LG Refrigerator Linear Compressor Amp Draw Test: DIY... | appliancefaults.com

Technical Background:

The LG linear compressor is controlled by an inverter board, which receives commands from the main control board (MCU). The MCU monitors temperature sensors and adjusts the compressor speed to maintain the desired temperature. Voltage is supplied to the inverter board from the main control board (approx 120V AC), which then outputs a variable DC voltage to the compressor. Proper functioning relies on consistent voltage paths and accurate sensor readings.

Symptoms:

The homeowner observes that the refrigerator is not cooling, the compressor is not running or is running erratically, and there may be clicking sounds coming from the compressor area. The unit may display a cooling error or simply fail to maintain temperature.

Possible Causes:

Compressor overload or failure
Inverter board malfunction
Wiring harness damage or loose connections
Main control board (MCU) failure
Refrigerant leak leading to excessive compressor strain

Solution:

1

Disconnect power to the refrigerator at the breaker panel.
2

Locate the compressor in the lower rear of the refrigerator.
3

Using a multimeter, check the compressor windings for continuity. A short or open winding indicates compressor failure.
4

Reconnect power to the refrigerator.
5

Using a clamp meter, measure the compressor amp draw during start-up and while running. Normal running amp draw should be specified on the compressor label, typically around 1-2 amps.
6

If the amp draw is significantly higher than specified, and the compressor is running erratically or not at all, the compressor or inverter board is likely faulty.
7

If the amp draw is zero, check the wiring harness and connections between the inverter board and compressor for continuity and proper voltage (typically 120V AC from the main control board to the inverter, then DC voltage from the inverter to the compressor).

Safety Warning:

Disconnect power to the refrigerator at the breaker panel before performing any electrical tests or repairs. The inverter board operates at high voltage and can pose a shock hazard. Always use proper lockout/tagout (LOTO) procedures.

Prevention:

Regularly clean the condenser coils (located at the back or bottom of the refrigerator) using a vacuum cleaner to remove dust and debris. This improves airflow and reduces compressor strain. Avoid overloading the refrigerator, as this can also strain the compressor.

Expert Tip:

Some LG refrigerators have a service mode that allows you to run compressor tests and view error codes. To access the service mode, simultaneously press and hold the Freezer and Refrigerator temperature buttons for 5 seconds. Consult the service manual for specific test procedures.

Frequently Asked Questions

•What is the typical resistance range I should expect when checking the compressor windings with a multimeter?

Typically, you should see a low resistance reading (a few ohms) between each of the compressor terminals. An open circuit (infinite resistance) or a short circuit (zero resistance) indicates a faulty compressor.

•How can I test the inverter board separately from the compressor?

With power disconnected, inspect the inverter board for any signs of damage, such as burnt components or swollen capacitors. Use your multimeter to check for continuity on the input side of the board (120V AC input) and proper DC voltage output to the compressor when the refrigerator is running. Consult the service manual for specific test points and voltage values.

•Where can I find the service manual for my LG LFXS26973S refrigerator?

You can often find the service manual online by searching for "LG LFXS26973S service manual" or "LG LFXS26973S repair manual". AppliancePartsPros.com and similar sites often have downloadable manuals. Be sure to download the correct manual for your specific model.

LG Refrigerator Linear Compressor Amp Draw Test: DIY Troubleshooting Guide

Technical Background:

Symptoms:

Possible Causes:

Solution:

Safety Warning:

Prevention:

Expert Tip:

Frequently Asked Questions

•What is the typical resistance range I should expect when checking the compressor windings with a multimeter?

•How can I test the inverter board separately from the compressor?

•Where can I find the service manual for my LG LFXS26973S refrigerator?

Related questions

Technical Background:

Symptoms:

Possible Causes:

Solution:

Safety Warning:

Prevention:

Expert Tip: