Samsung AM072BXV Series Service Manual page 317

Test Operation
9-1 Auto Trial Operation (cont.)
9-1-3 How to resolve NG items (cont.)
4) Pressure sensor (when only one outdoor unit is installed)
∙ What to inspect: Pressure sensors (high and low pressures)
∙ Error code: None ("NG" is only indicated in the result report)
∙ How to determine error: Check the pressure difference between the high and low pressure sensors before
the compressors are started.
∙ Perform inspection according to the steps shown below.
Keep all the outdoor units in vacuum mode for 5 min.
- See the instructions on Key operation modes
No
between pressure sensors on outdoor units
greater than 0.2MPa?
sensor connectors properly connected
voltage between pins # 3 and 4 of the pressure
sensor terminal* on the Hub PBA 5V?
pressure* different from the value
on the pressure sensor?
Perform Auto Trial Operation again.
■ Precautions
- To replace a component or inspect the PBA, be sure to cut off the power supply first.
If inspection must be performed with the power supply on, exercise extra care to prevent electric shock.
Samsung Electronics
Is the deviation
Yes
Are the pressure
to the PBA?
Yes
Is the pin-to-pin
Is the actua
No
No
Take corrective measures.
No
Replace the Hub PBA.
* Pressure sensor terminal
Pin # 1 is indicated by ▼ .
Measure the voltage between pins # 3 and 4.
Yes
Replace the pressure sensor.
* The actual pressure can be checked by calculating
the saturation pressure for the outdoor air tem-
perature or connecting a manifold gauge.
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