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BCS6000C-9
MOTOR CALIBRATION
The control motor DEADBAND settings determine the allowable deviation of actual
control motor position from setpoint without corrective action by the motor control
outputs (minimum 0.5%, maximum 5.0%, typically set at 1.0%). These parameters
should be set as low as possible without causing the control motors to ‘hunt’ excessively.
Touch the numeric displays and use the popup keypad to enter a deadband setting for
each motor.
Press the ZERO button to drive all control motors closed for calibration and record the
feedback signals. Confirm that all motors, and the combustion air VFD, if applicable,
have reached their low fire positions, or minimum frequency, before beginning span
calibration.
Press the SPAN button to drive the motors open and record the resulting feedback
signals. Verify that all motors and the combustion air VFD, if applicable have fully
opened, or reached their maximum frequency, before pressing the OFF button to store
the span values and end motor calibration.
BURNER OPERATING PARAMETERS
Set the BURNER OUTPUT LIMIT at 100.0% for normal operation. This value may need
to be lowered to accommodate system limitations.
If the optional gas flow display and totalizer are installed, set the GAS PRESSURE to
match the pressure, in osig, measured just upstream of the gas orifice flange assembly.
TEMPERATURE DISPLAY
If the Material and Stack temperatures displayed on the touchscreen are significantly
different from the instrument displays, a positive or negative BIAS value may be entered
for each instrument.
CONTROL LOOP TUNING Screen
After setting and recording all parameters on the Motor Calibration & Setup screen, press MAIN
MENU key to return to the menu screen then select the CONTROL LOOP TUNING button to
display the loop tuning screen. This screen is used to enter tuning constants for each of the
three PID control loops. MATERIAL or STACK temperature control may also be selected on
this screen. Manual control of the burner firing rate and exhaust damper control motors are also
provided. Note that the tuning parameters for the draft control loop are different for the standard
duplex time proportional and the optional 4-20mA control modes.
Enter a GAIN setting for each loop. Note that Gain = 100/Proportional Band% or
Proportional Band% = 100/Gain. For example, a Gain of 2 is equivalent to a
Proportional Band setting of 50%
Enter a DEADBAND setting (
°F for temperature and "WC for draft) for each loop. This
value should be as small as possible without excessive ‘hunting’ by the control
actuators.
Enter a RESET setting for the Material and Stack control loops. Note that Reset is
expressed in minutes per repeat rather than repeats per minute. Therefore, the smaller
the setting the more frequently reset action will be repeated.
Enter a RATE setting (seconds) if desired for Material and Stack control. Note that Rate
tends to de-stabilize the control and may be left at zero.
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