Midea DLFSAB Series User manual

Specifications subject to change without notice.
TABLE OF CONTENTS
PAGE
SAFETY CONSIDERATIONS ....................................................... 1
INTRODUCTION............................................................................ 1
MODEL NUMBER NOMENCLATURE ....................................... 2
AUXILLIARY CONTACTS FOUND ON THE MAIN BOARD .. 3
ROTARY AND DIP SWITCHES ................................................... 6
WIRING ........................................................................................... 8
CONNECTION DIAGRAMS AND CONTROL METHODS........ 9
WIRING DIAGRAMS..................................................................... 10
REFRIGERANT LINES .................................................................. 12
TROUBLESHOOTING ................................................................... 13
DIAGNOSIS AND SOLUTION...................................................... 16
APPENDICES.................................................................................. 36
DISASSEMBLY INSTRUCTIONS ................................................ 38
SAFETY CONSIDERATIONS
Installing, starting up, and servicing air-conditioning equipment can
be hazardous due to unit pressures, electrical components, and
equipment location (roofs, elevated structures, etc.).
Only trained, qualified installers and service mechanics should install,
start-up, and service this equipment.
Untrained personnel can perform basic maintenance functions such as
coil cleaning. All other operations should be performed by trained
service personnel only.
When working on the equipment, observe the precautions in the
literature and on tags, stickers, and labels attached to the equipment.
Follow all safety codes. Wear safety glasses and work gloves. Keep a
quenching cloth and fire extinguisher nearby when brazing. Use care
in handling, rigging, and setting bulky equipment.
Read this manual thoroughly and follow all the warnings or cautions
included in the literature and attached to the unit. Consult local
building codes and the National Electrical Code (NEC) for special
requirements.
Recognize safety information. This is the safety-alert symbol .
When you see this symbol on the unit and in instructions or manuals,
be alert to the potential for personal injury. Understand these signal
words: DANGER, WARNING, and CAUTION.
These words are used with the safety-alert symbol. DANGER
identifies the most serious of hazards which will result in severe
personal injury or death. WARNING signifies hazards which could
result in personal injury or death. CAUTION is used to identify
unsafe practices which may result in minor personal injury or product
and property damage. NOTE is used to highlight suggestions which
will result in enhanced installation, reliability, or operation.
INTRODUCTION
This service manual provides the necessary information to service,
repair, and maintain the indoor units. This manual contains an
“APPENDICES” on page 36 with data required to troubleshoot issues.
Use the “TABLE OF CONTENTS” on page 1 to locate a desired topic.
ELECTRICAL SHOCK HAZARD
Failure to follow this warning could result in personal injury or
death. Before installing, modifying, or servicing the unit, the
main electrical disconnect switch must be in the OFF position.
There may be more than 1 disconnect switch. Lock out and tag
switch with a suitable warning label.
WA R N I N G
EXPLOSION HAZARD
Failure to follow this warning could
result in death, serious personal
injury, and/or property damage.
Never use air or gases containing
oxygen for leak testing or operating
refrigerant compressors. Pressurized
mixtures of air or gases containing
oxygen can lead to an explosion.
WAR NI NG
EQUIPMENT DAMAGE HAZARD
Failure to follow this caution may result in equipment damage
or improper operation.
Do not bury more than 36 in. (914 mm) of refrigerant pipe in the
ground. If any section of pipe is buried, there must be a 6 in. (152
mm) vertical rise to the valve connections on the outdoor units. If
more than the recommended length is buried, refrigerant may
migrate to the cooler buried section during the extended periods
of unit shutdown. This causes refrigerant slugging and could
possibly damage the compressor at start-up.
CAUTION
DLFSAB and DLFLAB
Service Manual
Air Handler Unit Ductless System - Sizes 18 to 60

DLFSAB and DLFLAB: Service Manual
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2
MODEL NUMBER NOMENCLATURE
Table 1 — Unit Sizes
KBTUH V-PH-HZ ID MODEL NO.
18
208/230-1-60
DLFSABH18XB3
24 DLFSABH24XB3
30 DLFSABH30XB3
36 DLFSABH36XB3
36 DLFLABH36XA3
48 DLFLABH48XA3
60 DLFLABH60XA3
INDOOR UNIT
DLF
SL AH24 XA
K
DLF = INDOOR UNIT
S&L = MODEL
VOLTAGE
K = 208/230-1-60
INDOOR FAN COIL UNIT TYPE
A = AIR HANDLER
INDOOR FAN COIL TYPE
H = Heat Pump
MAXIMUM NUMBER OF FAN COIL UNITS
CONNECTED TO THE OUTDOOR UNIT
A=1:1
NOMINAL CAPACITY
18 - 1 1/2 TON
24 - 2 TONS
30 - 2 1/2 TONS
36 - 3 TONS
48 - 4 TONS
60 - 5 TONS
B
MAJOR SERIES A = VARIATION
X = NOT USED
21
22 10001
Week of Manufacture Sequential Serial Number
V
V = ALL MODELS
Year of Manufacture
Use of the AHRI Certified
TM Mark indicates a
manufacturer’s
participation in the
program For verification
of certification for individual
products, go to
www.ahridirectory.org.

DLFSAB and DLFLAB: Service Manual
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3
AUXILLIARY CONTACTS FOUND ON THE MAIN BOARD
Work Terminal Port CN23 - Normally Open Dry Contact (Output)
•The WORK terminal port is linked to the unit's indoor blower
• When the indoor blower is off, the contact is open
• When the indoor blower is running, the contact is closed
• There is no voltage from CN23, power is provided from the external control system and not from the unit.
• The contacts are rated at 250VAC and 10 AMP maximum
• If an active 24V signal output is required, G and C ports (thermostat connections) may be used instead.
Fig. 1 — Auxiliary Contacts
ALARM Terminal Port CN33 - Normally Open DRY CONTACT (OUTPUT):
• Allows the terminal port to connect to an external ALARM interface or annunciator
• There is no voltage from
CN33 , power is provided from the ALARM system and not from the unit.
• The contacts are rated at
250VAC and 10 AMP maximum
• When the unit experiences a problem, the contact closes, and the
ALARM is triggered.
Fig. 2 — Auxiliary Contacts

DLFSAB and DLFLAB: Service Manual
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4
WATER LEVEL Switch Terminal Port CN5 - SWITCH INPUT:
• To enable this switch, jumper J1 must be removed
• A field supplied float switch can be directly connected to
CN5
• CLOSED contacts = normal
• OPEN contacts = overflow
• When an overflow condition occurs, a signal is sent to the system to turn it off
•Alarm
EE appears.
Fig. 3 — Auxiliary Contacts
UV LED terminal port CN43 - OUTPUT 24VAC:
•The UV LED port is linked to the unit's fan
• When the fan is running, the relay is closed and there is an output of
24VAC through the contacts that can be used to power a compatible UV LED LIGHT
• May also be used to power a pilot relay with 24VAC coil to control other peripherals
Fig. 4 — Auxiliary Contacts

DLFSAB and DLFLAB: Service Manual
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5
Auxiliary Contacts found on the 24V interface Board:
Remote control (ON-OFF) terminal port CN2 and jumper JR1 - INPUT:
• Remove the jumper JR1 to enable the ON-OFF function
• When the remote switch is off (
OPEN ); the unit is OFF
• When remote switch is on ( CLOSE ); the unit is ON
• When the remote switch is close/open, the unit responds to the demand within 2 seconds
• When the remote switch is on, you can use the included remote controller or wired controller to operate the unit as normal.
• When the remote switch off, the unit will not respond to the command from the remote controller or wired controller and a CP code is displayed on the
board.
Fig. 5 — Auxiliary Contacts

DLFSAB and DLFLAB: Service Manual
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6
ROTARY AND DIP SWITCHES
Micro-Switch Setting:
Fig. 6 —Net Address
Micro-switch S1 and dial-switch S2 are for address setting when the user wants to control the unit with a central controller.
Range: 00-63
Fig. 7 — Unit Configuration
Fig. 8 — Unit Configuration Factory Settings
0
8
4
1
2
3
5
6
7
C
9
A
B
D
E
F
12
ON
0
8
4
1
2
3
5
6
7
C
9
A
B
D
E
F
12
ON
0
8
4
1
2
3
5
6
7
C
9
A
B
D
E
F
12
ON
0
8
4
1
2
3
5
6
7
C
9
A
B
D
E
F
12
ON
S1+S2
0~F 0~F 0~F 0~F
NETADDRESS
CODE
0~15 16~31 32~47 48~63
FACTORYS ETTING
FOR SETTING NETADDRESS
0
8
4
1
2
3
5
6
7
C
9
A
B
D
E
F
0~F ON~OFF
CODE
FACTORY
1 2 3
ON
4
SW1
12 3
ON
4
SW2
1 2 3
ON
4
SW3
S3
12 3
ON
4
SW4
12
ON
S4
24V THERMOSTATS SETTING
SETTI
ON~OFF ON~OFF ON~OFF ON~OFF

DLFSAB and DLFLAB: Service Manual
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7
CONNECTORS (CONT.)
Table 2 — Unit Configuration Settings
DIAL CODE FEATURES ON OFF (DEFAULT)
S3 Electric heating turns on outdoor T4 temperature
0 (zero) means that the temperature protection is not turned on.
1 through F maps to -4°F through 46°F (-20°C through 8°C).
Each increment represents 3.6°F (2°C).
SW1-1 Whether 24V control selection YES NO
SW1-2 Cold wind protection option NO YES
SW1-3 Single cooling/heating and cooling options Cooling Heating and Cooling
SW1-4 Set machine.single internal machine Indoor unit KIT
SW2-1 The first group controls the electric heating to turn on the
temperature difference 1.8°F (1°C) 3.6°F (2°C)
SW2-2 Whether the electric heating is delayed YES NO
SW2-3 Electric auxiliary heating delay start time 30 minutes 15 minutes
SW2-4 Electric heating/compressor allow opening limit Compressor allowed to operate to low
limit set by S3
Electric heating allowed to operate
to high limit set by S3
SW3-1 Continuous running time when the 1.8°F (1°C) set temperature
is not reached E-square value (0.5 hour) 1.5 hours
SW3-2 Cooling and heating Y2 signal setting temperature adjustment
value A 1.8°F (1°C) 3.6°F (2°C)
SW3-3 Hysteresis of the second group of electric heating 3.6°F (2°C) 5.4°F (3°C)
SW3-4 Reserve //
S4-1 Default ON Short circuit W1 and W2 W1, W2 separate
S4-2 Default ON DH is off by default DH on
SW4-1 000 is the default
000/001/010/011/100/101/110/111, internal machines with different abilities, electric heating and PSC classification for use
SW4-2
SW4-3

DLFSAB and DLFLAB: Service Manual
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8
WIRING
Use the following steps to wire the indoor unit.
NOTE: Wiring in this section is for the base unit ONLY.
1. Prepare the cable for connection.
a. Using wire strippers, strip the insulation from both ends of the
signal cable to reveal about 1/2 in (12mm) of wire.
b. Strip the insulation from both ends of the wires.
c. Use a wire crimper to crimp the fork terminals to the ends of
the wires.
2. Open the indoor unit’s front panel. Use a screwdriver to remove the
cover of the electric control box on the indoor unit.
3. Thread the power cable and the signal cable through the wire outlet.
4. Connect the fork terminals to the terminals. Match the wire colors/
labels with the labels on the terminal block.
5. Firmly screw the fork terminals of each wire to its corresponding
terminal. Refer to the serial number and wiring diagram located on
the cover of the electric control box.
Fig. 9 — Control Box and Wiring Diagram
6. Clamp down the cable with the cable clamp. The cable must not be
loose or put strain on the fork terminals.
7. Reattach the electric box cover.
Fig. 10 — Ferrite Core (Magnetic Ring)
The main power is supplied to the outdoor unit. When disconnecting the
power of the outdoor unit, the indoor unit would lose power. A disconnect
switch is not required on the indoor unit side on the wiring between the
outdoor and indoor unit. A 3 pole disconnect (purchased separately) may
be used for extra protection between the indoor and outdoor Unit.
Fig. 11 — Wiring Connection of Indoor Unit
The Auxiliary Heater must have a separate branch electric circuit with a
field-supplied disconnect switch located within sight from, and readily
accessible from, the unit.
Fig. 12 — Wiring Connection of Electric Heater
(optional)
While connecting the wires, strictly follow the wiring diagram.
The refrigerant circuit can become very hot.
Keep the interconnection cable away from the copper tube.
CAUTION
L1 L2 S
Pass the belt through the hole
of the ferrite core
(Magnetic Ring
to secure it to the cable
Circuit Breaker
3 Pole Disconnect
(purchased separately)
(purchased separately)
(purchased separately)
Electrical heater unit power wires
Electrical
heater
unit
Circuit Breaker
(DO NOT connect to
the indoor unit
circuit breaker!)

DLFSAB and DLFLAB: Service Manual
Manufacturer reserves the right to change, at any time, specifications and designs without notice and without obligations.
9
CONNECTION DIAGRAMS AND CONTROL METHODS
The air handler fan coil unit can be controlled mainly through the
following methods.
• SCENARIO #1 Wired controller (Included, optional accessory) -
KSACN1001AAA:
Non-polarity controller used to operate all functions. The wired
controller is equipped with an infrared receiver and can be used in
conjunction with the wireless controller.
For this scenario to be enabled SW1-1 must be set to the OFF positions
(Default)
• SCENARIO #1 Wireless controller (Included):
Hand-held wireless remote provides the same functionality as the
wired controller and can be used in conjunction with the wired
controller. Refer to the owner’s manual for the remote’s operational
instructions.
For this scenario to be enabled SW1-1 must be set to the OFF position
(Default).
• SCENARIO #2 Third party heat pump thermostat (Not Included):
Allows the control of the air handler via the built-in 24V interface.
For this scenario to be enabled SW1-1 must be set to the ON position.
Fig. 13 — Connection Methods for 18K-36K Residential Units
Fig. 14 — Connection Methods for 36K-60K Light Commercial Units

DLFSAB and DLFLAB: Service Manual
Manufacturer reserves the right to change, at any time, specifications and designs without notice and without obligations.
10
WIRING DIAGRAMS
Fig. 15 — Wiring Diagram Sizes 18K/24K/30K/36K - Non Light-Commercial Models
Table 3 — Wiring Diagram Sizes 18K/24K/30K/36K - Non Light-Commercial Models
INDOOR UNIT
MAINBOARD
Y/G
Cn1 8
CN2 3
Alarm
CN3 3
work

6
Cn1 0
CN 5
WATER LEVEL
CN4 6
T1
ECM

Cn15
M
4(3) 3
Cn34
CN4 3
UVLE D
Output
BLU E
RED
RED
TRAN S
CN2 2
RED
CN 9
J1
CN2 9
T2
Cn1 2
3
HEATER
2
CN1 1
L1
L2
RE D
BLAC K
TO OUTDOOR UNIT
OR POWER
2
NL
L and N :230VAC
SWITCH
Output:5VDC
Output:24VAC
Output:5VDC
Output:5VDC
Output:220VAC
Output:12VDC
Output:24VAC
Output:15VDC
Output:220VAC
Output:24VAC
JR1
CN 5
CN 4
Cn 1
CN2
ON/OF F
Remot e
Contro l
CN6 CN9 CN1 0 CN1 1
CN7
2 WIR E WIR E
CONTROLLE R
CN1 4
4
48 5 POR T
CN3
E Y X
To CCM
Comm.Bu s
Output:24VAC Output:24VAC
Output:+15VDC
Output:+12VDC
Output:+15VDC Output:+12VDC
Output:+5VDC
Output:24VAC Output:24VAC Output:24VAC Output:24VAC
Y/ G
DRY CONTACT
DRY CONTACT
T2B
T2A
CN 6
CN 21
Output:5VDC
2
2
Output:12VDC
S1 S2
CN2 0
COMMUNICATION
TO OUTDOOR UNIT
W1
DH
R C
L
G Y1
Y/Y 2
B
W
W2
E/AU X
24V THERMOSTAT
CODE PART NAME
ECM Indoor ECM Motor
T1 Room Temperature
T2 Coil Temperature Sensor
T2A Indoor Coil Inlet Temperature Sensor
T2B Indoor Coil Outlet Temperature Sensor