Run Mode Control Procedure - SAWTOOTH SPG-410 Operating Manual

RUN MODE CONTROL PROCEDURE

Deciding whether to control to the Meat Probe Setpoint or the Grill Probe Setpoint
Any time the system is in the run mode, it is attempting to control the Meat Probe to the Meat Probe setpoint first
and the Grill Probe to the Grill Probe setpoint second. If a Meat Probe isn't detected, the system does not attempt
to control to it. While a Meat Probe is present and the Meat Probe temperature is below the Meat Probe setpoint,
the system will control the Grill Probe to the Grill Probe setpoint. When the Meat Probe is within 5 degrees of the
Meat Probe setpoint or higher, the system will no longer control the grill temperature to the Grill Probe setpoint,
but will instead use the minimum Grill Probe setpoint of 150°F and the display will change to .
Taking this action can prevent exceeding the Meat Probe setpoint for some time, but in the case where the Meat
Probe setpoint is significantly below the minimum Grill Probe Setpoint (for example if the Meat Probe setpoint is
80°F), the temperature of the item being monitored will likely continue to rise depending on the mass and the
amount of time it is allowed to stay in this state. For the best results, either use a Meat Probe setpoint above 150°F
or monitor the meat probe closely.
Note – if you are planning on doing multiple stage temperature cooking, you may consider NOT setting the Meat
Probe set point. For example, if your recipe calls for cooking at 225° for 1.5 hours, then 250° for another 1.5 hours,
the grill will automatically reduce to 150° as described in section above.
Controlling the Grill Probe temperature to the Grill Probe Setpoint
Regardless of whether the system has a meat probe connected, the primary function of the controller is to increase
the output of fuel to the combustion chamber when the Grill Probe actual temperature is measured to be below the
Grill Probe setpoint, and decrease the fuel when the measured temperature exceeds the setpoint. Additionally, the
fan output can be reduced in some cases where the call for heat is very low. This is an attempt to maintain a
minimum air to fuel ratio for the best combustion at low temperatures. Because the system is attempting to
monitor and control to a setpoint, operation with the lid open can dramatically affect the ability to control the
system to a setpoint. It is recommended that the grill be operated with the lid closed to the extent this is possible.
Reactions to falling temperatures
The system will react to a falling temperature in several ways. First, it will increase the amount of fuel and possibly
the amount of air being supplied to the combustion area. If the temperature continues to fall more than 25°F
below the setpoint, the igniter will turn on. If the system continues to fall below a minimum operating temperature
of 115°F, it will reenter the ignition mode, and if after 30 minutes, the system has failed to reach at least 150°F, it
will shut down and display the error code for failure to start ( ).
Reaction to Over-Temperature
If the system detects a temperature on the Grill Probe exceeding 700°F, it will shut down and display the Over
Temperature error code ( ).
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