Daikin Altherma 3 M - Page 158

3 | Components
Service manual
158
EBLA09~16DA + EDLA09~16DA
Daikin Altherma 3 M
ESIE20-06A – 2021.03
High pressure switch Operating pressure (MPa) Reset pressure (MPa)
S1PH 4.15 3.2
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 "6.2 Wiring
diagram"[4314].
For single phase units ONLY: Make sure that the compressor thermal protector
(which is wired in series with the high pressure switch) functions correctly, see
"3.8.1Checking procedures"[4146].
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.
INFORMATION
If the high pressure switch is activated and the pressure has dropped below the
operating pressure, you can also reset the high pressure switch with the manual
reset button.
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
"3.11.2Repair procedures"[4159].