ICE MACHINES Q-Model Service Manual

Section 7Refrigeration SystemLOW ON CHARGE VERIFICATIONThe remote ice machine requires more refrigerantcharge at lower ambient temperatures than at highertemperatures. A low on charge ice machine mayfunction properly during the day, and then malfunction atnight. Check this possibility.If you cannot verify that the ice machine is low oncharge:1. Add refrigerant in 2 lb. increments, but do notexceed 6 lbs.2. If the ice machine was low on charge, theheadmaster function and discharge pressure willreturn to normal after the charge is added. Do not letthe ice machine continue to run. To assure operationin all ambient conditions, the refrigerant leak mustbe found and repaired, the liquid line drier must bechanged, and the ice machine must be evacuatedand properly recharged.3. If the ice machine does not start to operate properlyafter adding charge, replace the headmaster.FAN CYCLE CONTROL VS. HEADMASTERA fan cycle control cannot be used in place of aheadmaster. The fan cycle control is not capable ofbypassing the condenser coil and keeping the liquid linetemperature and pressure up.This is very apparent when it rains or the outsidetemperature drops. When it rains or the outsidetemperature drops, the fan begins to cycle on and off. Atfirst, everything appears normal. But, as it continuesraining or getting colder, the fan cycle control can onlyturn the fan off. All the refrigerant must continue to flowthrough the condenser coil, being cooled by the rain orlow outside temperature.This causes excessive sub-cooling of the refrigerant. Asa result, the liquid line temperature and pressure are notmaintained for proper operation.Part No. 80-1100-3 7-31