Manitowoc indigo series Technician's Handbook

Also see for Indigo ID0302A: Installation, operation and maintenance manual Technician's handbook

Contents

Manitowoc indigo series Technician's Handbook Manual pdf 197 page image

Part Number STH025 11/16 197Refrigeration ComponentsHEAD PRESSURE CONTROL VALVEManitowoc remote systems require head pressure controlvalves with special settings. Replace defective headpressure control valves only with “original” Manitowocreplacement parts.Refrigerant Charge VerificationThe correct amount of refrigerant (name plate charge) isrequired to operate correctly at all ambient conditions.An ice machine with an overcharge or undercharge ofrefrigerant may function properly at higher ambienttemperatures and fails at lower ambient temperatures.Symptoms of incorrect refrigerant amount are:• Works during the day and malfunctions at night, and/or fails whenever the outdoor temperature drops.• A Safety limit is stored in control board memory.Refrigerant loss and ambient temperature are directlyrelated to each other. As the ambient temperature drops,more refrigerant is stored in the condenser.When the refrigerant charge and ambient temperaturecreate an undercharge of refrigerant in the freeze cycle,the receiver dip tube will lose it’s liquid seal. Withoutliquid refrigerant to the TXV, the ice machine fails tomake a full sheet of ice in 35 minutes and a safety limit #1results.NOTE: When a head pressure control valve is beingreplaced or refrigerant charge is suspected, verify therefrigerant charge is correct by recovering the refrigerant,weighing and comparing to the nameplate amount.Refer to Refrigerant Recovery/Evacuation” page 207 forrecovery procedures.