Bard Complete Guide to Wall Mount Wiring Diagram and Start-Up Procedures
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START UP

IMPORTANT INSTALLER NOTE

For improved start up performance wash the indoor coil with a dish washing detergent.

CRANKCASE HEATERS

WA421 units are provided with compressor crankcase heat. WA602 and WA482 units are not provided with crankcase heat. These units utilize scroll compressors which do not require crankcase heat in this application.

The WA421 models have an insertion well-type heater located in the lower section of the compressor housing. This is a self-regulating type heater that draws only enough power to maintani the compressor at a safe termperature on these units.

Some form of crankcase heat is essential to prevent liquid refrigerant from migating to the compressor causing oil pump out on compressor start up and possible valve failure due to compressing a liquid.

The decal in Figure 9 is affixed to all WA421 units detailing start up procedure. This is very important. Please read carefully.

HIGH PRESSURE SWITCH

The WA482 and WA602 models are supplied with a remote reset high pressure switch. If tripped, this pressure switch may be reset by turning the themostat off then back on again.

THREE PHASE SCROLL COMPRESSOR START UP INFORMATION

Scroll compressors, like several other types of compressors, will only compress in one rotational direction. Direction of rotation is not an issue with single phase compressors since they will always start and run in the proper direction.

However, three phase compressors will rotate in either direction depending upon phasing of the power. Since there is a 50-50 chance of connecting power in such a way as to cause rotation in the reverse direction, verification of proper rotation must be made. Verification of proper rotation direction is made by observing that suction pressure drops and discharge pressure rises when the compressor is energized. Reverse rotation also results in an elevated sound level over that with correct rotation, as well as, substantially reduced current draw compared to tabulated values.

Verification of proper rotation must be made at the time the equipment is put into service. If improper rotation is corrected at this time there will be no negative impact on the durability of the compressor. However, reverse operation for over one hour may have a negative impact on the bearing due to oil pump out.

FIGURE 9

STARTING PROCEDURE

IMPORTANT

THESE PROCEDURES MUST BE FOLLOWED AT INITIAL START UP AND AT ANY TIME POWER HAS BEEN REMOVED FOR 12 HOURS OR LONGER.

To prevent compressor damage which may result from the presence of liquid refrigerant in the compressor crankcase.

1.Make certain the room thermostat is in the “off” position (the compressor is not to operate).

2.Apply power by closing the system disconnect switch. This energizes the compressor heater which evaporates the liquid refrigerant in the crankcase.

3.Allow 4 hours or 60 minutes per pound of refrigerant in the system as noted on the unit rating plate, which ever is greater.

4.After properly elapsed time, the thermostat may be set to operate the compressor.

5.Except as required for safety while servicing, Do not open system disconnect switch.

7961-061

NOTE: If compressor is allowed to run in reverse rotation for several minutes, the compressor’s internal protector will trip.

All three phase ZR3 compressors are wired identically internally. As a result, once the correct phasing is determined for a specific system or installation, connecting properly phased power leads to the same Fusite terminal should maintain proper rotation direction.

The direction of rotation of the compressor may be changed by reversing any two line connections to the unit.

CONDENSER FAN OPERATION

The condenser fan motor on 230/208 volt, one and three phase, 60 HZ units is a two speed motor that comes factory wired on high speed for peak performance. If ambient conditions permit, it can be reconnected to low speed (red wire) for lower sound level. See wiring diagram.

50 HZ models must have fan wired on low speed. These models are factory wired on low speed.

Manual 2100-218 Page 14

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Contents WA421 WA482 WA602 ModelsContents Getting Other Information and Publications Heat Pump Wall Mount Model Nomenclature Wall Mount General InformationElectric Heat Table Unit Dimensions Front View Side View Back ViewElectrical Specifications Single CircuitGeneral Shipping DamageDuct Work Filters Fresh AIR IntakeCondensate Drain Fresh AIR DamperWall Mounting Information Installation InstructionsMounting the Unit Mounting Instructions Electric Heat Clearance Wall Mounting Instructions See Mounting InstructionsCommon Wall Mounting Installations Wiring Main Power Wiring LOW Voltage WiringThermostat Wire Size TAP RangeUnit 24V Terminal Board Start UP Sequence of Operation Service HintsCompressor Control Module Pressure Service Ports Phase MonitorTypical Settings for Dual Unit Installation Troubleshooting FAN Blade Setting DimensionsRemoval of FAN Shroud Refrigerant ChargeMaximum ESP of Operation Electric Heat only Recommended AirflowPressure Table Cooling Optional Accessories

WA482, WA421 specifications

Bard WA482 and WA421 are high-performance air conditioning units designed for commercial and industrial applications. These models are renowned for their exceptional cooling efficiency, durability, and versatile performance, making them suitable for a variety of settings, including schools, factories, and office buildings.

One prominent feature of the Bard WA482 is its powerful cooling capacity. It has an impressive cooling output that can effectively manage indoor temperatures, even in the hottest conditions. This capability ensures optimal comfort for occupants while maintaining energy efficiency. Similarly, the Bard WA421 offers substantial cooling capacity, catering to smaller commercial spaces without compromising on performance.

Both models utilize advanced technology to enhance their operational efficiency. The units are equipped with a high-efficiency scroll compressor that minimizes energy consumption while delivering consistent cooling. This technology allows businesses to reduce their energy costs significantly, contributing to environmental sustainability.

Another significant characteristic of Bard WA482 and WA421 is their robust construction. Built with heavy-gauge galvanized steel, these units are designed to withstand tough environmental conditions. This durability ensures a long operational life, reducing the need for frequent repairs and replacements. The units are also corrosion-resistant, making them ideal for coastal or humid regions.

Efficiency is further enhanced by the inclusion of a multi-speed fan that allows for better airflow management. This feature enables the units to adjust their functioning based on the current cooling demand, optimizing energy use and minimizing noise levels. Consequently, users experience a comfortable environment without disruptive sound.

Maintenance is made simple with these models thanks to their accessible design. The units feature removable panels that provide easy access to internal components for routine servicing. This design minimizes downtime and helps maintain the overall efficiency of the system.

In terms of versatility, Bard WA482 and WA421 can be customized with various kits and options, including digital thermostats and advanced control systems. This adaptability enables users to tailor the cooling solutions to their specific needs, enhancing overall satisfaction.

In summary, Bard WA482 and WA421 stand out in the commercial air conditioning sector due to their impressive cooling capacity, energy-efficient technologies, robust construction, and ease of maintenance. These characteristics make them a reliable choice for businesses looking to maintain a comfortable and sustainable indoor environment.
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