Repair manual

MT3255 and MT3270
4-5
BELT SPEED CALIBRATION - OPEN LOOP
NOTE: The following procedures must be perĆ
formed after dc voltage levels have been
set and are known to be accurate.
The cooking time digital display should be adĆ
justed when changing any of the system compoĆ
nents. Prior to adjusting the display, determine the
following two specifications:
1. The number of pulses per spindle revoluĆ
tion generated by the Hall effect pickup.
Move the plastic endĆcaps on the pickup loĆ
cated on the DC motor. If the pickup is marked
with the number 2, it is a single pulse per revoĆ
lution pickup. If the pickup is marked with the
number 10 (Standard After 6Ć1Ć91) it is a five
pulse per revolution pickup. Replace the endĆ
caps. Refer to page 5-1 for pickup troubleĆ
shooting.
2. The manufacturer and the voltage rating of
the DC drive motor.
This information is embossed on the nameĆ
plate located on the motor's case.
Once the above specifications have been deterĆ
mined, perform the following calibration proceĆ
dures.
1. Remove the screws securing the cooking time
display lens cover. Remove the lens cover. If a
5 pulse pickup is used, verify that the multiplier
potentiometer is set to the x10 position (refer
to FIGURE 5 for the potentiometer location).
Cooking Time
INCREASE DECREASE
X1
X10
Belt speed DIP switch located
behind cooking time digital display
Multiplier potentiometer located behind
cooking time digital display
For 5 pulse pickups set to x10
FIGURE 5
Set The Belt Speed DIP Switches.
Set the DIP switches using the data from the table
below.
Pickup DIP Switch Setting
MT3255 - 60 Hz Motors
Single 7, 6, 5, 4, 3 ,2 , 1 - set to OFF
5 Pulse 7 - set to OFF
MT3270 - 60 Hz Motors
Single 8, 6, 2 - set to OFF
5 Pulse 7, 5, 1 - set to OFF
MT3255 - 50 Hz Motors
Single 8, 5, 3, 2 - set to OFF
5 Pulse 7, 4, 2, 1 - set to OFF
MT3270 - 50 Hz Motors
Single 8, 6, 5, 4, 3, 2, 1 - set to OFF
5 Pulse 7, 5, 4, 3, 2, 1 - set to OFF
TABLE 2
128 64 32 16 8 4 2 1
OFF
Rear Of
Control
Switch Number
Switch Value
87654321
FIGURE 6