Associated Environmental Systems SD-302 User manual

The test & measurement
equipment you need at
the price you want.
Alltest carries the world’s largest selection of
used/refurbished benchtop test & measurement
equipment at 50% the price of new.
O
Our equipment is guaranteed working, warrantied, and
available with certified calibration from our in-house staff
of technicians and engineers.
• 10+ full time technicians with over 150 years of
specialization
• 90 day warranty & 5 day right of return on all
equipment
•
• 1-3 year warranties for new and
premium-refurbished equipment
• Every unit tested to OEM specifications
• Satisfaction guaranteed
You have plans, we will help you achieve them.
Any project. Any budget.
Get a quote today!
CCall [phone] or email [e-mail].
t
Alltest Instruments, Inc.
500 Central Ave.
Farmingdale, NJ 07727
P: [phone]
F: [phone]
alltest.net
s
[e-mail]

INSTRUCTION MANUAL
INSTRUCTION MANUALINSTRUCTION MANUAL
INSTRUCTION MANUAL
MODEL #: SD-302
BENCHTOP TEMPERATURE CHAMBER
Associated Environmental Systems
31 Willow Road
Ayer, MA 01432
Phone [phone] Fax [phone]
http://www.associatedenvironmental.com

TABLE OF CONTENTS
TABLE OF CONTENTSTABLE OF CONTENTS
TABLE OF CONTENTS
I. Safety Inf rmati n 1-1
II. Descripti n 2-1
General Information 2-1
Heating System 2-2
Refrigeration System 2-2
III. Installati n 3-1
Unpacking 3-1
Placement 3-1
Power Requirements 3-1
Initial Inspection 3-3
IV. Operati n 4-1
Overview 4-1
Live Loads 4-2
Pilot Lights 4-3
Watlow PM Controller 4-4
Watlow F4 Temperature Controller 4-5
Overview 4-5
CO2/LN2 Boost 4-7
Dry Nitrogen Purge 4-8
Profile Programming 4-9
High Temperature Limit 4-14
High/Low Temperature Safety (Optional) 4-15
V. Maintenance 5-1
Cleaning CO
2
5-2
Refrigeration System 5-3
Service guide 5-4

VI. Frequently Asked Questi ns 6-1
This chamber is being sent to another country, will their power work? 6-1
Why do I smell something when operating the chamber for the fist time? 6-1
Why does the chamber heat/cool slower than specified? 6-1
Should I put a filter in front of the air intake? 6-1
How to Clean the chamber FAQ 6-1
Why is there ice or “snow” buildup in the chamber? 6-1
Refrigeration System FAQ 6-2
Storage FAQ 6-2
Appendix
A. Parts List
B. Warranty
C. Wiring Print
D. Refrigeration Print
E. Controller/Programmer Manual

SAFETY INFORMATION
1-1
PLEASE READ
Follow all warnings to prevent possible injury or damage to the chamber. Failure to follow
all warnings may void the warranty.
Warning:
Warning:
Warning:
Warning:
Warning:
Warning:
Allow a minimum of 18" clearance in front and rear of chamber for
ventilation across air cooled condenser. The internal components
and general performance of the chamber will be impaired if it is
placed in a corner or boxed in by other equipment. Do not block the
air vent on the top or the sides of the chamber because overheating
could occur.
The power requirements are 120V 1PH 60HZ. These requirements
are noted on the model nameplate located on the back of the
chamber. If a contradiction exists, follow the power requirements on
the nameplate.
The Programmer in your chamber has been “set up” and tested at the
factory. DO NOT change any parameters. Disregard programmer
instruction manual for setup procedures. Contact factory before
changing any settings.
Do not put explosive, corrosive, or materials that may emit fumes
into the chamber
Excessive live load in chamber may impair performance of the
chamber or damage the refrigeration system.
On CO
2
or LN
2
models it is important to remove the exhaust port
plug, as these systems are high pressure. Not removing the plug
from the exhaust port will cause a dangerous condition.

DESCRIPTION
2-1
MODEL SD-302
The Model SD-302 is a Low Temperature/High Temperature Test Chamber which has 2 cubic
feet of working volume. The SD-302 is designed to generate and control low and high
temperature environments in the range of -65°C to +200°C (-85°F to +392°F)
For temperature control, it incorporates an all solid state microprocessor programmer which
features +/- ¼°C (+/- ½°F) temperature control stability at the sensor. Fast response nichrome
type heaters on ceramic cores are used to raise the temperature and a two stage cascade
mechanical refrigeration system lowers the temperature.
The chamber also has a high temperature failsafe to prevent the temperature from exceeding a
preset limit.
The power requirements are 120V 1PH 60HZ. These requirements are noted on the model
nameplate located on the back of the chamber. If a contradiction exists, follow the power
requirements on this nameplate.

DESCRIPTION
2-2
CIRCULATION SYSTEM
The circulation system consists of electric motor(s) and fan blade(s). The electric motor is a split
phase, TEFC with automatic reset thermal overload. The motor has a stainless steel shaft, which
extends into the chamber and then into the fan blade. The bearings are the permanently
lubricated type, so no further lubrication is required. Since the motor is single phase there is no
need to check for proper rotation after new chamber installation. If motor is replaced or
serviced, rotation should be checked since the motor can be wired for standard or opposite
rotation.
HEATING SYSTEM
Heating is produced by nichrome wire on ceramic core type heaters, used for their quick
response. Consult electrical schematic for heating capacity.
When the controller senses heat is required, it energizes a series of relays and the pilot light.
Should the failsafe circuit be energized, a separate relay will de-energize the chamber heat and
illuminate the failsafe pilot.
There are also heat links located in the chamber. Their purpose is for chamber protection only.
Once they are opened, replacement is necessary. Never short or jump out heat links.
REFRIGERATION SYSTEM
Cooling is accomplished by a cascade stage mechanical system using two (2) semi hermetic
compressors. Compressor utilizes polyester oil (POE) for lubrication. The actual cascade is a
brazed heat exchanger. The low or SUVA-95 system removes the heat from the chamber and
delivers it to the cascade in the form of high pressure gas. The high or R-404A system removes
the heat from the cascade and delivers it to the surroundings using the fan (or water) cooled
condenser. In the cascade, the SUVA-95 goes from a high pressure gas to a high pressure liquid
or simply condenses. The R-404A transforms from a low pressure liquid to a low pressure gas or
simply evaporates. An air cooled condenser is utilized.
SUVA-95 SYSTEM
When the controller senses that cooling is required, it energizes the mechanical refrigeration
(cool) pilot light and a solenoid valve (located before the SUVA-95 evaporator expansion valve,)
letting liquid refrigerant into the chamber evaporator. When cooling is not required a solenoid
valve energizes bypassing hot gas (through a regulating valve or restricted tubing) from the high
side to the low side. The hot gas bypass has been incorporated to “unload” the compressor
during low or no load conditions since the compressor does not cycle on an off.

DESCRIPTION
2-3
A de-superheating expansion valve has been added to maintain acceptable suction gas
temperatures returning to the compressor when bypassing or when chamber pulls down from
high temperatures to low temperatures.
A pressure relief valve opens when the high side pressure goes above approximately 280 psig
and diverts the gas to the expansion tank. The gas is returned to the low side of the system via a
restrictive tube.
Charging is by static pressure or weight if system is empty. To check a static charge the unit
must not have been operated for at least 6 hours and have an ambient temperature of
approximately 70ºF. Leaving system off, connect gauges and equalize pressure between high
and low side. Optimum pressure should be between 100 psig and 125 psig.
R-404A-SYSTEM
When the mechanical refrigeration is switched on the R-404A compressor will start about 60
seconds before the SUVA-95 compressor to pre-cool the cascade and to minimize starting
current required for the chamber. The R-404A system incorporates a hot gas bypass system to
“unload” the compressor during low or no load conditions. Charging is done until the sight glass
is full.
Service Technician Please Note: When the refrigeration system is bypassing hot gas, bubbles or
a low liquid level will appear in the sight glass. This is normal and does not indicate an under
charged system. Likewise, when charging system make sure hot gas is not bypassing, or the
system will be overcharged. Bypass valve should be set to maintain 5-10 psig during no load
conditions. Charging is done to full or near to full sight glass.

INSTALLATION
3-1
UNPACKING
Inspect the chamber in its crate for obvious damage that may have occurred during shipment. If
any such damage exists, file a claim with the carrier within 7 days.
If crated, the wooden crate can be dismantled with a hammer and the steel compression straps
can be cut with tin snips. Remove clear plastic wrap from the outside of the chamber. Be
careful not to pull excessively on any protruding switches, pipes etc.
PLACEMENT
Place the chamber on a level, hard surface.
Allow a minimum of 18" clearance in front and rear of chamber for ventilation across air cooled
condenser. The internal components and general performance of the chamber will be impaired if
it is placed in a corner or boxed in by other equipment. Do not block the air vent on the top or
the sides of the chamber because overheating could occur.
POWER REQUIREMENTS
The specific power requirements for the individual chamber are stamped on the model nameplate
affixed to the rear of the chamber. This is the correct requirement for the chamber and should be
followed precisely in order for maximum efficiency and performance standards to be met. The
power must also include a positive earth ground to avoid any shock hazards.
ATTENTION: Not all products from Associated Environmental Systems ship with a means of
disconnect from the main voltage feed. If equipped with a wall plug, this is often sufficient to
satisfy the disconnect requirement of the local electric code. However in instances where the
chamber is hard wired into an electrical service panel, code often requires the installation of a
wall mounted disconnect switch. It is the responsibility of the customer to determine the local
requirements for their chamber. A chamber mounted disconnect switch is available as an option
from Associated Environmental Systems.
INSTALLATION
Observe and follow the instructions given on any tags affixed to the chamber itself. The tags
have specific instructions relating to that individual chamber. The information on the tags may
not be found in this manual.

INSTALLATION
3-2
CHAMBER DRAIN
Connect copper chamber drain in accordance with local codes. It is located on the bottom rear of
the chamber.
Copper Drain (5/16” ID 3/8” OD)

INSTALLATION
3-3
INITIAL CHECKOUT
This test chamber has been thoroughly inspected and tested prior to leaving the factory. To
ensure that it is in proper working order after receipt, please perform the following initial
checkout steps:
STEP 1: Place the Power (Circulation) switch ON and with the door opened, confirm that
there is airflow from the circulation blower.
STEP 2: a. Set the digital failsafe control to a setting above the desired test
temperature.
b. Close the door and turn the power and heat switches on.
c. Set the primary controller temperature set point at the desired test temperature.
d. Allow the chamber to reach the set point and then wait 15 minutes for the
system to stabilize itself at that temperature.
e. Reset the digital failsafe control at the temperature above the set point
temperature where you want the chamber to go into “safety mode.”
f. Open door, turn heat switch off, let cool down to room ambient.
Close the chamber door and set chamber temperature controller to your desired
high setting. Push heat and cool (mechanical refrigeration) switches on. Confirm
an increase in chamber temperature by observing the digital display. As the
chamber temperature approaches the set point, the Heat pilot light will begin to
flash, indicating proper operation of the temperature control instrument at high
temperatures.
STEP 3: The power, heat, and cool switches should all be on. Set chamber temperature to
a low temperature. Confirm a decrease in chamber temperature by observing the
digital display. As the chamber temperature approaches the low set temperature,
the cool pilot light will begin to flash indicating proper operation of the
temperature control instrument at low temperatures. Set the chamber temperature
controller to your lowest testing temperature (within chamber specifications.) Let
the unit run to verify proper operation of refrigeration system.
NOTE: As an option some models may be equipped with CO
2
or LN
2
cooling
systems. These systems will have a CO
2
or LN
2
pilot light. On CO
2
or LN
2
models it is important to remove the exhaust port plug, as these systems are high
pressure. Not removing the plug from the exhaust port will cause a dangerous
condition. Make certain exhaust port plug is removed!

INSTALLATION
3-4
OPTIONS:
Your chamber may have been equipped with an auxiliary cooling system utilizing either LN
2
or
CO
2
.
These capabilities are listed in the model nameplate.
Attach auxiliary system to connection on rear of chamber as indicated.
NOTE: All auxiliary systems require an exhaust due to pressure being introduced into the
chamber. The exhaust port as indicated on the chamber must be open when using CO
2
or LN
2
.

OPERATION
4-1
OVERVIEW
CHAMBER QUICK USE GUIDE
TEMPERATURE
WARNING: This chamber is designed to operate within the range of temperature specified in
the DESCRIPTION, SECTION II of this manual. Any attempt to test outside of
this range will result in damage to the chamber and its contents.
Close the chamber door, check that all ports are plugged, turn the power (circulation) on, and set
the temperature required with the programmer by referring to the quick use guide provided in
this manual. Then, turn on the heat and cool (mechanical refrigeration) switches. Setting the
correct temperature before switching on the heat and cool switches prevents the chamber (and
your product) from going to the previous set temperature while programming in the new one.
IMPORTANT!!! ALWAYS CHECK THE FAIL-SAFE LIMIT FOR PROPER PRODUCT
PROTECTION!
To save energy, wear and tear during operation, the refrigeration system will shut off
automatically if no cooling or dehumidity is required for a period of five (5) minutes and turn on
automatically if cooling is required. The refrigeration system will not be damaged at high
temperature (200°C) due to de-superheating expansion valve and the hot gas bypass system
incorporated in the refrigeration system.

OPERATION
4-2
LIVE LOADS
The following data is an estimate, actual chamber performance may vary.
SD-302 -65 50W
SD-308 -40 500W
SD-308 -65 250W
SD-405 -10 500W
SD-408 -10 500W
SD-502 -37 75W
SD-508 -20 500W
SD-508 -37 200W

OPERATION
4-3
PILOT LIGHTS
The switch and pilot light are integrated into one unit. Light will illuminate when switch is
actuated
POWER - (Circulation) When the power light is ON, the chambers’ circulation fan is activated
and the primary power for the chamber is ON.
HEAT – When the heat light is steady ON, the heater circuit(s) are energized. Flashing of the
heat pilot light indicates the chamber’s temperature is at or near the set temperature.
COOL – (Mechanical Refrigeration) When the cool light is ON, the chamber’s cooling mode is
in operation. Flashing of the cool pilot light indicates that the chamber temperature is at or near
the set temperature.
CO
2
(Optional) – When the CO
2
pilot light is steady ON, the chamber’s optional CO
2
cooling
system is in operation. Flashing of the CO
2
pilot light indicates that the chamber temperature is
at or near the set temperature.
LN
2
(Optional) – When the LN
2
pilot light is steady on, the chamber’s optional LN
2
cooling
system is in operation. Flashing of the LN
2
light indicates that the chamber temperature is at or
near the set temperature.
LIGHT (Optional) - When the pilot light is steady ON, this indicates that the light is on in the
chamber.
PURGE (Optional) – When the pilot light is steady ON, this indicates that the Dry Nitrogen
Purge is active.

OPERATION
4-4
SERIES WATLOW PM CONTROLLER
SET UP
The Watlow PM Controller has been “set-up” by Associated Environmental Systems. It has
been tuned for your chamber and should not require any changes in the PID parameters. See the
temperature control setup page after the controller manual for the PID parameters.
QUICK USE
Do not alter any parameters on the PM controller they have been preset.
Press the ▲or ▼button to the desired set point, and push the heat or cool pilot light on the
control panel.
SENSORS
TEMPERATURE ONLY MODELS - Uses 100 OHM (at 0°C) platinum resistance temperature
detectors (RTD) based on the din curve.
Alpha = .00385

OPERATION
4-5
SERIES F4SH (OPTIONAL)
MICROPROCESSOR-BASED CONTROLLER
SETUP
The series F4SH has been setup by Associated Environmental Systems. The internal dip switch
has already been set. It has also been tuned for you chamber and should not require any changes
in the PID parameters.
QUICK USE GUIDE
The best way to learn about the Series F4SH is to read the Series F4 User’s Manual. The
following section is not intended to replace the manual, it is to serve as a quick use guide to
check and use the chamber without extensive reading of the Series F4 Manual.
After switching the chamber power on, you will notice numbers on upper display of the F4
controller. This is the actual temperature inside the chamber. The units will be determined by
the led located by °F or °C. Lower display shows various information by pressing navigation
key up or down and is used for changing set point or setup. SP1 is the set point. To change set
point select SP1 by moving cursor up or down using navigation key up or down. Press right
arrow key to enter then press up or down key until desired temperature is displayed. Then press
right arrow key to enter that value. New set point has been established. Press Heat and Cool
switches on control panel of chamber.
If you are having difficulty understanding any of the above, read chapters 2 & 3 of the F4 User’s
Manual.
SENSORS
TEMPERATURE ONLY MODELS: Uses 100 OHM (at 0°C) platinum resistance temperature
detectors (RTD) based on the din curve.
Alpha = 0.00385