Manitowoc Ice QF0400, QF2300 Section, Refrigeration System, 7-11, QF400 SELF-CONTAINEDAIR COOLED

Section 7 Refrigeration System

Cycle Time/24 Hour Ice Production/Refrigerant Pressure Charts

These charts are used as guidelines to verify correct ice machine operation. Accurate collection of data is essential to obtain the correct diagnosis.

•Refer to “Refrigeration System Diagnostics” for the data that must be collected. This list includes: before beginning service, ice production check, installation/ visual inspection, water system checklist, ice formation pattern, safety limits, safeguards and suction pressure analysis.

•Ice production checks that are within 10% of the chart are considered normal. This is due to variances in water and air temperature. Actual temperatures will seldom match the chart exactly.

•Zero out manifold gauge set before obtaining pressure readings to avoid misdiagnosis.

•Discharge and suction pressure are highest at the beginning of the cycle. Suction pressure will drop throughout the cycle. Verify the pressures are within the range indicated.

•All pressure readings must be obtained at the ice machine head section. Lineset length will affect pressures at the condensing unit.

QF400 SELF-CONTAINED AIR COOLED

NOTE: These characteristics may vary depending on operating conditions.

24 Hour Ice Production

Air Temp.	Water Temperature °F/°C
Entering
Condenser	50/10.0	70/21.1	90/32.2
°F/°C
70/ 21.1	395	360	335
80/26.7	375	320	300
90/32.2	335	300	270
100/37.8	295	250	240
110/43.3	255	230	225

Operating Pressures

Air Temp. Entering	Freeze Cycle
	Discharge	Suction
Condenser °F/°C
	Pressure PSIG	Pressure PSIG
50/10.0	160-180	27-29
70/21.1	210-235	32-35
80/26.7	250-295	34-39
90/32.2	285-315	37-41
100/37.8	320-360	40-46
110/43.3	370-405	44-49

Part No. 80-1214-3 Revised 8/2003 7-11