Despatch RAD1-42 -2E with Protocol 3 - Manual (Page 15)

RFD1-42-2E Oven Owner’s Manual T HEORY OF O PERATION
Version 1 15
Copyright © 2012 by Despatch Industries.
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retrieval systems without the written permission of Despatch Industries, unless for purchaser's personal use.
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.
Notice
Overpressurizing 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. Stop this hot air from entering the room by
closing the damper slightly until the air stops blowing.
3.3. The Protocol 3 Controller
The Protocol 3™ controller is a microprocessor based digital temperature controller designed for
simple and flexible oven operation (Figure 4). The Protocol 3 controller 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.
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.