Blodgett MT3255 Series Service And Repair Manual page 40

face exceeds the rating on the back of the
switch and may start the fans even if the oven
is off. If this switch is cold, it should be made
between common and N.C. terminals sending
power to the cooling fans (18).
NOTE: The SPDT thermal switch is located in
the ceiling of the convection fan
compartment.
4. The conveyors are driven by an open loop DC
control system consisting of two DC speed
control boards (5), two 130 VDC motors (20)
and the DAC located in the cooking computer
(1). If a time is programmed into the cooking
computer, a voltage ranging between .47 and
4.7 is applied to the DC speed control boards.
The output voltage measured at A1 and A2 of
the boards to the motors varies from 20 to130
VDC based on the DAC voltage applied to the
board or the time programmed into the com-
puter.
NOTE: The DAC receives 20 VDC from the
speed control boards. The DAC re-
turns a portion of the voltage (between
.47 and 4.7 VDC). The amount of volt-
age is dependent on the time pro-
grammed into the computer.
NOTE: This type of system does not sense the
weight of the product and will slow
down slightly if the belt is fully loaded.
NOTE: This oven, supplied with remote con-
trol, is equipped with an emergency
shut down switch. Should you need to
stop the belt, fans, or heat press the
emergency switch. Do not use the
emergency switch as a GENERAL
on/off switch!
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OPERATION