Mitsubishi Electric LAHN-1 Operating manual

MANUFACTURED FOR:
MITSUBISHI ELECTRIC US, INC.
MANUFACTURED FOR:
MITSUBISHI ELECTRIC US, INC.
CITY MULTI®PUHY-P-T/Y(S)NU-A(-BS), PUHY-EP-T/Y(S)NU-A(-BS),
and PUHY-HP-T/Y(S)NU-A Series
Outdoor Units
for use with:
2019
TECHNICAL & SERVICE MANUAL
Model LAHN-1/LAHN-3 Low Ambient Hood
4000292
2015
TECHNICAL & SERVICE MANUAL
Model LAHK-1 Low Ambient Hood
4000292

2
Specications are subject to change without notice. © 2019 Mitsubishi Electric US, Inc.
Contents
1. Control box component identication
2. Operating sequence
LAHK-1 Control Box Component Identification
Operating Sequence
Outdoor Unit in Cooling Mode
The LAHK-1 low ambient hood is designed to reduce
the airflow through the outdoor units as the ambient
temperature drops. This maintains the head pressure
at a level that will allow the system to perform at 100%
capacity down to -10oF outdoor temperature.
A thermistor mounted on the side of the unit senses
the outdoor temperature. As the outdoor temperature
drops, the resistance of the thermistor increases. The
thermistor is connected to the specially designed circuit
board and the resistance value from the thermistor is
converted to a DC voltage output within the circuit
board. This DC voltage output drives the damper
actuator to a predetermined position based on the
outdoor temperature.
The inverter driven fan motor will adjust the discharge
pressure based on system capacity demand. The
motor will speed up and force more air through the
damper if there is a higher system capacity demand, or
slow down if system capacity demand decreases.
Outdoor Unit in Heating Mode
Heating mode requires the damper be in the fully open
position to allow full airflow and maximum heating
capacity.
Heating mode automatically deactivates the kit through
an interlock relay. The coil for this relay is tied into the
reversing valve connection on the outdoor unit. When
the unit switches to heating mode, the reversing valve
is energized. This in-turn energizes the interlock relay.
When the relay is energized, the normally closed
contact opens. By opening this contact, the power to
the transformer and control board is interrupted, this
allows the damper to spring to the full open position.
Outdoor Unit in Defrost Mode
If the outdoor unit will be running in heating mode, a
defrost period is inevitable. During defrost the low
ambient controls see this as the unit operating in
cooling mode. If the outdoor temperature is below 50 F,
the damper will close to a position equal to that
required during the cooling cycle. Once the unit comes
back out of defrost and into heating mode, the damper
will again spring wide open for full airflow.
Operation Test
Outdoor unit must be in cooling mode
December 2013
© 2013 Mitsubishi Electric US, Inc. 2
Outdoor unit in cooling mode
The LAHN-1/LAHN-3 low ambient hood is designed to reduce the
airow through the outdoor units as the ambient temperature drops.
This maintains the head pressure at a level that will allow the system
to perform at full capacity down to -10°F outdoor temperature.
A thermistor mounted on the side of the unit senses the outdoor
temperature. As the outdoor temperature drops, the resistance of
the thermistor increases. The thermistor is connected to the specially
designed circuit board and the resistance value from the thermistor
is converted to a DC voltage output within the circuit board. This DC
voltage output drives the damper actuator to a predetermined position
based on the outdoor temperature.
The inverter driven fan motor will adjust the discharge pressure based
on system capacity demand. The motor will speed up and force more
air through the damper if there is a higher system capacity demand,
or slow down if system capacity demand decreases.
Outdoor unit in heating mode
Heating mode requires the damper be in the fully open position to
allow full airow and maximum heating capacity.
Heating mode automatically deactivates the kit through an interlock
relay. The coil for this relay is tied into the reversing valve connection
on the outdoor unit. When the unit switches to heating mode, the
reversing valve is energized. This in turn energizes the interlock relay.
When the relay is energized, the normally closed contact opens. By
opening this contact, the power to the transformer and control board is
interrupted, this allows the damper to spring to the full open position.
Outdoor unit in defrost mode
If the outdoor unit will be running in heating mode, a defrost period
is inevitable. During defrost the low ambient controls see this as the
unit operating in cooling mode. If the outdoor temperature is below
40°F, the damper will close to a position equal to that required during
the cooling cycle. Once the unit comes back out of defrost and into
heating mode, the damper will again spring wide open for full airow.
Operation test
Outdoor unit must be in cooling mode.
All hoods and damper controls are tested at the factory before shipping.
To perform an operational test once the installation is complete, follow
the steps below. Please refer to the chart and table below for detailed
control logic.
Operation testing when the outdoor ambient is ABOVE 40°F
1. Turn on power to the outdoor unit.
1. Control box component identication .....................................2
2. Operating sequence ...............................................................2
3. Damper blade adjustment ......................................................5
4. Damper actuator manual override .........................................8
5. Parts list ..................................................................................9
6. Wiring diagram .....................................................................10

3
© 2019 Mitsubishi Electric US, Inc. Specications are subject to change without notice.
2. Make sure the outdoor unit is in cooling mode.
3. Locate the outdoor temperature sensing thermistor at the end of
the short conduit coming out the side of the control panel; it can
be seen inside the plastic shield.
4. Using an aerosol dusting sprayer, invert the can and spray the
thermistor with very short bursts of the cold liquid.
Caution! Do Not overspray the thermistor as it could be
damaged. It may take 10 – 20 seconds for the internal
thermistor temperature to drop.
The damper will start to move toward the closed position after
the thermistor drops below 35°F.
5. Once the thermistor warms above 40°F, it will move back to the
full open position indicating the low ambient kit is working as
designed.
Operation testing when the outdoor ambient is BELOW 35°F
1. Turn on power to the outdoor unit.
2. Make sure the outdoor unit is in cooling mode.
3. The damper will move toward the closed position to a
predetermined position based on the outdoor ambient
temperature, indicating the low ambient kit is working as
designed.
Ambient Temp Hood Angle Output Voltage Resistance
[ °F ] [ ° ] vΩ
-10 80 8.78 117960
-5 80 8.78 100184
0 70 7.9 85340
570 7.9 72906
10 70 7.9 62460
15 70 7.9 53658
20 60 7.04 46220
25 60 7.04 39917
30 60 7.04 34562
35 60 7.04 30000
40 OPEN 226104
45 OPEN 222767
If neither of these tests work, proceed with the component
troubleshooting instructions.
Component troubleshooting
Thermistor
The thermistor is a 10,000 Ω, NTC Type.
The circuit board has a blinking indicator light built in to reference what
the thermistor is sensing. The chart below shows what the blinking
light sequence means.
(1 Blink)
45
50
55
Outside Ambient Temperature (°F)
15
20
25
30
35
40
-15
-10
-5
0
5

10

(3 Blinks)

(2 Blinks)
If the light is on constantly, the thermistor is open or shorted and
needs to be replaced. If the blinking light sequence doesn’t fall within
the range given in the chart, the thermistor needs to be replaced. If
it’s suspected that the thermistor is operating inaccurately, check the
tolerance in the following instructions.
Disconnect the thermistor from the control board. Measure the
resistance across the two leads. Measure the temperature of the
thermistor. (Accuracy on the temperature reading is important to
prevent a good thermistor from being replaced).
Compare the ohm reading with the temperature on the chart below.
Based on the thermistor temperature the ohm reading should be within
3% of the number shown below. If not, and the thermistor connections
are not corroded, the thermistor should be replaced.
All hoods and damper controls are tested at the factory
before shipping. To perform an operational test once
the installation has been completed, follow the steps
below.
Operation testing when the outdoor ambient is
ABOVE 50°F
1. Turn on power to the outdoor unit.
2. Make sure the outdoor unit is in cooling mode.
3. Locate the outdoor temperature sensing
thermistor at the end of the short conduit
coming out the side of the control panel, it can
be seen inside the plastic shield.
4. Using an aerosol dusting sprayer, invert the
can and spray the thermistor with very short
bursts of the cold liquid. Caution! Do Not
overspray the thermistor as it could be
damaged. It may take 10 – 20 seconds for
the internal thermistor temperature to drop.
The damper will start to move toward the
closed position after the thermistor drops
below 50°F
5. Once the thermistor warms above 50°F, it will
move back to the full open position indicating
the low ambient kit is working as designed.
Operation testing when the outdoor ambient is
BELOW 50°F
1. Turn on power to the outdoor unit.
2. Make sure the outdoor unit is in cooling mode.
3. The damper will move toward the closed
position to a predetermined position based on
the outdoor ambient temperature, indicating
the low ambient kit is working as designed.
If neither of these tests work. Proceed with the
component troubleshooting instructions.
Component Troubleshooting
Thermistor
The thermistor is a 10,000 Ω, NTC Type.
The circuit board has a blinking indicator light built in to
reference what the thermistor is sensing. The chart
below shows what the blinking light sequence means.
1
2
3
Constant ON
Thermistor is open or shorted
Blink(s)
Thermistor Temperature
Above 50F
50F to 20F
Below 20F
If the light is on constantly, the thermistor is open or
shorted and needs to be replaced. If the blinking light
sequence doesn’t fall within the range given in the
chart, the thermistor needs to be replaced. If it’s
suspected that the thermistor is operating inaccurately,
check the tolerance in the following instructions.
Disconnect the thermistor from the control board.
Measure the resistance across the two leads. Measure
the temperature of the thermistor. (Accuracy on the
temperature reading is important to prevent a good
thermistor from being replaced).
Compare the ohm reading with the temperature on the
chart below. Based on the thermistor temperature the
ohm reading should be within 1-2% of the number
shown below. If not, and the thermistor connections
are not corroded, the thermistor should be replaced.
o
FOhms
o
FOhms
o
FOhms
o
FOhms
86 8,05659 15,71432 32,650572,906
84 8,44857 16,55130 34,562377,620
82 8,86255 17,43828 36,601182,676
81 9,07754 17,90227 37,671085,340
79 9,52652 18,87326 38,776-2 90,962
77 10,00050 19,90323 42,315-4 96,999
75 10,50148 20,99721 44,875-6 103,486
73 11,03146 22,15919 47,610-8 110,460
72 11,30745 22,76718 49,047-9 114,141
70 11,88443 24,04016 52,069-11 121,921
68 12,49341 25,39414 55,301-13 130,295
66 13,13939 26,83512 58,759-15 139,313
64 13,82237 28,36810 62,460-17 149,030
63 14,17936 29,171964,408-18 154,169
61 14,92434 30,856768,510-20 165,048
Circuit Board
Confirm the thermistor is operating properly before
troubleshooting the circuit board.
Make sure the control board has 24 Volts AC when
measured at the 24 VAC and the com terminals. If not,
find the cause of voltage failure.
The circuit board is designed to convert the thermistor
ohm input to a 2 - 9.16 VDC output to control the
position of the damper actuator. Above 2 VDC output
the actuator will start to move the damper toward the
closed position. At 9.16 VDC, the actuator will have
moved 85 degrees and the damper will be
approximately 95% closed. The damper should never
be 100% closed. The chart below includes the various
damper angles based on the different outdoor
temperatures. Measure the DC voltage output on the
circuit board at com (-) and the out (+) terminals. If the
output doesn’t match the thermistor input ohms as
shown below, replace the circuit board.
OutdoorThermistor Control board Damper
Temperature Ohms DC volts output Angle
Above 52oFN/A 2.00 0ofull open
52 18,873 2.00
0o
50 19,903 3.25
15o
45 22,767 4.50
30o
40 26,104 5.80
45o
35 30,000 7.04
60o
30 34,562 7.90
70o
25 39,917 8.75
80o
20 46,220 9.16
85o
Below 20oFN/A 9.16 85o
Transformer
December 2013
© 2013 Mitsubishi Electric US, Inc. 3
LAHN Damper Hysteresis Control
OPEN 60 70 80
50
45
40
35
30
25
20
15
10
5
0
-5
-10
= As Temperature Increases
= As Temperature Decreases
Damper Angle [°]
Outdoor Ambient Temperature [°F]

4
Specications are subject to change without notice. © 2019 Mitsubishi Electric US, Inc.
Circuit board
Conrm the thermistor is operating properly before troubleshooting
the circuit board.
Make sure the control board has 24 Volts AC when measured at the
24 VAC and the com terminals. If not, nd the cause of voltage failure.
The circuit board is designed to convert the thermistor ohm input to
a 2 - 9.16 VDC output to control the position of the damper actuator.
Above 2 VDC output the actuator will start to move the damper toward
the closed position. At 9.16 VDC, the actuator will have moved 85
degrees and the damper will be approximately 95% closed. The
damper should never be 100% closed. The chart below includes the
various damper angles based on the different outdoor temperatures.
Measure the DC voltage output on the circuit board at com (-) and
the out (+) terminals. If the output doesn’t match the thermistor input
ohms as shown below, replace the circuit board.
Ambient Temp Hood Angle Output Voltage Resistance
[ °F ] [ ° ] vΩ
-10 80 8.78 117960
-5 80 8.78 100184
0 70 7.9 85340
570 7.9 72906
10 70 7.9 62460
15 70 7.9 53658
20 60 7.04 46220
25 60 7.04 39917
30 60 7.04 34562
35 60 7.04 30000
40 OPEN 226104
45 OPEN 222767
Transformer
The transformer is 208/230 – 24 volt AC. For proper connections to
the outdoor unit, refer to the following diagram and instructions.
The transformer is 208/230 – 24volt AC. For proper
connections to the outdoor unit, the following diagram
and instructions should be referred to.
The low ambient kit is designed to function with both
208/230 volt and also 460 volt outdoor units.
On 208 volt units the CNAC2 connector will provide
208 volts to the control transformer.
On 230 volt units the CNAC2 connector will provide
230 volts to the control transformer.
The 460 volt units include a transformer that reduces
the outdoor unit internal voltage to 230 volts. Because
of this, on the 460 volt units the CNAC2 connector will
also provide 230 volts to the control transformer.
Once the proper connection is confirmed, measure
voltage on the primary side of the transformer. It
should be 208 or 230 +- 10% depending on the supply
voltage at the outdoor unit. If there is no voltage on the
primary side of the transformer check the fuse that is
located in the fuse holder inside the outdoor unit. See
wiring diagram for fuse location. Once power has been
confirmed at the primary side of the transformer, check
the secondary/low voltage side of the transformer it
should be approximately 27 volts. If no voltage is
present, replace transformer.
Interlock Relay
The interlock relay uses a normally closed contact to
allow power to flow to the transformer energizing the
low ambient kit control circuitry. Any time the outdoor
unit is in cooling mode, this contact will be in closed.
When the outdoor unit reversing valves energizes
(switches to heating mode) the coil of the relay is
energized, opening this contact. This in-turn de-
energizes the transformer, disconnecting power to the
low ambient kit control circuitry. This allows the damper
to spring return to the full open position during heating
mode.
To check, make sure the contact is closed when the
outdoor unit is in cooling mode (coil de-energized) and
the contact is open when the outdoor unit is in the
heating mode (coil energized).
Damper Actuator
Before trouble shooting the damper motor, verify the
two factory switches are in the position shown below.
(1) Common
(2) + Hot
(3) 2-10VDC
(5)
Factory switch positions
Damper Actuator
Orange
White
Black
Red
red
black
white
Y=0
Y=0
Make sure the motor has 24 volts on the (1) Common
and(2) +Hot connections. If not, find the cause of the
voltage failure and correct.
The damper actuator receives a DC voltage signal
from the circuit board. This voltage can be measured
between (1) Common and (3) 2-10VDC connections.
The damper actuator has an angle indicator where it
clamps onto the damper shaft linkage.
Compare the DC voltage supply to the damper angle
indicator position in the chart below. The angle should
be within 2% of the chart shown below. If not, check to
make sure the damper started off in the correct
position. 0 Degrees
IMPORTANT!
It’s possible that during shipping, the damper shaft
may have moved in the actuator shaft clamp
assembly. With power off, make sure the damper is
in the full open position. 0 degrees If necessary,
loosen the shaft clamp on the actuator, move the
damper to the 100% open position, and re-clamp
tightly.
If the damper actuator angle doesn’t match within 2%,
with the corresponding control board voltage supplied
as shown below, the damper actuator should be
replaced.
OutdoorThermistor Control board Damper
Temperature Ohms DC volts output Angle
Above 52
o
FN/A 2.00 0
o
full open
52 18,873 2.00
0
o
50 19,903 3.25
15
o
45 22,767 4.50
30
o
40 26,104 5.80
45
o
35 30,000 7.04
60
o
30 34,562 7.90
70
o
25 39,917 8.75
80
o
20 46,220 9.16
85
o
Below 20
o
F
N/A 9.16
85
o
December 2013
© 2013 Mitsubishi Electric US, Inc. 4
The low ambient kit is designed to function with both 208/230 volt
and also 460 volt outdoor units.
On 208 volt units the CNAC2 connector will provide 208 volts to the
control transformer.
On 230 volt units the CNAC2 connector will provide 230 volts to the
control transformer.
The 460 volt units include a transformer that reduces the outdoor
unit internal voltage to 230 volts. Because of this, on the 460 volt
units the CNAC2 connector will also provide 230 volts to the control
transformer.
Once the proper connection is conrmed, measure voltage on the
primary side of the transformer. It should be 208 or 230 +- 10%
depending on the supply voltage at the outdoor unit. If there is no
voltage on the primary side of the transformer, check the fuse that
is located in the fuse holder inside the outdoor unit. See the wiring
diagram for fuse location. Once power has been conrmed at the
primary side of the transformer, check the secondary/low voltage
side of the transformer. It should be approximately 27 volts. If no
voltage is present, replace the transformer.
Interlock relay
The interlock relay uses a normally closed contact to allow power to
ow to the transformer energizing the low ambient kit control circuitry.
Any time the outdoor unit is in cooling mode, this contact will be in
closed. When the outdoor unit reversing valves energizes (switches to
heating mode) the coil of the relay is energized, opening this contact.
This in turn de-energizes the transformer, disconnecting power to
the low ambient kit control circuitry. This allows the damper to spring
return to the full open position during heating mode.
To check, make sure the contact is closed when the outdoor unit is in
cooling mode (coil de-energized) and the contact is open when the
outdoor unit is in the heating mode (coil energized).
Damper actuator
Before trouble shooting the damper motor, verify the two factory
switches are in the position shown below.
The transformer is 208/230 – 24volt AC. For proper
connections to the outdoor unit, the following diagram
and instructions should be referred to.
The low ambient kit is designed to function with both
208/230 volt and also 460 volt outdoor units.
On 208 volt units the CNAC2 connector will provide
208 volts to the control transformer.
On 230 volt units the CNAC2 connector will provide
230 volts to the control transformer.
The 460 volt units include a transformer that reduces
the outdoor unit internal voltage to 230 volts. Because
of this, on the 460 volt units the CNAC2 connector will
also provide 230 volts to the control transformer.
Once the proper connection is confirmed, measure
voltage on the primary side of the transformer. It
should be 208 or 230 +- 10% depending on the supply
voltage at the outdoor unit. If there is no voltage on the
primary side of the transformer check the fuse that is
located in the fuse holder inside the outdoor unit. See
wiring diagram for fuse location. Once power has been
confirmed at the primary side of the transformer, check
the secondary/low voltage side of the transformer it
should be approximately 27 volts. If no voltage is
present, replace transformer.
Interlock Relay
The interlock relay uses a normally closed contact to
allow power to flow to the transformer energizing the
low ambient kit control circuitry. Any time the outdoor
unit is in cooling mode, this contact will be in closed.
When the outdoor unit reversing valves energizes
(switches to heating mode) the coil of the relay is
energized, opening this contact. This in-turn de-
energizes the transformer, disconnecting power to the
low ambient kit control circuitry. This allows the damper
to spring return to the full open position during heating
mode.
To check, make sure the contact is closed when the
outdoor unit is in cooling mode (coil de-energized) and
the contact is open when the outdoor unit is in the
heating mode (coil energized).
Damper Actuator
Before trouble shooting the damper motor, verify the
two factory switches are in the position shown below.
(1) Common
(2) + Hot
(3) 2-10VDC
(5)
Factory switch positions
Damper Actuator
Orange
White
Black
Red
red
black
white
Y=0
Y=0
Make sure the motor has 24 volts on the (1) Common
and(2) +Hot connections. If not, find the cause of the
voltage failure and correct.
The damper actuator receives a DC voltage signal
from the circuit board. This voltage can be measured
between (1) Common and (3) 2-10VDC connections.
The damper actuator has an angle indicator where it
clamps onto the damper shaft linkage.
Compare the DC voltage supply to the damper angle
indicator position in the chart below. The angle should
be within 2% of the chart shown below. If not, check to
make sure the damper started off in the correct
position. 0 Degrees
IMPORTANT!
It’s possible that during shipping, the damper shaft
may have moved in the actuator shaft clamp
assembly. With power off, make sure the damper is
in the full open position. 0 degrees If necessary,
loosen the shaft clamp on the actuator, move the
damper to the 100% open position, and re-clamp
tightly.
If the damper actuator angle doesn’t match within 2%,
with the corresponding control board voltage supplied
as shown below, the damper actuator should be
replaced.
OutdoorThermistor Control board Damper
Temperature Ohms DC volts output Angle
Above 52
o
FN/A 2.00 0
o
full open
52 18,873 2.00
0
o
50 19,903 3.25
15
o
45 22,767 4.50
30
o
40 26,104 5.80
45
o
35 30,000 7.04
60
o
30 34,562 7.90
70
o
25 39,917 8.75
80
o
20 46,220 9.16
85
o
Below 20
o
F
N/A 9.16
85
o
December 2013
© 2013 Mitsubishi Electric US, Inc. 4
Make sure the motor has 24 volts on the (1) Common and (2) +Hot
connections. If not, nd the cause of the voltage failure and correct.
The damper actuator receives a DC voltage signal from the circuit
board. This voltage can be measured between (1) Common and (3)
2-10VDC connections.
The damper actuator has an angle indicator where it clamps onto the
damper shaft linkage.
Compare the DC voltage supply to the damper angle indicator position
in the chart below. The angle should be within 2% of the chart shown
below. If not, check to make sure the damper started off in the correct
position, 0 Degrees.
IMPORTANT!
It’s possible that during shipping, the damper shaft may have
moved in the actuator shaft clamp assembly. See Section 3.
Damper Blade Adjustment.
If the damper actuator angle doesn’t match within 2%, with the
corresponding control board voltage supplied as shown below, the
damper actuator should be replaced.
Ambient Temp Hood Angle Output Voltage Resistance
[ °F ] [ ° ] vΩ
-10 80 8.78 117960
-5 80 8.78 100184
0 70 7.9 85340
570 7.9 72906
10 70 7.9 62460
15 70 7.9 53658
20 60 7.04 46220
25 60 7.04 39917
30 60 7.04 34562
35 60 7.04 30000
40 OPEN 226104
45 OPEN 222767

5
© 2019 Mitsubishi Electric US, Inc. Specications are subject to change without notice.
3. Damper blade adjustment
IMPORTANT!
It’s possible that during shipping, the damper shaft may have
moved in the actuator shaft clamp assembly.
In some cases due to manufacturing tolerances the LAHN blades
could close 100%. The damper should never be 100% closed
during operation. When working properly the damper will be
approximately 95% closed at -5°F and below. The following procedure
will allow proper adjustment.
The Belimo damper motor within the LAHN control box has a built in
mechanical stop to adjust the maximum angle of rotation. This must
be adjusted to 85 degrees and the damper blade position veried or
re-set to the proper position (1/4” open) to ensure the unit functions
properly.
Belimo motor angle indicating
scale shown below.
The factory setting for the mechanical stop
is shown below at 85 degree hood angle.
IMPORTANT! ENSURE POWER IS OFF BEFORE STARTING!!
Basic service overview
1. Set the damper motor stop to 85 degrees.
2. Loosen “U” bolts on damper shaft.
3. Crank the motor against the 85-degree stop then lock into
position.
4. Set the damper to approx. ¼” open.
(Use the damper crank handle as spacer.)
5. Re-tighten “U” bolts on damper shaft.
6. Release the motor by slightly cranking with the handle.
Check the operation manually.
7. The goal is to have ¼” opening on the damper assembly
in the 85 degree position.
LOW AMBIENT HOOD – LAHK-1 DAMPER BLADE ADJUSTMENT
IMPORTANT!
It’s possible that during shipping, the damper shaft may have moved in the actuator shaft
clamp assembly. In some cases due to manufacturing tolerances the LAHK blades could close
100%. The damper should never be 100% closed during operation. When working properly
the damper will be approximately 95% closed at 20 degrees and below. The following
procedure will allow proper adjustment.
The Belimo damper motor within the LAHK control box has a built in mechanical stop to
adjust the maximum angle of rotation. This must be adjusted to 85 degrees and the damper
blade position verified or re-set to the proper position (1/4” open) to ensure the unit
functions properly.
The factory setting for the mechanical
stop is shown below at 95.
Belimo motor angle indicating
scale shown below.
IMPORTANT! ENSURE POWER IS OFF BEFORE STARTING!!
Basic Service Overview
1.) Set damper motor stop to 85 degrees.
2.) Loosen “U” bolts on damper shaft
3.) Crank motor against 85 degree stop then lock into position
4.) Set damper to approx. ¼” open. (Use damper crank handle as spacer.)
5.) Re-Tighten “U” bolts on damper shaft
6.) Release motor by slightly cranking with handle. Check operation manually
7.) The goal is to have ¼” opening on damper assembly in the 85 degree position.

6
Specications are subject to change without notice. © 2019 Mitsubishi Electric US, Inc.
STEP BY STEP INSTRUCTIONS:
1. Loosen the Philips head screw for the mechanical stop.
Loosen the Philips head screw for the
mechanical stop.
Slide the mechanical stop to 85 (halfway
between 8 and 9) and tighten the screw,
making sure the locating teeth on the stop
are engaged into the actuator motor teeth.
Loosen the (2) nuts on the
damper shaft “U” clamp
Using the crank handle turn the motor
counterclockwise until the indicator snugs
against the stop at 85 degrees.
STEP BY STEP INSTRUCTIONS
1 2
3 4
Lock the motor in the
85 degree position.
5
Close the blades by hand and insert
Crank handle under damper blade near
the screws as shown to ensure it is open
approximately ¼ inch at 85 degrees
6
1.
2. Slide the mechanical stop to 85 (halfway between 8 and 9) and
tighten the screw, making sure the locating teeth on the stop are
engaged into the actuator motor teeth.
Loosen the Philips head screw for the
mechanical stop.
Slide the mechanical stop to 85 (halfway
between 8 and 9) and tighten the screw,
making sure the locating teeth on the stop
are engaged into the actuator motor teeth.
Loosen the (2) nuts on the
damper shaft “U” clamp
Using the crank handle turn the motor
counterclockwise until the indicator snugs
against the stop at 85 degrees.
STEP BY STEP INSTRUCTIONS
1 2
3 4
Lock the motor in the
85 degree position.
5
Close the blades by hand and insert
Crank handle under damper blade near
the screws as shown to ensure it is open
approximately ¼ inch at 85 degrees
6
3. Loosen the (2) nuts on the damper shaft “U” clamp.
Loosen the Philips head screw for the
mechanical stop.
Slide the mechanical stop to 85 (halfway
between 8 and 9) and tighten the screw,
making sure the locating teeth on the stop
are engaged into the actuator motor teeth.
Loosen the (2) nuts on the
damper shaft “U” clamp
Using the crank handle turn the motor
counterclockwise until the indicator snugs
against the stop at 85 degrees.
STEP BY STEP INSTRUCTIONS
1 2
3 4
Lock the motor in the
85 degree position.
5
Close the blades by hand and insert
Crank handle under damper blade near
the screws as shown to ensure it is open
approximately ¼ inch at 85 degrees
6
4. Using the crank handle turn the motor counterclockwise until the
indicator snugs against the stop at 85 degrees.
Loosen the Philips head screw for the
mechanical stop.
Slide the mechanical stop to 85 (halfway
between 8 and 9) and tighten the screw,
making sure the locating teeth on the stop
are engaged into the actuator motor teeth.
Loosen the (2) nuts on the
damper shaft “U” clamp
Using the crank handle turn the motor
counterclockwise until the indicator snugs
against the stop at 85 degrees.
STEP BY STEP INSTRUCTIONS
1 2
3 4
Lock the motor in the
85 degree position.
5
Close the blades by hand and insert
Crank handle under damper blade near
the screws as shown to ensure it is open
approximately ¼ inch at 85 degrees
6
5. Lock the motor in the 85 degree position.
Loosen the Philips head screw for the
mechanical stop.
Slide the mechanical stop to 85 (halfway
between 8 and 9) and tighten the screw,
making sure the locating teeth on the stop
are engaged into the actuator motor teeth.
Loosen the (2) nuts on the
damper shaft “U” clamp
Using the crank handle turn the motor
counterclockwise until the indicator snugs
against the stop at 85 degrees.
STEP BY STEP INSTRUCTIONS
1 2
3 4
Lock the motor in the
85 degree position.
5
Close the blades by hand and insert
Crank handle under damper blade near
the screws as shown to ensure it is open
approximately ¼ inch at 85 degrees
6
6. Close the blades by hand and insert crank handle under
damper blade near the screws as shown to ensure it is open
approximately ¼ inch at 85 degrees.
Loosen the Philips head screw for the
mechanical stop.
Slide the mechanical stop to 85 (halfway
between 8 and 9) and tighten the screw,
making sure the locating teeth on the stop
are engaged into the actuator motor teeth.
Loosen the (2) nuts on the
damper shaft “U” clamp
Using the crank handle turn the motor
counterclockwise until the indicator snugs
against the stop at 85 degrees.
STEP BY STEP INSTRUCTIONS
1 2
3 4
Lock the motor in the
85 degree position.
5
Close the blades by hand and insert
Crank handle under damper blade near
the screws as shown to ensure it is open
approximately ¼ inch at 85 degrees
6

7
© 2019 Mitsubishi Electric US, Inc. Specications are subject to change without notice.
7. Holding the blades against the handle re-tighten the (2) nuts on
the damper shaft “U” clamp.
7
Slightly crank the handle to release
the motor. The damper will return
to the open position.
8
Review and Manual Test
To ensure the LAHK unit is functioning as designed. Crank the Belimo motor back to
the 85 degree position and visually check that the damper does not close completely.
Your goal is approximately ¼” opening between the blades at the 85 degree position.
Holding the blades against the
handle re-tighten the (2) nuts
on the damper shaft “U” clamp.
Ensure end of shaft is flush to
edge of clamp black surface as
shown.
Ensure end of shaft is ush to edge of clamp black surface as shown.
7
Slightly crank the handle to release
the motor. The damper will return
to the open position.
8
Review and Manual Test
To ensure the LAHK unit is functioning as designed. Crank the Belimo motor back to
the 85 degree position and visually check that the damper does not close completely.
Your goal is approximately ¼” opening between the blades at the 85 degree position.
Holding the blades against the
handle re-tighten the (2) nuts
on the damper shaft “U” clamp.
Ensure end of shaft is flush to
edge of clamp black surface as
shown.
8. Slightly crank the handle to release the motor. The damper will
return to the open position.
7
Slightly crank the handle to release
the motor. The damper will return
to the open position.
8
Review and Manual Test
To ensure the LAHK unit is functioning as designed. Crank the Belimo motor back to
the 85 degree position and visually check that the damper does not close completely.
Your goal is approximately ¼” opening between the blades at the 85 degree position.
Holding the blades against the
handle re-tighten the (2) nuts
on the damper shaft “U” clamp.
Ensure end of shaft is flush to
edge of clamp black surface as
shown.
7
Slightly crank the handle to release
the motor. The damper will return
to the open position.
8
Review and Manual Test
To ensure the LAHK unit is functioning as designed. Crank the Belimo motor back to
the 85 degree position and visually check that the damper does not close completely.
Your goal is approximately ¼” opening between the blades at the 85 degree position.
Holding the blades against the
handle re-tighten the (2) nuts
on the damper shaft “U” clamp.
Ensure end of shaft is flush to
edge of clamp black surface as
shown.
Review and manual test
To ensure the LAHN unit is functioning as designed, crank the Belimo motor back to the 85 degree position and visually check that the damper
does not close completely. Your goal is an approximately ¼” opening between the blades at the 85 degree position.

8
Specications are subject to change without notice. © 2019 Mitsubishi Electric US, Inc.
4. Damper actuator manual override
IMPORTANT! Never manually override the damper position if the
outdoor unit could switch to heating mode during the override
period. Heating mode requires the damper to be fully open for
full capacity.
It may be desirable to manually override the damper position and lock
it into position until repairs can be completed. If so, select an average
temperature, typical for the outside environment during the override
period, and then use that average temperature to nd the desired
damper angle in the chart below.
Ambient Temp Hood Angle Output Voltage Resistance
[ °F ] [ ° ] vΩ
-10 80 8.78 117960
-5 80 8.78 100184
0 70 7.9 85340
570 7.9 72906
10 70 7.9 62460
15 70 7.9 53658
20 60 7.04 46220
25 60 7.04 39917
30 60 7.04 34562
35 60 7.04 30000
40 OPEN 226104
45 OPEN 222767
Follow the instructions below for manually positioning and locking the
damper in place.
IMPORTANT! Disconnect power to the damper motor before
locking in place.
The damper actuator comes with a crank handle attached, to manually
move the damper position. The crank handle is removable and if it’s
missing, a 3/16” allen wrench will work just as well.
Use the following diagrams and instructions for this procedure.
Damper Actuator Manual Override
IMPORTANT! Never manually override the damper
position if the outdoor unit could switch to heating
mode during the override period. Heating mode
requires the damper to be fully open for full
capacity.
It may be desirable to manually override the damper
position and lock it into position until repairs can be
completed. If so, select an average temperature typical
for the outside environment during the override period,
and then use that average temperature to find the
desired damper angle in the chart below.
OutdoorThermistor Control board Damper
Temperature Ohms DC volts outputAngle
Above 52
o
FN/A 2.00 0
o
full open
52 18,8732.00
0
o
50 19,9033.25
15
o
45 22,7674.50
30
o
40 26,1045.80
45
o
35 30,0007.04
60
o
30 34,5627.90
70
o
25 39,9178.75
80
o
20 46,2209.16
85
o
Below 20
o
FN/A 9.16 85
o
Follow the instructions below for manually positioning
and locking the damper in place.
IMPORTANT! Disconnect power to the damper
motor before locking in place.
The damper actuator comes with a crank handle
attached, to manually move the damper position. The
crank handle is removable and if it’s missing, a 3/16”
allen wrench will work just as well.
Use the following diagrams and instructions for this
procedure.
Angle Indicator
December 2013
© 2013 Mitsubishi Electric US, Inc. 5
Winding the damper
actuator
Locking the damper
actuator
Unlocking the
damper actuator
(2 options)
- Insert crank handle
- Turn the handle in
the direction of the
arrow.
- Flip the lock switch
to the position
pointing to the
“locked” symbol.
- Flip the lock switch
to the position
pointing to the
“unlocked” symbol.
- Remote control by
supplying power to
the unit for > than 3
sec.
Damper Actuator Manual Override
IMPORTANT! Never manually override the damper
position if the outdoor unit could switch to heating
mode during the override period. Heating mode
requires the damper to be fully open for full
capacity.
It may be desirable to manually override the damper
position and lock it into position until repairs can be
completed. If so, select an average temperature typical
for the outside environment during the override period,
and then use that average temperature to find the
desired damper angle in the chart below.
OutdoorThermistor Control board Damper
Temperature Ohms DC volts outputAngle
Above 52
o
FN/A 2.00 0
o
full open
52 18,8732.00
0
o
50 19,9033.25
15
o
45 22,7674.50
30
o
40 26,1045.80
45
o
35 30,0007.04
60
o
30 34,5627.90
70
o
25 39,9178.75
80
o
20 46,2209.16
85
o
Below 20
o
FN/A 9.16 85
o
Follow the instructions below for manually positioning
and locking the damper in place.
IMPORTANT! Disconnect power to the damper
motor before locking in place.
The damper actuator comes with a crank handle
attached, to manually move the damper position. The
crank handle is removable and if it’s missing, a 3/16”
allen wrench will work just as well.
Use the following diagrams and instructions for this
procedure.
Angle Indicator
December 2013
© 2013 Mitsubishi Electric US, Inc. 5

9
© 2019 Mitsubishi Electric US, Inc. Specications are subject to change without notice.
5. Parts list
Part Description Part Number
Damper Actuator NFB24-SR
Transformer 208/230 - 24vac, 40VA R68AA0005
Interlock Relay 240 volt coil R68AB0006
Circuit Board CB-LAHN-1
Thermistor harness assy TH-LAHK-1-A
CN505 Connector HC-LAHK-1-1A
CNAC2 Connector HC-LAHK-1-2A
Wire Harness Components
CN505 Connector
Part Number: HC-LAHK-1-1A
Includes everything shown
White
CNAC2 Connector
Part Number: HC-LAHK-1-2A
Includes everything shown
Black
Note:
Damper linkage parts can be purchased locally.
If damper blades or complete assembly needs replacing, order new LAHN-2/LAHN-4 hood and damper assembly.
Damper Control Box
Red
Red
White
1 amp fuse
Black
White
White
Orange
Black

10
Specications are subject to change without notice. © 2019 Mitsubishi Electric US, Inc.
6. Wiring diagram
Ground
R
(1) Common
C(2) + Hot
(3) 2-10VDC
(5)
Terminal strip
Factory switch positions
10Kohm thermistor
CNAC2 Connection
LAHN-1/LAHN-3 Wiring Diagram
Outdoor Unit Control Board
Black
Red
230V
Control Box Mounted on Hood
Transformer
40 VA
Damper Actuator
Orange
208v
White
24 V
240 volt ac
NC Relay
24v
C
Circuit Board
black
white
orange
Com
red
red
red
red
black
white
blue
green
orange
white
black
red
red
1
3
4
5
+
+
-
-
Sensor 2-10VDC
Y=0
Y=
0
To reversing valve 21S4a
Serial Number
Date of Manufacture
Initials
connector) to the wire that corresponds to the
outdoorunit supply voltage as shown below
CN505 Connection
CNAC2
1amp
on the board. Connect the white wire (male
For Use with Modular N-Generation
Y-Series Outdoor Units Only
plug with fourwires onto the spare connection.
208 volt = orange wire (female connector)
move and secure cap to unused wire
the CN505 connection. Connect the white
the CN505 connection. Plug the white
male connector from the low ambient kit onto
Disconnect white plug with fourwires from
230/460 volt = white wire (female connector)
Insert the black plug into the CNAC2 connection
Manufactured for Mitsubishi Electric US, Inc.
Low Ambient Hood
Part Number LAHN-1/LAHN-3
Supply Voltage 208/230V, 1-phase,60Hz
Amps 0.20
Fuse Size
230/460v (wh)
208v (or)
common (blk)
M
F
F
red
red
green
1 amp fuse black
white
6
5
4
3
2
1
F
M
M
F
yellow

11
© 2019 Mitsubishi Electric US, Inc. Specications are subject to change without notice.

Specications are subject to change without notice. © 2019 Mitsubishi Electric US, Inc.
Please be sure to put the contact address/telephone number on
this manual before handing it to the customer.
This product is designed and intended for use in the
commercial environment.
Manufactured for MITSUBISHI ELECTRIC US, INC.
www.mylinkdrive.com
Toll Free: 800-433-4822
MEUS DOC# MD-1922-K002 Ver. 2, November 2019