Lennox XC21-024 Installation Instructions Manual Download Page 7

Page 7

SL18XC1 SERIES

STEP 3 -- REFRIGERANT PIPING — 
Flushing Existing Line Set & Indoor Coil 

F

lush the existing line set per the following instruc­

tions. For more information, refer to the Installation
and Service Procedures manual available on Dav­
eNet. 

CAUTION - 

DO NOT attempt to flush and re-use

existing line sets or indoor coil when the system con­
tains

 

contaminants (i.e., compressor burn out).

NOTE -

 When installing refrigerant lines longer than 50

feet, refer to the Refrigerant Piping Design and Fabrication
Guidelines manual available on DaveNet (Corp. 9351-L9),
or contact the Technical Support Department Product Ap­
plication group for assistance.

NOTE -

 For new or replacement line set installation, refer

to Service and Application Note - Corp. 9112-L4 (C-91-4).

TABLE 1

REFRIGERANT LINE SET — INCHES (MM)

Model

Size

Field

Connections

Recommended Line Set

Liquid

Line

Suction

Line

Liquid

Line

Suction

Line

L15

Line Sets

Feet (Meters)

-024

3/8“
(10)

3/4“
(19)

3/8“
(10)

3/4“
(19)

L15-41

15 - 50' (5 - 15)

-030

-036

3/8“
(10)

7/8“
(22)

3/8“
(10)

7/8“
(22)

L15-65

15 - 50' (5 - 15)

-042

3/8“
(10)

7/8“
(22)

3/8“
(10)

7/8“
(22)

-048

-060

3/8“
(10)

1-1/8“.

(29)

3/8“
(10)

1-1/8“

(29)

Field Fabricated

NOTE — Some applications may require a field-provided 7/8” to
1-1/8” adapter

IMPORTANT !

If this unit is being matched with an approved line
set or indoor unit coil that was previously charged
with mineral oil, or if it is being matched with a coil
which was manufactured before January of 1999,
the coil and line set must be flushed prior to installa­
tion. Take care to empty all existing traps. Polyol es­
ter (POE) oils are used in Lennox units charged with
HFC-410A refrigerant. Residual mineral oil can act
as an insulator, preventing proper heat transfer. It
can also clog the expansion device and reduce sys­
tem performance and capacity.
Failure to properly flush the system per this instruc­
tion and the detailed Installation and Service Proce­
dures manual will void the warranty.

WARNING

When using a high pressure gas such as
nitrogen to pressurize a refrigeration or air
conditioning system, use a regulator that
can control the pressure down to 1 or 2
psig (6.9 to 13.8 kPa).

WARNING

Refrigerant can be harmful if it is inhaled. Refrigerant
must be used and recovered responsibly.
Failure to follow this warning may result in personal injury
or death.

WARNING

Fire, Explosion and Personal Safety Haz­
ard. Failure to follow this warning could re­
sult in damage, personal injury or death.
Never use oxygen to pressurize or purge
refrigeration lines. Oxygen, when exposed
to a spark or open flame, can cause fire
and/or an explosion, that could result in
property damage, personal injury or death.

WARNING

Polyol ester (POE) oils used with HFC-410A
refrigerant absorb moisture very quickly. It is very
important that the refrigerant system be kept closed
as much as possible. DO NOT remove line set caps
or service valve stub caps until you are ready to make
connections.

IMPORTANT !

Some scroll compressors have an internal vacuum
protector that will unload scrolls when suction pres­
sure goes below 20 psig. A hissing sound will be
heard when the compressor is running unloaded.
Protector will reset when low pressure in system is
raised above 40 psig. DO NOT REPLACE COM­
PRESSOR.

Summary of Contents for XC21-024

Page 1: ...RUCTIONS Dave Lennox Signature Collection SL18XC1 System AIR CONDITIONERS 507353 01 7 2018 WARNING Improper installation adjustment alteration service or maintenance can cause property damage personal...

Page 2: ...subject to damage e g being bent or scratched While handling or stowing the panels consider any weather conditions especially wind that may cause panels to be blown around and damaged CAUTION As with...

Page 3: ...e and uneven surfaces Concrete slab use two plastic anchors hole drill 1 4 COIL BASE PAN CORNER POST STABILIZING BRACKET 18 GAUGE METAL 2 WIDTH HEIGHT AS REQUIRED 10 X 1 2 LONG SELF DRILLING SHEET MET...

Page 4: ...erforming any service procedure to neutralize electrostatic charge NOTE For proper voltages select control wires gauge per table below WIRE RUN LENGTH AWG INSULATION TYPE LESS THAN 100 30 METERS 18 TE...

Page 5: ...ontinued Outdoor Control A175 Jumpers and Terminals 55 50 DEGREE TARGET 45 DEGREE TARGET 40 DEGREE TARGET DEFAULT 55 50 45 40 55 50 45 40 55 50 45 40 55 50 45 40 DEGREE TARGET 30 0 30 SECOND DELAY SEC...

Page 6: ...o stage electric heat cut factory installed metal link between W1 and W2 Then connect thermostat wire between the air handler control s W2 and the thermostat s W2 terminal 5 Cut on board link clippabl...

Page 7: ...existing traps Polyol es ter POE oils are used in Lennox units charged with HFC 410A refrigerant Residual mineral oil can act as an insulator preventing proper heat transfer It can also clog the expa...

Page 8: ...line orifice housing LOW HIGH EXISTING INDOOR UNIT GAUGE MANIFOLD CYLINDER CONTAINING CLEAN HCFC 22 TO BE USED FOR FLUSHING Positioned to deliver liquid refrigerant LIQUID LINE SERVICE VALVE INLET DIS...

Page 9: ...ort nitrogen flow will have an exit point NITROGEN HIGH LOW B A C PIPING PANEL REMOVAL PREPARING LINE SET CAP AND CORE REMOVAL Remove piping panel to access service valves Cut ends of the refrigerant...

Page 10: ...ter saturated cloths under the valve body to protect the base paint 4FLOW NITROGEN Flow regulated nitrogen at 1 to 2 psig through the refrigeration gauge set into the valve stem port connection on the...

Page 11: ...SION VALVE KIT MATCH UPS AND APPLICATION INFORMATION 1 REMOVE THE FIELD PROVIDED FITTING THAT TEMPORARILY RECON NECTED THE LIQUID LINE TO THE INDOOR UNIT S DISTRIBUTOR ASSEM BLY 2 INSTALL ONE OF THE P...

Page 12: ...linder of HFC 410A refrigerant to the center port of the manifold gauge set Open the valve on the HFC 410A cylinder vapor only B Open the high pressure side of the manifold to allow HFC 410A into the...

Page 13: ...IGH LOW NITROGEN CONNECT GAUGE SET A B C D LINE SET AND INDOOR COIL NOTE Remove cores from service valves if not already done FIGURE 16 EVACUATE LINE SET AND INDOOR COIL The unit is shipped with a fac...

Page 14: ...rigerant Open the mani fold gauge valve 1 to 2 psig in order to release the vac uum in the line set and indoor unit 9 Perform the following S Close manifold gauge valves S Shut off HFC 410A cylinder S...

Page 15: ...and clean as neces sary 4 Inspect the condition of refrigerant piping and confirm that pipes are not rubbing copper to copper Also check the condition of the insulation on the refrigerant lines Repair...

Page 16: ...Up and Performance Checklist Customer Address Indoor Unit Model Serial Outdoor Unit Model Serial Solar Module Mfg and Model Serial Notes START UP CHECKS Refrigerant Type Rated Load Amps Actual Amps Ra...

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