Despatch LAC2-12-5 User Manual
LAC SERIES OVEN
C-184
PN 143365
REVISION H
11/2007
WITH PROTOCOL
PLUS
INSTRUCTION MANUAL
™
Notice
Users of this equipment must comply with operating procedures and training of
operation personnel as required by the Occupational Safety and Health Act (OSHA)
of 1970, Section 6 and relevant safety standards, as well as other safety rules and
regulations of state and local governments. Refer to the relevant safety standards in
OSHA and National Fire Protection Association (NFPA), section 86 of 1990.
Caution
Setup and maintenance of the equipment should be performed by qualified
personnel who are experienced in handling all facets of this type of system.
Improper setup and operation of this equipment could cause an explosion that may
result in equipment damage, personal injury or possible death.
Dear Customer,
Thank you for choosing Despatch Industries. We appreciate
the opportunity to work with you and to meet your heat
processing needs. We believe that you have selected the
finest equipment available in the heat processing industry.
At Despatch, our service does not end after the purchase
and delivery of our equipment. For this reason we have
created the Service Products Division within Despatch. The
Service Products Division features our Response Center for
customer service. The Response Center will direct and track
your service call to ensure satisfaction.
Whenever you need service or replacement parts, contact
the Response Center at 1-800-473-7373: FAX 612-781-
5353.
Thank you for choosing Despatch.
Sincerely,
Despatch Industries
i
ii
PREFACE
NOTE:
Read the entire
INTRODUCTION and
THEORY OF OPERATION
before installing the oven.
WARNING:
Failure to heed warnings in
this instruction manual and on
the oven could result in
personal injury, property
damage or death.
This manual is your guide to the Despatch oven. It is organized to give you the
information you need quickly and easily.
The INTRODUCTION section provides an overview
of the Despatch oven.
The THEORY OF OPERATION section details the
function and operation of assemblies and
subassemblies on the Despatch oven.
The INSTRUCTIONS section provides directions on
unpacking, installing, operating and maintaining the
Despatch oven.
The APPENDIX section contains special instructions
on air atmosphere and nitrogen atmosphere Burn-In
ovens, a Troubleshooting Table, a list of Accessories
and a Warranty.
The parts are listed in the corner of the attached prints, the electrical items on the
electrical print and the mechanical items on the mechanical prints.
An efficient way to learn about the oven would be to read the manual while working with
the corresponding oven control system. This will give you practical hands-on
experience with information in the manual and the oven.
Before operating the equipment, be sure you understand all of the technical information
contained in this manual. Information skipped, not understood or misunderstood could
create the possibility of operating the equipment in an unsafe manner. This can cause
damage to the oven or personnel or reduce the efficiency of the equipment.
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Revision B: Corrected Sensor Calibration Page instruction
Revision C: Added definitions and sample profile to Program Page description
Revision D: Correction to Relay Outputs (optional) table
Revision E: Modified per Rev C Protocol Plus software
Revision F: Updated drawings.
Revision G: Revised Protocol Plus times. Updated Despatch address.
Revision H: Updated warranty
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TABLE OF CONTENTS
INTRODUCTION .......................................................................................................................... 1
Special Features ....................................................................................................................... 1
Specifications ............................................................................................................................ 2
Dimensions ........................................................................................................................... 2
Capacities ............................................................................................................................. 3
Temperature .......................................................................................................................... 3
Power .................................................................................................................................... 4
THEORY OF OPERATION ........................................................................................................... 5
Damper Control ......................................................................................................................... 6
Determining Damper Settings ............................................................................................... 6
Full Closed Position .......................................................................................................... 6
Full Open Position ............................................................................................................. 7
Other Damper Settings ..................................................................................................... 7
INSTRUCTIONS ........................................................................................................................... 8
Unpacking and Inspection ......................................................................................................... 8
Set-up ....................................................................................................................................... 9
Operating ................................................................................................................................ 10
Operating Environment ....................................................................................................... 10
Loading the Oven ................................................................................................................ 10
Pre-Startup Checklist .......................................................................................................... 11
Startup ................................................................................................................................. 12
CONTROL .................................................................................................................................. 13
Theory of Control Operation ................................................................................................... 13
Operating Modes ................................................................................................................. 15
Setup Mode ......................................................................................................................... 15
Fast Start Mode ................................................................................................................... 15
High Limit ............................................................................................................................ 16
Indicators ............................................................................................................................. 16
Displays ............................................................................................................................... 17
Key Functions ..................................................................................................................... 17
Outputs ................................................................................................................................ 18
Communication ................................................................................................................... 19
Optional Software ................................................................................................................ 19
Instructions .............................................................................................................................. 20
Start-Up ............................................................................................................................... 20
Operation ............................................................................................................................ 21
Manual Mode .................................................................................................................. 21
Timer Mode ..................................................................................................................... 22
Profile Mode .................................................................................................................... 23
Auto Start Mode .............................................................................................................. 23
Setup Mode ..................................................................................................................... 24
Instructions for Setup Mode Pages ..................................................................................... 25
Program Page ................................................................................................................. 25
Sample Profile ................................................................................................................. 28
Auto Start Page (optional) ............................................................................................... 29
PID Page ......................................................................................................................... 31
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Control Page ................................................................................................................... 32
Communication Page (optional) ...................................................................................... 33
Real Time Clock Page (optional) .................................................................................... 33
Relay Outputs Page (optional) ........................................................................................ 34
Test Page ........................................................................................................................ 35
Zone Calibration Page .................................................................................................... 36
Sensor Calibration Page ................................................................................................. 38
Enable Page .................................................................................................................... 40
Digital Inputs (optional) ................................................................................................... 41
Error Messages and Alarms ................................................................................................ 42
Quick Reference and Default Values .................................................................................. 43
Technical Specifications ...................................................................................................... 50
MAINTENANCE .......................................................................................................................... 51
Checklist ................................................................................................................................. 51
Tests ....................................................................................................................................... 52
Replacement ........................................................................................................................... 53
Parts .................................................................................................................................... 53
Protocol Plus™ Instrument ..................................................................................................... 54
Heater Unit .............................................................................................................................. 54
Fan Motor ................................................................................................................................ 55
TROUBLESHOOTING ................................................................................................................ 57
DRAWINGS ................................................................................................................................ 59
LAC1-10-5 ............................................................................................................................... 59
LAC1-38A-5 ........................................................................................................................... 61
LAC1-38B-5 ............................................................................................................................ 63
LAC1-67-5 .............................................................................................................................. 65
LAC2-12-5 ............................................................................................................................... 67
LAC2-18-5 ............................................................................................................................... 69
APPENDIX: Temperature Scale Conversion and Optional MRC5000 Setup ............................. 71
Temperature Scale Conversion (C/F) ..................................................................................... 71
Optional MRC5000 Recorder Setup ....................................................................................... 72
1
INTRODUCTION
This section provides an overview of the Despatch LAC Series forced air oven. The
LAC Series Ovens have the most effective heat distribution and the fastest processing
time of any lab oven their size. Air is discharged from the left side wall of the oven and
circulates through the chamber.
Special Features
The sturdy construction and three inch insulation of the Despatch LAC Series ovens
contribute to excellent temperature uniformity.
Other special features include the following:
Unique Despatch design to combine higher fan volume of forced recirculated air
with a system of perforated stainless steel walls for the ultimate in temperature
uniformity.
Welded double wall construction and fiberglass insulation to reduce heat loss.
Silicone rubber gaskets further minimize heat leakage.
Rapid response heater.
Scratch-resistant baked enamel exterior and stainless steel interior for easy
cleaning.
Space-saving, stackable design.
Simple pull-open door with "no-hands" closing
2
Specifications
LAC
Model
No.
Chamber Size
in (cm)
Capacity
feet
3
(liters)
Overall Size
in (cm)
Max.
Number of
Shelf
Positions
Exhaust
Diameter
Located on Back
of Chamber (in)
W* D H W D
H
1-10
1-38A
1-38B
1-67
2-12
2-18
13.75
(35)
18.75
(48)
18.75
(48)
23.75
(60)
23.75
(60)
35.25
(91)
12
(31)
18
(46)
18
(46)
20
(51)
24
(61)
24
(61)
12
(31)
19
(48)
19
(48)
24
(61)
36
(91)
36
(91)
1
(33)
3.7
(105)
3.7
(105)
6.6
(187)
12
(336)
18
(500)
23
(58)
28
(71)
28
(71)
36
(91)
36
(91)
48
(122)
19
(48)
25
(64)
25
(64)
27
(69)
31
(79)
31
(79)
29.5
(75)
35.5
(90)
35.5
(90)
40.5
(103)
52.5
(133)
52.5
(133)
5
9
9
11
17
17
1
2½
2½
2½
2 - 2½
2 - 2½
Dimensions
* Allow 0.5" clearance on each side for shelf supports.
3
Capacities
LAC Model Number
1-10
1-38 A & B
1-67
2-12
2-18
Maximum Load Lbs
Maximum Shelf Load Lbs
Exhaust CFM
Recirculating Fan CFM
H.P.
Approx. Weight Net Lbs
KG
Shipping Weight Lbs
KG
100
50
Adjustable
to 5
150
1/25
110
50
175
80
125
25
Adjustable
to 12
300
¼
185
84
270
124
150
25
Adjustable
to 12
300
¼
255
115
360
163
175
25
Adjustable
to 30
600
¼ x 2
360
164
480
217
200
25
Adjustable
to 40
600
¼ x 2
450
205
600
271
LAC Model Number
1-10
1-38 A
1-38 B
1-67
2-12
2-18
Time to Temperature 40°C - 100°C
(approximate minutes 40°C - 200°C
with no load) 40°C - 260°C
8
25
40
9
32
60
6
22
36
6
20
34
6
19
31
4
17
29
Recovery Time - Door Open 100°C
One Minute (approximate 200°C
minutes with no load) 260°C
1
3
7
1
6
14
1
4
8
1
3
5
1
6
9
1
4
8
Temperature Uniformity at 100°C*
200°C*
260°C*
±1.5°C
±3°C
±4°C
±1°C
±2°C
±2.5°C
Operating Range with 20 C Ambient
40°C - 260°C
Control Stability
±0.5°C per 5°C change in ambient
Repeatability
±0.5°C
Temperature
* Figures are based on actual tests in an empty oven. Uniformity can vary slightly depending on unit and
operating conditions.
4
Power
Model
Volts
Amps
Hertz
Phase
Heater
KW
Cord and Plug
LAC 1-10
LAC 1-38A
LAC 1-38B*
LAC 1-67*
LAC 2-12*
LAC 2-18*
120
120
240
240
240
240
10.0
16.5
9.5
12.0
18.5
23.5
50/60
50/60
50/60
50/60
50/60
50/60
1
1
1
1
1
1
1
1.6
1.8
2.4
3.6
4.8
Included, 15 Amp (NEMA 5-15)
Included, 20 Amp (NEMA 5-20)
Included, 15 Amp (NEMA 6-15)
Included, 15 Amp (NEMA 6-15)
None, Hardwired
None, Hardwired
Line voltages may vary in some geographical locations. If your line voltage is much
lower than the oven voltage rating, warm up time will be longer and motors may
overload or run hot. If your line voltage is higher than name plate rating, the motor may
run hot and draw excessive amps.
If the line voltage varies more than 10% from the oven voltage rating, some electrical
components such as relays, temperature controls, etc. may operate erratically.
Power Requirements
* Oven designed for 240 volts (see name plate on oven) will operate satisfactorily on a
minimum of 208 volts, but with a 25% reduction in heater power. If your power
characteristics are lower, contact Despatch Industries. An option is available to
regain the full heater power when operating on 208V.
The LAC 2-12 and LAC 2-18 must be hardwired to the electric supply using 10 AWG or
larger wires suitable for at least 75°C (167°F).
5
THEORY OF OPERATION
WARNING:
Do not remove the hat bracket as it distributes exhaust air and protects the exhaust
opening from being completely covered.
This section details the function and operation of assemblies and subassemblies on the
Despatch LAC Series Ovens. These ovens have the most effective heat distribution
system and the fastest processing time of any lab oven its size. They are especially
useful for testing, preheating, sterilizing, drying, aging and curing as well as other
production applications. Horizontal airflow with precision digital control delivers uniform,
fast processing. The overall result is efficient productivity under strenuous conditions.
The unique Despatch computerized design, moves forced convected heat through
perforated stainless steel walls. The air is recirculated with a high volume fan.
Despatch LAC Series Ovens employ higher volume fans than any competitive model.
The chamber can be densely loaded without interfering with the process. Air delivery
temperature is within 1 C of the number appearing on the digital display. Fresh air
intake is regulated by a panel-mounted damper control, while the exhaust opening is
fixed. The exhaust port, on the back of the oven, is covered by a hat bracket.
6
Damper Control
The oven is equipped with a manually adjustable damper mechanism. The damper
control arm is located on the front panel of the oven. The damper adjustment controls
the fresh air opening which, due to pressurization of the oven chamber, controls the flow
of exhaust. If the damper is in the full open position, the maximum exhaust rate is
achieved. If the damper is in the fully closed position, the minimum exhaust rate is
achieved.
Determining Damper Settings
The optimum setting for the damper depends on several factors. These factors include
ambient environment temperature, load conditions, load distribution, heat up rates, cool
down rates, desired temperature uniformity and most importantly the desired operating
temperature. To consider all of these variables at any one point in time is not practical
and there are engineering tradeoffs that should be considered. Therefore guidelines
should be used to determine the damper setting.
In general, the damper should be set so that the amount of fresh air flowing into and
exhausting from the chamber agrees with the desired operating temperature conditions.
The following outline shows the considerations involved with various damper position
settings.
Full Closed Position
When the damper is in the full closed position, the chamber will be able to achieve the
maximum attainable heat up rates for the chamber. In addition, the chamber will use
the minimum amount of power to operate at the desired temperature. In almost all
cases, the damper should be in the full closed position in order to efficiently operate at
the maximum operating temperature for the chamber.
7
Full Open Position
When the damper is in the full open position, the chamber will operate at its minimum
operating temperature.
Friction heat from the air recirculation system builds up in the chamber. This causes
chamber temperature to rise slightly even though the heating system is not turned on.
After the recirculation motor has been on for an extended period of time, the chamber
will reach a thermal equilibrium temperature.
When the damper is not set to the full open position, the chamber has no way to readily
dissipate the heat generated by the friction. With the damper fully open, the thermal
equilibrium temperature is the minimum operating temperature of the chamber.
Other Damper Settings
The damper can be set to several other distinct operating positions. In most cases the
damper setting is influenced by two specific performance factors. The two performance
factors are uniformity and cool down rates.
The uniformity of the chamber is influenced by the inside chamber pressure of the
system. The pressure inside the chamber is dependant on the amount of fresh air
flowing into the chamber. When a large volume of fresh air is flowing into the chamber,
the chamber becomes slightly pressurized and the overall temperature uniformity
improves. The slightly pressurized chamber produces the effect of "pushing" the air to
the corners of the chamber. Typically the corners of the chamber will improve with
respect to temperature distribution while the core of the chamber will maintain excellent
uniformity characteristics regardless of the damper position. Therefore, the
pressurization of the chamber typically is a factor when the chamber is loaded heavily.
The best uniformity results, with respect to the product, are achieved when no more
than two-thirds of any inside chamber dimension are used. The best overall results are
achieved when the product(s) are located in the center of the chamber.
8
INSTRUCTIONS
The INSTRUCTIONS section provides directions for unpacking, installation, operation
and maintenance of the LAC Series oven.
Unpacking and Inspection
Remove all packing materials and thoroughly inspect the oven for damage of any kind
that could have occurred during shipment.
See whether the carton and plastic cover sheet inside carton are still in good
condition.
Look at all outside surfaces and corners of the oven for scratches and dents.
Check the oven controls and indicators for normal movement, bent shafts, cracks,
chips or missing parts such as knobs and lenses.
Check the door and latch for smooth operation.
If there is damage that may have occurred during shipment, follow these instructions.
1. Contact the shipper immediately and file a written damage claim.
2. Contact Despatch Industries to report your findings and to order replacement parts
for those that were damaged or missing.
3. Send a copy of your filed damage claims to Despatch.
4. Next, check to make sure you have received all the required materials. Your
shipment should include:
One (1) Despatch oven,
One (1) Instruction manual,
One (1) Warranty card,
Two (2) Shelves
One (1) Package containing four rubber feet
9
5. If any of these items are missing from the packaged contents, contact Despatch
WARNING:
All grounding and safety
equipment must be in compliance with applicable codes,
ordinances and accepted
safe practices.
WARNING:
Do not use the oven in a wet
or corrosive, explosive
atmosphere unless the oven
has been specifically
designed for a special
atmosphere.
Industries to have the appropriate materials forwarded to you.
6. Finally, to protect the warranty on your new LAC Series Oven, complete the
warranty card and mail it to Despatch within 15 days after receipt of the equipment.
Set-up
1. Remove adhesive backing sheet from the rubber
feet.
2. Attach rubber feet to the bottom corners of the
oven.
3. Place oven on a bench top or an optional
cabinet base.
The oven must have a minimum of two (2)
inches clearance in the rear to provide proper
ventilation. The oven may be placed next to
another cabinet, or next to another oven, with
three (3) inch clearance (the doors will still
open).
Make sure oven is level and plumb; this will
assure proper heat distribution and operation of
all mechanical components.
4. Identify correct power source indicated on the specification plate.
5. Plug or hardwire oven directly to the electric supply.
10
Operating
WARNING:
Do not use oven in wet,
corrosive or explosive
atmospheres unless this
oven is specifically designed
for a special atmosphere.
Users and operators of this oven must comply with
operating procedures and training of operating
personnel as required by the Occupational Safety and
Health Act (OSHA) of 1970, Section 5 and relevant
safety standards, and other safety rules and
regulations of state and local governments. Refer to
the relevant safety standards in OSHA and National
Fire Protection Association (NFPA), Section 86 of 1990.
Operating Environment
The Despatch oven is designed to operate in an industrial setting. Despatch does
recommend the following environmental operating guidelines:
1. The oven is placed on a solid foundation.
2. The oven is not exposed to excessive external vibration.
3. All electrical cabinet covers must remain affixed.
4. Reasonable particulate matter in the atmosphere. Where excessive particulate
matter is present, such as on a construction site or coal processing, Despatch
recommends periodic (usually monthly) cleaning of all electrical compartments.
5. The power supply is within the specifications provided by Despatch. If the facility
power supply is not stable, Despatch recommends a line conditioner.
Loading the Oven
Despatch Industries cannot be responsible for either the process or process
temperature used, or for the quality of the product being processed. It is the
responsibility of the purchaser and operator to see that the product undergoing
processing in a Despatch oven is adequately protected from damage.
Carefully following the instructions in this manual will help the purchaser and operator in
fulfilling that responsibility.
When loading the oven avoid spills of anything onto the heater elements or onto the
floor of the oven. Do not place the load on the oven floor plate. This may cause the
load to heat unevenly and the weight may cause shorting out of the heater elements.
Use the shelves provided.
11
The two shelves are designed to be pulled out about half way without tipping for loading
WARNING:
Do not use flammable solvent or flammable material in this oven. Do not process
closed containers of any substance or liquid in this oven because they may explode
under heat.
and unloading. The support capacity of the shelves is listed in the Capacities Table in
the Specifications section in this manual. Do not overload the shelves.
Distribute the workload evenly so that airflow is not restricted. Do not overfill your oven.
The workload should not take up more than two-thirds of any dimension of the inside
cavity.
Pre-Startup Checklist
Know the system. Read this manual carefully. Make use of its instructions and
explanations. Safe, continuous, satisfactory, trouble-free operation depends
primarily on your understanding the system and your willingness to keep all parts
in proper operating condition.
Check line voltage. Voltage must correspond to nameplate requirements of
motors and controls. Refer to the section on power connections in the
INTRODUCTION of this manual.
Fresh air and exhaust. Do not be careless about restrictions in and around the
fresh air and exhaust openings and stacks. Under no condition permit them to
become so filled with dirt that they appreciably reduce the air quantity. The
proper ventilation clearances should be fulfilled at all times. Refer to the Set-up
instructions in this manual.
Ventilation There is an exhaust opening in the rear of the unit that is covered by
a hat bracket. Do not remove the hat bracket as it protects the exhaust opening
from being completely covered.
Helpful hints
For drying ovens, open vent to prevent buildup of moisture.
For sample heating, close the vent when no ventilation is required.
12
Startup
For fastest oven heat-up time, close the fresh-air vent. After the desired temperature is
reached, the vent may be adjusted as needed.
1. Start Fan.
a. Open oven door.
b. Press Power switch to the On position. You will hear the recirculating fan
start.
c. Shut oven door.
d. Check that the control display turns on.
2. Operate the temperature control as desired by following the control operation
instructions that follow.
13
CONTROL
The special features of the Protocol PlusTM control include:
PID tuning
Ramp/Soak programming of up to 64 segments
Segment looping and profile linking
Built-in manual reset high limit control
Built-in process timer
Dedicated LED display for process temperature
Multi-purpose two-line LCD display with backlight
Auto-tuning
Security access
Process temperature retransmission signal
Digital inputs for remote profile control
Optional relay outputs for events, alarms, or end-of-cycle signal
Optional real-time-clock
Optional RS232/RS422/RS485 MODBUS communications
Theory of Control Operation
The Protocol Plus is a modular microprocessor based digital temperature controller. The
Protocol Plus operates as a dual functioning controller/high limit instrument. The control
portion utilizes a time-proportioning voltage signal to control heating devices with
minimal temperature fluctuations.
The high limit portion protects the product and/or the oven from overheating. If the
product being processed has a critical high temperature limit, the high limit setpoint
should be set to a temperature somewhat below the temperature at which the product
could be damaged. If the product does not have a critical high temperature limit, the
high limit setpoint should be set 5 to 15 degrees higher than the maximum programmed
setpoint at which the oven will operate.
14
Protocol Plus Faceplate and Wiring Diagram
15
Operating Modes
The Protocol Plus control has five modes of operation available:
Stopped Mode: All control and relay outputs are off. Stopped Mode is integrated
into each of the following four modes of operation.
Manual Mode: Control operates as a single setpoint control until Stopped mode is
accessed
Timer Mode: Control operates as a single setpoint control until preset time period
has expired.
Profile Mode: Control operates as a ramp/soak profiling control until the end of
the profile. 8 profiles are available with up to 8 ramp/soak segments
in each profile.
Auto Start Mode (optional): Control may automatically start Manual, Timer, or
Profile mode based on a preset time and day.
Requires the optional real-time clock feature.
The optional event outputs can be utilized during Manual, Timer, or Profile modes.
Setup Mode
The control has a Setup Mode which provides access to control configuration and
programming of profiles. The Setup Mode contains ten separate electronic Pages where
the configuration and programming parameters (Menu items) are found. The Setup
Mode Pages are described in detail elsewhere in this manual.
Fast Start Mode
The Protocol Plus control has the ability to automatically start an operating mode when
power is applied. This feature may be useful if the same mode of operation is used
everyday. The user can turn on the power and the oven will start the desired process
automatically. The Fast Start Mode is controlled by the Power-Up Start parameters on
the Control page (see Setup Mode).
16
High Limit
The control has an integrated high limit function which will disable the heater output
when tripped. If the high limit does trip, the relay will need to be manually reset. When
the high limit relay is tripped, the Hi-Limit indicator will be lit. Allow the oven to cool
several degrees (or increase the high limit setpoint) and then press the Reset key. The
indicator will turn off.
The control will not allow the high limit setpoint to be set below the current setpoint
value.
Indicators
The Protocol Plus control has 12 indicating LEDs that provide operational information to
the user.
Power LED: Indicates that power is supplied to the instrument.
Heater LED: Indicates that the heater output is active.
Profile LED: Indicates that the Profile Mode is in operation.
Timer LED: Indicates that the Timer Mode is in operation.
Manual LED: Indicates that the Manual Mode is in operation.
Cycle Complete LED: Indicates that the control is in Stopped mode.
Hi-Limit Alarm LED: Indicates that the high limit relay has tripped (de-energized).
Soak Alarm LED: Indicates that the guaranteed soak deviation is in alarm condition.
Outputs 1 through 4: Indicate that the optional relay outputs are in the ON state.
These outputs may be configured as timed event outputs, process temperature trip
point outputs, alarm outputs, or as an end of cycle relay output. The ON state can be
configured as energized or de-energized.
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