Despatch LAC-6 Series User manual

LAC Series Oven Owner’s Manual ABOUT THIS MANUAL
Version 106 1
Copyright © 2011 by Despatch Industries.
All rights reserved. No part of the contents of this manual may be reproduced, copied or transmitted in any form or by any
means including graphic, electronic, or mechanical methods or photocopying, recording, or information storage and
retrieval systems without the written permission of Despatch Industries, unless for purchaser's personal use.
ULTRAFLEX DRYING AND FIRING
FURNACE
MODELS 1000, 3615, 3630, 3640
OWNERS MANUAL
C-204
VERSION 10
10/2008
LAC-6 SERIES OVEN
OWNER’S MANUAL
C-194
PN 150138
VERSION 16
3/2011

ABOUT THIS MANUAL LAC Series Oven Owner’s Manual
2 Version 10
Copyright © 2011 by Despatch Industries.
All rights reserved. No part of the contents of this manual may be reproduced, copied or transmitted in any form or by any
means including graphic, electronic, or mechanical methods or photocopying, recording, or information storage and
retrieval systems without the written permission of Despatch Industries, unless for purchaser's personal use.
Revision History
Revision
Date
Author
Description
B
Updated contents of Drawings Section
Updated Protocol Plus instructions
C
Added “Operating Environment” note to Operating
section. Updated drawings. Modified Preface
D
Modified per Rev C Protocol Plus software
E
Various corrections
F
Updated drawings
G
Updated Despatch warranty.
H
Updated drawing
I
Update to Protocol Plus Version 4
J
Ref. CAR 1165C
K
Changes to Unpacking and Inspection
L
Changed drawings
M
Revised Protocol numbers. Updated Despatch
address
N
Updated warranty
O
Updated Protocol Plus Section
16
3/2011
K. Livingston
Revise format.

LAC Series Oven Owner’s Manual ABOUT THIS MANUAL
Version 106 3
Copyright © 2011 by Despatch Industries.
All rights reserved. No part of the contents of this manual may be reproduced, copied or transmitted in any form or by any
means including graphic, electronic, or mechanical methods or photocopying, recording, or information storage and
retrieval systems without the written permission of Despatch Industries, unless for purchaser's personal use.
Table of Contents
1. About This Manual................................................................................................. 5
1.1. Important User Information.......................................................................... 5
1.2. Manufacturer & Service................................................................................ 6
1.3. Organization of this Manual ......................................................................... 6
1.4. Conventions .................................................................................................. 7
1.5. Specifications................................................................................................ 8
1.5.1. Dimensions................................................................................................ 8
1.5.2. Capacities.................................................................................................. 9
1.5.3. Power....................................................................................................... 10
1.5.4. Temperature ............................................................................................ 11
2. Safety .................................................................................................................... 12
2.1. Safety Information...................................................................................... 12
2.1.1. Lockout.................................................................................................... 12
2.1.1.1. Lockout Requirements......................................................................... 12
2.1.1.2. Lockout Procedure............................................................................... 12
2.1.2. Door and Panel........................................................................................ 13
2.2. Maintenance................................................................................................ 13
2.3. Electrical Power.......................................................................................... 13
2.4. Fire.............................................................................................................. 14
2.5. Equipment Lockout Requirements ............................................................. 15
2.5.1. Emergency Stop ...................................................................................... 15
3. Theory of Operation.............................................................................................. 16
3.1. The LAC-6 Series Oven.............................................................................. 16
3.2. Damper Control .......................................................................................... 17
3.2.1. Determining Damper Settings................................................................. 17
3.2.1.1. Damper Full-Closed Position .............................................................. 17
3.2.1.2. Damper Full-Open Position................................................................. 17
3.2.1.3. Other Damper Settings ........................................................................ 18
3.3. The Protocol Plus Controller ...................................................................... 19
4. Assembly & Setup ................................................................................................ 20
4.1. Unpack & Inspect the LAC-6 Series Oven................................................. 20
4.1.1. If Damaged During Shipping.................................................................. 20
4.2. Set-up the LAC-6 Series Oven ................................................................... 20
4.2.1. Select Oven Location/Operating Environment ....................................... 20
4.2.2. Set-up Procedure..................................................................................... 21
4.2.3. Wiring & Power Connections................................................................. 22
4.2.3.1. Wire LAC-6 Models 2-12 and 2-18 .................................................... 23
4.3. MRC5000 Setup (Optional)........................................................................ 25
5. Operation............................................................................................................... 26
5.1. Load Oven................................................................................................... 26
5.2. Pre-Startup Checklist .................................................................................. 27
5.3. Operating Procedure ................................................................................... 28
5.3.1. Start Oven................................................................................................ 28
5.3.2. Working with Protocol Plus Operating Modes....................................... 28
6. Maintenance.......................................................................................................... 29

ABOUT THIS MANUAL LAC Series Oven Owner’s Manual
4 Version 10
Copyright © 2011 by Despatch Industries.
All rights reserved. No part of the contents of this manual may be reproduced, copied or transmitted in any form or by any
means including graphic, electronic, or mechanical methods or photocopying, recording, or information storage and
retrieval systems without the written permission of Despatch Industries, unless for purchaser's personal use.
6.1. Checklist ..................................................................................................... 29
6.2. Lubrication.................................................................................................. 30
6.3. Routine Tests .............................................................................................. 30
6.4. Door Adjustment......................................................................................... 30
6.5. Replacement Parts....................................................................................... 30
6.5.1. Replace the Protocol Plus Controller...................................................... 31
6.5.2. Replace Heater Unit ................................................................................ 31
6.5.3. Replace Fan Motor.................................................................................. 32
7. Troubleshooting.................................................................................................... 34
7.1. Troubleshooting Error Messages and Alarms............................................. 34
7.2. Troubleshooting Symptoms........................................................................ 34
8. Appendices............................................................................................................ 36
8.1. Standard Products Warranty....................................................................... 36
8.2. Electrical Schematics.................................................................................. 37
Figures
Figure 1. LAC High-performance Bench-top Oven. ........................................................ 16
Figure 2. Horizontal Airflow through the LAC Oven. ..................................................... 16
Figure 3. Damper Positions............................................................................................... 17
Figure 4. Protocol Plus Displays and Control Buttons..................................................... 19
Figure 5. LAC-6 Series Oven Nameplate......................................................................... 22
Figure 6. Rear Access Panel for Hard-Wired Connections. ............................................. 23
Figure 7. Hinged Panel for Simpler Access to Power Connections. ................................ 23
Figure 8. Power Connections at Main Circuit Board........................................................ 24
Figure 9. Remove Screws to Remove Floor Plate............................................................ 31
Figure 10. Heater Panel and Inlet Cone............................................................................ 31
Figure 11. Remove Screws to Remove Side Panels......................................................... 32
Figure 12. Remove Heater Panel by Removing Screw in Front Edge of Each Panel. ..... 32
Figure 13. LAC1-10-6 (Excerpt from drawing 146271D01)............................................ 38
Figure 14. LAC1-38A-6 (Excerpt from drawing 146273D01)......................................... 38
Figure 15. LAC1-38B-6 (Excerpt from drawing 146275D01)......................................... 38
Figure 16. LAC1-67-6 (Excerpt from drawing 146277D01)............................................ 38
Figure 17. LAC2-12-6 (Excerpt from drawing 146279D01)............................................ 38
Figure 18. LAC2-18-6 (Excerpt from drawing 146281E01)............................................ 38
Tables
Table 1. MRC 5000 Settings............................................................................................. 25
Table 2. Error Messages and Next Steps.......................................................................... 34
Table 3. Troubleshooting Oven Symptoms...................................................................... 35

LAC Series Oven Owner’s Manual ABOUT THIS MANUAL
Version 106 5
Copyright © 2011 by Despatch Industries.
All rights reserved. No part of the contents of this manual may be reproduced, copied or transmitted in any form or by any
means including graphic, electronic, or mechanical methods or photocopying, recording, or information storage and
retrieval systems without the written permission of Despatch Industries, unless for purchaser's personal use.
1. About This Manual
1.1. Important User Information
Copyright © 2011 by Despatch Industries.
All rights reserved. No part of the contents of this manual may be reproduced, copied, or
transmitted in any form or by any means including graphic, electronic, or mechanical
methods or photocopying, recording, or information storage and retrieval systems without
the written permission of the publisher, unless it is for the purchaser's personal use.
Printed and bound in the United States of America.
The information in this manual is subject to change without notice and does not represent
a commitment on the part of Despatch Industries. Despatch Industries does not assume
any responsibility for any errors that may appear in this manual.
In no event will Despatch Industries be liable for technical or editorial omissions made
herein, nor for direct, indirect, special, incidental, or consequential damages resulting
from the use or defect of this manual.

Values displayed on screens are examples only. Though
those values may be typical, contact Despatch Industries for
the final value.

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.

ABOUT THIS MANUAL LAC Series Oven Owner’s Manual
6 Version 10
Copyright © 2011 by Despatch Industries.
All rights reserved. No part of the contents of this manual may be reproduced, copied or transmitted in any form or by any
means including graphic, electronic, or mechanical methods or photocopying, recording, or information storage and
retrieval systems without the written permission of Despatch Industries, unless for purchaser's personal use.
Danger!
Only fully-trained and qualified personnel should setup and
maintain this equipment. Improper setup and operation of this
equipment could cause an explosion that may result in
equipment damage, personal injury or possible death.
The information in this document is not intended to cover all possible conditions and
situations that might occur. The end user must exercise caution and common sense when
installing or maintaining Despatch Industries products. If any questions or problems
arise, call Despatch Industries at 1-888-DESPATCH or 1-952-469-5424.
1.2. Manufacturer & Service
The LAC-6 Series Oven is manufactured by Despatch Industries.
Despatch has specialized in thermal processing for over 100 years. Technical expertise
gained over those years helps provide innovative solutions to critical applications in
vertical markets and cutting edge technology worldwide. Despatch products are backed
by a drive for long-term customer satisfaction and a strong sense of responsibility. The
worldwide network of factory-trained Service Professionals is available to support your
Despatch equipment. From full service preventive maintenance to routine repair and
certified calibration and uniformity, the Despatch service network is positioned to
respond to your business needs. Our service programs are customized to meet your
specific needs using our Advantage Service Assurance Program (ASAP). For more
information on ASAP, visit www.despatch.com.
Global Headquarters
Contact
Service & Technical
Support
Despatch Industries
8860 207th Street
Lakeville, MN 55044
USA
International/Main: 1-952-469-5424
US toll free: 1-888-337-7282
Fax: [phone]
[email protected]
www.despatch.com
Service: 1-952-469-8230
US toll free: 1-800-473-7373
Service @despatch.com
1.3. Organization of this Manual
This owner’s manual contains the most comprehensive set of information for the
Despatch LAC-6 Series ovens, including installation instructions, theory of operation,
operating instructions, among other things.

LAC Series Oven Owner’s Manual ABOUT THIS MANUAL
Version 106 7
Copyright © 2011 by Despatch Industries.
All rights reserved. No part of the contents of this manual may be reproduced, copied or transmitted in any form or by any
means including graphic, electronic, or mechanical methods or photocopying, recording, or information storage and
retrieval systems without the written permission of Despatch Industries, unless for purchaser's personal use.
Danger!
Failure to heed warnings in this instruction manual and on the
oven could result in personal injury, property damage or death.
1.4. Conventions

This icon signifies important information.
This icon signifies information that describes an unsafe condition
that may result in death, serious injury, or damage to the
equipment.
Danger!
A condition that may result in death, serious injury, or damage to
equipment.
Warning!
Acondition that may result in serious injury or damage to
equipment.
Caution!
A condition that may result in damage to equipment or product.
LOG OUT
Reversed-out, Bold, 10pt Arial typeface indicates a specific key or
button on screen to click.

ABOUT THIS MANUAL LAC Series Oven Owner’s Manual
8 Version 10
Copyright © 2011 by Despatch Industries.
All rights reserved. No part of the contents of this manual may be reproduced, copied or transmitted in any form or by any
means including graphic, electronic, or mechanical methods or photocopying, recording, or information storage and
retrieval systems without the written permission of Despatch Industries, unless for purchaser's personal use.
1.5. Specifications
1.5.1. Dimensions
LAC
Model
No.
Chamber Size
in (cm)
Capacity
feet3
(liters)
Overall Size
in (cm)
Max.
Number of
Shelf
Positions
Exhaust Diameter
Located on Back
of Chamber
in (cm)
W0F
*
D
H
W
D
H
1-10
13.75
(35)
12
(28)
12
(31)
1
(33)
23
(58)
19
(48)
29.5
(75)
5
1
(2.5)
1-38A
18.75
(48)
18
(46)
19
(48)
3.7
(105)
28
(71)
25
(64)
35.5
(90)
9
2½
(6.4)
1-38B
18.75
(48)
18
(46)
19
(48)
3.7
(105)
28
(71)
25
(64)
35.5
(90)
9
2½
(6.4)
1-67
23.75
(60)
20
(51)
24
(61)
6.6
(187)
36
(91)
27
(69)
40.5
(103)
11
2½
(6.4)
2-12
23.75
(60)
24
(61)
36
(91)
12
(340)
36
(91)
31
(79)
52.5
(133)
17
2 x 2½
(6.4)
2-18
35.25
(91)
24
(61)
36
(91)
18
(510)
47
(119)
29.5
(75)
52.5
(133)
17
2 x 2½
(6.4)

The LAC-6 oven is not intended to process solvents or other
volatile or flammable materials. Oven exhaust is intended for
cooling purposes only.
*Allow 0.375" (0.95 cm) clearance on each side for shelf supports (3/4 in (1.9 cm) total).
Warning!
Do not place this oven in an environment harmful to electrical
components.
Placing this oven in an environment detrimental to electrical
components (for example, environments where carbon fibers,
coal dust or similar contaminants may be present) may result
in component failure.
Contact Despatch for options available to help prevent such
failures.

LAC Series Oven Owner’s Manual ABOUT THIS MANUAL
Version 106 9
Copyright © 2011 by Despatch Industries.
All rights reserved. No part of the contents of this manual may be reproduced, copied or transmitted in any form or by any
means including graphic, electronic, or mechanical methods or photocopying, recording, or information storage and
retrieval systems without the written permission of Despatch Industries, unless for purchaser's personal use.
1.5.2. Capacities
LAC-6 Model Number
1-10-6
1-38 A-6
& B-6
1-67-6
2-12-6
2-18-6
Maximum Load
Lbs (Kg)
150 (68)
175 (79)
250 (113)
300 (136)
300 (136)
Maximum Shelf Load
Lbs (Kg)
50 (23)
50 (23)
50 (23)
50 (23)
50 (23)
Exhaust
CFM
(LPS)
Adjustable
to 5
(2.4)
Adjustable
to 12
(5.6)
Adjustable
to 12
(5.6)
Adjustable
to 30
(14.2)
Adjustable
to 40
(18.9)
Recirculating Fan
CFM
(LPS)
150
(71)
300
(141)
300
(141)
600
(282)
600
(282)
H.P.
1/25
¼
¼
¼ x 2
¼ x 2
Approx. Weight Net
Lbs
(KG)
110
(50)
185
(84)
255
(116)
360
(163)
450
(204)
Shipping Weight
Lbs
(KG)
175
(79)
270
(123)
360
(163)
480
(218)
600
(272)

ABOUT THIS MANUAL LAC Series Oven Owner’s Manual
10 Version 10
Copyright © 2011 by Despatch Industries.
All rights reserved. No part of the contents of this manual may be reproduced, copied or transmitted in any form or by any
means including graphic, electronic, or mechanical methods or photocopying, recording, or information storage and
retrieval systems without the written permission of Despatch Industries, unless for purchaser's personal use.
1.5.3. Power
If the line voltage for your LAC-6 Series Oven varies more than 10% from the oven
voltage rating, electrical components such as relays and temperature controls may operate
erratically.
If the line voltage is lower than the oven voltage rating, heat-up time may be
significantly longer and motors may overload or run hot
If the line voltage is higher than the nameplate rating, motors may run hot and draw
excessive amperage
Model
Volts
Amps
Hertz
Phase
Heater
KW
Cord and Plug
LAC 1-10-6
120
10.0
50/60
1
1
Included, 15 Amp (NEMA 5-15)
LAC 1-38A-6
120
16.5
50/60
1
1.6
Included, 20 Amp (NEMA 5-20)
LAC 1-38B-61F
†
240
9.5
50/60
1
1.8
Included, 15 Amp (NEMA 6-15)
LAC 1-67-6†
240
12.0
50/60
1
2.4
Included, 15 Amp (NEMA 6-15)
LAC 2-12-6† 2F
‡
240
18.5
50/60
1
3.6
None, Hardwired
LAC 2-18-6†‡
240
23.5
50/60
1
4.8
None, Hardwired
†The LAC Series Oven designed for 240 volts (see oven nameplate) will operate satisfactorily on a
minimum of 208 Volts, but will result in 25% reduced heater output. If your power characteristic is 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).

LAC Series Oven Owner’s Manual ABOUT THIS MANUAL
Version 106 11
Copyright © 2011 by Despatch Industries.
All rights reserved. No part of the contents of this manual may be reproduced, copied or transmitted in any form or by any
means including graphic, electronic, or mechanical methods or photocopying, recording, or information storage and
retrieval systems without the written permission of Despatch Industries, unless for purchaser's personal use.
1.5.4. Temperature
LAC-6 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 °C3F
§
200 °C§
260 °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
§Figures are based on actual tests in an empty oven. Uniformity can vary slightly depending on unit and
operating conditions.

SAFETY LAC Series Oven Owner’s Manual
12 Version 106
Copyright © 2011 by Despatch Industries.
All rights reserved. No part of the contents of this manual may be reproduced, copied or transmitted in any form or by any
means including graphic, electronic, or mechanical methods or photocopying, recording, or information storage and
retrieval systems without the written permission of Despatch Industries, unless for purchaser's personal use.
2. Safety
2.1. Safety Information
Do not work on the LAC-6 Series Oven without reading and understanding this section
which contains important information and warnings. Ignoring these warnings can result
in death, serious injury or damage to the machine and product.
2.1.1. Lockout

Carefully follow the established Lock Out Tag Out policies of
your company in all cases.
Machine lockout places the LAC-6 Series Oven into a zero energy state and prevents
accidental machine start up. Always follow the Lockout Procedure described in this
Section before cleaning, maintaining or repairing the LAC-6 Series Oven. An accidental
start-up, while working on the LAC-6 Series Oven, can result in serious injury or death.
2.1.1.1. Lockout Requirements
1. Every power source that can energize any element of the LAC-6 Series Oven must be
shut off at the closest possible power source. This includes air, water and electricity,
including the Disconnect Switch.
2. After energy sources are locked out, test to ensure circuits are de-energized.
2.1.1.2. Lockout Procedure
Personnel authorized to lockout equipment must have the necessary locks to perform the
lockout.
1. Physically disconnect all electrical power to the machine or lockout the appropriate
breaker or disconnects.
Danger!
Electrical panels contain high voltage. Disconnect and lock out
the power supply before working inside any electrical panels.
Failure to lock out the power supply can result in death or injury.

LAC Series Oven Owner’s Manual SAFETY
Version 10 13
Copyright © 2011 by Despatch Industries.
All rights reserved. No part of the contents of this manual may be reproduced, copied or transmitted in any form or by any
means including graphic, electronic, or mechanical methods or photocopying, recording, or information storage and
retrieval systems without the written permission of Despatch Industries, unless for purchaser's personal use.
2. Close all valves and bleed off any pressure.
3. Test for power by attempting a start with the machine controls.
4. Identify the Lockout Condition with a tag on the electrical disconnect and pneumatic
shut off valve.
5. When work is complete, remove all tags and restore the machine to its working state.
2.1.2. Door and Panel
The control panel on the LAC-6 Series Oven protect against hazards. Operation without
the control panel in place creates hazards that the control panel is intended to render safe
for personnel.
2.2. Maintenance
Only qualified and trained personnel should perform maintenance or repair.
2.3. Electrical Power
Only qualified and trained personnel should perform electrical maintenance or electrical
repair.
Danger!
Electrical panels contain high voltage. Disconnect and lock out
the power supply before working inside any electrical panels.
Failure to lock out the power supply can result in death or injury.
Warning!
Do not place this oven in an environment harmful to electrical
components.
Placing this oven in an environment detrimental to electrical
components (for example, environments where carbon fibers,
coal dust or similar contaminants may be present) may result
in component failure.
Contact Despatch for options available to help prevent such
failures.

SAFETY LAC Series Oven Owner’s Manual
14 Version 106
Copyright © 2011 by Despatch Industries.
All rights reserved. No part of the contents of this manual may be reproduced, copied or transmitted in any form or by any
means including graphic, electronic, or mechanical methods or photocopying, recording, or information storage and
retrieval systems without the written permission of Despatch Industries, unless for purchaser's personal use.
Danger!
Contact with energized electrical sources may result in serious
injury or death.
Before performing maintenance, disconnect all electrical power from the machine.
Use a padlock and lockout all disconnects feeding power to the machine.
Never clean, or repair the oven when in operation.
Unauthorized alterations or modifications to LAC-6 Series Oven are strictly
forbidden. Never modify any electrical circuits. Unauthorized modifications can
impair the function and safety of the LAC-6 Series Oven.
2.4. Fire
Keep the LAC-6 Series Oven clean and free of scrap materials, oil or solvents to prevent
the possibility of fire. In the event of fire, use a fire extinguisher as follows.
1. Leave door as it is.
2. De-energize the machine immediately by turning OFF the main power.
3. Shut off fuel (if applicable)
4. Call the fire department or extinguish the fire.
Danger!
Always disconnect all power before extinguishing a fire.
Attempting to extinguish a fire in a machine connected to
electrical power can result in serious injury or death!
Warning!
Do not place this oven in an environment harmful to electrical
components.
Placing this oven in an environment detrimental to electrical
components (for example, environments where carbon fibers,
coal dust or similar contaminants may be present) may result
in component failure.
Contact Despatch for options available to help prevent such
failures.

LAC Series Oven Owner’s Manual SAFETY
Version 10 15
Copyright © 2011 by Despatch Industries.
All rights reserved. No part of the contents of this manual may be reproduced, copied or transmitted in any form or by any
means including graphic, electronic, or mechanical methods or photocopying, recording, or information storage and
retrieval systems without the written permission of Despatch Industries, unless for purchaser's personal use.
2.5. Equipment Lockout Requirements
To prevent injury or equipment damage during inspection or repair, the LAC-6 Series
Oven must be locked out.
2.5.1. Emergency Stop
When a risk of personal injury or damage to the LAC-6 Series Oven exists, turn OFF the
oven by removing/unplugging the cord. This shuts off all electrical power to the oven.

THEORY OF OPERATION LAC Series Oven Owner’s Manual
16 Version 106
Copyright © 2011 by Despatch Industries.
All rights reserved. No part of the contents of this manual may be reproduced, copied or transmitted in any form or by any
means including graphic, electronic, or mechanical methods or photocopying, recording, or information storage and
retrieval systems without the written permission of Despatch Industries, unless for purchaser's personal use.
3. Theory of Operation
3.1. The LAC-6 Series Oven
The LAC-6 high-performance bench-top
oven uses digitally-controlled, horizontal
recirculating airflow to ensure uniform
temperatures throughout the oven for fast-
processing (Figure 1). A high-volume fan
circulates air through perforated, stainless
steel walls to create a constant horizontal
airflow across all sections of the oven
(Figure 2). The result is proven reliability in
demanding production and laboratory
applications such as curing, drying,
sterilizing, aging and other process-critical
procedures.
The LAC-6 oven is especially useful for testing, preheating, sterilizing, drying, aging and
curing along with other production applications. The overall result is efficient
productivity under strenuous conditions. 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.
Damper
Control
Power Switch
Protocol Plus Controller
Figure 1. LAC High-performance Bench-top Oven.
Figure 2. Horizontal Airflow through the LAC Oven.

LAC Series Oven Owner’s Manual THEORY OF OPERATION
Version 106 17
Copyright © 2011 by Despatch Industries.
All rights reserved. No part of the contents of this manual may be reproduced, copied or transmitted in any form or by any
means including graphic, electronic, or mechanical methods or photocopying, recording, or information storage and
retrieval systems without the written permission of Despatch Industries, unless for purchaser's personal use.
3.2. Damper Control
The LAC-6 oven is equipped with a manually-adjustable damper mechanism. The
damper control arm is located on the front panel of the oven (Figure 1). 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.
3.2.1. Determining Damper Settings
The optimum setting for the damper depends on a variety of
factors. These factors include ambient environment
temperature, load conditions, load distribution, heat-up and
cool-down rates, desired temperature uniformity and most
importantly the desired operating temperature. Additionally,
engineering tradeoffs for each factor must be carefully
weighed. While considering each factor independently may
be too daunting, guidelines provide a simpler way to
determine damper settings.
In general, set the damper so the amount of fresh air flowing
into and exhausting from the chamber agrees with the
desired operating temperature conditions. The following
outline provides practical considerations for various damper
position settings (Figure 3).
3.2.1.1. Damper Full-Closed Position
The damper in full-closed position allows maximum attainable heat-up rates for the
chamber. In addition, the chamber uses minimum power to operate at the desired
temperature. In most cases, maintain the damper in the full-closed position to efficiently
operate at the maximum operating temperature for the chamber.
3.2.1.2. Damper Full-Open Position
The damper in full-open position allows minimum operating temperature for the
chamber. Friction heat from the air recirculation system builds up in the chamber. This
causes chamber temperature to rise slightly though the heating system is not ON. After
Warning!
Do not remove the hat bracket (located in rear of oven) as it
distributes exhaust air and protects the exhaust opening from
being completely covered.
Figure 3. Damper Positions.

THEORY OF OPERATION LAC Series Oven Owner’s Manual
18 Version 106
Copyright © 2011 by Despatch Industries.
All rights reserved. No part of the contents of this manual may be reproduced, copied or transmitted in any form or by any
means including graphic, electronic, or mechanical methods or photocopying, recording, or information storage and
retrieval systems without the written permission of Despatch Industries, unless for purchaser's personal use.
the recirculation motor has been ON for an extended period of time, the chamber reaches
a thermal equilibrium temperature.
When the damper is not set to 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.

When the damper is in the full-open position, the oven may not
be able to heat to the maximum oven operating temperature.
3.2.1.3. 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: uniformity and cool-
down rates.
Chamber Uniformity
The system’s inside chamber pressure influences chamber uniformity. Pressure inside the
chamber depends on the amount of fresh air flowing into the chamber. When a large
volume of fresh air flows into the chamber, the chamber pressurizes slightly and overall
temperature uniformity improves. The slightly pressurized chamber produces the effect
of "pushing" air to the corners of the chamber. Typically the corners of the chamber
improve with respect to temperature distribution while the core of the chamber maintains
excellent uniformity characteristics regardless of damper position.
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.
Cool-Down Rates
The more open the damper, the faster the cool-down.

Over-pressuring the chamber can cause hot air to blow out
around the door seal and cause the area around the door to
be hot to the touch. Eliminate this hot air from entering the
room by closing the damper slightly until the air stops
blowing.

LAC Series Oven Owner’s Manual THEORY OF OPERATION
Version 106 19
Copyright © 2011 by Despatch Industries.
All rights reserved. No part of the contents of this manual may be reproduced, copied or transmitted in any form or by any
means including graphic, electronic, or mechanical methods or photocopying, recording, or information storage and
retrieval systems without the written permission of Despatch Industries, unless for purchaser's personal use.
3.3. The Protocol Plus Controller
The Protocol Plus controller has two displays. A dedicated LED upper display shows the
oven temperature (Figure 4). A two line LCD lower display provides information on
control status, high limit temperature and allows changes to be made to the control
settings. Review the Protocol Plus Controller Owner’s Manual for more information.
Figure 4. Protocol Plus Displays and Control Buttons.

ASSEMBLY &SETUP LAC Series Oven Owner’s Manual
20 Version 106
Copyright © 2011 by Despatch Industries.
All rights reserved. No part of the contents of this manual may be reproduced, copied or transmitted in any form or by any
means including graphic, electronic, or mechanical methods or photocopying, recording, or information storage and
retrieval systems without the written permission of Despatch Industries, unless for purchaser's personal use.
4. Assembly & Setup
Assembly and Setup provides directions for unpacking and installing your LAC-6 Series
Oven.
4.1. Unpack & Inspect the LAC-6 Series Oven
Remove all packing materials and thoroughly inspect the oven for any damage that might
have occurred during shipment.
Note whether the carton and plastic cover sheet inside carton are still in good
condition
Observe all outside surfaces and corners of the oven for scratches and dents
Check 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
4.1.1. If Damaged During Shipping
If damage occurred during shipping:
1. Contact the shipper immediately and file a written damage claim.
2. Contact Despatch Industries (1-800-473-7373 or 1-952-469-8230 or
[email protected]) to report your findings and to order replacement parts for
those damaged or missing. Send a copy of your filed damage claims to Despatch
industries (Despatch Industries, 8860 207th Street, Lakeville, MN 555044, USA).
3. Check the packing list to ensure you received all the specified components of the
oven system. If any items are missing, contact Despatch Industries to have missing
products forwarded to you. Your shipment should include:
One (1) Despatch oven
One (1) Instruction manual and Protocol Plus Manual
One (1) Warranty card
Two (2) Shelves
4. Complete the warranty card and mail it to Despatch within 15 days after receipt of the
equipment.
4.2. Set-up the LAC-6 Series Oven
4.2.1. Select Oven Location/Operating Environment
The Despatch LAC-6 Series oven is designed to operate in an industrial setting.
Despatch recommends the following environmental operating guidelines:
1. Place the oven on a flat, level solid foundation