Comfort Star EHK05A User manual

- 0 -
DC Inverter R410A
Air Conditioners & Heat Pump
Service Manual 2014

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CONTENTS
1. Precaution......................................................................................................................................... - 2 -
1.1 Safety Precaution.............................................................................................................- 2 -
1.2 Warning & Caution...........................................................................................................- 2 -
2. Function ............................................................................................................................................ - 4 -
2.1 Model Names Of Indoor/Outdoor Units................................ Error! Bookmark not defined.
2.2 Specifications....................................................................... Error! Bookmark not defined.
3. Dimension......................................................................................................................................... - 4 -
3.1 Indoor Units .....................................................................................................................- 4 -
3.2 Outdoor Units...................................................................................................................- 5 -
4. Refrigerant Cycle Diagram.............................................................................................................. - 6 -
5. Wiring Diagram................................................................................................................................. - 7 -
5.1 Indoor Units .....................................................................................................................- 7 -
5.2 Outdoor Units.................................................................................................................- 12 -
6. Installation Details ......................................................................................................................... - 14 -
6.1 Outdoor Unit Installation ................................................................................................- 14 -
6.2 Indoor Unit Installation ...................................................................................................- 27 -
6.3 Maintenance And Replacement Of Outdoor Unit Electronic Control Box.......................- 41 -
7. Operation Characteristics ............................................................................................................. - 43 -
8. Electronic Function........................................................................................................................ - 44 -
8.1 Abbreviation...................................................................................................................- 44 -
8.2 Main Control Logic .........................................................................................................- 44 -
8.3 Main Control Board Ports Instructions ...........................................................................- 48 -
8.4 Outdoor Unit Status Display...........................................................................................- 52 -
9. Troubleshooting ............................................................................................................................. - 53 -
9.1 Outdoor Unit Error Display.............................................................................................- 53 -
9.2 Diagnosis And Solution..................................................................................................- 54 -

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1. Precaution
1.1 Safety Precaution
This is a safety alert symbol. When you see this symbol on labels or in manuals, be
alert to the potential for personal injury.
This is an attention alert symbol. When you see this symbol on labels or in manuals,
be alert to the potential for personal injury.
Understand and pay particular attention to the signal words DANGER, WARNING, or CAUTION.
DANGER indicates an imminently hazardous situation, which, if not avoided, will result in death or
serious injury.
WARNING indicates a potentially hazardous situation, which, if not avoided, could result in death or
serious injury.
CAUTION indicates a potentially hazardous situation, which, if not avoided may result in minor or
moderate injury. It is also used to alert against unsafe practices and hazards involving only property
damage.
1.2 Warning & Caution
Outdoor Installation
Improper installation may create a condition where the operation of the product could
cause personal injury or property damage.
Improper installation, adjustment, alteration, service or maintenance can cause injury or
property damage. Refer to this manual for assistance or for additional information, consult a
qualified contractor, installer or service agency.
This product must be installed in strict compliance with the installation instructions and any
applicable local, state, and national codes including, but not limited to building, electrical, and
mechanical codes.
Fire or electrical hazard

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Failure to follow the safety warnings exactly could result in serious injury, death or property
damage.
A fire or electrical hazard may result causing property damage, personal injury or loss of
life.
If using existing refrigerant lines make certain that all joints are brazed, not soldered.
Do not touch the top of compressor, it may cause minor to severe burning.
Indoor Installation
Disconnect all power to unit before installing or servicing. More than one disconnect switch
may be required to de-energize the equipment. Hazardous voltage can cause server personal
injury or death.
If removal of the blower assembly is required, all disconnect switches supplying power to
the equipment must be de-energized and locked (if not in sight of unit ) so the field power wires
can be safely removed from the blower assembly. Failure to do so can cause electrical shock
resulting in personal injuring or death.
Because of possible damage to equipment or personal injury, installation, service, and
maintenance should be performed by a trained, qualified service personnel. Consumer service is
recommended only for filter cleaning / replacement. Never operate the unit with the acess panels
removed.
These instructions are intended as an aid to qualified, licensed service personnel for
proper installation, adjustment and operation of this unit. Read these instructions thoroughly
before attempting installation or operation. failure to follow these instructions may result in
improper installation, adjustment, service or maintenance possibly resulting in fire, electrical shock,
property damage, personal injury or death.
The unit must be permanently grounded. Failure to do so can result in electrical shock
causing personal injury or death.

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2. Function (Refer the specification)
3. Dimension
3.1 Indoor Units
DIMENSIONAL DATA
MODEL SIZE
Dimensions inch
UNIT HEIGHT "H" IN. UNIT WIDTH "W" IN. UNIT LENGTH "D" IN.
LIQUID LINE /
VAPOR LINE
24 46-1/2" 19-5/8" 21-5/8" 3/8"/3/4"
36 54-1/2" 22” 24" 3/8"/3/4"
48 54-1/2" 22" 24" 3/8"/7/8"
60 54-1/2" 22" 24" 3/8"/7/8"
H
D

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3.2 Outdoor Units
DIMENSIONAL DATA
Mode size Dimensions
Refrigerant connection
Service Valve Size
AC HP “H” in. “W” in. “L” in. Liquid in. Suction in.
24/36 24/36 24-15/16 29-1/8 29-1/8 3/8 3/4
48/60 48/60 33-3/16 29-1/8 29-1/8 3/8 7/8
W

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4. Refrigerant Cycle Diagram
For cooling only models:
For heat pump models:
stop
volve
stop
volve
COM P
Outdoor Unit
FAN
nut
nut
Indoor Unit
evaporator
FAN
expansion
valve
T5
discharge
temp.sensor
high pressure
switch
pressure
senser
T3
condenser temp.
sensor
condenser
REFRIGERATION FLOW
FAN
evaporator
Indoor Unit
nut
nut
FAN
T3
condenser
temp. sensor
Outdoor Unit
high pressure
switch
T5
stop
volve
stop
volve
SV4
expansion
valve
COMP
condenser
discharge
temp.sensor
low pressure
receiver
T4 ambient
temp. sensor
pressure
senser
filter
filter
EEV
check valve
REFRIGERATION
FLOW HEATING
COOLING

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5. Wiring Diagram
5.1 Indoor Units
Indoor unit wiring diagram for PSC motor A/C systems and H/P systems.

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Indoor unit wiring diagram for ECM motor A/C systems and H/P systems(24K/36K/48K).

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Indoor unit wiring diagram for ECM motor A/C systems and H/P systems (60K).

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Indoor unit wiring diagram for electric heat.
POWER
RED
BLACK
Fl
BLUE
4
1 3
2
Cb1
W1
WHITE
L1Ў
L2Ў
L1
L2
BLUE
RED
RELAY1 LS ELEMENTS
BROWN
BLACK
1
2
3
4
5
6
C
5kW HEAT KIT
HEATER KIT PLUG
6
2YELLOW
8
4
CB CIRCUIT BREAKER
LS LIMIT SWITCH
FL FUSE LINK
CN6
PCB
1
2
3
4
5
6
NOTE1
POWER
RED
RED
BLACK
FL
FL
BLUE
BLUE
4
1 3
2
10kW HEAT KIT
Cb1
W1
WHITE
L1Ў
L2Ў
L1
L2
BLUE
RED
LS
LS
ELEMENTS
ELEMENTS
BROWN
BLACK
1
2
3
4
5
6
0
7.5kW HEAT KIT
HEATER KIT PLUG
7.5kW CB1 50A
10kW CB1 60A
4
8
2
6
C 1
0
1
BLACK
YELLOW
4
8
2
6
RELAY2
YELLOW
RELAY1
CB CIRCUIT BREAKER
LS LIMIT SWITCH
FL FUSE LINK
WHITE
BLACK
CN6
PCB
1
2
3
4
5
6

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POWER
YELLOW
RED
FL
BLUE
4
1 3
2
Cb2:30A
W2
L1Ў
L2Ў
L1
L2
LS ELEMENTS
0
C 1
4
8
2
6
RELAY2
POWER
RED
RED
BLACK
FL
FL
BLUE
BLUE
4
1 3
2
Cb1:60a
W1
WHITE
L1Ў
L2Ў
L1
L2
BLUE
RED
LS
LS
ELEMENTS
ELEMENTS
BROWN
BLACK
1
2
3
4
5
6
0
15kW HEAT KIT(10kW+5kW)
HEATER KIT PLUG
4
8
2
6
C 1
0
1
BLACK
YELLOW
4
8
2
6
RELAY2
YELLOW
RELAY1
CB CIRCUIT BREAKER
LS LIMIT SWITCH
FL FUSE LINK
WHITE
BLACK
BLACK/WHITE
BLACK
BLACK
CN6
PCB
1
2
3
4
5
6
NOTE1
POWER
RED
RED
BLACK
FL
FL
BLUE
BLUE
4
1 3
2
Cb2
W2
L1Ў
L2Ў
L1
L2
LS
LS
ELEMENTS
ELEMENTS
0
4
8
2
6
C
1
0
1
BLACK
YELLOW
4
8
2
6
RELAY2
YELLOW
RELAY1
BLACK/WHITE
BLACK
POWER
RED
RED
BLACK
FL
FL
BLUE
BLUE
4
1 3
2Cb1
W1
WHITE
L1Ў
L2Ў
L1
L2
BLUE
RED
LS
LS
ELEMENTS
ELEMENTS
BROWN
BLACK
1
2
3
4
5
6
0
20kW HEAT KIT/CB 60A
HEATER KIT PLUG
4
8
2
6
C 1
0
1
BLACK
YELLOW
4
8
2
6
RELAY2
YELLOW
RELAY1
CB CIRCUIT BREAKER
LS LIMIT SWITCH
FL FUSE LINK
WHITE
BLACK
BLACK/WHITE
CN6
PCB
1
2
3
4
5
6
NOTE1
15kW HEAT KIT(7.5kW+7.5kW )/CB 50A
BLACK

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5.2 Outdoor Units
Outdoor unit wiring diagram for 28/36K models:
TF
T5
Cn4
Cn3 WHITE
Cn2
L2
TF
Y/G
XT1
PFC-L
L1L2
ON
FERRITE CORE
1 CIRCLE
L1
BLACK
T4
Cn1
HPC
EEV
YW CB
P5
P6
P1
W Y B C
PS
Cn14
SV1
RV
Cn29
COMP
U
VW
P
V
W
BLUE
BLUE
UV
W
U
P2
P4
RED
BLACK
CCH
Cn30
FAN
BROWN
YELLOW
Y/G
RC 2
HL
COM
Cn22 P3
WARNING:
CABINET MUST BE PERMANMENTLY
GOUNDED AND ALL WIRING TO CONFORM
TO I.E.C,N.E.C,C.E.C,C.L.C,AND LOCAL
CODES AS APPLICABLE REPLACEMENT
WIRE MUST BETHE SAME GAUGE AND
INSULATION TYPE AS ORIGINAL WIRE
USE COPPER CONDUCTORS ONLY
Cn12
SW5-1
SW5-2
OFF
ON
OFF
OFF
ON
Time Delay of the end defrosting:60S
Normal defrosting
Advance into the defrosting
COMP
CAP
CAPACITANCE
CCH
4-WAY VALVE
EEV
ELECTRIC EXPANSIVE VALVE
HPC
HIGH PRESSURE SWITCH
T3
T5
T4
CONDENSER TEMPERATURE SENSOR
CRANKCASE HEATING COMP. DISCHARGE TEMPERATURE SENSOR
SV1
PFC-L
PFC INDUCTANCE
PS
PRESSURE SENSOR
ONLY FOR HP MODEL
J1: ONLY FOR HP MODEL
B AND W ONLY FOR HP MODEL
YELLOWYELLOW
BLACK
BLUE
ORANGE
ORANGE ORANGE
ORANGE
RED
To Thermostat
Y/g
BLACK
RED
N
RED
BROWN
RADIATOR TEMP. SENSOR
COMPRESSOR
BLACK
BLUE
BLACK
YELLOW
BLACK
PURPLE
+
-
SW4-2
SW4-3
Not used
SW4-4
OFF
ON
Normally cooling/heating
OFF
ON
Accelerated cooling/heating
Adaptive capacity output disable
Adaptive capacity output enable
SW4-1
Not used
H4
H5
H6
3 times (P4) protection in 100 minutes
HC
Environmental temperature sensor fault
Hb
high pressure protection in Heating
HH
Compressor liquid return 3 times in 180 minutes
E5
E7
E6
Voltage protection
DC fan motor error
The exhaust gas sensor is not seated fault
E4
CODE
H0
Communication fault in main control chip
3 times (P6) protection in 60 minutes
5times (P2) protection in 100 minutes
P6
PH
CE
High pressure protection
C3
The T3 sensor is not seated fault
F4
5 times T3 high temp. protection in180 minutes
P2
P4
P3
Low pressure Protection
Over current protection
5times (P1) protection in 100 minutes
The exhaust temp. of the compressor protection
P1
P0
The module radiator temp. Tf protection
P5
High The tube temp. protection
Instantaneous overcurrent protection for compressor
Compressor liquid return
F3
Fault description
H8
Pressure sensor fault
H9
Reserved
Reserved
3 times (P0) protection in 120 minutes
Time Delay of the end defrosting:120S
ON
OFF
GND
GREEN
GND
GREEN LED
Electric control board fault
Standby
FORCE
The IPM module protection
Low dc voltage protection
Compressor phase error
The IPM control fault
RED LED FLSAH
Compressor operation
202075590748
Y/G
POWER
FERRITE CORE
1 CIRCLE
J1
OFF
ON
OFF
ON
Cooling only
J2
HP system
3 ton
2 ton
FACTORY SETTINGS
T3
Cn9
AMBIENT TEMPERATURE SENSOR( FOR HP SYSTEM)
10K¦RESISTANCE ( FOR COOLING ONLY SYSTEM)
PRESS
6s TEST MODE
PRESS
1s
PRESS
1s
PRESS
1s
PRESS
6s
CHECK
FORCED DEFROSTING
Communication fault
CHECK THE SYSTEM PARAMETERS
FORCED COOLING /HEATING

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Outdoor unit wiring diagram for 48/60K models:
TF
T5
Cn4
Cn3 WHITE
Cn2
L2
TF
POWER
XT1
PFC-L
L1 L2
FERRITE CORE
L1
BLACK
T4
Cn1
HPC
EEV
YW
CB
W Y B C
PS
Cn14
SV1
MOTOR
Cn22
CCH
UVW
P
V
W
BLUE
BLUE
UV
W
P8
P2
BLACK
ORANGE
Cn27
P_1
FAN
L_2
WARNING: CABINET MUST BE PERMANMENTLY
GOUNDED AND ALL WIRING TO CONFORM TO
I.E.C,N.E.C,C.E.C,C.L.C,AND LOCAL CODES AS APPLICABLE
REPLACEMENT WIRE MUST BE THE SAME GAUGE AND
INSULATION TYPE AS ORIGINAL WIRE
USE COPPER CONDUCTORS ONLY
Cn12
COMP
CAP
CAPACITANCE
CCH
4-WAY VALVE
EEV
ELECTRIC EXPANSIVE VALVE
HPC
HIGH PRESSURE SWITCH
T3
T5
T4
CONDENSER TEMPERATURE SENSOR
CRANKCASE HEATING
COMP. DISCHARGE TEMPERATURE SENSOR
SV1
PFC-L
PFC INDUCTANCE
PS
PRESSURE SENSOR
ONLY FOR HP MODEL
B AND W ONLY FOR HP MODEL
GND
Y/G
Y/G
BLACK
BROWN
BLACK
RADIATOR TEMP. SENSOR
COMPRESSOR
BLUE
YELLOW
RED
PURPLE
+
-
U
N
FERRITE CORE
VIN_N
YELLOW
P9
P10
BROWN
+
-
N_1
YELLOW
123
45
DB1
L_1
CN9
L1'
L2'
WHITE
CN19
ORANGE
RED
WHITE
BLUE
BLUE
BLUE
PFC-L
H4
H5
H6
3 times (P4) protection in 100 minutes
F1
Temperature sensor fault(T3 ЎT4ЎT5ЎTF)
Hb
High pressure protection in Heating
HH
Compressor liquid return 3 times in 180 minutes
E5
Eb
E6
Voltage protection
DC fan motor fault
The exhaust gas sensor(T5) is not seated fault
E4
CODE
H0
Communication fault in main control chip
3 times (P6) protection in 60 minutes
5 times (P2) protection in 100 minutes
P6
PH
P8
Typhoon protection of the fan motor
CE
High pressure protection
C3
The T3 sensor is not seated fault
F5
P2
P4
P3
Low pressure Protection
5 times (P1) protection in 150 minutes
P1
P0
The exhaust temp. Of the comp. (T5) Protection
P5
High The tube temp. (T3) protection
The IPM module protection
Compressor liquid return
F3
Fault description
H8
Pressure sensor(PS) fault
2 times (E6) protection in 10 minutes
High p ressure switch(HPC) fault
5 times (Hb) protection in 180 minutes
CN6
CN1
Compressor over current protection
5 times (P5) protection in180 minutes
F4
3 times (P0) protection in 120 minutes
The module radiator temperature (TF)protection
ON
SW5-1
SW5-2
OFF
ON
OFF
OFF
ON
Time Delay of the end defrosting:60S
Normal defrosting
Advance into the defrosting
SW4-2
SW4-3
Not used
SW4-4
OFF
ON
Normally cooling/heating
OFF
ON
Accelerated cooling/heating
Adaptive capacity output disable
Adaptive capacity output enable
SW4-1
Not used
Time Delay of the end defrosting:120S
ON
OFF
Y/G
GREEN LED
Electric control board fault
Standby
The IPM module protection
Low dc voltage protection
Compressor phase error
The IPM control fault
RED LED FLSAH
Compressor operation
Communication fault
P4
T3
Cn10
RED
YELLOW
FORCE
PRESS
6s TEST MODE
PRESS
1s
PRESS
1s
PRESS
1s
PRESS
6s
CHECK
FORCED DEFROSTING
CHECK SYSTEM PARAMETERS
FORCED COOLING /HEATING
RV
ONLY FOR HP MODEL
AMBIENT TEMPERATURE SENSOR( FOR HP SYSTEM)
10K¦RESISTANCE ( FOR COOLING ONLY SYSTEM)
COMP
202075890714
E7

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6. Installation Details
6.1 Outdoor Unit Installation
6.1.1 Location
Before starting the installation, select and check the suitability of the location for both the indoor and
outdoor unit. Observe all limitations and clearance requirements. The outdoor unit must have
sufficient clearance for air entrance to the condenser coil, for air discharge and for service access.
NOTE
For multiple unit installations, units must be spaced a minimum of 18 inches apart. (Coil face to
coil face.)
If the unit is to be installed on a hot sun exposed roof or a black-topped ground area, the unit should
be raised sufficiently above the roof or ground to avoid taking the accumulated layer of hot air into
the outdoor unit.
Provide an adequate structural support.
6.1.2 Ground Installation
The unit may be installed at ground level on a solid base that will not shift or settle, causing strain on
the refrigerant lines and possible leaks. Maintain the clearances and install the unit in a level
position.
Normal operating sound levels may be objectionable if the unit is placed directly under windows of
certain rooms (bedrooms, study, etc.). Top of unit discharge area must be unrestricted for at least 60
inches above the unit.
WARNING
The outdoor unit should not be installed in an area where mud or ice could cause personal injury
or system damage.
Elevate the unit sufficiently to prevent any blockage of the air entrances by snow in areas where
there will be snow accumulation. Check the local weather bureau for the expected snow
accumulation in your area. Isolate the unit from rain gutters to avoid any possible wash out of the
foundation.

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6.1.3 Roof Installation
When installing units on a roof, the structure must be capable of supporting the total weight of the
unit, including a padded frame unit, rails, etc., which should be used to minimize the transmission of
sound or vibration into the conditioned space.
6.1.4 Unit Placement
1. Provide a base in the pre-determined location.
2. Remove the shipping carton and inspect for possible damage.
3. Compressor tie-down nuts should remain tightened.
4. Position the unit on the base provided.
CAUTION
This system uses R410A refrigerant which operates at higher pressure than R-
22. No other
refrigerant may be used in this system. Gauge sets, hoses, refrigerant containers, and recovery
system must be designed to handle
R410A. If you are unsure, consult the equipment
manufacturer.
The outdoor unit must be connected to the indoor coil using field supplied refrigerant grade copper
tubing that is internally clean and dry. Units should be installed only with the tubing sizes for
approved system combinations. The refrigerant charge shown in the nameplate is for standard size
interconnecting liquid line lengths up to 15 feet.
NOTE
Using a larger than specified line size could result in oil return problems. Using a too small line
will result in loss of capacity and other problems caused by insufficient refrigerant flow. Slope
horizontal suction lines at least 1" every 20 feet toward the outdoor unit to facilitate proper oil
return.
6.1.5 Unit Mounting
If elevating the heat pump, either on a flat roof or on a slab, observe the following guidelines.
1. The base pan provided elevates the heat pump 2” above the base pad.
2 . If elevating a unit on a flat roof , use 4”× 4”(or equivalent) stringers positioned to distribute unit

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weight evenly and prevent noise and vibration (See Fig.1).
NOTE:Do not block drain openings shown in Fig.1.
3. If unit must be elevated because of anticipated snow fall, secure unit and elevating stand such
that unit and/or stand will not tip over or fall off.
NOTE: To tie down unit, see 6.1.6.
6.1.6 Factory-Preferred Tie-Down Method
Step 1: Prior to installing clear pad of debris.
Important
Then cement pad must meet local codes and must be the proper thickness to accommodate
Fig.1 RECOMMENDED ELEVATED INSTALLATION
ELEVATION ABOVE ANTICIPATED
SNOW IS NECESSARY
BASE PAD
(CONCRETE OR
OTHER SUITABLE
MATERIAL)
BASE PAN (BOTTOM VIEW) DO NOT
OBSTRUCTDRAIN HOLES
(SHADED)

- 17 -
fasteners.
Step 2: Center and level unit onto pad.
Step 3: Using field supplied L-shaped bracket to locate holes on concrete and drill pilot holes which
is at least 1/4” deeper than fastener being used.
Important
Self drilling screws to base pan should not exceed 3/8” long to avoid damaging coil.
Step 4: Using conventional practices to install brackets, tighten concrete fasteners and self-tapping
screws (See Fig.2).
Note: 1. One bracket for each side. For extra stability, 2 brackets for each side.
2. Do not over-tighten the concrete fastener to avoid weakening the concrete.
Important Note:
These instructions are intended to provide a method to tie-down system to cement slab as a
securing procedure for high wind areas. It is recommended to check Local Codes for tie-down
methods and protocols.
REQUIRED PARTS LIST
SEE DETAILA
#7 X 3/8” Self Tapping Screws
(Don’t Exceed 3/8” long)
1/4” Χ 1-1/2” Hex Washer Head Concrete Screws
(3/16” Pilot Hole Needed. Pilot Hole Should Be1/4” Deeper
Than The Fastener Embedment)
Fig.2 PREFERRED TIE-DOWN METHOD
DETAILA
Brackets:
2” width, 1/16” thickness,
height as required.
Available from distributor
or in market place.

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6.1.7 Precautions During Line Installation
1. Install the lines with as few bends as possible. Care must be taken not to damage the couplings
or kink the tubing. Use clean hard drawn copper tubing where no appreciable amount of bending
around obstruction is necessary, if soft copper must be used, care must be taken to avoid sharp
bends which may cause a restriction.
2. The lines should be installed so that they will not obstruct service access to the coil, air handling
system or filter.
3. Care must also be taken to isolate the refrigerant lines to minimize noise transmission from the
equipment to the structure.
4. The suction line must be insulated. Tape and suspend the refrigerant lines as shown. DO NOT
allow tube metal-to-metal contact. See Fig.3.
5. Use PVC piping as a conduit for all underground installations as shown in Fig.4. Buried lines
should be kept as short as possible to minimize the build up of liquid
refrigerant in the suction line during long periods of shutdown.
6. Pack a sealing material such as perma gum around refrigerant lines where they penetrate a wall
to reduce vibration and to retain some flexibility.
InsulatedLiquidLine
Tape
SheetMetalHanger
optional
Suggested
Incorrect
Fig.3 Tubing Hanger
InsulatedSuctionLine
Fig.4 Underground Installation

- 19 -
6.1.8 Precautions During Brazing Of Lines
All outdoor unit and evaporator coil connections are copper-to-copper and should be brazed with a
phosphorous-copper alloy material such as Silfos-5 or equivalent. DO NOT use soft solder. The
outdoor units have reusable service valves on both the liquid and suction connections. The total
system refrigerant charge is retained within the outdoor unit during shipping and installation. The
reusable service valves are provided to evacuate and charge per this instruction.
Serious service problems can be avoided by taking adequate precautions to assure an internally
clean and dry system.
CAUTION
Dry nitrogen should always be supplied through the tubing while it is being brazed, because the
temperature required is high enough to cause oxidation
of the copper unless an inert
atmosphere is provide. The flow of dry nitrogen should continue until the joint has cooled. Always
use a pressure regulator and safety valve to insure that only low pressu
re dry nitrogen is
introduced into the tubing.Only a small flow is necessary to displace air and prevent oxidation.
Fig.5
Typical Installation
TO
INDOOR
BLOWER
TO
POWER
SUPPLY
TO
COIL
WEATHERPROOF
DISCONNECT
SWITCH
Sealopening(s)with
permagumorequivalent
24Vcontrolsignal
NOTE:Alloutdoorwiringmustbeweatherproof