Manitowoc Q450 - Page 96

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DISCHARGE PRESSURE HIGH CHECKLIST
Problem
• Cause
Improper Installation
• Refer to “Installation/Visual Inspection Checklist”
Restricted Condenser Air Flow
• High inlet air temperature (110°F/43.3°C max.)
• Condenser discharge air recirculation
• Dirty condenser filter
• Dirty condenser fins
• Defective fan cycling control
• Defective fan motor
Restricted Condenser water flow
• Low water pressure (20 psi min.)
• High inlet water temperature (90°F/32.2°C max.)
• Dirty condenser
• Dirty/Defective water regulating valve
• Water regulating valve out of adjustment
Improper Refrigerant Charge
• Overcharged
• Non-condensable in system
• Wrong type of refrigerant
Other
• Non-Manitowoc components in system
• High side refrigerant lines/component restricted
(before mid-condenser)
• Defective head pressure control valve