Component Testing - Haier GE NS23AM Service Manual

Component Testing

Verifying High Pressure Switch and Low Pressure Protection Operation
Operation:
The unit's pressure S4 high pressure switch is factory wired into the control on the HPS terminals.
NOTE:
the same protection as a tradition low pressure switch. If the event the suction pressure transducer fails, back up protection
Low Suction Pressure Protection – See Figure 29 for low suction pressure protection sequence of operation.
High Pressure Switch (HI-PS) – See for high pressure switch sequence of operation.
Pressure Switch Event Settings
The following pressures are the auto-reset event value triggers for low and high pressure thresholds:
• High Pressure (auto-reset) - trip at 590 psig; reset at 418.
• Low Suction Pressure Protection (Suction pressure transducer emulates LPS) (auto-reset) – trip at 40 psig; reset at 90.
Checkout – S4 High Pressure Switch
Using a multimeter set to ohms with the terminals disconnected from the control board, check the resistance between the
two terminals of the pressure switch. If the resistance reading is 0 ohms, the switch is closed.
Verifying Suction Pressure Transducer Operation
Using a multimeter set to VDC with the Suction Pressure Transducer connected to the "Suct P" 3-pin connector on the
control board. Pin 1 (Red wire +5VDC) to Pin 3 (Black wire - GND) should read 5 VDC continuous. Pin 2 (Blue wire output
from transducer) to Pin 3 (Black - GND) should read 0.5 to 4.5 VDC and will vary depending on suction pressure measured.
See Table 18.
Figure 28. Verifying High Pressure Switch Operation
VDC
Figure 29. Suction Pressure Transducer Voltage
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S4
HIGH
PRESSURE
SWITCH
31-5000746 Rev. 0