section 7
Low Temp Incubator viThermo Scientific
Table of Contents
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-1
Unpacking and Damage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-1
Performance Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-2
Theory of Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-2
General Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-2
Explanation of Front Panel Controls . . . . . . . . . . . . . . . . . . . . . . . . .1-3
Explanation of Auxiliary Panel . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-4
Instrumentation Port . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-5
Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-1
Safety Precautions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-2
Operation and Calibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-1
Service . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-1
Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-1
Symptoms and Possible Causes . . . . . . . . . . . . . . . . . . . . . . . . . . .4-1
Possible Solutions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-3
Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5-1
General Cautions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5-1
Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6-1
RS232 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6-1
Setting Up the Incubator for Communication . . . . . . . . . . . . . . . .6-2
Using the Communication . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6-5
Setting up the Computer for Communication . . . . . . . . . . . . . . . .6-5
Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7-1
Spare Parts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8-1
Accessories . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8-2
Section 1
Section 2
Section 3

Low Temp Incubator 1-1Thermo Scientific
Section 1 Introduction
Your satisfaction and safety are important to Thermo and a complete
understanding of this unit is necessary to attain these objectives.
Warning As a routine laboratory precaution, always wear safety glasses
when working with this apparatus. ▲
This product is not intended, nor can it be used, as a sterile or patient
connected device. In addition, this apparatus is not designed for use in
Class I, II or III locations as defined by the National Electrical Code.
Save all packing material until unit is put into service. This merchandise
was carefully packed and thoroughly inspected before leaving our factory.
Responsibility for safe delivery was assumed by the carrier upon acceptance
of the shipment; therefore, claims for loss or damage sustained in transit
must be made upon the carrier by the recipient as follows:
1. Visible Loss or Damage: Note any external evidence of loss or damage
on the freight bill, or express receipt, and have it signed by the carrier's
agent. Failure to adequately describe such external evidence of loss or
damage may result in the carrier's refusing to honor your damage
claim. The form required to file such claim will be supplied by the
carrier.
2. Concealed Loss or Damage: Concealed loss or damage means loss or
damage which does not become apparent until the merchandise has
been unpacked and inspected. Should either occur, make a written
request for inspection by carrier's agent within fifteen (15) days of the
delivery date; then file a claim with the carrier since the damage is the
carrier's responsibility.
If you follow the above instructions carefully, we will guarantee our full
support of your claim to be compensated for loss or concealed damage.
Note Do not - for any reason - return this unit without first obtaining
authorization. In any correspondence to Thermo, please supply the
nameplate data, including catalog number and serial number. ▲
Unpacking and
Damage

Theory of Operation
1-2 Low Temp Incubator Thermo Scientific
Section 1
Installation and Start-Up
The incubator is commonly referred to as the standard model 815.
The Model 815 Low Temp Incubator has been designed to provide the
ultimate in temperature control. The user is assured of dependable and
precise performance through the use of microprocessor technology in the
temperature control circuitry. This incubator is operable in the range of
-10° to 50°C. These temperature ranges will meet a wide variety of
applications, such as BOD determination, general incubation, as well as
the preservation of critical materials.
Heat-Up Time: From -10°C to 50°C; 120 minutes (Compressor "ON");
Cool-Down Time: From 50° to -10°C; 100 minutes.
Note The above performance figures are based upon the following
operating conditions: Line Voltage ............... 110.5 to 112.5
Ambient Temperature ... 22.5° to 24°C
The refrigeration system, defrost heater, and air circulating fan are used in
conjunction with a microprocessor controlled proportioning circuit to
achieve sensitive temperature control. An RTD (Resistance Temperature
Detector) located in the airstream senses any temperature deviation from
the control point, and heat is provided proportionally to maintain the
desired temperature. Regardless of what temperature is being maintained,
the compressor operates continuously. This constant operation alleviates
component failures associated with cycle type operation.
The circulating fan provides even air distribution throughout the chamber
and ensures temperature uniformity.
General Information
Performance Data
Temperature Set Point (°C) Uniformity (±°C) Temperature Sensitivity
-10.0 ±0.9
±0.1C
20.0 ±0.5
37.0 ±0.5
50.0 ±0.

Heater On Lamp - The "Heater On" lamp is illuminated when power is
applied to the heater.
LED Display - Four digits are used to display the actual, set, calibrate,
high limit and low limit values.
Indicator Lamps - There are five (5) green indicator lamps that are used to
inform the user which parameter the display is indicating. The sixth
indicator is for a high or low temperature alarm condition. An internal
audible alarm will also operate when this alarm indicator illuminates.
On/Off Switch - The On/Off switch provides the main power to the incu-
bator.
Mute Key - This key is used to silence the internal audible alarm and to
also de-activate the external alarm device if one is being used.
High/Low Limit Key - This key is used to view the high or low tempera-
ture alarm setpoint The first depression of the key selects the high limit.
The second depression selects the low limit. The respective green indica-
tor lamp will light.
Set Temp/Cal Key - This key is used to view the operating setpoint tem-
perature or calibrate the unit to a certified/traceable thermometer. The
first depression of the key selects the operating setpoint and the second
depression selects the calibration mode. The respective green indicator
lamp will light.
Enter Key - This key is used after any setpoint selection is made to enter
the value into memory.
Up/Down Arrow keys - These keys are used to increase or decrease the
desired setpoint value.
Low Temp Incubator 1-3Thermo Scientific
Section 1
Installation and Start-Up
Explanation of Front
Panel Controls

1-4 Low Temp Incubator Thermo Scientific
Section 1
Installation and Start-Up
On the left side of the incubator control panel, there is an auxiliary panel
which has the items shown in the illustration below. They are described as
follows:
1) Fuse - This fuse is in line with the main power cord that comes into the
incubator. The rating of this fuse is printed above the fuse holder. The
physical size of this fuse is 5 MM x 20 MM.
2) Alarm Relay - This Alarm Relay output is provided to the user for the
purpose of remotely monitoring the incubator in case of a high or low
temperature alarm condition. This alarm relay will operate just as the
audible alarm would. The contact itself is an isolated form C (normally
open/normally closed) dry contact. This contact is to be used for low
voltage class 2 connections only. The contact rating is 24 volts, 1.25
amps resistive. Typical usages of the output are shown below.
In the above configuration, the light will illuminate whenever the unit goes
into an alarm condition...High or Low.
In the configuration below, the light will go off in a high or low
temperature alarm condition.
Warning Wiring must conform to all local electrical codes. ▲
3) RS-232 Output (Optional Kit P/N 3166245) - This output is used for
two way communications between the incubator and a personal
computer. With the use of communications/modem software program,
the user can record the temperature of the incubator at their selected
time periods and store it in a file for use with a spreadsheet program.
The user can also change the setpoint temperature from their personal
computer and periodically monitor the actual temperature, setpoint
temperature, and alarm status.
Explanation of Auxiliary
Panel
VOLTAGE SOURCE
VOLTAGE SOURCE

Low Temp Incubator 1-5Thermo Scientific
Section 1
Installation and Start-Up
4) Recorder Output - This is a DC millivolt output which represents the
temperature of the incubator. The recommended main use of this is
with a chart recorder having an input impedance of at least 1 megohm.
The scaled temperature output change is 10 millivolt/degree C. When
the incubator is operating at a negative temperature, the chart recorder
output is still positive. Use the chart below to relate temperature to
output voltage.
Located on the chart recorder printed circuit board is an offset
potentiometer R3. If, for some reason, the recorder output voltage does
not match the temperature as shown in the chart, this potentiometer
can be used to tune it in.
When connecting a chart recorder to the recorder output connector, it
is recommended to use a shielded cable with the shield grounded at
the chart recorder and to keep the cable short as possible.
Located on the rear side of the incubator is an instrumentation port for the
user to insert sensor wires, external meter leads, etc. into the chamber. The
rubber plug provided must always be used in this port to insure the
uniformity specifications. An extra plug is supplied for the user's
convenience. Be sure to seal any gaps around the wire(s) going through the
plug.
Explanation of Auxiliary
Panel (continued)
Instrumentation Port

Low Temp Incubator 2-1Thermo Scientific
Section 2 Installation
Use the proper lifting equipment when moving this unit. The unit weighs
315 lbs. ((142.9kg).
To assure proper ventilation, allow a minimum of 4" of clearance between
the rear, top, and sides of the incubator and adjacent walls. If two or more
incubators are positioned side by side, allow a minimum of 8" between
cabinets. Adjust the front leveling feet of the incubator so that the front is
higher than the rear. This will assist in door closing. Choose a site free
from rapidly changing ambient temperature conditions.
Wall mount brackets are attached to the top rear of the cabinet. Remove
any packaging materials from the brackets. Rotate the bracketsso they
point straight out from the back. Secure in place with the included
hardware. Secure bracketsto wall.
The power cord is the mains disconnect. Make sure the outlet and power
cord are accessible at all times.
Caution The incubator should not be operated in an environment where
the ambient temperature exceeds 90°F as the compressor thermo-overload
will be tripped and will result in a wide band control cycle of
approximately ±4°C. Such cycling should not be misinterpreted as a
malfunction of the electronic controls. ▲
Radiators, air-conditioning outlets, other ventilating system outlets, and
drafts can affect the operation of the incubator by a sudden inrush of air
that is at a temperature different than operating conditions.
Warning For personal safety, this apparatus must be properly grounded. ▲
Figure 2-1. BracketsDuring Shipping Figure 2-2. BracketsDuring Use

2-2 Low Temp Incubator Thermo Scientific
Section 2
Calibration
The power cord of this instrument is equipped with a three-prong
(grounding) plug which mates with a standard three-prong (grounding)
wall receptacle to minimize the possibility of electric shock hazard from
this apparatus. The customer should have the wall receptacle and circuit
checked by a qualified electrician to make sure the receptacle is properly
grounded.
Where a two-prong wall receptacle is encountered, it is the personal
responsibility and obligation of the user to have it replaced with a properly
grounded three-prong wall receptacle.
Warning Do not - under any circumstances - cut or remove third (ground)
prong from the power cord. Do not use a two-prong adapter plug. ▲
Determine the total amount of current presently being used by other
apparatus connected to the circuit that will be used for this unit. It is
critical that the added current demand and other equipment on the circuit
not exceed the rating of the fuse or circuit breaker in use.
Caution Be sure the power supply is the same voltage as specified on the
nameplate. ▲
When loading the incubator, a space of 1/2" must be allowed between
adjacent items. This will allow maximum air circulation, which is necessary
for proper temperature uniformity. The uniformity will be adversely
affected if air circulation is obstructed.
Liquid containers should never be placed in the incubator without covers.
The evaporation of moisture within the chamber will only add frost and
hasten the need for defrosting. This chamber is not self-defrosting.
Excessive frost buildup on the evaporator coil located on the lower rear
wall will also affect temperature uniformity.
1. Do not place any explosive, combustible, or flammable materials in the
chamber.
2. Do not place sealed containers in the chamber. Sealed containers, filled
with materials do not provide room for expansion and can develop
dangerous vapor pressure as the temperature increases.
3. Avoid spillage of liquids within the chamber.
4. Do not evaporate noxious fumes.
Caution Do not store containers filled with acidic or caustic solutions, as
vapors from these materials will attack the evaporator and void the
warranty. ▲
Safety Precautions

Low Temp Incubator 3-1Thermo Scientific
Section 3 Operation and Calibration
Power up by depressing the ON/OFF switch. Immediately after turning on
power, all the segments of the display and all of the indicators will be on.
After one second the display will show the actual temperature and the
actual temperature indicator light will be lit. If the setpoint temperature is
greater than the actual temperature, then the heater on lamp will be on or
start to flash. If it flashes, then the actual temperature is near setpoint
temperature.
To display any temperature value - With the use of either the SET
Temp/Cal key or the HIGH/LOW LIMIT key, any temperature value can
be displayed. To view the set temperature, press the set Temp/Cal key once.
The green indicator for the set temperature will light. If no other keys are
pressed, within 5 seconds, the display will automatically return to the
actual temperature. To view the calibrate temperature, press the SET
TEMP/CAL twice while the display is showing the actual temperature.
The same sequence of key operation is true for the use of the HIGH/LOW
LIMIT key.
To change the setpoint temperature - Press the SET TEMP/CAL key
once. Then press the UP or DOWN arrow key until the desired
temperature is displayed. When continuously pressing either the UP or
DOWN keys, the display will begin to change rapidly. With a little
practice, one will become accustomed to this. After the desired set
temperature is achieved, then press the ENTER key. The display will then
return to showing the actual temperature. If the ENTER key is not
pressed, the expected new set temperature will not be accepted and the
incubator will control at the previous set temperature.
The incubator is calibrated at the factory for use over a wide range of
temperatures. Due to the slight non-linearities in the control system, it
may be necessary to make the display match a calibrated thermometer's
reading, even though the difference might be only a few tenth's of a
degree.
The CALIBRATE key should be used ONLY to match a stable incubator's
actual temperature to the calibrated thermometer.

3-2 Low Temp Incubator Thermo Scientific
Section 3
Operation and Calibration
Place a calibrated thermometer or the probe of one at the center of the
third shelf of the incubator. Select the SETPOINT desired. Allow the unit
to run for at least an hour after it reaches the setpoint, before calibration is
performed.
Note If possible, place the thermometer into a liquid for stability. ▲
To perform calibration, press the SET TEMP/CAL twice. The green
calibration indicator should be lit. Then press either the UP or DOWN
arrow keys to make the display match the noted thermometer reading.
After the satisfied display is achieved, press the ENTER key. The display
will then return to showing the newly calibrated actual temperature.
To change the high temperature alarm/setpoint - After selecting a setpoint
temperature, the HIGH TEMPERATURE ALARM SETPOINT
automatically defaults to 1° higher than the setpoint that was entered. This
1° default difference can be overridden if desired. The following paragraph
describes this.
Press the HIGH/LOW LIMIT key once. The green "High Temperature
Alarm/Set Point" indicator should be lit. Use the UP or DOWN arrow
keys to select your limit value. Then press the ENTER key. If the HIGH
LIMIT value you have selected is below the operating SETPOINT
TEMPERATURE, the incubators' alarm will activate
To change the Low temperature alarm/setpoint - After selecting a setpoint
temperature, the LOW TEMPERATURE SETPOINT automatically
defaults to 1° lower than the setpoint that was entered. This 1° default
difference can be overridden if desired. The following paragraph describes
this.
Press the High/Low Limit key twice. The green "Low Temperature
Alarm/Setpoint" indicator should be lit. Use the UP or DOWN arrow keys
to select your limit value. Then press the ENTER key. If the LOW LIMIT
value you have selected is above the operating setpoint temperature, the
incubators' alarm will activate.
Note Software version 2.00 and later has a 30 minute delay for the low and
high alarm to avoid nuisance alarms caused by door openings. ▲

Low Temp Incubator 3-3Thermo Scientific
Section 3
Preventive Maintenance
Preventive Maintenance for Model 815/818 Incubators
Refer to
Manual
Section
Action Daily Weekly Yearly
3 Check temperature display versus setpoints, w/ independent instrument 9
-- Inspect door latch, hinges and door gasket seal. 9
3 Verify and document temp calibration, as applicable. See Calibration section. 9
5 Perform a complete decontamination procedure. Wipe down interior, shelves
and side panels with disinfectant. Rinse everything well with sterile distilled
water.
Between experiments
More frequent decontamination
may be required, depending on use
and environmental conditions
PREVENTIVE MAINTENANCE
Incubators
Your equipment has been thoroughly tested and calibrated before shipment. Regular preventive maintenance is important to keep your unit
functioning properly. The operator should perform routine cleaning and maintenance on a regular basis. For maximum performance and
efficiency, it is recommended the unit be checked and calibrated periodically by a qualified service technician.
The following is a condensed list of preventive maintenance requirements. See the specified section of the operating manual for further
details.
We have qualified service technicians, using NIST traceable instruments, available in many areas. For more information on Preventive
Maintenance or Extended Warranties, please contact us at the number listed below.
Cleaning and calibration adjustment intervals are dependent upon use, environmental conditions and accuracy required.
Tips for all incubators:
xDo NOT use bleach or any disinfectant that has high chloros
xUse sterile, distilled or demineralized water.
xDo not use powdered gloves for tissue cultures.