Failure Mode 4: Error Code And Led Display - Mitsubishi Electric LGH-F300RVX-E Handbook

(4) Failure mode 4: Error code and LED display

An error code displayed on the remote controller (PZ-61DR-E, PZ-43SMF-E) or the M-NET controller, and
blinking or illumination of LED1 (green) or LED2 (red) on the circuit board show the type of an error.
The LED blink interval is 0.25 seconds for both on and off. The display duration is approximately 7 seconds.
Error display list
Error LED1 LED2
code (Green) (Red)
3126 8
blinks
0.25 s 0.25 s 0.25 s
ON
OFF
Symptom
External de- When the terminals (TM3 [7] [10])
vice error are set for pre-heater output (func-
tion selection switch (SW5-6) on the
circuit board is ON, or the function
setting (No. 58) of PZ-61DR-E set
to "2"), the following conditions were
satisfied.
• Outdoor air temperature detected
by OA thermistor stays at 158°F
(70°C) or higher for one minute.
• Outdoor air temperature detected
by OA thermistor exceeds 59°F
(15°C) within 15 minutes after the
pre-heater output starts.
• Outdoor air temperature is still 14°F
(-10°C) or lower one hour after the
pre-heater output starts.
Causes of the above phenomenons
are described below.
The pre-heater is connected to the
wrong terminal.
Faulty connection of the pre-heater
The output capacity of the pre-heater
is too large with respect to the air
volume of the Lossnay unit.
The output capacity of the pre-heater
is too small with respect to the air
volume of the Lossnay unit.
Even though the pre-heater is in use,
the function selection switch (SW5-6)
on the circuit board is not set to ON,
or the function setting (No. 58) of PZ-
61DR-E is not set to "2".
Even though the pre-heater is not
in use, the function selection switch
(SW5-6) on the circuit board is set to
ON, or the function setting (No. 58) of
PZ-61DR-E is set to "2".
Pre-heater failure
Pre-heater relay failure
Circuit board failure
7 s
Error display example: Two blinks
Cause
─ 27 ─
Corrective action
See below.
Connect the pre-heater to the termi-
nals (TM3 [7] [10]).
(See the Lossnay technical manual.)
Check the pre-heater connections.
Adjust the output capacity of the
pre-heater. When the pre-heater is
used, run the Lossnay at a higher
fan speed.
Adjust the output capacity of the
pre-heater. When the pre-heater is
used, run the Lossnay at a lower
fan speed.
Check the setting of the function
selection switch (SW5-6) on the
circuit board or the function setting
(No. 58) of PZ-61DR-E.
(See the Lossnay technical manual.)
Replace the pre-heater.
Replace the relay for the pre-heater.
Replace the circuit board.