Carrier 50ZH Series Operation manual

Single-Package Heat Pump Units
with:
• easy installation design
• corrosion-proof basepan
• sloped drain pan for improved
indoor air quality
• scroll compressors
• through-the-top service access
• louvered panel coil protection
Features/Benefits
Compact, horizontal supply
and return unit, combin-
ing easy installation and
maintenance with efficient
performance.
Easy to install
The 50ZH units are light weight, com-
pact single-package units that are
easy to handle. Every 50ZH unit has
an identical 32 by 51-in. footprint
to make jobsite planning simple. The
precise design uses less sheet metal
and makes the 50ZH units lighter
than other units. The unit can be eas-
ily positioned on the jobsite with the
hand-holds built into the unit basepan.
Drop-in cartridge style heaters are
utilized to minimize installation time.
Top cover service access
The 50ZH units are designed to be
serviced from the top. The split-top
design allows easy access for installa-
tion and maintenance procedures
on the unit. Routine maintenance tasks
such as coil cleaning are sped up
with through-the-top access. Multiple
side panels do not need to be re-
moved as with other units.
Product
Data 50ZH
Single-Package
Heat Pump Units
2 to 5 Nominal Tons
Copyright 1998 Carrier Corporation Form 50ZH-2PD

Corrosion proof basepan
The 50ZH features a tough, high-
tech, single-piece, composite material
basepan with an integrated drain
pan. The composite material elimi-
nates the potential problem of rust
and premature replacement which are
common with standard metal pans.
Each 50ZH basepan is sloped to
eliminate standing water. This feature
minimizes the amount of standing
water inside the unit, which limits
algae growth.
Durable steel cabinet
The watertight construction and
corrosion-resistant finish of the 50ZH
will keep it looking like new for
years. Carrier’s paint treatment pro-
cess ensures quality protection against
the elements. A compact, low-profile
design utilizes a louvered coil
enclosure for maximum protection
against hail damage and vandalism.
Scroll compressors
Each 50ZH comes standard with
a high reliability design scroll
compressor. Each scroll compressor is
hermetically sealed against contami-
nation to help promote longer life and
dependable operation. All scroll
compressors have internal high-
pressure and overcurrent protection.
Coil efficiency
Indoor and outdoor coils are com-
puter designed for optimum heat
transfer and cooling efficiency.
Chronotemp™ defrost system
The system provides time/
temperature-based defrost cycles to
maintain unit efficiency. This highly
reliable system checks for coil icing
conditions at preset intervals and ini-
tiates a defrost cycle only if it is re-
quired. The defrost cycle ends as soon
as defrosting is accomplished. Each
defrost board is also equipped with
5-minute compressor time guard
protection.
Accessory electric heaters
A variety of accessory electric supple-
mentary heaters are available for
the 50ZH units. Each heater is a
drop-in style cartridge type with single-
point electrical connections for both
the heater and the unit.
Starter collars
Starter collars are provided with each
unit to provide easy connection to
the structure ductwork.
Dependable components
Direct-drive multispeed, PSC (perma-
nent split capacitor) blower motor is
standard on all models.
Direct-drive, PSC outdoor-fan mo-
tors are designed to help reduce
energy consumption and provide for
cooling operation down to 40 F.
Refrigerant system is designed to
provide dependability. Liquid refriger-
ant strainers are used to promote
clean, unrestricted operation. Each
unit leaves the factory with a full refrig-
erant charge and is fully run tested.
Refrigerant service connections make
checking operating pressures easier.
Model number nomenclature
Table of contents Page
Features/Benefits ...............................1,2
Model Number Nomenclature .....................2
ARI Capacities ..................................3
Physical Data ...................................3
Accessories .....................................4
Base Unit Dimensions ...........................5-7
Selection Procedure ..............................8
Performance Data ..............................9-16
Electrical Data .................................17
Typical Wiring Schematic ......................18,19
Controls ......................................19
Typical Piping and Wiring .......................20
Guide Specifications ...........................21,22
2

ARI* capacities
UNIT
50ZH NOMINAL TONS STANDARD CFM NET COOLING
CAPACITIES
AT 95 F (Btuh) SEER† NET HEATING
CAPACITIES
AT 47 F (Btuh) HSPF SOUND
RATINGS**
(bels)
024 2.0 800 22,800 10.00 21,800 6.8 7.8
030 2.5 1000 28,200 10.00 27,200 6.8 8.4
036 3.0 1200 34,200 10.00 33,800 6.8 8.0
042 3.5 1400 40,000 10.00 40,000 6.8 8.0
048 4.0 1600 46,000 10.00 45,000 6.8 8.2
060 5.0 2000 55,000 10.50 52,500 6.8 8.4
LEGEND
Bels — Sound Levels (1 Bel = 10 Decibels)
HSPF — Heating Seasonal Performance Factor
SEER — Seasonal Energy Efficiency Ratio
*Air Conditioning and Refrigeration Institute.
†Rated in accordance with U.S. Government DOE (Department of Energy) test
procedures and/or ARI Standard 210/240-89.
**Rated in accordance with ARI Standard 270-84.
Physical data
UNIT 50ZH 024 030 036 042 048 060
OPERATING WEIGHT (lb) 232 254 277 295 328 368
COMPRESSOR TYPE Scroll
REFRIGERANT R-22
Charge (lb) 3.1 5.6 5.9 6.6 8.6 9.7
REFRIGERANT METERING DEVICE Acutrol™ System
OUTDOOR COIL Copper Tubes, Aluminum Plate Fins
Rows...Fins/in. 1...17 2...17 1...17 2...17 2...17 2...17
Total Face Area (sq ft) 7.9 6.7 11.1 9.3 11.1 12.7
OUTDOOR-FAN MOTOR Propeller
Nominal Cfm 1800 2000 2600 2600 2600 3200
Nominal Rpm 825 1100 1100 1100 1100 1100
Motor Hp
1
⁄ 81 ⁄ 41 ⁄ 41 ⁄ 41 ⁄ 41 ⁄ 2
Diameter (in.) 20 20 20 20 20 20
INDOOR COIL Copper Tubes, Aluminum Plate Fins
Rows...Fins/in. 2...15 3...15 3...15 3...15 4...15 4...15
Total Face Area (sq ft) 3.1 3.1 4.0 4.0 4.4 4.9
INDOOR-FAN MOTOR Direct Drive
Blower Motor Size (in.) 10x8 10x8 10x9 10x9 10x9 10×10
Nominal Cfm 800 1000 1200 1400 1600 2000
Rpm Range 550-1000 550-1000 800-1050 800-1050 1000-1100 950-1100
Number of Speeds 3333 2 3
Factory Speed Setting Low Med Low Med Low Low
Motor Hp
1
⁄ 41 ⁄ 41 ⁄ 21 ⁄ 23 ⁄ 4 1
CONNECTING DUCT SIZES Round Square
Supply Air (in.) 14 13.9 × 13.9
Return Air (in.) 14 13.9 × 27.8
FIELD-SUPPLIED RETURN AIR FILTER*
Throwaway (in.) 24x24 24x24 24x24 24x24 24x30 24×30
*Required filter sizes shown are based on the ARI (Air Conditioning and Refrigeration Institute) rated
airflow at a velocity of 300 ft/min for throwaway type or 450 ft/min for high capacity type. Recom-
mended filters are 1-in. thick.
3

Accessories
ACCESSORY
Outdoor Thermostat
Thermostat and Subbase
Electronic Programmable Thermostat
Electric Heat with Single-Point Kit (5.0 to 20.0 kW)
Electronic programmable thermostat provides 2-stage
heating and 2-stage cooling control with remote communi-
cation ability.
Thermostat and subbase provide heating and cooling
unit control. The subbase provides system and fan switch-
ing at the thermostat location.
Electric heaters provide heat in the unit when required.
Each package has a heater module that slides into keyed
mounting slots in the fan inlet. Heater sizes range from 5.0
to 20.0 kW. The electric heater design allows the use of a
single-point power supply for the entire unit, resulting in
lower installed costs. See Electrical data table on page 17
for accessory electric heater usage.
Outdoor thermostat brings second stage of 2-stage elec-
tric heater on line when the outdoor-air temperature falls
below the set point.
THERMOSTATS
ODS CATALOG
ORDERING NO. DESCRIPTION
TSTATCCN2501-A Residential Thermostat — Autochangeover — 3 Heat/2 Cool, Non-Programmable
TSTATCCP2501-A Residential Thermostat — Autochangeover — 3 Heat/2 Cool, Programmable
33CSPTN-01 Commercial Thermostat — Autochangeover — 3 Heat/2 Cool, Programmable
ODS — Order Distribution System
4

Base unit dimensions — 50ZH024,030
REQUIRED CLEARANCES TO COMBUSTIBLE MAT’L Millimeters (in.)
Top of Unit ...................................0
Duct Side of Unit ...............................0
Side Opposite Ducts .............................0
Bottom of Unit .................................0
NEC REQUIRED CLEARANCES Millimeters (in.)
Between Units, Power Entry Side .................1066.8 (42.00)
Unit and Ungrounded Surfaces, Power Entry Side ....... 914.0 (36.00)
Unit and Block or Concrete Walls and Other Grounded
Surfaces, Power Entry Side ....................1066.8 (42.00)
REQUIRED CLEARANCES FOR SERVICING Millimeters (in.)
Outdoor Coil Access Side .......................762.0 (30.00)
Power Entry Side ............................762.0 (30.00)
(Except for NEC Requirements)
Unit Top ..................................914.0 (36.00)
Side Opposite Ducts ..........................762.0 (30.00)
LEGEND
NEC — National Electrical Code
NOTES:
1. Clearances must be maintained to prevent recirculation of air from outdoor-
fan discharge, with the exception of the outdoor coil (914 mm [36 in.]). A
removable fence or barricade requires no clearance.
2. Dimensions are in millimeters. Dimensions in ( ) are in inches.
3. is the center of gravity.
UNIT ELECTRICAL
CHARACTERISTICS UNIT WT CENTER OF GRAVITY mm (in.)
Lb Kg X Y Z
50ZH024 208/230-1-60 232 106 356 (14.0) 483 (19.0) 305 (12.0)
50ZH030 208/230-1-60; 208/230-3-60 254 116 356 (14.0) 483 (19.0) 305 (12.0)
5

Base unit dimensions — 50ZH036-048
REQUIRED CLEARANCES TO COMBUSTIBLE MAT’L Millimeters (in.)
Top of Unit ...................................0
Duct Side of Unit ...............................0
Side Opposite Ducts .............................0
Bottom of Unit .................................0
NEC REQUIRED CLEARANCES Millimeters (in.)
Between Units, Power Entry Side .................1066.8 (42.00)
Unit and Ungrounded Surfaces, Power Entry Side ....... 914.0 (36.00)
Unit and Block or Concrete Walls and Other Grounded
Surfaces, Power Entry Side ....................1066.8 (42.00)
REQUIRED CLEARANCES FOR SERVICING Millimeters (in.)
Outdoor Coil Access Side .......................762.0 (30.00)
Power Entry Side ............................762.0 (30.00)
(Except for NEC Requirements)
Unit Top ..................................914.0 (36.00)
Side Opposite Ducts ..........................762.0 (30.00)
LEGEND
NEC — National Electrical Code
NOTES:
1. Clearances must be maintained to prevent recirculation of air from outdoor-
fan discharge, with the exception of the outdoor coil (914 mm [36 in.]). A
removable fence or barricade requires no clearance.
2. Dimensions are in millimeters. Dimensions in ( ) are in inches.
3. is the center of gravity.
UNIT ELECTRICAL
CHARACTERISTICS UNIT WT CENTER OF GRAVITY mm (in.)
Lb Kg X Y Z
50ZH036 208/230-1-60, 208/230-3-60, 460-3-60 277 126 356 (14.0) 483 (19.0) 381 (15.0)
50ZH042 208/230-1-60, 208/230-3-60, 460-3-60 295 134 356 (14.0) 483 (19.0) 381 (15.0)
50ZH048 208/230-1-60, 208/230-3-60, 460-3-60 328 149 356 (14.0) 483 (19.0) 381 (15.0)
6

Base unit dimensions — 50ZH060
REQUIRED CLEARANCES TO COMBUSTIBLE MAT’L Millimeters (in.)
Top of Unit ...................................0
Bottom of Unit .................................0
Side of Unit with Duct Openings ......................0
Side of Unit Opposite Duct Openings ...................0
NEC REQUIRED CLEARANCES Millimeters (in.)
Between Units, Power Entry Side .................1066.8 (42.00)
Unit and Ungrounded Surfaces, Power Entry Side ....... 914.0 (36.00)
Unit and Block or Concrete Walls and Other Grounded
Surfaces, Power Entry Side ....................1066.8 (42.00)
REQUIRED CLEARANCES FOR SERVICING Millimeters (in.)
Top of Unit ................................914.0 (36.00)
Side of Unit Opposite Duct Openings ................762.0 (30.00)
Side of Unit with Power Entry ....................762.0 (30.00)
(Except for NEC Requirements)
LEGEND
NEC — National Electrical Code
NOTES:
1. Clearances must be maintained to prevent recirculation of air from outdoor-
fan discharge. A removable fence or barricade requires no clearance.
2. Dimensions are in millimeters. Dimensions in [ ] are in inches.
3. is the center of gravity.
UNIT ELECTRICAL CHARACTERISTICS
V-Ph-Hz
UNIT WEIGHT CENTER OF GRAVITY mm (in.)
Lb Kg X Y Z
50ZH060 208/230-1-60, 208/230-3-60,
460-3-60 368 167 356 (14.00) 508 (20.00) 406 (16.00)
7

Selection procedure
I Determine cooling and heating requirements at
design conditions.
Given:
Required Cooling Capacity (TC) .....28,000 Btuh
Sensible Heat Capacity (SHC) ......20,500 Btuh
Required Heating Capacity .........28,550 Btuh
Outdoor Entering-Air Temperature .........95F
Outdoor-Air Winter Design Temperature .....20F
Indoor-Air Winter Design Temperature ......70F
Indoor Entering-Air Temperature .......80Fedb,
67 F ewb
Indoor-Air Quantity ................1125 cfm
External Static Pressure ............0.20 in. wg
Electrical Characteristics (V-Ph-Hz) ......230-1-60
edb — entering dry bulb
ewb — entering wet bulb
II Select unit based on required cooling capacity.
Enter Cooling Capacities table at condenser entering
temperature of 95 F, indoor air entering at 1125 cfm
and 67 F ewb (entering wet bulb). The 50ZH030 unit
will provide a total cooling capacity of 28,800 Btuh
and a sensible heat capacity of 21,700 Btuh.
For indoor-air temperature other than 80 F edb
(entering dry bulb), calculate sensible heat capacity cor-
rection, as required, using the formula found in
Note 3 following the cooling capacities tables.
NOTE: Unit ratings are net capacities.
III Select electric heat.
Enter the unit 50ZH030 Heating Capacities table at
1125 cfm. At 70 F return indoor air and 20 F air en-
tering outdoor coil, the integrated heating capacity is
15,500 Btuh. (Select integrated heating capacity value
since deductions for outdoor-coil frost and defrosting
have already been made. No correction is required.)
The required heating capacity is 28,550 Btuh. There-
fore, 13,050 Btuh (28,550 – 15,500) additional elec-
tric heat is required.
Determine additional electric heat capacity in kW.
13,050 Btuh = 3.8 kW of heat required
3414 Btuh/kW
Enter the Electrical data table on page 17 for 208/
230 v, single-phase, 50ZH030 unit. The 5-kW heater
at 240 v most closely satisfies the heating required. To
calculate kW at 230 v, multiply the heater kW by mul-
tiplication factor 0.92 found in the Multiplication
Factors table on page 15.
5 kW x 0.92 = 4.6 kW
4.6 x 3414 = 15,704 Btuh
To calculate kW at 208 v, see Multiplication Factors
table on page 15.
Total unit heating capacity is 31,204 Btuh (15,500
+ 15,704).
IV Determine fan speed and power requirements
at design conditions.
Before entering the air delivery tables, calculate the
total static pressure required. From the given, the Ac-
cessory Electric Heat Pressure Drop table, Wet Coil
Pressure Drop table, and the Filter Pressure Drop table,
find:
External static pressure 0.20 in. wg
Filter 0.09 in. wg
Electric heat 0.11 in. wg
Wet coil 0.07 in. wg
Total static pressure 0.47 in. wg
Enter the table for Dry Coil Air Delivery — Hori-
zontal Discharge at 1125 cfm and 230-v high speed.
By interpolation, the standard motor will deliver
0.48 in. wg static pressure. This will adequately handle
job requirements.
8

Performance data
COOLING CAPACITIES
50ZH024 (2 TONS)
Temp (F)
Air Ent
Outdoor
Coil
(edb)
Indoor Entering Air — CFM/BF
700/0.12 800/0.14 900/0.15
Indoor Entering Air — Ewb (F)
72 67 63* 62 72 67 63* 62 72 67 63* 62
85 TC 26.6 24.1 22.2 22.0 27.0 24.5 22.6 22.4 27.3 24.9 23.0 22.8 SHC 13.2 16.7 16.2 19.8 13.8 17.7 17.1 21.1 14.4 18.6 18.0 22.1
kW 2.19 2.15 2.15 2.13 2.23 2.19 2.18 2.17 2.26 2.23 2.23 2.21
95 TC 25.6 23.0 21.2 20.9 26.0 22.8 21.6 21.4 26.3 23.8 21.8 21.7 SHC 12.9 16.4 15.7 19.3 13.5 17.4 16.6 20.6 14.1 18.3 17.5 21.7
kW 2.40 2.36 2.35 2.33 2.44 2.40 2.39 2.37 2.48 2.44 2.43 2.41
105 TC 24.4 21.9 20.0 19.8 24.8 22.3 20.4 20.2 25.1 22.6 20.7 20.7 SHC 12.5 15.9 15.2 18.8 13.1 16.9 16.2 20.0 13.7 17.9 17.0 20.7
kW 2.64 2.60 2.57 2.56 2.69 2.64 2.62 2.60 2.73 2.68 2.66 2.65
115 TC 23.2 20.6 18.7 18.5 23.5 21.0 19.0 19.1 23.8 21.3 19.3 19.7 SHC 12.0 15.4 14.7 18.1 12.7 16.4 15.6 19.1 13.2 17.3 16.4 19.7
kW 2.91 2.86 2.83 2.81 2.96 2.90 2.87 2.86 3.00 2.95 2.91 2.91
50ZH030 (2
1
⁄ 2 TONS)
Temp (F)
Air Ent
Outdoor
Coil
(edb)
Indoor Entering Air — CFM/BF
875/0.10 1000/0.11 1125/0.12
Indoor Entering Air — Ewb (F)
72 67 63* 62 72 67 63* 62 72 67 63* 62
85 TC 31.6 29.2 27.1 26.4 32.2 29.6 27.5 26.9 31.9 29.9 27.8 27.2 SHC 15.0 19.8 19.5 23.9 15.7 20.9 20.7 25.4 15.9 22.0 21.7 26.6
kW 2.80 2.76 2.73 2.71 2.87 2.82 2.79 2.77 2.90 2.88 2.84 2.83
95 TC 30.9 28.1 26.0 25.3 31.2 28.2 26.4 25.7 31.4 28.8 26.7 26.1 SHC 15.0 19.4 19.1 23.4 15.6 20.6 20.3 24.9 16.1 21.7 21.3 26.0
kW 3.05 3.00 2.96 2.94 3.11 3.05 3.02 3.00 3.16 3.11 3.07 3.06
105 TC 29.7 26.9 24.8 24.1 30.0 27.2 25.1 24.5 30.1 27.5 25.4 25.1 SHC 14.6 19.0 18.6 22.8 15.2 20.2 19.8 24.2 15.7 21.4 20.9 25.1
kW 3.31 3.26 3.21 3.19 3.37 3.32 3.27 3.26 3.41 3.37 3.34 3.33
115 TC 28.4 25.5 23.5 22.9 28.7 25.8 23.8 23.4 28.8 26.1 24.0 24.0 SHC 14.2 18.6 18.1 22.2 14.9 19.8 19.2 23.4 15.4 20.9 20.3 24.0
kW 3.58 3.53 3.46 3.44 3.64 3.60 3.53 3.51 3.69 3.65 3.59 3.59
LEGEND
BF — Bypass Factor
Edb — Entering Dry-Bulb
Ewb — Entering Wet-Bulb
kW — Total Unit Power Input
Ldb — Leaving Dry-Bulb
Lwb — Leaving Wet-Bulb
SHC — Sensible Heat Capacity (1000 Btuh) Net
TC — Total Capacity (1000 Btuh) Net
*At 75 F entering dry bulb (Tennessee Valley Authority [TVA] rating
conditions); all others at 80 F entering dry bulb.
NOTES:
1. Direct interpolation is permissible. Do not extrapolate.
2. The following formulas may be used:
sensible capacity (Btuh)
tldb =t
edb –1.10 x cfm
tlwb = Wet-bulb temperature corresponding to enthalpy of air
leaving indoor coil (hlwb)
total capacity (Btuh)
hlwb =h
ewb –4.5 x cfm
Where: hewb = Enthalpy of air entering evaporator coil
3. The SHC is based on 80 F edb temperature of air entering evapo-
rator coil.
Below 80 F edb, subtract (corr factor x cfm) from SHC.
Above 80 F edb, add (corr factor x cfm) to SHC.
Correction Factor = 1.10 x (1 – BF) x (edb – 80).
9

Performance data (cont)
COOLING CAPACITIES (cont)
50ZH036 (3 TONS)
Temp (F)
Air Ent
Outdoor
Coil
(edb)
Indoor Entering Air — CFM/BF
1050/0.09 1200/0.11 1350/0.12
Indoor Entering Air — Ewb (F)
72 67 63* 62 72 67 63* 62 72 67 63* 62
85 TC 39.9 35.8 33.1 32.3 40.5 36.4 33.7 32.9 40.9 36.8 34.0 33.3 SHC 19.1 24.2 23.4 29.0 19.9 25.7 24.8 30.8 20.7 27.0 26.0 32.4
kW 3.49 3.37 3.29 3.27 3.57 3.45 3.36 3.35 3.64 3.52 3.43 3.42
95 TC 38.5 34.5 31.8 31.0 39.1 34.2 32.3 31.6 39.4 35.4 32.7 32.0 SHC 18.7 23.7 22.9 28.4 19.5 25.2 24.3 30.3 20.4 26.6 25.6 31.8
kW 3.80 3.67 3.58 3.56 3.88 3.75 3.66 3.64 3.95 3.82 3.73 3.72
105 TC 36.9 33.0 30.4 29.6 37.5 33.5 30.9 30.1 37.9 33.8 31.2 30.8 SHC 18.2 23.2 22.4 27.8 19.0 24.7 23.8 29.6 19.9 26.1 25.1 30.8
kW 4.15 4.01 3.91 3.89 4.23 4.08 3.99 3.97 4.30 4.16 4.06 4.05
115 TC 35.2 31.4 28.9 28.2 35.7 31.9 29.3 28.7 36.1 32.1 29.6 29.6 SHC 17.6 22.6 21.8 27.1 18.5 24.1 23.2 28.7 19.3 25.5 24.5 29.5
kW 4.51 4.36 4.26 4.24 4.60 4.44 4.34 4.33 4.68 4.52 4.14 4.42
50ZH042 (3
1
⁄ 2 TONS)
Temp (F)
Air Ent
Outdoor
Coil
(edb)
Indoor Entering Air — CFM/BF
1225/0.11 1400/0.13 1575/0.14
Indoor Entering Air — Ewb (F)
72 67 63* 62 72 67 63* 62 72 67 63* 62
85 TC 45.9 41.1 38.0 37.0 46.6 41.8 38.6 37.6 47.2 42.3 39.1 38.2 SHC 22.1 28.0 27.1 33.5 23.2 29.8 28.7 35.6 24.2 31.5 30.3 37.5
kW 4.28 4.15 4.06 4.04 4.37 4.24 4.15 4.13 4.45 4.32 4.23 4.21
95 TC 43.9 39.2 36.2 35.2 44.6 40.0 36.8 35.8 45.2 40.3 37.2 36.4 SHC 21.5 27.3 26.4 32.7 22.5 29.1 28.0 34.7 23.5 30.8 29.6 36.4
kW 4.65 4.51 4.42 4.39 4.74 4.60 4.50 4.48 4.82 4.68 4.58 4.56
105 TC 41.8 37.2 34.3 33.4 42.5 37.8 34.8 34.0 42.9 38.2 35.2 34.9 SHC 20.8 26.6 25.6 31.8 21.8 28.3 27.2 33.7 22.8 30.0 28.8 34.9
kW 5.00 4.90 4.80 4.78 5.09 4.99 4.89 4.87 5.17 5.07 4.97 4.97
115 TC 39.7 35.2 32.4 31.5 40.2 35.7 32.8 32.3 40.7 36.0 33.1 33.3 SHC 20.1 25.8 24.8 30.8 21.1 27.5 26.4 32.3 22.1 29.2 27.9 33.3
kW 5.44 5.32 5.21 5.19 5.53 5.41 5.30 5.29 5.61 5.50 5.40 5.40
LEGEND
BF — Bypass Factor
Edb — Entering Dry-Bulb
Ewb — Entering Wet-Bulb
kW — Total Unit Power Input
Ldb — Leaving Dry-Bulb
Lwb — Leaving Wet-Bulb
SHC — Sensible Heat Capacity (1000 Btuh) Net
TC — Total Capacity (1000 Btuh) Net
*At 75 F entering dry bulb (Tennessee Valley Authority [TVA] rating
conditions); all others at 80 F entering dry bulb.
NOTES:
1. Direct interpolation is permissible. Do not extrapolate.
2. The following formulas may be used:
sensible capacity (Btuh)
tldb =t
edb –1.10 x cfm
tlwb = Wet-bulb temperature corresponding to enthalpy of air
leaving indoor coil (hlwb)
total capacity (Btuh)
hlwb =h
ewb –4.5 x cfm
Where: hewb = Enthalpy of air entering evaporator coil
3. The SHC is based on 80 F edb temperature of air entering evapo-
rator coil.
Below 80 F edb, subtract (corr factor x cfm) from SHC.
Above 80 F edb, add (corr factor x cfm) to SHC.
Correction Factor = 1.10 x (1 – BF) x (edb – 80).
10