Bard Q24A1 Description of Standard Equipment, Optional CFM Q36A1, Q42A1, Q48A1 and Q60A1 only

START UP

DESCRIPTION OF STANDARD

EQUIPMENT

High Pressure Switch

Provides refrigerant circuit high pressure protection. Includes lockout circuit that is resettable from room thermostat.

Compressor Control Module

Provides short cycle protection for the compressor which extends compressor life, as well as high and low pressure switch monitoring and alarm functions.

Service Lights

One service light indicates when service is required.

•Check System – detects high or low pressure switch operation for compressor protection.

OPTIONAL CFM (Q36A1, Q42A1, Q48A1 AND Q60A1 ONLY)

These units are shipped from the factory set to operate at the optional CFM level shown in Table 7. This provides lower operating sound levels for non-ducted, free discharge applications. This CFM level will reduce the system capacity performance by approximately 2% at the same energy efficiency.

Rated CFM is required for ducted applications for maximum performance rating. To obtain full CFM on these models, connect jumper wire as follows:

1.Disconnect all power to the unit. Failure to do so may result in damage to the motor.

2.Open return air service panel

3.Open inner control panel cover

4.Locate low voltage terminal strip. There is a pink jumper wire with both ends attached to terminal marked “G2”. Move one end of this jumper to terminal “Y”.

5.Reverse steps to reassemble.

IMPORTANT INSTALLER NOTE

For improved start-up performance, wash the indoor coil with a dishwasher detergent.

CAUTION

Do not plug in or unplug blower motor

connectors while the power is on.

Failure to do so may result in motor failure.

PHASE MONITOR

All units with three phase scroll compressors are equipped with a 3 phase line monitor to prevent compressor damage due to phase reversal.

The phase monitor in this unit is equipped with two LEDs. If the Y signal is present at the phase monitor and phases are correct the green LED will light and the compressor contactor is allowed to energize.

If phases are reversed, the red fault LED will be lit and compressor operation is inhibited.

If a fault condition occurs, reverse two of the supply leads to the unit. Do not reverse any of the unit factory wires as damage may occur.

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 even one hour may have a negative impact on the bearing due to oil pump out.

Manual	2100-522B
Page	28 of 38