Armstrong air conditioner troubleshooting

Armstrong HWC PREMIER 122 air conditioner troubleshooting

Problem:Solution:
Initial TestingIf a compressor failure is suspected, several simple checks should be done initially to make sure that the right course of action is being taken. The following is a list of items and points that should be looked at before a determination is made of the condition of the compressor.
• Is the correct voltage available at the unit? Using a volt/ohm meter, check the voltage and compare with the voltage specified by the manufacturer (found on the data plate on the unit). Many compressors are replaced only to find later that there was either no power or incorrect power available to the unit.
• Is the contactor closing? Check to make sure that there is 24 volts at the coil side of the contactor. Check to make sure the points in the contactor are in good condition. Are they pitted or corroded to the point where they no longer conduct electricity?
• Is the capacitor in good condition? Does it have the correct rating for the application? Using a meter, determine if it still has the correct capacitance.
• The last of these initial tests to do is a touch test. This should be done very carefully as the compressor can become very hot in certain situations. This information may be helpful if further tests are needed to determine the condition of the compressor.
Further TestingUse extreme caution when conducting the following tests. The power must be turned off before continuing with the testing.
Checking Continuity
1. Remove wires from the fusite plug in the compressor, recording the location of each wire as it is removed. If a wire is misplaced when the
test is complete, serious damage could be done to the compressor.
2. Set an ohm meter to the lowest possible setting. On a note pad, write the following: “C to ground", “S to ground” and “R to ground.”
3. Using the ohm meter, check for continuity between C terminal on the fusite plug and the case of the compressor (a spot may have to be cleaned on the compressor to get a good reading.) Record what was observed on the note pad next to the heading *C to ground”. Do the same to the other two terminals and record the findings in the proper places.
4. If any sign of continuity between any of the terminals and ground was observed, recheck the terminal to confirm that the readings were correct. Any indication of continuity between any of the terminals and ground would point to an internal winding being shorted to the compressor case. This suggests that the compressor has an internal failure and it would need to be replaced.
5. If no continuity is noted between any of the terminals and ground, the compressor must be checked out further.
Checking WindingsThe following test is used to check the condition of the internal start and run windings.
1. Write the following down: “C to S’, “C to R" and “S to R."
2. Using the volt/ohmmeter, measure the resistance between terminals C and S. Record the findings on the note pad in the correct place.
Measure and record the resistance between the remaining terminals in the same manner.
Checking the Thermal Overload DeviceIf during the time that resistance was being checked in the previous test infinity was ever registered (meter indicated no continuity), the assumption could be made that there is an open winding (or a break in the wires of the winding). This may indicate that the windings had burned out and that the compressor had failed.
In the motor windings there is a thermal overload device. This device is designed to open if the internal temperature of the windings exceed preset limit. Since the resistance reading of a winding where the thermal overload device has opened would show no resistance, the assumption would most likely be made that the winding was burned out. This is where the temperature of the compressor as noted in the touch test becomes very important. If at the time of the touch test the compressor was found to be very hot, then there is a good chance that the thermal overload protector has opened. Before the compressor can be condemned as having a burned out start or run winding, it must be determined that the overload switch is in fact closed. It may take several hours for the compressor to cool down enough to guarantee that the switch has closed. After enough time has elapsed for the switch to close, the resistance between each of the terminals should be measured. It may be found that with the overload switch closed, the compressor checks out electrically sound. If this is the case, then other possibilities have to be looked at as to what caused the compressor to overheat.
There are several reasons why a compressor would overheat. If the capacitor was incorrect or failing, the amp draw (current flow) would be increased. This could cause the motor to heat up very rapidly, activating the thermal overload protection device. This would interrupt power and protect the motor windings from damage.
A loss of charge could also cause the operating temperature of the compressor to rise and open the thermal overload switch.
Restricted airflow through the coil could also cause the operating temperature of the unit to rise.
It is important to perform these checks before making a decision as to the condition of the compressor. An open thermal overload device in a motor does not mean that the motor was damaged or harmed in any way.

Armstrong HWC PREMIER 302 air conditioner troubleshooting

PROBLEMPOSSIBLE CAUSESUGGESTED SOLUTION
Air conditioner will not operateNo power to the unit.Check connection of power cord to power source.
Check fuse or circuit breaker.
Set FAN CONTROL to position other than "OFF".
Inefficient or no coolingDirty air filter.Clean or replace air filter.
Inappropriate capacity for application.Check with dealer to determine proper unit capacity for application.
Blocked air flow.Remove obstruction from grill or outdoor louvers.
Power interruption, settings change too quickly, or compressor overload tripped.Let fan run to restart compressor (in approximately 10 minutes).
Noisy unitLoose parts.Tighten loose parts.
Inadequate support.Provide additional support to unit.
OdorsFormation of mold, mildew, or algae on wet surfaces.Remove drain plug and drain base pan.
Replace drain plug.
Clean unit thoroughly.
Water dripping outsideCondensation run-off is normal during hot and humid weatherAdd flexible tubing to redirect water flow.
Water dripping insideUnit is not properly angled to allow water to drain outside.Unit must be installed on an angle for proper condensation run-off. Check the unit and make adjustments.
Ice or frost build-upLow outside temperature.When outdoor temperature is approximately 65°F or below, frost may form when unit is in cooling mode. Switch unit to FAN (only) operation until frost melts.
Unit air filter is dirty.Remove and clean filter.