Daikin FTXA20A - Page 68

2 | Components
Service manual
68
FTXA20~50A(W)(S)(T) + FTXA20~50B(B)(S)(T) + RXA42+50A +
RXA20~35A(9) + RXA42+50B
Split Stylish R32
ESIE18-03D – 2021.05
a
b
ef
d
c
a High pressure switch protection control
b Pressure
c High pressure switch closed
d High pressure switch open
e High pressure switch operating pressure
f High pressure switch reset pressure
3 Disconnect the Faston connectors from the high pressure switch.
INFORMATION
Measure the continuity of all wiring between the high pressure switch and the
appropriate PCB. If NO continuity is measured, repair as needed, see "5.2 Wiring
diagram"[4171].
4 Measure the resistance between the Faston connections of the high pressure
switch.
Result: The switch MUST be closed.
5 Fill the refrigerant circuit with nitrogen until pressurized just above operating
pressure of the high pressure switch.
6 Measure the resistance between the Faston connections of the high pressure
switch.
Result: The switch MUST be open.
INFORMATION
If the high pressure switch was triggered open, it will stay open until the refrigerant
pressure drops below the reset pressure of the high pressure switch.
7 Lower the pressure of the nitrogen in the refrigerant circuit just above reset
pressure of the high pressure switch.
8 Measure the resistance between the Faston connections of the high pressure
switch.
Result: The switch MUST be open.
9 Lower the pressure of the nitrogen in the refrigerant circuit just below reset
pressure of the high pressure switch.
10 Measure the resistance between the Faston connections of the high pressure
switch.
Result: The switch MUST be closed.
High pressure switch connector
measurements are correct?
Then
Yes High pressure switch is OK. Return to
the troubleshooting of the specific error
and continue with the next procedure.
No Replace the high pressure switch, see
"2.5.2Repair procedures"[469].