Manitowoc Q130 series, Technician'S Handbook

Page: 130 / 236

130 Part Number 8001119 10/19
FINAL ANALYSIS
The column with the highest number of check marks
identifies the refrigeration problem.
Column 1 – Hot Gas Valve Leaking
A leaking hot gas valve must be replaced.
Column 2 – Low Charge/TXV Starving
Normally, a starving expansion valve only affects the
freeze cycle pressures, not the harvest cycle
pressures. A low refrigerant charge normally affects
both pressures. Verify the ice machine is not low on
charge before replacing an expansion valve.
Add refrigerant charge in 2 oz. increments as a
diagnostic procedure to verify a low charge. (Do not
add more than the total charge of refrigerant). If the
problem is corrected, the ice machine is low on
charge. Find the refrigerant leak.
The ice machine must operate with the nameplate
charge. If the leak cannot be found, proper refrigerant
procedures must still be followed. Change the liquid
line drier, evacuate the system and weigh in the proper
charge.
If the problem is not corrected by adding charge, the
expansion valve is faulty.
Column 3 – TXV Flooding
A loose or improperly mounted expansion valve bulb
causes the expansion valve to flood. Check bulb
mounting, insulation, etc., before changing the valve.
Column 4 – Compressor
Replace the compressor and start components. To
receive warranty credit, the compressor ports must be
properly sealed by crimping and soldering them
closed. Old start components must be returned with
the faulty compressor.