Desert Aire LW User Manual

Installation and Operation Manual
• Designed for low
ambient temperatures,
35° to 80°F
• Defrost cycle uses hot
gas defrost to quickly
eliminate frost from
evaporator coils
• Timed defrost cycle
initiated automatically
only when required
• Heat of rejection can
be delivered to the
space or optional
remote condenser
LW System

Desert Aire LW Specifications

General

Brand	Desert Aire
Model	LW
Category	Dehumidifier
Language	English

Summary

Introduction

Inspection

Inspect the dehumidifier for transit damage before signing receiving papers. Document any visible or concealed damage.

Freight Damage Claims

Document shipping damage, take pictures, and file a claim with the carrier promptly.

Rigging

Follow all rigging instructions to avoid equipment damage and personal injury. Use proper lifting methods.

Installation

Location of Dehumidifier

Allow 36 inches clearance; install on a sturdy, level base to prevent vibration and sound transmission.

Duct Installation

Conform to ASHRAE/SMACNA standards. Avoid restrictive ductwork to maintain efficiency and capacity.

Condensate Drain Piping

Requires a p-trap and 1/4" per foot pitch to prevent cabinet corrosion from condensate backup.

High Voltage Wiring

Comply with codes. Connect power supply wires to the correct blocks and verify blower rotation.

Controls and Wiring

Controlled by CM3540. Connect controller to humidity sensor and dehumidifier per diagram.

Remote Condenser (Optional)

May require additional oil/refrigerant charge. Refer to submittal docs for charge and connection tube sizes.

Start-Up Procedures

Preliminary Inspection

Verify contractor work, remove shipping blocks, ensure leveling, check power, tighten connections, and adjust belts.

System Operation Modes

Covers dehumidification, air reheat, air cooling, and defrost modes for optimal performance.

Refrigeration Testing

Ensures a clean and tight refrigeration system, critical for system longevity and performance.

General Testing

Verify operation of interlocked equipment like heaters, alarms, pumps, and BMS.

Routine Maintenance Schedule

Outlines monthly and semi-annual checks for filters, coils, belts, and electrical connections.

Troubleshooting

Supply Blower Will Not Run

Addresses possible causes like terminal switch issues, loss of power, or overload trips.

Compressor Will Not Run

Covers controller settings, power loss, faulty wiring, and compressor overload or failure.

Evaporator Coil Does Not Fully Defrost

Identifies issues like faulty defrost cycles, solenoid issues, or low refrigerant.

Head Pressure Is Too High

Includes causes like insufficient airflow, excessive refrigerant charge, or non-condensables.

Unit Runs but Excess Condensate Forms

Discusses poor air distribution, high airflow, or undersized units as potential causes.

Frost Build-up on the Compressor or Suction Line

Indicates lack of superheat, which can lead to compressor damage from liquid floodback.

Appendix

Compressor Failure

Explains causes like system contamination, heat, or electrical issues and procedures for replacement.

Recommended Duct Design

Provides diagrams for proper duct design to ensure effective operation and prevent premature compressor failure.

Unit Airflow

Details how to check and adjust system airflow for optimal performance and to prevent issues.

Unit Operation

Covers controller set-points, space pressurization, and operating parameters for efficiency.

Component Replacement, Charge, Evacuation, & Leak Instructions

Provides detailed procedures for servicing the refrigeration system, including recovery and charging.

Rating Plate

Details the information found on the unit's rating plate, including model, serial, and electrical specifications.

System Start-Up Report

Explains the importance of the start-up report for warranty validation and troubleshooting assistance.

Service Bulletin 027

Factory Start-Up Supervision

Outlines requirements for factory or Certified Service Technician start-up supervision and site preparation.