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3.9.2 Automatic PTI (Pre-Trip Inspection)
● The automatic PTI function is provided so as to ensure correct inspection and to shorten inspection
time.
(1) Appearance inspection of unit
q
Physical damage
w
Casing insulation through hole area
e
Drain hose (dust and clogging)
r
Power cable and plug damage
t
Condition of refrigerant piping fasteners.
y
Condition of each sensor installation
u
Loose mounting sections
Bolts and nuts
-----
Casing frame, compressor, fan motor control box and temperature recorder box
Cable glands
-----
Control box
i
Conditions of control box cover packing (water-proof) and temperature recorder box cover packing
(water-proof)
o
Magnetic contactor contact point for burning out.
(2) Inspection before unit operation
q
Gas leakage inspection
w
Power voltage inspection (Automatic PTI range)
(3) Starting inspection and operation inspection of safety device and control equipment
q
Starting Inspection whether the starting procedure is proper or not
Inspection for abnormal noise and abnormal vibration
Moisture in the refrigerant ----- This is reinspected at the end of PTI.
Rotating direction of fan motor.
w
Safety device HPS ----- Measurement of the actuating pressure by stopping the condenser
fan motor.
e
Control equipment Solenoid valve ----- Inspection of operation (open and close) and leakage
EFM ----- Speed switchover and rotating direction
EV, SMV
----- Inspection of operation (open and close) and leakage
(4) Operation in each mode
q
Pull-down / 0˚C Pull-down time, voltage and current
w
Chilled control 0˚C
Electronic temperature
Return, supply air temperature differential, voltage and current
recorder calibration
e
Defrosting Defrosting time
r
Pull-down / –18˚C
Pull-down time, evaporator fan motor speed switchover
t
Frozen control –18˚C
Electronic temperature
(Temperature differential and rotating direction)
recorder calibration ON/OFF, voltage and current
Remained frost inspection
(5) PTI report preparation
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