How To Use The Refrigeration System Operational Analysis Tables; Tables - Manitowoc Q450 Service Technician's Handbook

How to Use the Refrigeration System
Operational Analysis Tables
GENERAL
These tables must be used with charts, checklists and
other references to eliminate refrigeration components
not listed on the tables and external items and
problems which can cause good refrigeration
components to appear defective.
The tables list five different defects that may affect the
ice machine's operation.
NOTE: A low-on-charge ice machine and a starving
expansion valve have very similar characteristics and
are listed under the same column.
NOTE: Before starting, see "Before Beginning
Service" for a few questions to ask when talking to the
ice machine owner.
PROCEDURE
Step 1. Complete the "Operation Analysis"
column.
Read down the left "Operational Analysis" column.
Perform all procedures and check all information
listed. Each item in this column has supporting
reference material to help analyze each step.
While analyzing each item separately, you may find an
"external problem" causing a good refrigerant
component to appear bad. Correct problems as they
are found. If the operational problem is found, it is not
necessary to complete the remaining procedures.
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Step 2. Enter check marks ( ).
Each time the actual findings of an item in the
"Operational Analysis" column matches the published
findings on the table, enter a check mark.
Example: Freeze cycle suction pressure is determined
to be low. Enter a check mark in the "low" box.
Step 3. Add the check marks listed under each of the
four columns. Note the column number with the
highest total and proceed to "Final Analysis."
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