Despatch RFD Series - Manual (Page 21)

RFD Oven Series Owner’s Manual T HEORY OF O PERATION
Version 1 21
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.
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.

The purchaser is responsible for setting the High Limit Control
per the instructions in this manual.
The Protocol 3 controller provides three primary operating modes:

Manual: Oven operates continuously at a fixed temperature until turned off.

Timer: Oven operates at a fixed temperature for a user-selected time period, and then
automatically turns off.

Profile: Temperatures increase or decrease as defined by 255 segments that can be allocated
to 64 ramp and soak profiles. The profiles can be linked to provide additional temperature
combinations.
Review the Protocol 3 Controller Owner’s Manual for more information.
Danger!
Failure to attend to High Limit Control Warning may result in
property damage, serious bodily injury or death.
Figure 9. Protocol 3 Operator Interface.