Lennox TAA090S4D - User Manual

Page 1
 2012 Lennox Industries Inc.
Litho U.S.A.
Corp. 0905−L2
TAA
Service Literature
Revised March 13, 2012
TAA SERIES UNITS
Lennox TAA model blower−coil units are designed for up
flow or horizontal air and indoor applications only. TAA
blower units are available in six models; 072, 090, 120,
150, 180 and 240. The units match up with Lennox TSA
condensing units and Lennox TPA heat pump units
charged with HFC−410A refrigerant.
Information and specifications contained in this manual
are subject to change. Procedures outlined in this manual
are presented as a recommendation only and do not su-
persede or replace local or state codes.
WARNING
Improper installation, adjustment, alteration, service or
maintenance can cause personal injury, loss of life, or
damage to property.
Installation and service must be performed by a licensed
professional installer (or equivalent) or a service agency.
WARNING
Electric shock hazard. Can cause in-
jury 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 Page 2. . . . . . . . . . . . . . . . . . . . . . .
Options / Accessories Page 4. . . . . . . . . . . . . . . .
Blower Data Page 5. . . . . . . . . . . . . . . . . . . . . . . . .
Electric Heat Data Page 15. . . . . . . . . . . . . . . . . . .
I Unit Components Page 21. . . . . . . . . . . . . . . . . . .
II Refrigeration System Page 22. . . . . . . . . . . . . . .
III Blower Speed and Belt Adjustment Page 22. .
IV Electric Heat Page 23. . . . . . . . . . . . . . . . . . . . . .
V Diagrams Page 24. . . . . . . . . . . . . . . . . . . . . . . . .

Summary

TAA Series Units

Safety Warnings

Critical warnings on installation, service, and electrical hazards.

Unit Specifications

General Data and Tonnage

Model numbers and nominal tonnage for TAA units.

Connections and Refrigerant

Pipe sizes and refrigerant type used.

Evaporator Coil Details

Face area, split, rows, and fins per inch.

Options and Accessories (Continued)

Electric Heat Options

Details on various kW electric heat kits available.

Economizer and Air Quality

TAA072 Blower Performance Data

TAA090 Blower Performance Data

TAA120 Blower Performance Data

TAA150 Blower Performance Data

TAA180 Blower Performance Data

TAA240 Blower Performance Data

TAA240 Blower Performance Data (Continued)

Static Pressure External to Unit

Air volume, RPM, and BHP at various static pressures.

Blower Drive Specifications

Motor HP and RPM Range

Nominal vs. Maximum HP and RPM ranges.

Blower Motor Electrical Data

Overcurrent protection and ampacity for motors.

Optional Electric Heat Data (TAA240)

Electric Heat Specifications

kW, Btuh, ampacity for TAA240.

Blower Speed and Belt Tension

Air Volume Adjustment Procedure

Belt Tension Adjustment Procedure

Electric Heat Components

Heating Elements and Contactors

Sequencer and Heat Relays

Fuses, Transformer, and Limits

Wiring Diagrams (TAA072;240)

Wiring Diagrams (T3 EH 072;150, 10-15 kW Y)

Wiring Diagrams (T3 EH 072;150, 25-35 kW Y)

Wiring Diagrams (T3 EH 072;150, 10-35 kW G, J, M)

Sequence of Operation

Wiring Diagram

Overview

1. Function Description
2. Important Technical Specifications
3. General Data
4. Evaporator Coil
5. Blower and Drive
6. Blower Motor Electrical Data
7. Optional Electric Heat Data (Examples for 10 kW)
8. Usage Features
9. Maintenance Features

The Lennox TAA Series Units are blower-coil units designed for upflow or horizontal air and indoor applications. They are available in six models: 072, 090, 120, 150, 180, and 240. These units are designed to match with Lennox TSA condensing units and Lennox TPA heat pump units, and are charged with HFC-410A refrigerant.

Function Description

The TAA units primarily function as indoor air handlers, providing air circulation and, when paired with a condensing or heat pump unit, facilitating cooling or heating. The blower-coil design integrates the blower and evaporator coil into a single unit. For cooling cycles, the 090-240 units feature a dual distribution system for two-stage capacity control, with each circuit having its own service valve connection and expansion valve. Electric heat options are available, with multiple-stage elements sequenced on and off by time delays in response to thermostat demand.

Important Technical Specifications

General Data:

• Nominal Tonnage: Ranges from 6 to 20 tons across the six models.
• Refrigerant: All units use R-410A.
• Connections:
  • Liquid line o.d. (sweat): (1) 5/8 in. for 072, (2) 5/8 in. for 090-240.
  • Suction/Vapor line o.d. (sweat): (1) 1-1/8 in. for 072, (2) 7/8 in. for 090-150, (2) 1-1/8 in. for 180-240.
  • Condensate drain (fpt): 1 (NPT) for all models.

Evaporator Coil:

• Net face area: 8.2 sq. ft. for 072-090, 11.3 sq. ft. for 120-150, and 16.9 sq. ft. for 180-240.
• Coil (Face) Split - 1st stage / 2nd stage (%): 50/50 for 090-240 models.
• Tube diameter: 3/8 in. for all models.
• Number of rows: 3 for 072, 4 for 090-150 and 240, 3 for 180.
• Fins per inch: 17 for 072-090, 14 for 120-240.

Blower and Drive:

• Wheel nominal diameter & width: (1) 15 x 15 in. for 072-150, (2) 15 x 15 in. for 180-240.
• Filter (Number and size): (3) 16 x 25 x 2 in. for 072-090, (4) 16 x 25 x 2 in. for 120-150, (6) 16 x 25 x 2 in. for 180-240.

Blower Motor Electrical Data:

• 1.5 HP Motor: Max Overcurrent Protection / Min Circuit Ampacity: 208/230V-3PH (15/8), 460V-3PH (15/4), 575V-3PH (15/3).
• 2 HP Motor: Max Overcurrent Protection / Min Circuit Ampacity: 208/230V-3PH (15/10), 460V-3PH (15/5), 575V-3PH (15/4).
• 3 HP Motor: Max Overcurrent Protection / Min Circuit Ampacity: 208/230V-3PH (20/14), 460V-3PH (15/6), 575V-3PH (15/5).
• 5 HP Motor: Max Overcurrent Protection / Min Circuit Ampacity: 208/230V-3PH (35/21), 460V-3PH (15/10), 575V-3PH (15/8).
• 7.5 HP Motor: Max Overcurrent Protection / Min Circuit Ampacity: 208/230V-3PH (50/31), 460V-3PH (20/14), 575V-3PH (20/12).

Optional Electric Heat Data (Examples for 10 kW):

• 10 kW, 208V-3ph: 7.5 kW Input, 25,600 Btuh Output. Min Circuit Ampacity: 34 (1.5 hp), 36 (2 hp). Max Overcurrent Protection: 35 (1.5 hp), 40 (2 hp).
• 10 kW, 460V-3ph: 9.2 kW Input, 31,400 Btuh Output. Min Circuit Ampacity: 19 (1.5 hp), 20 (2 hp). Max Overcurrent Protection: 20 (1.5 hp), 20 (2 hp).

Usage Features

• Air Volume Adjustment: The units allow for adjustment of air volume. This involves running the blower without a cooling demand, measuring static pressure external to the unit, and measuring the indoor blower motor's RPM. These readings are then used with blower performance tables to determine the unit's air volume. The adjustable pulley's Allen screw can be loosened, and the sheave turned clockwise to increase air volume or counterclockwise to decrease it. Once the desired air volume is achieved, the Allen screw is tightened. It's important that the indoor coil is dry and air filters are in place during these measurements.
• Belt Tension Adjustment: The belt tensioner allows for proper belt tension. The belt is placed over three pulleys, and a 15/16" wrench is used on the tensioner body nut to apply force until alignment marks align. While holding the tensioner in position, the mounting bolt is tightened to 23 ft-lbs using a 9/16" wrench.
• Economizer Control: An economizer relay (K43) is used to control the economizer. During a call for cooling, K43-1 contacts close, energizing the economizer and the blower contactor (K3).
• Condensate Management: A reversible drain pan is provided. A trap must be installed in the condensate drain line at the unit exit. K220 and S149 are field-installed to prevent condensate overflow. If the drain plug is blocked and condensate rises, N.O. S149 closes, energizing relay K220, which then opens N.C. K220 contacts, de-energizing the TAA unit.
• Electric Heat Stages: Electric heat elements are sequenced on and off by time delays. Contactors (K15, K16) and sequencer relays (K32) manage the energization of different heat stages based on thermostat demand. Relays K9 and K19 electrically isolate 24-volt components.

Maintenance Features

• Safety Warnings: The manual emphasizes critical safety warnings, including the risk of personal injury, loss of life, or property damage from improper installation, adjustment, alteration, service, or maintenance. It explicitly states that installation and service must be performed by a licensed professional installer or service agency.
• Electrical Safety: A prominent warning highlights the electric shock hazard, advising users to turn off electrical power at the disconnect switch(es) before performing any service or maintenance, noting that the unit may have multiple power supplies.
• Overcurrent Protection: The blower motor is protected by an overload relay (S42) for "M" voltage and high-efficiency motors. S42 monitors current flow and opens N.C. contacts to de-energize 24-volt circuits if an overload is detected. Electric heating elements are protected by fuses (F3) in series with each leg of electric heat, and the indoor blower (B3) is protected by fuse F4.
• High Temperature Limits: Primary (S15) and secondary (S20) high-temperature limits provide over-temperature protection for the electric heat elements. S15, wired in series with the first stage contactor coil, de-energizes K15 and subsequent heat stages if it opens, while the indoor blower continues operating. S20 limits are connected in series with one leg of the three-phase element assembly, with three-phase operating characteristics ensuring protection for the third leg as well.
• Accessibility: All field wiring connections are made at a terminal block (TB1) for ease of installation and service.
• Documentation: Information and specifications are subject to change, and procedures are recommendations that do not supersede local or state codes. The manual includes detailed blower performance tables, accessory air resistance tables, and electrical heat data to aid in selection and troubleshooting.

Lennox TAA090S4D Specifications