Embed Size (px)
Citation preview
3DJH �
PRODUCT LITERATURE
¤1997
/LWKR 8�6�$�
TABLE OF CONTENTS
SHIPPING AND PACKING LIST 1. . . . . . . . . . . . . . . . . . . . . .
GENERAL INFORMATION 1. . . . . . . . . . . . . . . . . . . . . . . . . .
UNIT DIMENSIONS 2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
PARTS ARRANGEMENT 3. . . . . . . . . . . . . . . . . . . . . . . . . . .
SETTING THE UNIT 4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
RIGGING 4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
ELECTRICAL 5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
PLUMBING 7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
REFRIGERATION 14. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
LEAK TESTING 15. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
EVACUATION & DEHYDRATION 15. . . . . . . . . . . . . . . . . . .
START--UP 16. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
CHARGING 17. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
SYSTEM OPERATION 18. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
MAINTENANCE 18. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
START--UP AND PERFORMANCE CHECK LIST 19. . . . . .
SHIPPING AND PACKING LIST
1 -- Assembled condensing unit
1 -- Filter drier
Check unit for shipping damage. Consult last carrier
immediately if damage is found.
INSTALLATION
INSTRUCTIONS
/6$���& ��� 721�
/6$���& ��� 721�
&21'(16,1* 81,76
�������0����
GENERAL INFORMATION
These instructions are intended as a general guide and
do not supersede national or local codes in any way.
Authorities having jurisdiction shouldbe consultedbe-
fore installation.
IMPORTANT
The Clean Air Act of 1990 bans the intentionalventingof refrigerant (CFC�s andHCFC�s) as of July1, 1992. Approved methods of recovery, recyclingor reclaiming must be followed. Fines and/or in-carceration may be levied for non--compliance.
LSA180C/240C
3DJH �
LSA180C AND LSA240C DIMENSIONS--INCHES (MM)
CORNER WEIGHT � lbs. (kg)
Model AA BB CC DDModelNo. lbs. kg lbs. kg lbs. kg lbs. kg
LSA180C 230 104 230 104 230 104 230 104
LSA240C 262 119 262 119 262 119 262 119
CENTER OF GRAVITY � in. (mm)
Model NoEE FF
Model No.inch mm inch mm
LSA180C 29-5/16 745 32-1/2 826
LSA240C 29-5/16 745 32-1/2 826
65(1651)
57-5/8(1464)
49-7/8(1267)
OUTDOORFANS ANDGUARDS (4)
FRONT VIEW SIDE VIEW
TOP VIEW
OUTDOORCOILS
SLIDE OUTCONTROL BOX
LIFTING HOLES(For Rigging)
REFRIGERANT LINECONNECTIONS(flush with unit)
COMPRESSORS (2)
8-1/4(210)
14-3/8(365)
3-3/8(86)
14-3/8(365)
3-3/8(86)
8-1/4(210)
CENTEROF GRAVITY
AA BB
CCDD
ELECTRICALINLETS
(Both Sides)
SLIDE OUTCONTROL BOXDISCHARGE AIR
INLETAIR
INLETAIR
INLETAIR
INLETAIR ACCESS
PANELACCESSPANEL
INLETAIR
3-1/4(83)
ELECTRICALINLETS
(Both Sides)
INLETAIR
INLETAIR
INLETAIR
INLETAIR
REFRIGERANT LINECONNECTIONS(flush with unit)
FF
EE
OPTIONAL DISCONNECT(Factory Installed)
OPTIONAL115 VOLT OUTLET(Factory Installed)
7-1/2(191)
7-1/2(191)
REFRIGERANTLINE
CONNECTIONS
15-1/2(394)
OPTIONAL HAIL GUARD(Field Installed Both Sides)
3DJH �
LSA180C, 240C UNITS ---- PARTS ARRANGEMENT
LSA180C, 240C PARTS ARRANGEMENT
FIGURE 1
LOW PRESSURE
SWITCH (S87)
SUCTION LINE
SERVICE VALVE
(TYP.)
FILTER DRIER
LIQUID LINE
SERVICE
VALVE (TYP.)
THERMOWELL
HIGH PRESSURE
SWITCH (S4)
LOW AMBIENT SWITCH
(S11) ON LIQUID LINE NOT SHOWN
CONDENSER FANS
(B4, B5, B21, B22)
LOW AMBIENT
SWITCH (S84)
HIGH PRESSURE
SWITCH (S7)
LOW PRESSURE
SWITCH (S88)
COMPRESSORS
(B2, B1)
CONTROL BOX
FAN GUARDS
ACCESS PANEL
LSA180C, 240C CONTROL BOX ARRANGEMENT
FIGURE 2
LSA180C, 240C CONTROL BOX
K167 LATCHING 1
K168 LATCHING 2
K66 STAGE 1 COOL
K67 STAGE 2 COOL
K58 LOW AMB. KIT
K68 OUTDOOR FAN 2
K10 OUTDOOR FAN 1
K149 OUTDOOR FAN 3
K150 OUTDOOR FAN 4
CIRCUIT BREAKER
CB7
CONTACTOR K1 CONTACTOR K2
TIMER DL33
TIMER DL34
C1 C2 C18 C19
THERMOSTAT LOW
AMBIENT S41
TRANSFORMER T18
TERMINAL STRIP
TB34
3DJH �
WARNING
Product contains fiberglass wool.
Disturbing the insulation in this product duringinstallation, maintenance, or repair will exposeyou to fiberglass wool. Breathing this may causelung cancer. (Fiberglass wool is known to theState of California to cause cancer.)
Fiberglass wool may also cause respiratory, skin,and eye irritation.
To reduce exposure to this substanceor for furtherinformation, consult material safety data sheetsavailable from address shown below, or contactyour supervisor.
Lennox Industries Inc.P.O. Box 799900Dallas, TX 75379--9900
SETTING THE UNIT
Refer to unit dimensions onpage 1 for sizingmounting
slab, platforms or supports. Refer to figure 3 for instal-
lation clearances.
A--Slab Mounting
When installing unit at grade level, install on a level
slabhighenoughabovegrade toallowadequatedrain-
age of water. Top of slab should be located so run--off
water from higher ground will not collect around unit.
B--Roof Mounting
Install unit at aminimumof 4 inches above surface of the
roof. Caremust be taken to ensure weight of unit is prop-
erly distributed over roof joists and rafters. Either red-
wood or steel supports are recommended.
NOTE-- 48� (1219mm) CLEARANCE REQUIRED
ON TOP OF UNIT.
LSA180C, 240C INSTALLATION CLEARANCES
FIGURE 3
36(914)
36(914)
48(1219)
36(914)
RIGGING UNIT FOR LIFTING
Rig unit for lifting by attaching four cables to holes in unit
base rail. See figure 4.
1 -- Detach wooden base protection before rigging.
2 -- Connect rigging to the unit base using both holes in
each corner.
3 -- All panels must be in place for rigging.
4 -- Place field-provided H-style pick in place just above
topedge of unit. Framemust beof adequate strength
and length. (H-style pick prevents damage to top of
unit.)
Note -- Lifting frame is not required if each of the four
hoisting cables is at least 15 feet (5m) long.
&$87,21 � � 'R QRW
ZDON RQ XQLW�
,03257$17 � � $// 3$1(/6 0867
%( ,1 3/$&( )25 5,**,1*�
/,)7,1* 32,17 6+28/' %( ',5(&7/<
$%29( &(17(5 2) *5$9,7<
�������
������
81,7 :(,*+7
/%6� .*�
0D[LPXP ZHLJKW ZLWK DOO DYDLODEOHIDFWRU\� �LQVWDOOHG DFFHVVRULHV�
/6$���&/6$���&
1RWH � � /LIWLQJ IUDPH LV QRW UHTXLUHG LIHDFK RI WKH IRXU KRLVWLQJ FDEOHV LV DW
OHDVW �� IHHW ��P� ORQJ�
RIGGING INSTRUCTIONS
FIGURE 4
3DJH �
ELECTRICAL
Wiringmust conform to current standards of theNational
Electric Code (NEC), Canadian Electrical Code (CEC) and
local codes. Refer to theblower coil or furnace installation
instructions for additional wiring application diagrams
and refer to unit rating plate for minimum circuit ampac-
ity and maximum overcurrent protection size.
WARNING
Unit must be grounded in accordance withnational and local codes.Electric Shock Hazard.Can cause injury or death.
Knockouts are provided in both sides of the cabinet
to facilitate field wiring.
A--Line Voltage
Power wiring enters the make--up box through the bot-
tom and connects to the top of the terminal / disconnect
switch. Separate line voltage connections may be made
to theoptional ground fault interrupter (GFI). See figure5.
Note -- Units are approved for use with copper conduc-
tors only.
B--24V, Class II Circuit
24V, Class II Circuit wiring enters the make--up box
through the bottom and connections aremade in the
low voltage section of themake--up box. Refer to fig-
ure 5 and 6 for field wiring.
Note -- A complete unit wiring diagram is located inside
the unit access panel.
FIGURE 5
Knockouts
GFI line voltage wiring
Unit line voltage wiring
Low voltage wiring
Make--up box
GFI receptacle
Disconnect switch
Y RG
LSA CONDENSING
UNIT CB17/CBH17
BLOWER
CONTACTOR
ROOM THERMOSTAT
24v
COMMON
Y1
TO 24V CLASS II POWER SOURCE
70 VA MINIMUM
NOTE--IF INDOOR UNIT IS NOT EQUIPPED WITH BLOWER RELAY,
IT MUST BE FIELD PROVIDED AND INSTALLED
(P--8--3251 OR EQUIVALENT)
NOTE--SEE UNIT WIRING DIAGRAM
FOR POWER SUPPLY CONNECTIONS.
LINE VOLTAGE FIELD INSTALLED
24V, CLASS II VOLTAGE FIELD INSTALLED
CONDENSING UNIT
FIELD WIRING DIAGRAM
(CB17/CBH17 Shown)FIELD PROVIDED
TRANSFORMER
TO
POWER
SUPPLY
6 4
LOW VOLTAGE
MAKE-UP BOX
BLUE BLUE
YELLOW
RED
RED
RED
BLOWER
MOTOR
CONTROL
RELAY
FIGURE 6
3DJH �
7<3,&$/ 81,7 :,5,1* ',$*5$0
/6$���&� ���&
3DJH �
PLUMBING
Field refrigerant piping consists of liquid and suction
lines from the condensing unit. Pipingmay be brought
into the unit through either side. Remove the knock-
outs on the mullions and install the provided rubber
grommets into the piping holes. Remove the plugs
from the liquid and suction lines. Refer to table 1 for
field-fabricated refrigerant line sizes for runs up to 50
linear feet (15m).
7$%/( �5()5,*(5$17 /,1( 6,=(6
/6$
81,7
/,48,'
/,1(
68&7,21
/,1(
���&�� ���� LQ���� PP�
���&��� LQ�
��� PP��� ���� LQ���� PP�
��� LQ���� PP�
Refrigerant Line Brazing Procedure
1 -- End of refrigerant line must be cut square, kept
round, free from nicks or dents and deburred (I.D.
and O.D.)
2 -- Wrapawet cloth around the valvebodywhenbraz-
ing to prevent possible heat damage to the valve
core and port.
3 -- Install filter drier, provided with unit, in the liquid
line as close as possible to the expansion device.
Refrigerant Line Limitations
Unit applications with line set lengths up to 50 linear
feet (15m) (excluding equivalent lengthof fittings)may
be installed using refrigerant line sizes as outlined in
table 1. Refrigerant lines from 50 to 100 linear feet (15
to 30m) should be sized in accordancewith the follow-
ing section. Line lengths greater than 100 feet (30m)
are not recommended. Contact Lennox� Application
Department for engineering assistance.
Maximum suction lift must not exceed 70 linear feet
(21m) and maximum liquid lift must not exceed 50 lin-
ear feet (15m).
When line lengths exceed50 feet (15m), a liquid line so-
lenoid should be installed at the evaporator coil. In
addition, only expansion valvesmay be used (RFC and
cap-tube expansion devices are not acceptable). In
applications where the lines exceed 75 feet (23m),
the solenoid valve should be installed with a non-re-
cycling pump-down control.
NOTE -- When refrigerant line solenoid valves are
installed, velocities should not exceed300 fpm inorder
to avoid liquid line hammer.
In applications where cooling operation below 50qF
(10qC) is anticipated andaneconomizer is not beingused,
low ambient (head pressure) controls must be installed.
Due to the additional refrigerant required to fill the
lines, the likelihood of slugging is greatly increased
with lines over 50 feet (15m) in length. An incremental
increase in liquid line size results in a 40 to 50 percent
increase in liquid to fill the line. Therefore, it is desir-
able to use the smallest liquid line size possible.
Addition of Refrigeration Oil Line Lengths� 50 ft.
Add 3 oz. refrigeration oil to the system for each 10 ft.
(3m) above 50 ft. (15m) for suction lines 7/8� and small-
er. Suction lines 1--1/8� and larger require an additional
4 oz. per each 10 ft. (3m) over 50 ft. (15m) in length. Use
non-foaming refrigeration oilwith a viscosity above 200
(3G or 4G).
Pipe Sizing, Line Layout and Design
[Line Set Lengths of 50 -- 100 Linear Feet (15 -- 30m)]
Start by making a sketch of the system showing rela-
tive locations of condensing unit and evaporator,
length of each piping segment, elbows, tees, valves,
etc. This information will be used to determine the
equivalent length of the piping run. Also, take note of
any difference in elevation between the outdoor and
indoor units. Vapor and liquid lift must be considered
to ensure proper pipe sizing.
Liquid Line Function and Design
The liquid linemust convey a full columnof liquid from
the condenser to themetering device at the evaporator
coil without flashing. In order to ensure this, liquid line
pressure drop and pressure across the expansion de-
vice and distributor must be considered.
NOTE -- In units over 5 tons, subcooled liquid begins to
form flash gas at 245psi.
7$%/( �
+&)&��� 6$785$7,21 7(03(5$785(6
�&RQGHQVLQJ 7HPSHUDWXUHV DW 'LIIHUHQW 3UHVVXUHV�
HCFC-22 Pressure Temperature Table (Psig)
Degrees F (qC) HCFC22 Degrees F (qC) HCFC22 Degrees F (qC) HCFC22 Degrees F (qC) HCFC22 Degrees F (qC) HCFC22
--40 (--41) 0.6 18 (--8) 41.1 36 (2) 63.3 75 (24) 133.4 120 (49) 262.5
--30 (--34) 409 20 (--7) 43.3 38 (3) 66.1 80 (27) 145.0 125 (52) 280.7
--20 (--28) 10.2 22 (--6) 45.5 40 (4) 69.0 85 (29) 157.2 130 (54) 299.7
--10 (--23) 16.6 24 (--4) 47.9 45 (7) 76.6 90 (32) 170.0 135 (57) 319.6
0 (--18) 24.1 26 (--3) 50.3 50 (10) 84.7 95 (35) 183.6 140 (60) 340.3
10 (--12) 32.9 28 (--2) 52.7 55 (13) 93.3 100 (38) 197.9 145 (63) 362.0
12 (--11) 34.9 30 (--1) 55.2 60 (16) 102.4 105 (41) 212.9 150 (66) 384.6
14 (--10) 36.9 32 (0) 57.8 65 (18) 112.2 110 (43) 228.6 155 (68) 406.3
16 (--9) 39.0 34 (1) 60.5 70 (21) 122.5 115 (46) 245.2 160 (71) 433.3
3DJH �
HCFC-22 LIQUID LINE PRESSURE DROP/VELOCITYAt 45EF Evaporating Temperature and 125EF Condensing Temperature
30
25
20
15
10
9
8
7
6
5
4
3
2
1.5
1.0
.9
.8
.7
10 9 8 7 6 5 4 3 2 1.5 1.0 .9 .8 .7 .6 .5 .4 .3 .2
HCFC-22 LIQUID LINE PRESSURE DROP (lbs./100 Feet)
COOLINGCAPACITY(TONS)
30
25
20
15
10
9
8
7
6
5
4
3
2
1.5
1.0
.9
.8
.7
COOLINGCAPACITY(TONS)
10 9 8 7 6 5 4 3 2 1.5 1.0 .9 .8 .7 .6 .5 .4 .3 .2HCFC-22 LIQUID LINE PRESSURE DROP (lbs./100 Feet)
NOTE -- Shaded area denotes unacceptable velocity range.
FIGURE 7
12.5
To use this chart, first find capacity (tons) on left side of chart. To find pipe size, proceed right to smallest pipe size. Pressure drop (verticalline) and velocity (diagonal lines) can then be determined for the pipe size selected. For example, for 15 ton unit, select 3/4 in. O.D. line.
EXAMPLE:
15 TON UNIT
3/4 IN. O.D. LINE 3.2 PSI
DROP PER 100 FEET
275 FPM VELOCITY
40 30 20 15
40 30 20 15
3DJH �
7$%/( �
Equivalent Length in Feet of Straight Pipefor Valves and Fittings
LineSizeO.D.in.
Solenoid/GlobeValve
AngleValve
90ELong*RadiusElbow
45ELong*RadiusElbow
TeeLine
TeeBranch
3/8 7 4 0.8 0.3 0.5 1.5
1/2 9 5 0.9 0.4 0.6 2.0
5/8 12 6 1.0 0.5 0.8 2.5
3/4 14 7 1.3 0.6 0.9 3.0
7/8 15 8 1.5 0.7 1.0 3.5
1-1/8 22 12 1.8 0.9 1.5 4.5
1-3/8 28 15 2.4 1.2 1.8 6.0
1-5/8 35 17 2.8 1.4 2.0 7.0
2-1/8 45 22 3.9 1.8 3.0 10
2-5/8 51 26 4.6 2.2 3.5 12
Long radius elbow. Multiply factor by 1.5 for short radius elbow equivalentlength.
Lennoxequipment above five tons in capacity typically
operates at a saturated condensing temperature of
125qF (280psi per table 2). Lennox equipment is de-
signed to hold a charge allowing 10qF subcooling at
95qF (35qC) ambient. The condensing temperature and
the subcooling are used to calculate the maximum al-
lowable pressure drop as detailed below.
NOTE -- 95qF (35qC) ambient is an arbitrary temperature
chosen to represent typical summer operating condi-
tions used to calculate maximum allowable pressure
drop. This temperature (and the corresponding sub-
cooling) may vary with regional climate.
Example ---- Calculating maximum allowable pressure
drop: Find themaximumallowable liquid line pressure
drop of a unit operating at 10qF subcooling and 125qF
(280 psi) condensing temperature. Subtract 10qF sub-
cooling temperature from 125qF condensing tempera-
ture to equal 115qF subcooled liquid temperature (245
psi / point at which flash gas will begin to form). Sub-
tract 245psi subcooledpressure from280psi condens-
ing pressure to find a maximum allowable pressure
drop of 35 psi.
To calculate actual pressure drop in the liquid line, cal-
culate pressure drop due to friction and pressure drop
due to vertical lift and add the two.
Pressure drop due to friction in pipe, fittings and field-
installed accessories such as driers, solenoid valves or
other devices must all be considered. Pressure drop
ratings for different pipe sizes are given in figure 7.
Pressuredrop ratingsof field-installeddevices are typi-
cally supplied by the manufacturer.
Pressure drop due to vertical lift (1/2 pound per foot) is
typically large and can be a limiting factor in the design
of the system.
The liquid refrigerant pressure must be sufficient to
produce the required flow through the expansion de-
vice. Liquid refrigerant (free of flash gas) should be de-
livered to the expansion valve at a minimum of 175psi
to ensure the 100 psi necessary to produce full refriger-
ant flow at the rated capacity.
Example ---- Liquid Line Pipe Sizing
Given: 15-ton condensing unit on ground level with a
15-ton evaporator on the third level above ground and
a total of 96 linear feet of piping. Unit is charged with
10EF subcooling at 125EF condensing temperature
(280 psi HCFC-22 liquid). Refer to figure 8.
Find: Select tube size from figure 7.
15 TON
CONDENSING
UNIT
15 TON
EVAPORATOR
53 FT.
3 FT. 40 FT.
GIVEN; 15 TON EVAPORATOR15 TON CONDENSING UNITWITH 10EF SUBCOOLING at 125EFLENGTH OF LINE ---- 96 FT.
FIND; LIQUID LINE SIZE
LIQUID LINE SIZING EXAMPLE
),*85( �
FILTER/DRIER
3.2 psi100 ft.
x 98.6 ft. = 3.15 psi
ANSWER: 3/4� O.D. COPPER TUBING CAN BE USED. PRESSURE LOSS DOES NOTEXCEEDMAXIMUMALLOWABLEPRESSUREDROP (6EFTO7EFSUBCOOLINGWILLBE AVAILABLE AT THE EXPANSION VALVE) AND VELOCITY IS ACCEPTABLE.
SELECT A PROPOSED TUBINGSIZE: 3/4in. COPPER
SOLUTION: PRESSURE DROPCANNOT EXCEED 35 psi.
TOTAL PRESSURE DROP=TOTAL FRICTION LOSSES + LIFT LOSSES + FILTER/DRIER
TOTAL EQUIVALENT LENGTH =LINEAR LENGTH + EQUIVALENT LENGTH OF FITTINGS
TWO 90E LONG RADIUS ELBOWS @ 3/4in. O.D. = 1.3 EQUIV. FT. EA.
TOTAL EQUIVALENT LENGTH = 98.6 ft.
TOTAL FRICTION LOSSES =
LIFT LOSSES = 40ft. x 1/2psi per foot = 20psi
TOTAL PRESSURE DROP = 20 psi + 3.15 psi + 1 psi = 24.15 psi
FILTER DROP = 1 psi (by manufacturer)
Figure 7 illustrates the relationship between liquid line
sizing, pressure drop per 100 feet, velocity range and
tonnage. Remember, when using liquid line solenoid
valves, velocities should not exceed 300 fpm. Enter fig-
ure 7 from the left and extend to the right to the small-
est tube size that will not exceed 300 fpm velocity.
Solution: For a 15 ton system, 3/4 inch O.D. linewith 3.2
psi per 100 ft. drop (per figure 7) is selected.Now, calcu-
late pressure drop due to friction and liquid lift to deter-
mine if this is a good selection.
The total friction drop for the application will include 96
feet of 3/4 inch O.D. pipe plus 1 equivalent foot per el-
bow (two elbows) to equal 98.6 equivalent feet.
In a 15-ton system,we canexpect 3.2 psi drop per 100
feet of 3/4 inch O.D. copper (per figure 7). Multiply
3.2/100 by 98.6 equivalent feet to calculate the total
friction loss of 3.15 psi.
Now, we must add the pressure drop for vertical lift.
HCFC-22 pressure drop is 1/2 psi per foot of vertical lift.
In this applicationwhich has a 40-foot (12m) vertical lift,
we find that pressure drop due to lift equals 20 psi.
3DJH ��
Finally, we have added a filter drier to the liquid line
which has a 1 psi pressure drop (this number provided
by manufacturer).
Add the three components of pressure drop together
to find that the total pressure drop in this 3/4 inch line
equals 24.15 psi which is well within our acceptable
range. The 3/4 inch line, therefore, is a good selection
because it is well below the maximum allowable pres-
sure drop, is in a satisfactory velocity range, usesmini-
mum refrigerant and provides sufficient pressure at
the expansion valve.
Alternative Sizing: Suppose 7/8 inch O.D. line with 1.7
psi drop per 100 feet had been selected. The total equiv-
alent length is computed by adding the linear length (96
ft.) plus the equivalent length of the fittings (from table
3, two90E ells at 1.5 ft. each). The total equivalent length
is 99 feet. The total friction drop would have been
1.7/100 multiplied by 99 = 1.68 psi. When the pressure
drop due to lift (20 psi) and the filter drier (1 psi) are add-
ed we find that the total pressure drop for 7/8 inch line
equals 22.68 psi.
Though the 7/8 inch line provides a lower pressure
drop, the larger diameter pipe will require more refrig-
erant which will increase the risk of refrigerant slug-
ging. In addition, the smaller linewill be less costly. The
smaller line should be used.
Suction Line Function and Design
The suction line returns refrigerant vapor and oil from
the evaporator to the compressor. Suction line design
is critical. The design must minimize pressure loss in
order to achievemaximum unit efficiency and provide
adequate oil return to the compressor under all condi-
tions.
Because oil separates from refrigerant in the evapora-
tor, the suction velocitymust be adequate to sweep the
oil along the pipe. Horizontal suction lines require a
minimumof 800 fpmvelocity for oil entrainment. In or-
der to ensure oil entrainment, suction risers require a
minimum velocity of 1200 fpm (1500 fpm is preferred)
regardless of the length of the riser.
Figure 11 illustrates the relationship between suction
line sizing, pressure drop, velocity and cooling capac-
ity. Use this chart to determine suction line pressure
drop and velocity. As the pipe size increases, so does
the velocity required to ensure oil entrainment.
Vertical lift has no significant effect on systemcapacity.
However, systems loose approximately 1 percent of
capacity for every pound of pressure drop due to fric-
tion in the suction line. In order to calculate capacity
loss, you must first estimate pressure drop in the total
equivalent length of the piping run (refer to figure 11).
Capacity ratings given in the Lennox Engineering
Handbook include the loss for a25-foot refrigerant line.
Therefore, subtract the pressure loss of 25 feet of pip-
ing from the total calculated for your particular applica-
tion.
OUTDOOR
UNIT
INDOOR
UNIT
DETERMINING SUCTION LINE CAPACITY LOSSIF PRESSURE DROP IS KNOWN
Total Pressure DropFor Equivalent Length
25Ft.Line
Once Pressure Drop Is Found:Btuh lost = 1% x (Total Press. Drop minus 25Ft.) x rated capacity
FIGURE 9
Total Pressure DropMinus Press. Dropin 25Ft. of Line
When an evaporator is located above or on the same
level as the condensing unit, the suction line must rise
to the top of the evaporator. See figure 10. This helps
prevent liquid from migrating to the compressor dur-
ing the off cycle. Traps should also be installed at the
bottom of all vertical risers for migration protection in
the off cycle.
OUTDOORUNIT
INDOORCOIL
SUCTION PIPINGIndoor Coil Above or On Same Level with Outdoor Unit
),*85( ��
OUTDOORUNIT
INDOORCOIL
VAPOR LINE
VAPOR LINE
If equipment is on same level, inverted trap should still be usedin order to prevent liquid migration to compressor during off cycle.
TRAP
RAISE PIPETO TOP LEVEL
OF COIL
INSTALL TRAPS ATBOTTOM OFEACH RISER
Horizontal suction lines should be level or slightly
sloped toward the condensing unit. Pipe must avoid
dips or low spots that can collect oil. For this reason,
hard copper should be used, especially on long hori-
zontal runs.
As with liquid line sizing, begin bymaking a sketch of the
layout complete with fittings, driers, valves etc. Measure
the linear length of each line and determine the number
of ells, tees, valves, driers etc. Add equivalent length of
fittings (table 3) to linear lengthofpipe toget total equiva-
lent length used in determining friction loss. Again, refer
to manufacturer�s data for pressure drop information
on accessory components. The resultant pressure
drop must be considered.
3DJH ��
HCFC-22 SUCTION LINE PRESSURE DROP/VELOCITY PER 100ft. OF LINEAt 45EF Evaporating Temperature and 125EF Condensing Temperature
30
25
20
15
10
9
8
7
6
5
4
3
2
1.5
1.0
.9
.8
.7
10 9 8 7 6 5 4 3 2 1.5 1.0.9 .8 .7 .6 .5 .4 .3 .2
HCFC-22 SUCTION LINE PRESSURE DROP (lbs./100 Feet)
COOLINGCAPACITY(TONS)
30
25
20
15
10
9
8
7
6
5
4
3
2
1.5
1.0
.9
.8
.7
COOLINGCAPACITY(TONS)
10 9 8 7 6 5 4 3 2 1.5 1.0.9 .8 .7 .6 .5 .4 .3 .2
HCFC-22 SUCTION LINE PRESSURE DROP (lbs./100 Feet)
NOTE -- Shaded area denotes unacceptable velocity range.
FIGURE 11
40 30 20 15
40 30 20 15
EXAMPLE: 20 TON UNIT
2-1/8 IN. O.D. LINE
1.3 PSI DROP PER 100 FEET
1900 FPM VELOCITY
12.512.5
To use this chart, first find capacity (tons) on left side of chart. To find pipe size, proceed right to smallest pipe size. Pressure drop (verticalline) and velocity (diagonal lines) can then be determined for the pipe size selected. For example, for 20 ton unit, select 2-1/8 in. O.D. line.
Example ---- Suction Line Pipe Sizing
Given: 20 ton condensing unit with evaporator lower
than condenser. Application includes 82 linear feet of
piping and 4 ells. There is a 20-foot vertical lift and 62
feet of horizontal run. Refer to figure 12.
Find: Select tube size from figure 11.
Solution: 2-1/8 inch O.D. line with 1.3 psi per 100 feet
pressure drop and 1900 fpm velocity is selected. Now,
calculate pressure drop due to friction to determine if
this is a good selection.
3DJH ��
INDOOR COIL
EXAMPLE - Indoor Coil Below Condenser
SUCTION LINE
SUCTION RISER
OIL TRAP
�� )7�
� )7�
�� )7�
FIGURE 12
From table 3, four ells at 3.9 equivalent feet each
equals 15.6 equivalent feet. When added to the 82 feet
of pipe, the total equivalent feet becomes 97.6 feet
(round up to 98 feet).
Multiply 1.3/100 by 98 equivalent feet to calculate total
friction loss of 1.27 psi.
Use figure 11 to calculate the pressure drop in 25 feet of
2-1/8 inch line. Multiply 1.3/100 by 25 feet to calculate
friction loss of 0.33 psi. This loss has already been in-
cluded in the capacity given in Lennox� Engineering
Handbook, so it should be subtracted from the total.
The capacity lost in the �total equivalent length� of the
refrigerant line (using figures 9 and 11) equals 1 per-
cent x (1.27 --0.33) x 240,000.
Btuh lost= 0.01 x (0.94) x 240,000 = 2256
Capacity loss for the line selected is approximately 0.94
percent.
Theprecedingcalculation shows that this is aworkable
system, and that it will result in negligible losses in
both capacity and efficiency.
Alternative Sizing: Using the same (20 ton) example,
this time select 2--5/8 inch O.D. line. 2--5/8 inch O.D. line
with 0.42 psi per 100 feet pressure drop has 1250 fpm
velocity. Now calculate pressure drop due to friction
loss to determine if this is a better selection.
From table3, four ells at 4.6 equivalent feet eachequals
18.4 equivalent feet.When added to the 82 feet of pipe,
the total equivalent feet becomes 100.4 feet (round up
to 101 feet).
Multiply 0.42/100 by 101 equivalent feet to calculate to-
tal friction loss of 0.42 psi.
Use figure 11 to calculate the pressure drop in 25 feet of
2-5/8 inch line. Multiply 0.42/100 by 25 feet to calculate
friction loss of 0.11 psi. This loss has already been in-
cluded in the capacity given in Lennox� Engineering
Handbook, so it should be subtracted from the total.
The capacity lost in the �total equivalent length� of the
refrigerant line (using figures 9 and 11) equals 1 per-
cent x (0.42 -- 0.11) x 240,000.
Btuh lost= 0.01 x (0.31) x 240,000 = 774
Capacity loss for the line selected is approximately 0.31
percent.
The conditions in this example will allow either 2-1/8
inch or 2-5/8 inch suction line to be used, since capacity
loss is minimized and velocity is sufficient to return oil
to the compressor.
Double Suction Risers
If the condensing unit is equipped to run with a capac-
ity reduction of less than 50 percent, suction lines can
generally be sized in accordancewith the previous sec-
tions. If the suction velocity is high enough to entrain
oil when the unit is operating at reduced capacity,
double suction risers are generally not required.
In general, double suction risers are required any time
the minimum load on the compressor does not create
sufficient velocity in vertical suction risers to return oil to
the compressor. Double suction risers are also generally
required any time the pressure drop or velocity in a
single suction riser is excessive.
Figure 13 shows a typical double suction riser installa-
tion. A trap is installed between the two risers as shown.
During partial load operation when gas velocity is not
sufficient to returnoil throughboth risers, the trapgradu-
ally fills with oil until the second riser is sealed off. When
this occurs, the vapor travels up the first riser only. With
only the first riser being used, there is enough velocity to
carry the oil. This trapmust be close coupled to limit the
oil holding capacity to a minimum. Otherwise, the trap
could accumulate enoughoil on a partial load to serious-
ly lower the compressor crankcase oil level.
The second suction riser must enter the main suction
line from the top to avoid oil draining down the second
riser during a partial load.
Typical double suction riser construction is detailed in
figure 14.
EVAPORATOR
CONDENSINGUNIT
HORIZONTAL SUCTION LINE IS SIZED
TO HANDLE TOTAL LOAD.
IN THE VERTICAL PORTION OF THE LINE,
A SMALLER LINE IS SIZED TO HANDLE
THE REDUCED CAPACITY.
TYPICAL DOUBLE SUCTION RISER
DOUBLE SUCTIONRISER
THE REMAINING LINE IS SIZED TO
HANDLE THE REMAINING CAPACITY
FIGURE 13
3DJH ��
DOUBLE SUCTION RISER CONSTRUCTION
Method �A�
90E STREET ELL
METHOD
Method �B�
U-BEND
METHOD
�A� �B�VAPOR LINEFROM AIR HANDLER(Slope to Compressor)
REDUCING TEE
U-BEND
VAPOR LINETO COMPRESSOR
�A� �B�VAPOR LINEFROM AIR HANDLER(Slope to Compressor)
REDUCINGTEE
90ESTREETELBOW
90ESTREET ELBOW
REDUCING TEE
STREET ELL
VAPOR LINETO COMPRESSOR
FIGURE 14
FIGURE 15
EVAPORATOR
15 TONCONDENSING
15 FT.
40 FT.
2 FT.
DOUBLE SUCTION RISER EXAMPLE
DOUBLE SUCTIONRISER
A
B
Example ---- Double Suction Riser Sizing
Given: 15-ton condensing unit. Matched evaporator is
located below condensing unit. Piping will require 57
(linear) feet of pipe (figure 15). Construction without
double suction risers will only require 2 ells.
Find: Select tube sizes for horizontal runs and risers (fig-
ure 11). Determine if double suction risers are needed.
Size double suction riser for proper system perfor-
mance.
Solution: Size each segment based on the tons of re-
frigerant that will flow in the segment.
Full load capacity = 15 tons. Minimum load capacity is
35% of 15 tons = 5.25 tons. The difference between full
capacity and part load capacity is 9.75 tons.
From figure 11, select a pipe size for full load capacity.
1-5/8 inch O.D. pipe with 3.0 psi drop per 100 feet and
2600 fpm velocity is selected. Now, by using figure 11,
find the velocity for the selected pipe size at part loadca-
pacity. The part load velocity is approximately 900 fpm.
900 fpm is sufficient to return oil in horizontal runs but
not in vertical risers.
If we tried to size this systemby simply reducing the riser
size to 1-3/8 inch,wewould find the velocity in the riser to
be excessive (3600 fpm)when the system is operating at
full capacity. As a result of these obstacles, this system
will require construction of double suction risers.
Construction of double suction riserwill require five ells
and two tees total for a system.
Size small riser
(Riser carrying smallest part of load)
The unit produces 5.25 tons capacity atminimum load.
Select from figure 11 a 1--1/8 inch O.D. line (smallest
line with acceptable velocity). When operating at 5.25
tons capacity, this linewill operate at 2000 fpmandwill
produce 3.1 psi drop per 100 ft.
Size large riser
(Riser carrying largest part of load)
The larger line carries 9.75 tons capacity at full load. Se-
lect from figure 11 a 1-3/8 inch O.D. line (smallest line
with acceptable velocity). When operating at 9.75 tons
capacity, this line will operate at 2400 fpm and will pro-
duce 3.0 psi drop per 100 ft.
Putting the Segments Together
Next, we must determine if the line sizes we selected
will result in satisfactory pressure drop between the
condensing unit and the evaporator.
Start by finding the total equivalent feet of the large (B)
riser. Fifteen feet of pipe, plus two tees (branch side of
teeat 6.0 equivalent feet each), plus four ells (2.4 equiva-
lent feet each) = 36.6 equivalent feet length.
Now, find the total equivalent feet of the small (A) riser.
Fifteen feet of pipe, plus one ell (1.8 equivalent feet),
plus one tee (branch side of tee at 4.5 equivalent feet),
plus one tee (line side of tee at 1.5 equivalent feet) =
22.8 equivalent feet length.
Use the total equivalent lengthof each riser to compute
the pressure drop of each riser. For the large (B) riser,
1-3/8 inch O.D. suction line with 9.75 tons capacity has
3.0 psi drop per 100 feet.Multiply 3.0/100by 36.6 equiv-
alent feet to calculate the total friction loss of 1.1 psi.
For the small (A) riser, 1--1/8 inch O.D. suction line with
5.25 tons capacity has 3.1 psi drop per 100 feet.Multiply
3.1/100 by 22.8 equivalent feet to calculate the total fric-
tion loss of 0.71 psi.
3DJH ��
The total pressuredrop for the riser is equal to theaver-
age of the pressure drop in both risers:
1.1 (B riser drop) + 0.71 (A riser drop) = 1.81
1.81w 2 = 0.91 (average pressure drop through A and B
risers).
Find the pressure drop for the horizontal run of pipe.
1-5/8 inch pipe at 15 tons capacity has 3.0 psi drop per
100 feet. Multiply 3.0/100 by 42 feet calculate the total
friction loss of 1.26 psi.
The pressure drop through the risers is added to the
pressure drop through the horizontal run to find the to-
tal pressure drop for the system:
1.26 psi (horiz. run) + 0.91 psi (avg. riser) = 2.17 psi.
Use figure 11 to calculate the pressure drop in 25 feet of
1-5/8 inch line. Multiply 3.0/100 by 25 feet to calculate
the friction loss of 0.75 psi.
The capacity lost in the �total equivalent length� of the
refrigerant line (using figures 9 and 11) = 1% x (2.17 --
0.75) x 240,000.
Btuh lost= 0.01 x (1.42) x 240,000 = 3408
Capacity loss for the line selected is approximately 1.42
percent.
REFRIGERATION
Service Valves and Gauge Manifold Attachment
The liquid line and suction line service valves and
gauge ports are accessible on inside of unit. These
gauge ports are used for leak testing, evacuating,
charging and checking charge.
IMPORTANT -- Service valves are closed to line set con-
nections. Do not openuntil refrigerant lines and indoor
coil have been leak tested and evacuated. All precau-
tions should be exercised to keep the system free from
dirt, moisture and air.
Liquid Line Service Valve
LSA180C AND LSA240C units use liquid line valves
shown in figure 16. A schrader valve is factory
installed. A service port is supplied to protect the
schrader valve from contamination and serve as the
primary leak seal.
To Access Schrader Port:
1 -- Remove service port cap with an adjustable wrench.
2 -- Connect gauge to the service port.
3 -- When testing is completed, replace service port cap.
Tighten finger tight, then an additional 1/6 turn.
LIQUID LINE SERVICE VALVE (VALVE OPEN)
FIGURE 16
LIQUID LINE SERVICE VALVE (VALVE CLOSED)
STEM
CAP
SCHRADER VALVE OPEN
TO LINE SET WHEN VALVE
IS CLOSED (FRONT SEATED)
SERVICE
PORT
SERVICE
PORT CAP
RETAINING RING
OUTLET (TO
COMPRESSOR)
(VALVE FRONT
SEATED)
INLET
(TO INDOOR COIL)
SCHRADER
VALVE
SERVICE
PORT
SERVICE
PORT
CAP
INSERT
WRENCH HERE
INLET (TO
INDOOR COIL)
OUTLET (TO
COMPRESSOR)
STEM
CAP
To Open Liquid Line Service Valve:
1 -- Remove stem cap with an adjustable wrench.
2 -- Using service wrench back the stem out counter-
clockwise until the valve stem just touches the retain-
ing ring.
Do not attempt to backseat this valve. Attempts tobackseat this valve will cause snap ring to explodefrom valve body under pressure of refrigerant.Personal injury and unit damage will result.
'$1*(5
To Close Liquid Line Service Valve:
1 -- Remove stem cap with an adjustable wrench.
2 -- Using service wrench turn stem clockwise to seat the
valve. Tighten firmly.
3 -- Replace stem cap. Tighten finger tight, then tighten
an additional 1/6 turn.
3DJH ��
FIGURE 17
STEMCAP
VALVESTEM
INLET (TOINDOOR COIL)
OUTLET (TOCOMPRESSOR)
SERVICE PORT
SERVICEPORTCAP
NO SCHRADER
SERVICEPORT
SERVICEPORTCAP
NO SCHRADER
LSA180C AND LSA240C
SUCTION LINE SERVICE VALVE
Suction Line Service Valve
LSA180C and LSA240 units are equipped with a full ser-
vice front- and back-seating suction line service valve as
shown in figure 17. The valve is equipped with a ser-
vice port. There is no schrader valve installed in the
suction line service port. A service port cap is supplied
to seal off the port.
To Access Schrader Port:
1 -- Remove service port cap with an adjustable wrench.
2 -- Connect gauge to the service port.
3 -- When testing is completed, replace service port
cap. Tighten finger tight, then tighten an addi-
tional 1/6 turn.
To Open Suction Line Service Valve:
1 -- Remove stem cap with an adjustable wrench.
2 -- Using servicewrench and 5/16�hex head extension
(part #49A71) back the stem out counterclockwise
until the valve stem just touches the retaining ring.
3 -- Replace stem cap tighten firmly. Tighten finger tight,
then tighten an additional 1/6 turn.
To Close Suction Line Service Valve:
1 -- Remove stem cap with an adjustable wrench.
2 -- Using service wrench and 5/16� hex head exten-
sion (part #49A71) turn stem in clockwise to seat the
valve. Tighten firmly.
3 -- Replace stem cap. Tighten finger tight, then tight-
en an additional 1/6 turn.
LEAK TESTING
After the line set has been connected to the indoor and
outdoor units, the line set connections and indoor unit
must be checked for leaks.
WARNING
Never use oxygen to pressurize refrigeration or airconditioning system. Oxygenwill explode on con-tact with oil and could cause personal injury.When using high pressure gas such as nitrogen orCO2 for this purpose, be sure to use a regulatorthat can control the pressure down to 1 or 2 psig(6.9 to 13.8 kPa).
Using an Electronic Leak Detector or Halide
1 -- Connect a cylinder of nitrogen with a pressure reg-
ulating valve to the center port of the manifold
gauge set.
2 -- Connect the high pressure hose of the manifold
gauge set to the service port of the suction valve.
(Normally, the high pressure hose is connected to
the liquid line port, however, connecting it to the
suction port better protects themanifold gauge set
from high pressure damage.)
3 -- With both manifold valves closed, open the valve
on the HCFC-22 bottle (vapor only).
4 -- Open the high pressure side of the manifold to al-
low HCFC-22 into the line set and indoor unit.
Weigh in a trace amount of HCFC-22. [A trace
amount is a maximum of 2 ounces (57g) refriger-
ant or 3 pounds (31 kPa) pressure]. Close the valve
on the HCFC-22 bottle and the valve on the high
pressure side of the manifold gauge set. Discon-
nect HCFC-22 bottle.
5 -- Adjust nitrogenpressure to150psig (1034 kPa).Open
the valve on the high side of the manifold gauge set
which will pressurize line set and indoor unit.
6 -- After a short period of time, open a refrigerant port
tomake sure the refrigerant added is adequate tobe
detected. (Amounts of refrigerant will vary with line
lengths.) Check all joints for leaks. Purge nitrogen
and HCFC-22 mixture. Correct any leaks and re-
check.
EVACUATION & DEHYDRATION
Evacuating the system of non-condensables is critical
for proper operation of the unit. Non-condensables are
gases that will not condense under temperatures and
pressures present during operation of an air condition-
ing system. Non-condensables and water vapor com-
bine with refrigerant to produce substances that cor-
rode copper piping and compressor parts.
3DJH ��
1 -- Connect manifold gauge set to the service valve
ports as follows: low pressure gauge to suction
line service valve; high pressure gauge to liquid
line service valve.
,03257$17 � � &RPSOLDQW VFUROO FRPSUHVVRUV �DV ZLWK
DQ\ UHIULJHUDQW FRPSUHVVRU� VKRXOG QHYHU EH XVHG WR
HYDFXDWH D UHIULJHUDWLRQ RU DLU FRQGLWLRQLQJ V\VWHP�
NOTE -- A temperature vacuum gauge, mercury
vacuum or thermocouple gauge should be used.
The usual Bourdon tube gauges are inaccurate in
the vacuum range.
2 -- Connect the vacuum pump (with vacuum gauge)
to the center port of the manifold gauge set.
3 -- Openbothmanifoldvalves andstart vacuumpump.
4 -- Evacuate the line set and indoor unit to an absolute
pressure of 23mm of mercury or approximately 1
inch ofmercury. During the early stages of evacua-
tion, it is desirable to close the manifold gauge
valve at least once to determine if there is a rapid
rise in absolute pressure. A rapid rise in pressure
indicates a relatively large leak. If this occurs, the
leak testing procedure must be repeated.
NOTE -- The term absolute pressuremeans the to-
tal actual pressure within a given volume or sys-
tem, above the absolute zero of pressure. Absolute
pressure in a vacuum is equal to atmospheric pres-
sure minus vacuum pressure.
5 -- When theabsolute pressure reaches 23mmofmer-
cury, close the manifold gauge valves, turn off the
vacuum pump and disconnect themanifold gauge
center port hose from vacuum pump. Attach the
manifold center port hose to a nitrogen cylinder
with pressure regulator set to 150 psig (1034 kPa)
and purge the hose. Open the manifold gauge
valves to break the vacuum in the line set and in-
door unit. Close the manifold gauge valves.
&$87,21
Danger of Equipment Damage.Avoid deep vacuum operation. Do not use com-pressors to evacuate a system.Extremely low vacuums can cause internal arcingand compressor failure.Damage caused by deep vacuum operation willvoid warranty.
6 -- Shutoff thenitrogen cylinder and remove theman-
ifold gauge hose from the cylinder. Open the man-
ifold gauge valves to release the nitrogen from the
line set and indoor unit.
7 -- Reconnect the manifold gauge to the vacuum
pump, turn the pump on and continue to evacuate
the line set and indoor unit until the absolute pres-
sure does not rise above .5mmofmercury within a
20 minute period after shutting off the vacuum
pump and closing the manifold gauge valves.
8 -- Depending on the equipment used to determine
the vacuum level, absolute pressure of .5mm of
mercury is equal to 500 microns.
9-- When theabsolute pressure requirement abovehas
been met, disconnect the manifold hose from the
vacuumpump and connect it to an upright bottle of
HCFC-22 refrigerant. Open the manifold gauge
valves to break the vacuum in the line set and in-
door unit. Closemanifold gauge valves and shut off
HCFC-22 bottle and remove manifold gauge set.
START--UP
Cooling Start--up
IMPORTANT
Crankcase heater should be energized 24 hoursbefore unit start--up to prevent compressor dam-age as a result of slugging.
1 -- Rotate the fan to check for frozenbearings or binding.
2 -- Inspect all factory and field--installed wiring for
loose connections.
3 -- Open liquid line and suction line service valves to
release refrigerant charge (contained in condens-
ing unit) into system. Replace and tighten caps.
Use a back-up wrench on the suction and liquid
valves when removing or replacing valve caps.
4 -- To open suction valve, remove hex cap and turn
valve stem fully open using an Allen (hex) wrench.
To open liquid valve, remove cap and turn valve
stem until it is fully open and back-seated.
NOTE -- When replacing valve caps, the caps
should be made finger tight and then tightened an
additional 1/6th of a turn.
5 -- Check voltage supply at the disconnect switch. The
voltage must be within range listed on unit name-
plate. If not, do not start equipment until the power
company has been consulted and the voltage
condition corrected.
6 -- Set thermostat for a cooling demand, turn on pow-
er to blower and close condensing unit disconnect
switch to start.
7 -- Recheck unit voltage with unit running. Power
must be within range shown on unit nameplate.
Check amperage draw of unit. Refer to unit name-
plate for correct running amps.
3DJH ��
CHARGING
TABLE 4
UNIT MODEL
NUMBER
MATCHED
INDOOR UNIT
HCFC-22 FOR 25 FEET
(7.62M) OF LINE
LIQUID LINE
DIAMETER
ADJUSTMENT PER
FOOT (.305M) OF
LINE*
1/2 in. (13mm) 1.1 ozs. (31 g)
LSA180C CB17/CBH17--185V 15 lbs. (6.8 Kg.) 5/8 in. (16mm) 1.8 ozs. (51 g)g
3/4 in. (19mm) 2.6 ozs. (74 g)
1/2 in. (13mm) 1.1 ozs. (31 g)
LSA240C CB17/CBH17--275V 24 lbs. (11.0 Kg) 5/8 in. (16mm) 1.8 ozs. (51 g)
3/4 in. (19mm) 2.6 ozs. (74 g)
,I OLQH OHQJWK LV JUHDWHU WKDQ �� IW� ��P�� DGG WKLV DPRXQW� ,I OLQH OHQJWK LV OHVV WKDQ �� IW� ��P�� VXEWUDFW WKLV DPRXQW�
127( � � 5HIULJHUDQW OLQH VHWV VKRXOG QRW EH ORQJHU WKDQ ��� IHHW ���P�� 5HIULJHUDQW OLQH ORVVHV GHGXFW IURP WKH QHW FDSDFLW\
RI WKH V\VWHP� $GGLWLRQDO UHIULJHUDQW UHTXLUHG IRU VXFK V\VWHPV PD\ DOVR XSVHW WKH UHIULJHUDQW�WR�RLO UDWLR�
127( � � ,I WKH GLIIHUHQFH LQ HOHYDWLRQ EHWZHHQ WKH /6$ XQLW DQG WKH LQGRRU XQLW H[FHHGV �� IHHW ��P�� DGG �� R]V� ����J� RI
UHIULJHUDQW IRU WKH QH[W �� IW� ��P� LQFUHDVH LQ HOHYDWLRQ� ,I WKH GLIIHUHQFH LQ HOHYDWLRQ EHWZHHQ WKH WZR XQLWV LV JUHDWHU WKDQ ��
IHHW ��P�� FRQVXOW WKH /HQQR[ 7HFKQLFDO 6XSSRUW 'HSDUWPHQW IRU DSSOLFDWLRQ DVVLVWDQFH�
Suction+ 5psig
Discharge+ 10psig
TABLE 5NORMAL OPERATING PRESSURES
OutdoorCoil
EnteringAir Temp.
CIRCUIT 1 CIRCUIT 2
Suction+ 5psig
Discharge+ 10psig
*LSA180C tested with CB17/CBH17--185V.
Suction+ 5psig
Discharge+ 10psig
CIRCUIT 1 CIRCUIT 2
Suction+ 5psig
Discharge+ 10psig
**LSA240C tested with CB17/CBH17--275V.
LSA180C* LSA240C**
65qF (18qC)
75qF (24qC)
85qF (29qC)
95qF (35qC)
105qF (41qC)
115q F (46qC)
181
208
235
268
299
320
68
70
73
75
76
80
178
205
232
264
294
325
66
70
72
74
75
79
181
206
236
268
305
335
71
73
76
78
79
82
188
213
241
271
308
334
71
73
74
77
79
82
Units are shipped with a holding charge of dry air
andheliumwhichmustbe removedbefore theunit is
charged with refrigerant. In new installations, the
recommended and most accurate method of charg-
ing is to weigh the refrigerant into the unit as out-
lined in table 4. If weighing facilities are not avail-
able, or if chargeneeds tobe checked, use the follow-
ing method:
1 -- Attach gauge manifolds and operate unit in cool-
ing mode until system stabilizes (approximately
five minutes).
2 -- Use a thermometer to accurately measure the out-
door ambient temperature.
3 -- Apply the outdoor temperature to table 5 to deter-
mine normal operating pressures.
4 -- Compare the normal operating pressures to the
pressures obtained from the gauges. Minor varia-
tions in these pressures may be expected due to
differences in installations. Significant differences
couldmean that the system is notproperly charged
or that a problem exists with some component in
the system. Correct any system problems before
proceeding.
5 -- If discharge pressure is high, remove refrigerant
from the system. If discharge pressure is low, add
refrigerant to the system.
- Add or remove charge in increments.
- Allow the system to stabilize each time
refrigerant is added or removed.
6 -- Use approach method to confirm readings.
3DJH ��
Charge Verification Using Approach Method
1 -- Use the same thermometer to takeboth the liquid
line temperature and the outdoor ambient tem-
perature. Compare liquid line temperature to the
outdoor ambient temperature. Approach tem-
perature equals the liquid line temperature mi-
nus the outdoor ambient temperature.
2 -- The approach temperature should match values
given in table 6. An approach temperature great-
er than the value shown indicates an under-
charge. An approach temperature less than the
value shown indicates an overcharge.
3 -- Do not use the approach method if system pres-
sures donotmatch thepressures given in table 5.
The approach method is not valid for grossly
over- or undercharged systems.
TABLE 6
APPROACH TEMPERATURE
LIQUID TEMP. MINUS AMBIENT TEMP.
Circuit 1 Circuit 2
16EF + 1 (8.9EC + 0.5) 11EF + 1 (6.1EC+ 0.5)
18EF + 1 (10EC + 0.5)17EF + 1 (9.5EC+ 0.5)
MODEL NO.
LSA180C
LSA240C
NOTE -- For best results, the same thermometer should be usedto check both outdoor ambient and liquid temperatures.
SYSTEM OPERATION
Condensing unit and indoor blower cycle on demand
from room thermostat. When thermostat blower
switch is moved to ON position, indoor blower oper-
ates continuously.
Crankcase Heater
LSA180C and 240C units are equipped with external,
belly-band crankcase heaters. The crankcase heater
should be energized 24 hours before unit start--up to
prevent compressor damage as a result of slugging.
Minimum Run Timer Control
All units are equipped with a minimum run timer con-
trol. This control prevents compressor short cycling to
ensure proper oil return to the compressor. When a
cooling cycle begins, the run timer control keeps the
compressor in operation for a minimum of 4 minutes,
regardless of whether the cooling demand has been
satisfied. Do not bypass this control.
High Pressure Switch
LSA180Cand240Cunits areequippedwithahighpres-
sure switch that is located in the discharge line of each
compressor. The switch (SPST,manual reset, normally
closed) removes power from the compressor when
discharge pressure rises above factory setting at 410 +
10 psi.
Low Pressure Switch
LSA180C and 240C units are also equipped with a low
pressure switch that is located in the suction line of
each compressor. The switch (SPST, auto--reset, nor-
mally closed) removes power from the compressor
when suction line pressure drops below factory setting
at 25 + 5 psi.
MAINTENANCE
At the beginning of each cooling season, the system
should be checked as follows:
WARNING
Electric shock hazard. Can cause injuryor death. Before attempting to per-form any service or maintenance, turnthe electrical power to unit OFF at dis-connect switch(es). Unit may havemultiple power supplies.
Condensing Unit
1 -- Clean and inspect condenser coil. Coil may be
flushed with a water hose.
2 -- Condenser fanmotor is prelubricated and sealed. No
further lubrication is needed.
3 -- Visually inspect connecting lines and coils for evi-
dence of oil leaks.
4 -- Check wiring for loose connections.
5 -- Check for correct voltage at unit (unit operating).
6 -- Check amp--draw condenser fan motor.
Unit nameplate _________ Actual ____________ .
NOTE -- If owner complains of insufficient cooling,the unit should be gauged and refrigerant chargechecked. Refer to section on refrigerant charging inthis instruction.
Evaporator Coil
1 -- Clean coil, if necessary.
2 -- Check connecting lines and coils for evidence of oil
leaks.
3 -- Check condensate line and clean, if necessary.
Indoor Unit
1 -- Clean or change filters.
2 -- Adjust blower speed for cooling. The pressure dropover the coil should be measured to determine thecorrect blower CFM. Refer to unit information ser-vicemanual for pressure drop tables and procedure.
3 -- On belt drive blowers, check belt for wear and
proper tension.
4 -- Check all wiring for loose connections
5 -- Check for correct voltage at unit (blower operat-
ing).
6 -- Check amp--draw on blower motor
Unit nameplate_________ Actual ____________.
3DJH ��
LSA180C AND 240C START-UP AND PERFORMANCE CHECK LIST
-RE 1DPH
-RE /RFDWLRQ
,QVWDOOHU
8QLW 0RGHO 1R�
1DPHSODWH 9ROWDJH
0LQLPXP &LUFXLW $PSDFLW\
0D[LPXP 2YHUFXUUHQW 3URWHFWLRQ 6L]H
5HIULJHUDQW /LQHV�
6HUYLFH 9DOYHV %DFNVHDWHG"
&RQGHQVHU )DQ &KHFNHG"
-RE 1R�
&LW\
&LW\
6HULDO 1R�
'DWH
6WDWH
6WDWH
6HUYLFHPDQ
$PSV�
6XSSO\ &RQGHQVHU )DQ
&RPSUHVVRU
,QGRRU )LOWHU &OHDQ"
,QGRRU %ORZHU 530
(OHFWULFDO &RQQHFWLRQV 7LJKW"
6XSSO\ 9ROWDJH �8QLW 2II�
6�3� 'URS 2YHU (YDSRUDWRU �'U\�
&RQGHQVHU (QWHULQJ $LU 7HPSHUDWXUH
'LVFKDUJH 3UHVVXUH 6XFWLRQ 3UHVVXUH
&22/,1* 6(&7,21
7+(50267$7
5HIULJHUDQW &KDUJH &KHFNHG"
&DOLEUDWHG" 3URSHUO\ 6HW"
/HYHO"
3URSHUO\ ,QVXODWHG"
6HUYLFH 9DOYH &DSV 7LJKW"
9ROWDJH :LWK &RPSUHVVRU 2SHUDWLQJ
/HDN &KHFNHG"
6HUYLFH 9DOYH &DSV 7LJKW"
