Manitowoc b970 series, Technician'S Handbook

Page: 147 / 264

Part Number STH025 8/12 147
Comparing Evaporator Inlet and Outlet
Temperatures - Self-contained & Remote
Condenser Single Expansion Valve Machines
The temperatures of the suction lines entering and
leaving the evaporator alone cannot diagnose an ice
machine. However, comparing these temperatures
during the freeze cycle, along with using Manitowoc’s
Freeze Cycle Refrigeration System Operational
Analysis Table, can help diagnose an ice machine
malfunction.
The actual temperatures entering and leaving the
evaporator vary by model, and change throughout the
freeze cycle. This makes documenting the “normal”
inlet and outlet temperature readings difficult. The key
to the diagnosis lies in the difference between the two
temperatures five minutes into the freeze cycle. These
temperatures should be within 7° of each other.
Use this procedure to document freeze cycle inlet and
outlet temperatures.
1. Navigate to Service / Real Time Data / Time &
Temp / T3 & T4 Thermistors (See page 82
Service Menu Navigation for details).
2. Wait five minutes into the freeze cycle.
3. Record the evaporator inlet (T3) and outlet (T4)
temperatures at 5 minutes into the freeze cycle.
Determine the difference.
4. Record the information on the table.