Single Phase Resistance Test

WARNING

ELECTRIC SHOCK HAZARD

Turn off electric power before service or installation. Extreme care must be used, if it becomes necessary to work on equipment with power applied.

Failure to do so could result in serious injury or death.

Remove the leads from the compressor terminals and set the ohmmeter on the lowest scale (R x 1).

Touch the leads of the ohmmeter from terminals common to start (“C” to “S”). Next, touch the leads of the ohmmeter from terminals common to run (“C” to “R”).

Add values “C” to “S” and “C” to “R” together and check resistance from start to run terminals (“S” to “R”). Resistance “S” to “R” should equal the total of “C” to “S” and “C” to “R.”

In a single phase PSC compressor motor, the highest value will be from the start to the run connections (“S” to “R”). The next highest resistance is from the start to the common connections (“S” to “C”). The lowest resistance is from the run to common. (“C” to “R”) Before replacing a compressor, check to be sure it is defective.

GROUND TEST

Use an ohmmeter set on its highest scale. Touch one lead to the compressor body (clean point of contact as a good connection is a must) and the other probe in turn to each compressor terminal. If a reading is obtained the compressor is grounded and must be replaced.

Check the complete electrical system to the compressor and compressor internal electrical system, check to be certain that compressor is not out on internal overload.

Complete evaluation of the system must be made whenever you suspect the compressor is defective. If the compressor has been operating for sometime, a careful examination must be made to determine why the compressor failed.

Many compressor failures are caused by the following conditions:

1.Improper air flow over the evaporator.

2.Overcharged refrigerant system causing liquid to be returned to the compressor.

3.Restricted refrigerant system.

4.Lack of lubrication.

5.Liquid refrigerant returning to compressor causing oil to be washed out of bearings.

6.Noncondensables such as air and moisture in the system. Moisture is extremely destructive to a refrigerant system.

7.Capacitor test (see page 21).

CHECKING COMPRESSOR EFFICIENCY

The reason for compressor inefficiency is normally due to broken or damaged suction and/or discharge valves, reducing the ability of the compressor to pump refrigerant gas.

This condition can be checked as follows:

1.Install a piercing valve on the suction and discharge or liquid process tube.

2.Attach gauges to the high and low sides of the system.

3.Start the system and run a “cooling or heating perfor- mance test.” If test shows:

A.Below normal high side pressure

B.Above normal low side pressure

C.Low temperature difference across coil

The compressor valves are faulty - replace the compressor.

28

Page 29 Page 31
Page 30
Image 30
Friedrich 2008, 2009 service manual Single Phase Resistance Test, Ground Test, Checking Compressor Efficiency
Page 29 Page 31

2009, 2008 specifications

Friedrich 2008 and 2009 represent significant advancements in heating and cooling technology, particularly in the realm of air conditioning systems. Friedrich is known for producing robust and efficient HVAC solutions tailored for both residential and commercial applications. These models are particularly noteworthy for their innovative features and energy-efficient technologies that enhance user comfort and lower operational costs.

One of the main characteristics of the Friedrich 2008 and 2009 models is their emphasis on energy efficiency. Both units are designed to meet or exceed Energy Star standards, which indicates that they use less energy compared to standard models, contributing to greener living solutions. The incorporation of efficient compressors and high SEER (Seasonal Energy Efficiency Ratio) ratings ensures that users save money on their electricity bills while enjoying optimal cooling performance.

The units also feature advanced inverter technology, which allows for variable speed operation. This means that the system can adjust its cooling capacity based on the current temperature needs, resulting in more consistent comfort while reducing wear and tear on the equipment. Additionally, the inverter technology operates more quietly compared to traditional systems, making these models suitable for both home environments and commercial settings.

Friedrich 2008 and 2009 also provide users with enhanced control options. The inclusion of smart technology and Wi-Fi connectivity allows for remote monitoring and temperature adjustments via smartphones or tablets. Users can create schedules, set temperature preferences, and receive maintenance alerts, contributing to a more user-friendly experience.

Moreover, these models are designed with robust construction, featuring durable materials that withstand various weather conditions. Their compact footprint and sleek design make them suitable for window installation, while an array of sizes accommodates spaces of different dimensions.

Additionally, the air filtration systems in Friedrich 2008 and 2009 units improve indoor air quality. They effectively capture dust, allergens, and other particulates, ensuring a healthier environment for occupants.

In summary, Friedrich 2008 and 2009 models stand out for their energy efficiency, innovative inverter technology, smart controls, and robust construction. With a focus on user comfort and environmental responsibility, these models provide reliable solutions for effective heating and cooling in diverse applications.
Top Page Image Contents