Lennox CB26UH, CBX26UH Unit Information
Page 1
© 2005 Lennox Industries Inc.
Litho U.S.A.
Corp. 0527−L10
CB26UH
CBX26UH
Service Literature
CB26UH &CBX26UH Series
The CB26UH, and CBX26UH are high efficiency blower coils.
Several models are available in sizes ranging from 1-1/2
through 5 tons (5.3 through 17.6 kW). The CBX26UH is designed for R−410A refrigerant and the CB26UH is designed for
R−22 refrigerant. The units are up flow / horizontal that can be
field converted to down flow applications. The units come with
a factory installed check and expansion valve for cooling or
heat pump applications.
CB26UH and CBX26UH series units are designed to be
matched with the 13SEER air conditioner and heat pump line,
but can be matched with other air conditioners or heat pumps
as noted in the rating information. See Engineering Handbook.
Electric heat, in several kW sizes, can be field installed in the
CB26UH and CBX26UH cabinets.
Information contained in this manual is intended for use by experienced HVAC service technicians only. All specifications are
subject to change. Procedures outlined in this manual are presented as a recommendation only and do not supersede or replace local or state codes.
IMPORTANT
Improper installation, adjustment, alteration, service
or maintenance can cause property damage, personal injury or loss of life. Installation and service must
be performed by a qualified installer or service
agency.
WARNING
Electric shock hazard. Can cause injury
or death. Before attempting to perform
any service or maintenance, turn the
electrical power to unit OFF at disconnect switch(es). Unit may have multiple
power supplies.
Table of Contents
Specifications / Electrical Data NO TAG. . . . . .
Blower Data Page 3. . . . . . . . . . . . . . . . . . . . . .
I Application Page 4. . . . . . . . . . . . . . . . . . . . . .
II Unit Components Page 5. . . . . . . . . . . . . . . .
III Optional Electric Heat Page 6. . . . . . . . . . .
IV Configuration Modification Page 10. . . . . . .
V Start Up Page 13. . . . . . . . . . . . . . . . . . . . . . . .
VI Typical Operating Characteristics Page 14.
VII Maintenance Page 14. . . . . . . . . . . . . . . . . . .
VIII Wiring Diagrams Page 15. . . . . . . . . . . . . . .
Page 2
SPECIFICATIONS
General
Model Number (R−22) CB26UH−018 CB26UH−024 CB26UH−030 CB26UH−036
Data
Model Number (R−410A) CBX26UH−018
CBX26UH−024 CBX26UH−030 CBX26UH−036
Nominal tonnage 1.5 2 2.5 3
Connections
Suction/Vapor line (o.d.) − in. (mm) sweat 3/4 (19) 3/4 (19) 7/8 (22.2) 7/8 (22.2)
Liquid line (o.d.) − in. (mm) sweat 3/8 (9.5) 3/8 (9.5) 3/8 (9.5) 3/8 (9.5)
Condensate − in. (mm) fpt (2) 3/4 (19) (2) 3/4 (19) (2) 3/4 (19) (2) 3/4 (19)
Blower
Wheel nominal diameter x width − in. (mm) 10 x 6
(254 x 152)
10 x 6
(254 x 152)
11 x 8
(279 x 203)
11 x 8
(279 x 203)
Blower motor output − hp (W) 1/4 (187) 1/4 (187) 1/4 (187) 1/3 (249)
1
Filters Size of filter − in. (mm) 16 x 20 x 1
(406 x 508 x 25)
16 x 20 x 1
(406 x 508 x 25)
18 x 20 x 1
(457 x 508 x 25)
18 x 20 x 1
(457 x 508 x 25)
ELECTRICAL DATA
Voltage − 1 phase (60 hz) 208/240V 208/240V 208/240V 208/240V
2
Maximum overcurrent protection (unit only) 15 15 15 15
3
Minimum circuit ampacity (unit only) 1.5 1.5 1.6 1.8
Shipping Data −1 package − lbs. (kg) 129 (58) 131 (59) 148 (67) 148 (67)
SPECIFICATIONS
General
Model Number (R−22) CB26UH−042 CB26UH−048 CB26UH−060
Data
Model Number (R−410A) CBX26UH−042
CBX26UH−048 CBX26UH−060
Nominal tonnage 3.5 4 5
Connections
Suction/Vapor line (o.d.) − in. (mm) sweat 7/8 (22.2) 7/8 (22.2) 7/8 (22.2)
Liquid line (o.d.) − in. (mm) sweat 3/8 (9.5) 3/8 (9.5) 3/8 (9.5)
Condensate − in. (mm) fpt (2) 3/4 (19) (2) 3/4 (19) (2) 3/4 (19)
Blower
Wheel nominal diameter x width − in. (mm) 11 x 8
(279 x 203)
11 x 8
(279 x 203)
11−1/2 x 9
(292 x 229)
Blower motor output − hp (W) 1/3 (249) 1/2 (373) 1/2 (373)
1
Filters Size of filter − in. (mm) 18 x 25 x 1
(457 x 635 x 25)
18 x 25 x 1
(457 x 635 x 25)
18 x 25 x 1
(457 x 635 x 25)
ELECTRICAL DATA
Voltage − 1 phase (60 hz) 208/240V 208/240V 208/240V
2
Maximum overcurrent protection (unit only) 15 15 15
3
Minimum circuit ampacity (unit only) 1.9 2.6 4.1
Shipping Data −1 package − lbs. (kg) 172 (78) 177 (80) 190 (86)
1
Filter is not furnished and must be field supplied.
2
HACR type circuit breaker or fuse.
3
Refer to National or Canadian Electrical Code manual to determine wire, fuse and disconnect size requirements. Use wires suitable for at least 167°F (75_C).
OPTIONAL ACCESSORIES − MUST BE ORDERED EXTRA
Model
−018
−024
−030
−036
−042
−048
−060
Circuit Breaker Cover Kit 93M85 93M85 93M85 93M85
Down−Flow Conversion Kit 12W61 12W61 12W61 12W61
Horizontal Support Frame Kit 56J18 56J18 56J18 56J18
Side Return Unit Stand (Up−Flow Only) 45K32 45K32 45K32 45K32
Single Point Power Source Control Box (for Electric Heat) 21H39 21H39 21H39 21H39
Wall Hanging Bracket Kit (Up−Flow Only) 45K30 45K30 45K30 45K30
Page 3
BLOWER DATA
CB(X)26UH−018 BLOWER PERFORMANCE
External Static
Air Volume at
Specific Blower Taps
Pressure
High
Low
in. w.g. Pa cfm L/s cfm L/s
.10
25 1020 460 755 340
.20 50 960 435 715 325
.30 75 885 400 675 305
.40 100 800 365 625 285
.50 125 690 315 570 260
.60 150 525 250 500 235
NOTE − All air data measured external to unit with dry coil and 1 inch non−pleated air
filter in place.
Electric heaters have no appreciable air resistance.
CB(X)26UH−024 BLOWER PERFORMANCE
External Static
Air Volume at
Specific Blower Taps
Pressure
High
Low
in. w.g. Pa cfm L/s cfm L/s
.10
25 1040 470 1000 455
.20 50 980 445 940 425
.30 75 905 410 870 395
.40 100 815 370 785 355
.50 125 705 320 680 310
.60 150 535 250 530 250
NOTE − All air data measured external to unit with dry coil and 1 inch non−pleated air
filter in place.
Electric heaters have no appreciable air resistance.
CB(X)26UH−030 BLOWER PERFORMANCE
External Static
Air Volume at
Specific Blower Taps
Pressure
High
Low
in. w.g. Pa cfm L/s cfm L/s
.10
25 1350 610 1145 520
.20 50 1290 585 1090 495
.30 75 1225 555 1030 465
.40 100 1150 520 960 435
.50 125 1065 485 875 395
.60 125 965 455 775 365
NOTE − All air data measured external to unit with dry coil and 1 inch non−pleated air
filter in place.
Electric heaters have no appreciable air resistance.
CB(X)26UH−036 BLOWER PERFORMANCE
External Static
Air Volume at
Specific Blower Taps
Pressure
High
Low
in. w.g. Pa cfm L/s cfm L/s
.10
25 1560 705 1405 635
.20 50 1480 670 1340 610
.30 75 1390 630 1270 575
.40 100 1290 585 1185 540
.50 125 1170 530 1090 495
.60 150 1015 480 975 460
NOTE − All air data measured external to unit with dry coil and 1 inch non−pleated air
filter in place.
Electric heaters have no appreciable air resistance.
CB(X)26UH−042 BLOWER PERFORMANCE
External Static
Air Volume at
Specific Blower Taps
Pressure
High
Low
in. w.g. Pa cfm L/s cfm L/s
.10
25 1940 880 1785 810
.20 50 1845 835 1705 775
.30 75 1745 790 1615 730
.40 100 1630 740 1515 685
.50 125 1495 680 1400 635
.60 150 1330 630 1265 595
NOTE − All air data measured external to unit with dry coil and 1 inch non−pleated air
filter in place.
Electric heaters have no appreciable air resistance.
CB(X)26UH−048 BLOWER PERFORMANCE
External Static
Air Volume at
Specific Blower Taps
Pressure
High
Low
in. w.g. Pa cfm L/s cfm L/s
.10
25 1945 880 1870 850
.20 50 1860 845 1790 810
.30 75 1765 800 1700 770
.40 100 1660 155 1600 725
.50 125 1540 700 1485 675
.60 150 1395 660 1350 635
NOTE − All air data measured external to unit with dry coil and 1 inch non−pleated air
filter in place.
Electric heaters have no appreciable air resistance.
CB(X)26UH−060 BLOWER PERFORMANCE
External Static
Air Volume at
Specific Blower Taps
Pressure
High
Low
in. w.g. Pa cfm L/s cfm L/s
.10
25 2160 980 2075 940
.20 50 2065 935 1985 900
.30 75 1960 890 1885 855
.40 100 1845 835 1775 805
.50 125 1710 775 1645 745
.60 150 1550 730 1495 705
NOTE − All air data measured external to unit with dry coil and 1 inch non−pleated air
filter in place.
Electric heaters have no appreciable air resistance.
Page 4
CB26UH & CBX26UH PARTS ARRANGEMENT
FIGURE 1
ELECTRIC HEAT SECTION
(plate to be removed if installed)
CONTROL BOX
BLOWER COMPARTMENT
COIL
HORIZONTAL DRAIN PAN
EXPANSION VALVE
(R−22 or R−410A)
UPFLOW DRAIN PAN
I−APPLICATION
All major blower coil components must be matched according to Lennox recommendations for the unit to be
covered under warranty. Refer to the Engineering Handbook
for approved system matchups. A misapplied system will
cause erratic operation and can result in early unit failure. The
units come with factory installed check and expansion valve for
all applications. The TXV valve has been installed internally for
a cleaner installation and is accessible if required.
ELECTROSTATIC DISCHARGE (ESD)
Precautions and Procedures
CAUTION
Electrostatic discharge can affect electronic
components. Take precautions during unit installation and service to protect the unit’s electronic
controls. Precautions will help to avoid control
exposure to electrostatic discharge by putting
the unit, the control and the technician at the
same electrostatic potential. Neutralize electrostatic charge by touching hand and all tools on an
unpainted unit surface before performing any
service procedure.
Page 5
II−UNIT COMPONENTS
A−Control Box
The CB26UH and CBX26UH control box is located above
the blower section shown in figure 1. Line voltage and electric heat connections are made in the control box. Optional
electric heat fits through an opening located in the center of
the control box. When electric heat is not used, cover plates
cover the opening. The electric heat control arrangement is
detailed in the electric heat section of this manual.
1−Transformer
All CB26UH and CBX26UH series units use a single line
voltage to 24VAC transformer mounted in the control
box. The transformer supplies power to the control circuits in the indoor and outdoor unit. Transformers are
rated at 40VA. 208/240VAC single phase transformers use
two primary voltage taps as shown in figure 2.
FIGURE 2
BLUE
YELLOW
ORANGE
RED
BLACK
240 VOLTS
208 VOLTS
PRIMARY
SECONDARY
208 / 240 VOLT TRANSFORMER
2−Blower Relay
All CB26UH and CBX26UH units use a DPST relay to energize the blower motor. The relay coil is energized by
blower demand from indoor thermostat. When the coil is
energized, a set of N.O. contacts closes to energize the blower
motor on cooling speed. When de−energized, a set of N.C.
contacts allows the electric heat relay to energize the blower on
heating speed (refer to unit wiring diagram).
3−Time Delay Relay
The blower time delay is a 24 volt N.O. relay wired to the
blower relay. See unit diagram. The delay is between 10
and 60 seconds and delays the blower on and off time in the
cooling cycle.
BLOWER ASSEMBLY
FIGURE 3
B−Blower Motor (B3)
CB26UH and CBX26UH units use single phase direct drive
blower motors with a run capacitor. Figure 3 shows the
parts arrangement. All motors have two speed taps. Typically, the high speed tap is energized during normal operation.
All units are factory wired for the high blower speed for heat
pump and cooling applications with or without electric heat. No
field wiring is required. The wiring diagrams show factory set
blower speeds.
1−Blower Motor Capacitor
All CB26UH and CBX26UH series units use single phase direct drive motors with a run capacitor. The run capacitor is
mounted on the blower housing. See figure 3. Capacitor ratings are shown on side of capacitor and indoor blower motor
nameplate.
C−Coil
CB26UH and CBX26UH units have dual slab coils arranged in an A" configuration. Each coil has two or three
rows of copper tubes fitted with ripple−edged aluminum
fins. An expansion valve, feeds multiple parallel circuits through
the coils. The coil is designed to easily slide out of the unit cabinet.
D−Plastic Drain Pans
Drain pans are provided and installed on the CB26UH and
CBX26UH, The drain pans are made from fiberglass filled
plastic.
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