Manitowoc Ice S1800 Analyzing Discharge Pressure During Freeze or Harvest Cycle, Procedure

Refrigeration System Section 7

ANALYZING DISCHARGE PRESSURE DURING FREEZE OR HARVEST CYCLE

Procedure

1. Determine the ice machine operating conditions:

Air temp. entering condenser	______
Air temp. around ice machine	______
Water temp. entering sump trough	______

2.Refer to Operating Pressure Chart for ice machine being checked.

Use the operating conditions determined in step 1 to find the published normal discharge pressures.

Freeze Cycle _______ Harvest Cycle _______

Freeze Cycle Discharge Pressure High Checklist

3. Perform an actual discharge pressure check.

	Freeze Cycle	Harvest Cycle
	PSIG (kPa)	PSIG (kPa)
Beginning of Cycle	__________	__________
Middle of Cycle	__________	__________
End of Cycle	__________	__________

4.Compare the actual discharge pressure (step 3) with the published discharge pressure (step 2).

The discharge pressure is normal when the actual pressure falls within the published pressure range for the ice machine’s operating conditions.

Possible Cause	Check/Correct
Improper installation	See “Installation/Visual Inspection Checklist”
Restricted condenser water flow	Low water pressure [20 psi (138 kPa) 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-condensables in system
	Wrong type of refrigerant
Other	Non-Manitowoc components in system
	High side refrigerant lines/component restricted (before mid-condenser)
Freeze Cycle Discharge Pressure Low Checklist

Possible Cause	Check/Correct
Improper installation	See “Installation/Visual Inspection Checklist”
Improper refrigerant charge	Undercharged
	Wrong type of refrigerant
Water regulating valve	Out of adjustment
	Defective
Other	Non-Manitowoc components in system

NOTE: Do not limit your diagnosis to only the items listed in the checklists.

7-12 Part Number 80-1634-3