Midea DLFSAB Series User Manual

DLFSAB and DLFLAB: Service Manual
Manufacturer reserves the right to change, at any time, specifications and designs without notice and without obligations.
18
DIAGNOSIS AND SOLUTION (CONT.)
(S) Current Loop Communication:
Note: For certain models, outdoor PCB could not be removed separately. In this case, the outdoor electric control box should be
replaced as a whole.
Does the error code
disappear?
Power off, then restart the unit af ter 2
minutes.
Measure the DC voltage between N/L2
and S (Black pin to S , Red pin to N/L2).
The value is fixed and close
to 0
The value is alt ernative
from negative to positive
The value is alw ays posit ive
Check t he w iring connection
bet ween indoor and out door
unit, are they good?
Check t he w iring connection
from outdoor terminal to
outdoor PCB and wiring
bet ween PCBs if t here is
more t han 1 PCB
Check t he w iring connection
from indoor terminal to indoor
PCB, are they good?
Check if t he pow er LED is
on?
Yes
Yes
Unplug all the high voltage
components connected t o main
PCB such as 4 way valve, heater,
AC f an one by one t o check their
resist ance. Is there any component
short circuit?
Unplug electronic expansion valve.
Check if power LED is on?
No
No
Check t he AC volt age of L, N
output t o IPM board, is it same
as pow er input?
Check t he DC 5V, 12V
from IPM board t o main
PCB, are they normal?
Unplug all the high voltage
components connected t o main
PCB such as 4 way valve, heater,
AC f an one by one t o check their
resist ance. Is there any component
short circuit?
Yes
No
Unplug electronic expansion valve.
Check if t he DC 5V, 12V to m ain
PCB ar e O K
Replace short-circuited
component and main
PCB
Replace coil of electronic
expansion valve
Replace out door PCB
Replace short-circuited
component and outdoor
PCB
Yes
Yes
Yes
Yes
Replace main PCB
No
Yes
No
Replace IPM board
No
Repalce indoor PCB
Sol ve d
Correct the connection or
change w ires
No
No
Yes
For units with main PCB and IPM board
both
For units with only one
PCB
No

Midea DLFSAB Series Specifications

General

Brand	Midea
Model	DLFSAB Series
Category	Air Handlers
Language	English