Daikin Condensing Unit DX11SA0903AB

WARNING: Disconnect ALL power before servicing.

1. Disconnect the wire leads from the terminal (T) side of the contactor.

2. With power ON, energize the contactor.

WARNING: Line Voltage now present.

3. Using a voltmeter, test across terminals.

A. L2 - T1 - No voltage indicates CC1 contacts open.

If a no voltage reading is obtained - replace the contactor.

WARNING: HIGH VOLTAGE! Disconnect ALL power before servicing or installing. Multiple power sources may be present. Failure to do so may cause property damage, personal injury or death.

If all tests fail, proceed with the following steps:

Unit wiring removed from disconnect switch and test cord wired to the disconnect switch

NOTE: The wire size of the test cord must equal the line wire size and the fuse must be of the proper size and type.

Protective terminal cover in place and three leads connected to the compressor terminals

WARNING: HIGH VOLTAGE! Disconnect ALL power before servicing or installing. Multiple power sources may be present. Failure to do so may cause property damage, personal injury or death.

The compressor contactor and other relay holding coils are wired into the low or line voltage circuits. When the control circuit is energized, the coil pulls in the normally open contacts or opens the normally closed contacts. When the coil is de-energized, springs return the contacts to their normal position.

NOTE: Most single phase contactors break only one side of the line (L1), leaving 115 volts to ground present at most internal components.

Leads removed from the holding coil?

Ohmmeter reading across the coil terminals

Relay or contactor replaced if coil does not test continuous?

Sign off on the contactor and/or relays check

This unit is equipped with an aluminum tube evaporator coil.

The safest way to clean the evaporator coil is to simply flush the coil with water. This cleaning practice remains as the recommended cleaning method for both copper tube and aluminum tube residential cooling coils.

An alternate cleaning method is to use one of the products listed in the technical publication TP-109 (shipped in the literature bag with the unit) to clean the coils. The cleaners listed are the only agents deemed safe and approved for use to clean round tube aluminum coils. TP-109 is available on the web site in Partner Link > Service Toolkit.

Was the coil flushed with water?

Select the cleaning method used

Upload a photo of the cleaned coil

NOTE: Ensure coils are rinsed well after use of any chemical cleaners.

Remove outer case, control panel cover, etc., from unit being tested. WARNING: Line Voltage now present.

Measure the voltage across terminals L1 and L2 of the contactor for the condensing unit or at the field connections for the air handler or heaters.

No reading - indicates open wiring, open fuse(s) no power or etc., from unit to fused disconnect service. Repair as needed.

With ample voltage at line voltage connectors, energize the unit.

Measure the voltage with the unit starting and operating, and determine the unit Locked Rotor Voltage.

Locked Rotor Voltage is the actual voltage available at the compressor during starting, locked rotor, or a stalled condition. Measured voltage should be above minimum listed in chart below.

To measure Locked Rotor Voltage attach a voltmeter to the run 'R' and common 'C' terminals of the compressor, or to the T1 and T2 terminals of the contactor. Start the unit and allow the compressor to run for several seconds, then shut down the unit. Immediately attempt to restart the unit while measuring the Locked Rotor Voltage.

Locked rotor voltage should read within the voltage tabulation as shown. If the voltage falls below the minimum voltage, check the line wire size.

Long runs of undersized wire can cause low voltage. If wire size is adequate, notify the local power company in regard to either low or high voltage.