Low Pressure Switch; Checking Procedures - Daikin altherma 3 M Service Manual

3.13 Low pressure switch

3.13.1 Checking procedures

To perform an electrical check of the low pressure switch
EBLA09~16DA + EDLA09~16DA
Daikin Altherma 3 M
ESIE20-06A – 2021.03
Is the problem solved?
No
Prerequisite: Stop the unit operation via the user interface.
Prerequisite: Turn OFF the respective circuit breaker.
Prerequisite: Remove the required plate work, see
1 Recuperate the refrigerant from the refrigerant circuit, see
4
procedures" [ 291].
2 Connect a vacuum pump to the gas service port of the refrigerant circuit and
vacuum to just above operating pressure of the low pressure switch.
a
d
c
f
a Low pressure switch protection control
b Pressure
c Low pressure switch closed
d Low pressure switch open
e Low pressure switch reset pressure
f Low pressure switch operating pressure
Low pressure switch
S1PL
3 Disconnect the low pressure switch connector from the appropriate PCB.
4 Measure contacts between the pins 1‑2 of the low pressure switch connector.
Result: The switch MUST be closed.
5 Vacuum until pressurized just below operating pressure of the low pressure
switch.
6 Measure again contacts between the pins 1‑2 of the low pressure switch
connector.
Result: The switch MUST be open.
INFORMATION
If the low pressure switch was triggered open, it will stay open until the refrigerant
pressure rises above the reset pressure of the low pressure switch.
7 Fill the refrigerant circuit with nitrogen until pressurized just below reset
pressure of the low pressure switch.
Action
Return to
procedures" [
and continue with the next procedure.
e b
Operating pressure (MPa) Reset pressure (MPa)
−0.05~−0.01
3 Components
|
"3.12.1 Checking
4
160] of the hydro PCB
4
"3.17 Plate work" [ 230].
"4.2.2 Repair
0.02~0.08
Service manual
167