Despatch RFD Series - Manual (Page 20)

T HEORY OF O PERATION RFD Oven Series Owner’s Manual
20 Version 1
Copyright © 2012 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.
3.3.1. Purpose of Adjustable Airflow
Optional adjustable airflow has several purposes in the RFD 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.
3.4. The Protocol 3 Controller
The Protocol 3™ is a microprocessor based digital temperature controller designed for simple
and flexible oven operation (Figure 9). The Protocol 3 controller operates as a dual-functioning
Warning!
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.
Notice
It is particularly important that the oven operators have a
practical understanding of the automatic controls. These
regulate the temperature, provide safety features and generally
govern the consistently uniform and satisfactory performance
of the oven.