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Page 11

AC13 SERIES

1. Cut ends of the refrigerant lines square (free from

nicks or dents). Debur the ends. The pipe must remain
round, do not pinch end of the line.

2. Remove service cap and core from both the suction

and liquid line service ports.

3. Connect gauge low pressure side to liquid line service

valve.

4. To protect components during brazing, wrap a wet

cloth around the liquid line service valve body and
copper tube stub and use another wet cloth
underneath the valve body to protect the base paint.

5. Flow regulated nitrogen (at 1 to 2 psig) through the

refrigeration gauge set into the valve stem port
connection on the liquid line service valve and out of
the valve stem port connection on the suction service
valve. The TXV metering device at the indoor unit coil
will allow low pressure nitrogen to flow through the
system.)

NOTE − The fixed orifice or TXV metering device at the
indoor unit will allow low pressure nitrogen to flow through
the system.)

NOTE − Use silver alloy brazing rods with five or six percent
minimum silver alloy for copper−to−copper brazing or 45
percent silver alloy for copper−to−brass or copper−to−steel
brazing.

6. Braze the liquid line to the liquid line service valve.

Turn off nitrogen flow.

IMPORTANT

Repeat procedure starting at paragraph 4 for brazing the
suction line to service port valve.

7. After all connections have been brazed, disconnect

manifold gauge set the from service ports and remove
wrapping. Reinstall the service port core for both of the
outdoor unit’s service valves.

Removing Indoor Unit Metering Device

Remove the existing HCFC−22 refrigerant flow control
orifice or thermal expansion valve from the indoor coil.

REPLACEMENT PARTS

If replacement parts are necessary for the indoor unit,
order kit 69J46 (LB−95325A). The kit includes the
following:

TEFLON RINGS (20)

BRASS NUTS (10)

LIQUID LINE ASSEMBLIES

(INCLUDES STRAINER) (10)

LIQUID LINE ORIFICE HOUSINGS (10)

LIQUID LINE

ASSEMBLY

COPPER
TUBE

PISTON
RETAINER

STRAINER

Figure 19. 69J46 Kit Components

TYPICAL FIXED ORIFICE REMOVAL PROCEDURE

TEFLON RING

REMOVE AND DISCARD
VALVE STEM ASSEMBLY
(IF PRESENT)

FIXED
ORIFICE

(Uncased Coil Shown)

VALVE STEM

VALVE STEM CAP

BRASS NUT

LIQUID LINE ASSEMBLY

(INCLUDES STRAINER)

LIQUID LINE ORIFICE HOUSING

DISTRIBUTOR TUBES

DISTRIBUTOR

ASSEMBLY

Figure 20. Typical Fixed Orifice Removal

1. On fully cased coils, remove the coil access and

plumbing panels.

2. Remove any shipping clamps holding the liquid line

and distributor assembly.

3. Using two wrenches, disconnect liquid line from liquid

line orifice housing. Take care not to twist or damage
distributor tubes during this process.

4. Remove and discard fixed orifice, valve stem

assembly if present and Teflon ring as illustrated in
figure 20.

5. Use a field−provided fitting to temporary reconnect the

liquid line to the indoor unit’s liquid line orifice housing.

TYPICAL TXV REMOVAL PROCEDURE

TWO PIECE

PATCH PLATE

(UNCASED COIL

ONLY)

SUCTION

LINE

DISTRIBUTOR

ASSEMBLY

DISTRIBUTOR

TUBES

LIQUID

LINE

MALE EQUALIZER

LINE FITTING

SENSING

LINE

EQUALIZER
LINE

TXV

TEFLON
RING

(Uncased Coil Shown)

STUB END

TEFLON

RING

SENSING

BULB

LIQUID LINE

ORIFICE HOUSING

LIQUID LINE ASSEMBLY

WITH BRASS NUT

Figure 21. Typical TXV Removal

Summary of Contents for AC13 -018

Page 1: ...List 1 AC13 Air Conditioner Units 1 Unit Dimensions 2 General Information 3 Recovering Refrigerant from Existing System 3 Removing Existing Outdoor Unit 5 Positioning New Outdoor Unit 6 Removing and I...

Page 2: ...IT SUPPORT FEET AC13 BASE WITH ELONGATED LEGS H SUCTION LINE CONNECTION LIQUID LINE CONNECTION TOP VIEW RUN CAPACITOR CONTACTOR DISCHARGE LINE LIQUID LINE CONNECTIONS PARTS ARRANGEMENT AC13 A B C D E...

Page 3: ...Rockwell Harness Scale minimum Fully insert the wrench into the valve stem recess Service valve stems are factory torqued from 9 ft lbs for small valves to 25 ft lbs for large valves to prevent refrig...

Page 4: ...ppropriately sized wrench to turn an additional 1 12 turn clockwise as illustrated in figure 1 Operating Ball Type Service Valve To Access Ball Type Service Port A service port cap protects the servic...

Page 5: ...system charge recovery into the outdoor unit Outdoor unit s high or low pressure switches if applicable when tripped can cycled the compressor OFF Compressor can stop pumping due to tripped internal...

Page 6: ...roperty Install the unit as far as possible from the property line When possible do not install the unit directly outside a window Glass has a very high level of sound transmission For proper placemen...

Page 7: ...unit at a minimum of four inches above the surface of the roof Care must be taken to ensure weight of unit is properly distributed over roof joists and rafters Either redwood or steel supports are re...

Page 8: ...table an uneven surface ONE BRACKET PER SIDE MIN FOR EXTRA STABILITY 2 BRACKETS PER SIDE 2 FROM EACH CORNER CONCRETE SLAB USE PLASTIC PLASTIC ANCHOR HOLE DRILL 1 4 PLASTIC SLAB NO PLASTIC ANCHOR HOLE...

Page 9: ...ed to meter flow is 1 4 in diameter and copper INSTALLING LINE SET Line Set Isolation This reference illustrates procedures which ensure proper refrigerant line set isolation Installation of line set...

Page 10: ...to braze the line set to the new air conditioner unit Figure 18 is provided as a general guide for preparing to braze the line set to the air conditioner unit CAUTION Brazing alloys and flux contain m...

Page 11: ...r unit s service valves Removing Indoor Unit Metering Device Remove the existing HCFC 22 refrigerant flow control orifice or thermal expansion valve from the indoor coil REPLACEMENT PARTS If replaceme...

Page 12: ...AC13 ENGINEERING HANDBOOK See the AC13 Engineering Handbook for approved indoor outdoor match ups applicable fixed orifice and TXV kits and application information Figures 23 and 24 illustrates the ty...

Page 13: ...e provided Teflon rings around the stubbed end of the TXV and lightly lubricate the connector threads and expose surface of the Teflon ring with refrigerant oil 3 Attach the stubbed end of the kit val...

Page 14: ...nly 3 Open the high pressure side of the manifold to allow HCFC 22 into the line set and indoor unit Weigh in a trace amount of HCFC 22 A trace amount is a maximum of two ounces 57 g refrigerant or th...

Page 15: ...er of HCFC 22 refrigerant Open the manifold gauge valve 1 to 2 psig in order to release the vacuum in the line set and indoor unit 10 Close manifold gauge valves and shut off the HCFC 22 cylinder and...

Page 16: ...strain relief and to maintain separation of field installed low and high voltage circuits Start Up and Charging Procedures IMPORTANT If unit is equipped with a crankcase heater it should be energized...

Page 17: ...djust the fan speed See indoor unit instructions to in crease decrease fan speed Changing air flow affects all temperatures recheck temperatures to confirm that the temperature drop and DT are within...

Page 18: ...c sheet to restrict the airflow through the outdoor coil to achieve pressures from 200 250 psig 1379 1724 kPa Higher pressures are needed to check charge Block equal sections of air intake panels and...

Page 19: ...refrigerant If refrigerant is added or removed verify charge using the Subcooling Method MORE or LESS 018 024 030 036 042 048 060 TEMP 6 3 3 6 3 3 8 4 4 12 6 7 5 2 8 6 3 3 7 3 8 Temperature of air en...

Page 20: ...erature VAP _________ 10 Subtract to determine superheat SH VAP _____ SAT ______ SH ______ 11 Record the wet bulb temperature air entering indoor coil WB _______ 12 Record outdoor ambient temperature...

Page 21: ...73 80 27 175 77 186 77 190 73 201 79 195 78 185 76 193 76 85 29 189 79 200 79 205 75 215 81 209 80 198 77 208 78 90 32 203 81 216 81 221 77 231 82 224 81 213 79 224 80 95 35 218 82 232 82 237 79 247 8...

Page 22: ...cal power to the unit at the discon nect switch before performing any maintenance The unit may have multiple power supplies 3 Reusable Filter Many indoor units are equipped with reusable foam filters...

Page 23: ...e to cooling mode to maintain predetermined comfort settings Temperature Indicator The temperature indicator displays the actual room temperature PROGRAMMABLE THERMOSTATS Your Lennox system may be con...

Page 24: ...n Maximum Fuse or Circuit Breaker Electrical Connections Tight Indoor Filter clean Supply Voltage Unit Off Indoor Blower RPM S P Drop Over Indoor Dry Outdoor Coil Entering Air Temp Discharge Pressure...

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