DELUXE
Inverter
Service
M
anual
（
18
）
FA- recirculated sensor error (only models of electronic expansion valves are involved)
Explanation of
error
Cause:
The recirculated sensors are only used on machine models of electronic
expansion valves and the back temperature value is considered as the basis for
adjustment of the electronic expansion valve and
to
determin
e
if the four-way
valve
is
chang
ing to its
normal
position during heating. When the main
control panel detects open circuit or short circuit of the recirculated sensor,
it would raise an alarm of "recirculated sensor error" and send it to the
main internal control panel to indicate it.
Inspection path:
four-way valve →recirculated sensor → sensor wire →
connectors → main external control panel
Tools required
for inspection
Multimeter, pressure meter, normal 20KΩ recirculated sensor
Frequent
problematic part
Four-way valve, recirculated sensor, main external control panel.
Inspection
procedure and
key points
1. If the error appears in heating but not in cooling, first check if the four-way
valve failed to change the position or there is a back flow, which can be
estimated by measuring the high and low pressures with the pressure meter
.
Use a multimeter to evaluate
electricity control. During heating,
check if the
four-way valve terminal can switch a circuit of 220V, if
it does
and the
four-
way valve
is
still fault
y
in the position chang
e
, the four-way valve is
damaged.
I
f
in heating,
there is no circuit over 220V
,
it means the main external
control
valve is d
efective
.
2. If it is not the four-way valve that is
damag
ed, check on the resistance value
and
short circuit problems
. T
he resistance value sh
ould
be within a proper
range
(around 20KΩ at temperature of 25
℃
).
3. Check whether the terminal connectors are well fixed; check
if
the weld
between the terminal and the main control panel is loose
. P
ull the terminal
slightly for inspection if necessary.
4. Check
if
the sensor is affected with damp. For the recirculated sensor,
if the
led
tip of the sensor
is on the above
position
and the
copper pipe is below, it is
possibl
y
damp.
5. The maintenance personnel can replace the
possibly defective
recirculated
sensor with a
nother
one and if the error disappears, it means the
original
recirculated sensor is
damaged
and needs to be replaced
. I
f the error is
still
there, consider replac
ing
the main external control panel.
41
