Manitowoc QD0202A, Service Manual

Page: 102 / 175

Electrical System Section 6
6-46
Part No. 80-1100-3
General
Q-Model control boards use a dual voltage transformer.
This means only one control board is needed for both
115V and 208-230V use.
Safety Limits
In addition to standard safety controls, such as the high
pressure cut-out, the control board has built-in safety
limits.
These safety limits protect the ice machine from major
component failures. For more information, see “Safety
Limits” on
Page 7-13 .
Inputs
The control board, along with inputs, controls all
electrical components, including the ice machine
sequence of operation. Prior to diagnosing, you must
understand how the inputs affect the control board
operation.
Refer to specific component specifications (inputs),
wiring diagrams and ice machine sequence of operation
sections for details.
As an example, refer to “Ice Thickness Probe” on the
next page for information relating to how the probe and
control board function together.
This section will include items such as:
• How a harvest cycle is initiated
• How the harvest light functions with the probe
• Freeze time lock-in feature
• Maximum freeze time
• Diagnosing ice thickness control circuitry