Blodgett MT3870, Service And Repair Manual

Page: 43 / 69

CALIBRATION AND ADJUSTMENT
4-6
BELT SPEED CALIBRATION
CLOSED LOOP SYSTEM
To enter the calibration mode:
1. Press the ON/OFF key until OFF is displayed.
2. Press CLEAR 1 2 3 4 5 6 ENTER to enter the
Access mode. The display reads ACCESS .
3. Press CLEAR TIME TIME TIME ENTER to acĆ
cess the Belt Speed Calibration mode. The disĆ
play flashes INIT .
Belt speed calibration:
1. OVEN LENGTH - Set the length of the conveyĆ
or belt using the information from TABLE 3.
2. MOTOR RATIO - Set the motor gear ratio from
the information from TABLE 3.
3. SHAFT TEETH - Set the shaft teeth number
from the information from TABLE 3.
4. MOTOR TEETH - Set the motor teeth number
from the information from TABLE 3.
5. BELT RADIUS - Set the belt radius from the inĆ
formation from TABLE 3.
NOTE: The values given are estimates. If you
reenter the calibration mode after setĆ
ting the belt speed, the belt radius may
differ from the table.
6. The display gives a four digit value followed by
the letter K. Press ENTER twice to verify the
belt time.
Belt speed verification:
1. ENTER TEST TIME - Enter a test time to verify
the belt speed. The default setting is 7 minutes.
2. WAIT - 1 second delay before the belt moves.
3. ENTER ACTUAL TIME - Place an object on
the belt. Note the time from entrance to exit.
Enter the actual measured time.
4. ENTER TEST TIME - If the actual measured
time is not within 5 seconds of the test time, reĆ
peat the belt verification test to obtain better
accuracy. If the actual measured time is acĆ
ceptable, press the CLEAR key to continue the
belt speed calibration.
5. MAX/MIN CALC TIME - The control sets the
fastest and slowest cook time the user can proĆ
gram. This requires a 1 minute delay in the calĆ
ibration process.
NOTE: If the control cannot read the shaft enĆ
coder the display reads ERROR then
ABORT before exiting belt calibration.
Verify the connection of the encoder
Restart the belt speed calibration.
6. The display flashes MIN SET TIME? Press the
PROG/ENTER key to display the calculated
minimum set time. Press the PROG/ENTER
key to accept this value or enter a new time
with a value higher than the default. Press
PROG/ENTER again to accept.
7. The display flashes MAX SET TIME? Press the
PROG/ENTER key to display the calculated
maximum set time. Press the PROG/ENTER
key to accept this value or enter a new time
with a value lower than the default. Press
PROG/ENTER again to accept.
8. The display reads DONE .
To save the new belt speed:
1. Press ENTER to save the belt speed calibraĆ
tion program in the control's memory.
Oven Type Oven Length Motor Ratio Shaft Teeth Motor Teeth Belt Radius
MT3870 70 600 15 12 8,712
MT3855 55 600 15 12 8,712
MT3270 70 600 15 12 8,712
MT3240 40 600 15 12 8,893
MT2136 36 600 15 12 8,712
MT1828 28 600 24 24 7,209
TABLE 3