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.
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.
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.
RAD Oven Series Owner’s Manual PREFACE
Version 1 5
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.
ABOUT THIS MANUALRAD Oven Series Owner’s Manual
Before operating this equipment, carefully read instruction
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 5 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 1985.
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.
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.
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.
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: 1-952-469-4513
info@despatch.com
www.despatch.com
Service: 1-952-469-8230
US toll free: 1-800-473-7373
Service @despatch.com
Version 1 7
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 RAD oven series, which includes RAD2-13, RAD2-19 and RAD2-35, 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 factorytrained 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.
1.3. Organization of this Manual
This owner’s manual contains a the most comprehensive set of information for the Despatch
RAD oven series, including installation instructions, theory of operation, and operating
instructions, among other things. To save time and expense in case of trouble, it is urged that the
operators search this manual for helpful suggestions before requesting factory assistance.
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.
Failure to heed warnings in this instruction manual and on the
oven could result in personal injury, property damage or death.
This icon signifies information that describes an unsafe
condition that may result in death, serious injury, or damage to
the equipment.
Danger!
Danger is the signal word used to indicate a hazardous
situation that, if not avoided, will result in death or severe
injury.
Warning!
Warning is the signal word used to indicate a hazardous
situation that, if not avoided, could result in death or severe
injury.
Caution!
Caution is the signal word used to indicate a hazardous
situation that, if not avoided, could result in moderate or minor
injury.
Notice
Notice is the signal word used to indicate a hazardous situation
that, if not avoided, could result in property damage.
This icon signifies supplemental important information.
LOG OUT
Bold, 10 point sans-serif typeface indicates a specific key or
button on screen to click.
8 Version 1
1.4. Conventions
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.
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.
Control Stability (∆ represents the change in ambient
temperature)
+/- 0.5ºC/5ºC ∆
Repeatability
+/- 0.5ºC
*
Figure 1.
Design
Information
and
Specification
Label.
10 Version 1
1.5.3. Temperatures
Refer to the Design Information and Specification labels on your oven
for temperature specifics pertaining to your oven (Figure 1).
Uniformity figures are based on a nine-point test conducted in an empty oven after stabilization period.
Uniformity can vary slightly depending on unit and operating conditions. Minimum operating temperature
and cooling times are based on 20ºC ambient temperature measured at the fresh air inlet with the fresh air
and exhaust dampers fully open. Specifications are subject to change without notice.
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.
This oven is not designed for use with flammable material. If
your process involves flammable material, see the RFD Class A
series.
†
‡
Figure 2. Electrical Specification Label.
Version 1 11
1.5.4. Power
Line voltages may vary in some geographies. If the
line voltage for your RAD 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.
Refer to the Electrical Specifications on your oven
for the specifics pertaining to your oven (Figure 2).
An 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.
50 hertz electrical is available on all models.
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.
An accidental start-up, while working on the RAD oven, can
result in serious injury or death.
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.
12 Version 1
2. Safety
2.1. Safety Information
Do not work on the RAD 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
Machine lockout places the RAD 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 RAD oven.
2.1.1.1. Lockout Requirements
1. Every power source that can energize any element of the RAD oven must be shut off at the
closest possible power source. This includes air, water, electricity, and 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.
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.
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.
High voltage present on this equipment, service by authorized
personnel only. Contact with energized electrical sources may
result in serious injury or death.
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.
Version 1 13
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.
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 RAD oven are strictly forbidden. Never modify
any electrical circuits. Unauthorized modifications can impair the function and safety of the
RAD oven.
2.4. Fire
Keep the RAD oven clean and free of scrap materials, oil or solvents to prevent the possibility of
fire. In the event of fire, follow these steps.
1. Leave the door as it is.
2. Shut off electricity.
3. De-energize the machine immediately by turning OFF the DISCONNECT SWITCH.
4. Turn off the remote main disconnect (customer supplied disconnect).
5. Shut off fuel.
6. Call the fire department.
7. Stay away.
2.5. Equipment Lockout Requirements
To prevent injury or equipment damage during inspection or repair, the RAD oven must be
locked out.
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 RAD oven has an optional Disconnect Switch (Figure 3). This
Disconnect Switch is connected to the load break switch behind the
panel that disconnects or connects power from the main line. When a
risk of personal injury or damage to the RAD oven exists, turn OFF
the DISCONNECT SWITCH on the front of the oven. This shuts off
all electrical power to the oven.
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.
RAD Oven Series Owner’s Manual THEORY OF OPERATION
mechanism
Figure 4. RAD Oven Series.
Figure 5. RAD Fresh Air Damper.
Figure 6. RAD Exhaust Damper.
Version 1 15
3. Theory of Operation
3.1. The RAD Oven Series
The RAD ovens (Figure 4) feature horizontal
recirculating airflow to ensure exceptional temperature
uniformity throughout the oven. A high-volume fan
circulates air through perforated, stainless steel walls to
create a constant horizontal airflow across all sections of
the oven. The result is proven reliability in demanding
production and laboratory applications, such as curing,
drying, sterilizing, aging, and other process-critical
applications.
3.2. Damper Control
Fresh air and exhaust dampers (Figure 5 and Figure 6)
control the amount of air exchanged as well as the oven chamber pressure. When the fresh air
damper is closed and the exhaust damper is open, oven chamber pressure tends toward negative.
When the fresh air damper is open and the exhaust damper is closed, the oven chamber pressure
tends toward positive (Table 1).
A negative oven pressure may draw ambient air into any
opening, causing cool spots to occur. The slightly
pressurized chamber produces the effect of pushing air to
the corners of the chamber. However, too much positive
pressure may force hot air or process vapors out of any
openings in the oven into the work area. Ideally, the fresh
air and exhaust dampers should be closed as much as
possible and the oven should be maintained at a neutral or
slightly positive pressure.
Exhaust
damper
control
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.
Maintain slight positive pressure to regulate heat.
Too much positive pressure in an oven can create a high outer
skin temperature as hot air is forced out through panel joints
and around door seal. High outer skin temperature could warp
the front of the oven.
16 Version 1
Table 1. Damper Positions for Chamber Pressure.
3.2.1. Determining Damper Settings
The optimum setting for the amount of fresh air that should be distributed into the chamber
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. Carefully consider existing engineering
tradeoffs while using guidelines to determine the fresh air damper setting.
In general, the damper should be set so that the amount of fresh air flowing into the chamber
agrees with the desired operating temperature conditions. The following paragraphs show the
considerations involved with various damper position settings.
3.2.1.1. Fresh Air Damper Fully Closed Position
The chamber achieves maximum attainable heat-up rates when the fresh air damper lies in the full
closed position. With the damper in the full closed position, the chamber will operate at the
desired temperature using the minimum amount of power. In most cases, the oven also efficiently
operates at the chamber’s maximum operating temperature when in the full closed position.
3.2.1.2. Fresh Air Damper Fully Open Position
The chamber operates at its minimum operating temperature with the fresh air damper in full
open position.
Friction heat from the air recirculation system builds up in the chamber. This causes chamber
temperature to rise slightly even without the heating system on. The chamber reaches thermal
equilibrium temperature after the recirculation motor runs for an extended period of time.
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.
RAD Oven Series Owner’s Manual THEORY OF OPERATION
When the damper is in full open position, the oven may not be
able to heat to the maximum oven operating temperature.
This section applies only to ovens that include the optional
adjustable louvers. Ovens without the louver option do not have
adjustable airflow.
Optional adjustable
Version 1 17
The chamber cannot readily dissipate heat generated by friction without a fully open fresh air
damper. With the fresh air damper fully open, the thermal equilibrium temperature is the minimum operating temperature of the chamber.
3.2.1.3. Exhaust Damper Control
Adjusting the exhaust damper (Figure 6) aids in pressurizing the chamber.
3.3. Optional Adjustable Louvers
RAD oven series come standard with perforated supply and exhaust panels (Figure 7).
Optional adjustable louvers provide an extra measure of airflow customization. Figure 8
shows the initial factory settings for the optional louvers.
Standard perforated
panels
louvers
Figure 7. Standard perforated panels and adjustable louvers.
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.
Maintain slight positive pressure to regulate heat.
Too much positive pressure in an oven can create a high outer
skin temperature as hot air is forced out through panel joints
and around door seal. High outer skin temperature could warp
the front of the oven.
18 Version 1
Figure 8. Initial factory settings for optional louvers.
3.3.1. Purpose of Adjustable Airflow
Optional adjustable airflow has several purposes in the RAD oven:
1. Ability to get the best temperature and airflow uniformity.
2. Ability to “spot heat” special areas or specific parts of load.
3. Ability to prevent air flowing out or sucking in through the entrance and exit openings in the
oven.
3.3.2. Supply Air Adjustment
The adjustment of supply louvers is directly related to temperature uniformity in the work
chamber. A general guideline is that more heat is required next to doors, windows and outside
walls so, therefore, more air is required to deliver that heat.
3.3.3. Return Air Adjustment
Ensure there are no restrictive conditions which may limit the amount of air handled by the return
ducts. Restrictions in return air ducts may decrease the amount of air handled by the fan and/or
may result in pressurized conditions in the work chamber. The initial settings for return louvers
should be 50% more open than the supply louvers. Final adjustment may be necessary.
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.