Panasonic GHP - Page 7

Standard: ∞
Measure resistance between the ground screw and terminal board 1. Measure resistance between the ground screw and terminal board 2. Standard: ∞ If there is resistance, a sensor ground fault has occurred.
Ground
Outdoor unit (Indoor unit)
Sensor
Sensor ground fault check (* Sensor ground faults will also result in communication faults.) · Sensor type (thermistor) ground fault check (turn off power for units)
For each of the indoor/outdoor units connected by the operation cable, measure the resistance between the sensor wiring and ground screw for both of the sensor wires and ground screws.
Outdoor unit
Indoor unit 1
Ground
Ground Ground Ground
Ground
Remote controller
Indoor unit 2 Indoor unit 3 Indoor unit 4
Indoor/outdoor control wire
Ground Ground Ground
Remote controller
Outdoor unit
Indoor unit 1 Indoor unit 2 Indoor unit 3 Indoor unit 4
Ground
Ground
Indoor/outdoor control wire
Outdoor unit
Indoor unit 1 Indoor unit 2 Indoor unit 3 Indoor unit 4
Ground
Ground
Remote controller
Ground Ground Ground
Indoor/outdoor control wire
Ground fault check
Measure resistance between the ground screw and terminal board 1. Measure resistance between the ground screw and terminal board 2. Standard:∞
Wire break or disconnection check
Measure resistance on the termi- nal board of each unit.
Short circuit check
Measure resistance between terminal board 1 and terminal board 2. Standard:Approx.75to100Ω(with one terminal resistor present)
Example: A wire break or disconnection occurs at x (with one outdoor unit terminal resistor
present). The resistance value for

,

, and

isapprox.75to100Ω.
The resistance value for

and

is∞.
* If the resistance for

is∞,checktheterminalresistorfortheoutdoormain
board, and check wiring between the outdoor main board and the outdoor unit terminal board.
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