16
Final Check List
A. Check high-low pressure control setting for freezer unit.
Recommended Low Pressure Settings: Cut-in 20 PSIG, Cut-out 2 PSIG or Differential 24
Recommended High Pressure Setting: 400 PSIG Cut-out
B. Check operating pressures vs. box temperature and ambient temperatue.
Suction Pressure measured at around 15 PSIG when -10F box temp is reached.
Head pressure is floating but the if the TD ( = Condensing Temperature – Ambinet
Temperature ) is higher than 25 F, the system may be over charged or non-condensable gas
inside the system.
C. Check electrical requirements of unit to power supply voltage.
The power supply voltage should match the Lead Color Voltage of the 24VAC primary input
voltage. If NOT, switch the leads.
D. Set desired temperature range:
a. Cooler temperature is preset at 35
o
F cut-out, 38
o
F cut-in.
b. Freezer temperature is preset at –10
o
F cut-out, -5
o
F cut-in.
E. Check the operating True Superheat (SH) for proper refrigeration charge.
Never use level of fullness of sight glass to determine the charging level. Always use
weighing scale and Superheat Approach Charging Method mentioned above.
F. Check compressor oil level.
G. Check compressor crankcase heater operation.
H. Check systems for proper defrost operation.
Adjust the defrost termination set point (dS) to clear all frost if needed.
I. Check condensing unit for vibrating or rubbing tubing. Dampen or clamp as required.
J. Open all valves completely counter clockwise.
K. Check packing nuts on all service valves.
L. Insure that all covers and panels are fully secured to the unit.
M. Refer to the Master Controller Manual for system control.
N. Call Factory if there’s any doubt.
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