Lennox HS24-311 - User Manual

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SERVICE

HS24

UNIT

INFORMATION

Page 1

1992 Lennox Industries Inc.

Corp. 9201ĆL1 Litho U.S.A.

HS24 SERIES UNITS

The HS24 is a highĆefficiency residential splitĆsystem conĆ

densing unit. Extra large condensing coil, coil circuiting

and high condenser air volume result in a high SEER rating

(minimum of 10.0). The series is designed for use with an

expansion valve or RFCII system in the indoor unit.

All compressors are hermetically sealed for troubleĆfree

operation and long service life. Compressor components

are spring mounted within the sealed housing. The comĆ

pressor is installed in the unit on resilient rubber mounts to

assure quiet, vibrationĆfree operation. A builtĆin protection

device assures protection from excessive current and temĆ

peratures.

HS24-510 through HS24-650 models are furnished with

crankcase heaters as standard equipment to assure proper

compressor lubrication at all times. The heater is temperaĆ

tureĆactuated and operates only when required.

Several models are available in sizes ranging from 1

through 5 tons.

This manual is divided into sections which discuss the maĆ

jor components, refrigerant system, charging procedure,

maintenance and operation sequence.

All specifications in this manual are subject to change.

SPECIFICATIONS

Model No. HS24Ć141 HS24Ć211 HS24Ć261 HS24Ć311

N t f ( ft )

12 60

14 70

Net face area (sq. ft.) 12.60 12.60 12.60 14.70

Condenser

Coil

Tube diameter (in.) & no. of rows 3/8 Ċ 1 3/8 Ċ 1 3/8 Ċ 1 3/8 Ċ 1

Coil

Fins per inch 20 20 20 20

Diameter (in.) & no. of blades 20 Ċ 3 20 Ċ 3 20 Ċ 3 20 Ċ 3

Condenser Motor hp 1/6 1/6 1/6 1/6

Fan Cfm 2500 2500 2500 2700

Rpm 850 850 850 850

Watts 200 200 200 205

*Refrigerant Ċ 22 charge furnished 4 lbs. 5 oz. 4 lbs. 10 oz. 5 lbs. 7 oz. 5 lbs. 12 oz.

Liquid line (o.d. in.) connection (sweat) **3/8 ***3/8 ***3/8 3/8

Suction line (o.d. in.) connection (sweat) 1/2 5/8 5/8 3/4

Shipping weight (lbs.) 1 package 121 153 154 168

*Refrigerant charge sufficient for 25 ft. length of refrigerant lines.

** 3/8" x 1/4" reducer furnished to adapt to 1/4 field fabricated line set.

*** 3/8" x 5/16" reducer furnished to adapt unit to 5/16" line set.

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Summary

1 - Rotary Compressor (-141 Units Only)

3 - Reciprocating Compressor (all other units)

B - Service Valves

1 - Liquid Line Service Valve

Explains the full service liquid line valve, its operation, and service port procedures.

2 - Suction Line Service Valve

IV - CHARGING

A - Leak Testing

Outlines the procedure for leak testing the system using dry nitrogen and a gauge manifold.

B - Evacuating the System

Details the steps for evacuating the refrigeration system to the required vacuum level.

C - Charging

Explains the recommended method for charging the unit with refrigerant by weighing.

XII - WIRING DIAGRAMS AND SEQUENCE OF OPERATION

SINGLE PHASE OPERATING SEQUENCE

Details the sequence of operation for single phase HS24 units, including cooling demand and control signals.

OPERATING SEQUENCE

Explains the operational sequence for HS24 (P Voltage) units based on thermostat input.

THREE PHASE OPERATING SEQUENCE

The HS24 series units are high-efficiency residential split-system condensing units designed for use with an expansion valve or RFCII system in the indoor unit. These units feature extra-large condensing coils, optimized coil circuiting, and high condenser air volume, resulting in a high SEER rating (minimum of 10.0).

Function Description:

The primary function of the HS24 series is to provide cooling in a residential split-system air conditioning setup. It works by condensing refrigerant, which then circulates to an indoor coil to absorb heat from the indoor air. The units are designed for reliable and quiet operation, incorporating hermetically sealed compressors with spring-mounted components and resilient rubber mounts to minimize vibration. A built-in protection device safeguards the compressor from excessive current and temperatures. Models HS24-510 through HS24-650 are equipped with temperature-actuated crankcase heaters as standard to ensure proper compressor lubrication, operating only when needed.

Important Technical Specifications:

Models Available: Ranging from 1 to 5 tons in capacity.
Condenser Coil:
- Net face area: 12.60 sq. ft. (HS24-141 to HS24-261), 14.70 sq. ft. (HS24-311, HS24-411/413, HS24-461/463), 20.00 sq. ft. (HS24-511/513, HS24-651/653).
- Tube diameter & no. of rows: 3/8" - 1 row for most models, with some variations like 3/8" - 1.67 or 3/8" - 1.77 for specific HS24-463 and HS24-653 models.
- Fins per inch: 20 for all models.
Condenser Fan:
- Diameter & no. of blades: 20" - 3 blades for smaller units, 24" - 4 blades for larger units.
- Motor hp: 1/6 hp for smaller units, 1/4 hp for larger units.
- Cfm: Ranges from 2500 to 4000.
- Rpm: Ranges from 830 to 850.
- Watts: Ranges from 200 to 355.
Refrigerant (R-22) Charge Furnished: Varies by model, e.g., 4 lbs. 5 oz. (HS24-141) to 11 lbs. 5 oz. (HS24-651/653). This charge is sufficient for a 25 ft. length of refrigerant lines.
Liquid Line Connection (o.d. in., sweat): 3/8" for most models, with some requiring a 3/8" x 1/4" or 3/8" x 5/16" reducer.
Suction Line Connection (o.d. in., sweat): Varies by model, e.g., 1/2" (HS24-141) to 1-1/8" (HS24-651/653).
Shipping Weight (lbs., 1 package): Varies by model, e.g., 121 lbs. (HS24-141) to 271 lbs. (HS24-653).
Compressor Specifications (HS24 series units):
- Voltage: 208/230V (single-phase) or 208/230V, 460V, 575V (three-phase).
- LRA (Locked Rotor Amps): Ranges from 26.3 (HS24-141) to 150 (HS24-653).
- RLA (Rated Load Amps): Ranges from 4.8 (HS24-141) to 24 (HS24-651).
- Oil (fl.oz.): Ranges from 15 (HS24-141) to 70 (HS24-461/463).
Capacitors:
- Dual Capacitor (C12) for single-phase units: MFD ratings vary for fan and compressor sides (e.g., 5 MFD fan / 25 MFD herm for HS24-141/211).
- Fan Capacitor (C1) for three-phase units: MFD ratings vary (e.g., 5 MFD for HS24-413/463, 10 MFD for HS24-513/653Y,G).
- Start Capacitor (C7) for HS24-461, 511, 651 series units: MFD ratings vary (e.g., 189-227 MFD for HS24-461).
Transformer (T5): Used on all "J" voltage units (575V primary, 460V secondary, 3.4 VA).

Usage Features:

Compressor Contactor (K1): Energizes the compressor when the indoor thermostat demands cooling. It is powered by 24VAC from the indoor unit.
Capacitor Operation: Single-phase units use a dual capacitor (C12) for both the fan motor and compressor. Three-phase units use a single capacitor (C1) for the fan motor.
Potential (Start) Relay (K31): Used in HS24-461, 511, 651 series units to control the starting circuit, engaging the start capacitor (C7) during compressor start-up and disengaging it as the compressor gains speed.
Compressor Types: HS24-141 units utilize a hermetically sealed rotary-type compressor (Tecumseh Products), which uses a rotor shaft, eccentric, roller, and blade for continuous intake and compression. All other units use conventional reciprocating compressors.
Suction Muffler & Accumulator (HS24-141 Only): HS24-141 units are equipped with an external suction muffler (with wire mesh screen filters) for compressor protection and an accumulator in the suction line to protect against liquid slugging.
Compressor Cover: HS24-411 through -651 units feature a vinyl-faced fiberglass cover for acoustic insulation, secured with Velcro™ straps.
Condenser Fan Motor Access: Gained by removing six screws securing the fan guard. "Motor up" units have the fan motor attached to and removed with the fan guard.
Refrigerant Piping: Field refrigerant piping consists of liquid and suction lines with sweat connections. Lennox L10 series line sets or field-fabricated lines can be used.
Service Valves: Full service liquid line and suction line valves are provided for leak testing, evacuation, charging, and checking charge.
- Liquid Line Service Valve: Front and back seating valve. Backseating isolates the service port. No Schrader valve is installed; the valve must be backseated to turn off pressure to the service port.
- Suction Line Service Valve: Front-seating valve, non-backseating type. A Schrader valve is factory-installed in the service port. Attempting to backseat this valve can cause the snap ring to explode.
Charging Procedure:
- Units are factory-charged for a 25 ft. line set. Adjustments are required for different line lengths (e.g., add 1-3 oz. per 5 ft. for lines longer than 25 ft., subtract for shorter lines).
- Leak testing with dry nitrogen (max 150 psig).
- Evacuation to 29 inches (737mm) vacuum using a vacuum pump and vacuum gauge.
- Charging by weighing refrigerant into the unit for a completely void system.
- For expansion valve systems, charge using the approach method (liquid temp minus ambient temp).
- For RFCII systems, charge using the subcooling method (liquid subcooling + 1).

Maintenance Features:

Crankcase Heater: HS24-510 through HS24-650 models have self-regulating, temperature-actuated insertion-type crankcase heaters (27-30 watts) for proper compressor lubrication.
Seasonal Maintenance (Heating or Cooling Season):
- Outdoor Unit:
  - Clean and inspect condenser coil (can be flushed with water).
  - Condenser fan motor is prelubricated and sealed; no further lubrication is typically required. Oiling ports can be accessed after extended operation by removing plugs.
  - Visually inspect all connecting lines, joints, and coils for oil leaks.
- Indoor Coil:
  - Clean coil if necessary.
  - Check connecting lines, joints, and coil for oil leaks.
  - Check and clean condensate line.
- Indoor Unit:
  - Clean or change filters.
  - Lubricate blower motor: Prelubricated and sealed motors require no further lubrication. Direct drive motors with oiling ports should be relubricated with a few drops of SAE 10 non-detergent oil every two years for extended bearing life.
  - Adjust blower speed for cooling by checking static pressure drop over the coil to determine correct CFM.
  - Check all wiring for loose connections.
  - Check for correct voltage at the unit.
  - Check amp-draw on the blower motor.

Safety Warnings:

Shock Hazard (Single Phase Units): All single-phase HS24 units use single-pole contactors, meaning one leg of the compressor, capacitor, and condenser fan are always connected to line voltage. Always remove all power at the disconnect before servicing.
Service Port Access (Liquid Line): The service port cap seals the liquid line service valve. The service valve must be backseated to isolate the service port from the system; failure to do so will cause refrigerant leakage.
Schrader Valve (Liquid Line): No Schrader valve is provided on the liquid line service port. The valve must be backseated to turn off pressure to the service port.
Suction Valve (Non-Backseating): Suction valves are non-backseating. Do not attempt to backseat this valve, as it can cause the snap ring to explode from the valve body, leading to personal injury and unit damage.
Vacuum Gauges: Use a temperature vacuum gauge, mercury vacuum (U-tube), or thermocouple gauge for accurate vacuum readings, as Bourdon tube gauges are not accurate enough.
Compressor for Evacuation: The compressor should never be used to evacuate a refrigeration or air conditioning system.
Dry Nitrogen: When using dry nitrogen for leak testing, a pressure-reducing regulator must be used to prevent excessive pressure (max 150 psig / 1034 kPa) in the gauge manifold, hoses, and system. Failure to do so can cause equipment failure and injury.