Let’s take a look at the Thermocouple Attachment Process. This video will be useful for RnD members in the HVAC field, and especially for new employees.
There are various types of thermocouples such as T, J, E and K. LG uses the T-type thermocouple.
The purpose of the thermocouple is to accurately read the temperature of major cycle points. It is extremely important to be meticulous throughout the entire process, starting from preparation to the attachment stages.
Errors that occur during the preparation or attachment process can lead to inaccurate readings of the temperature within the major cycle points, resulting in incorrect data.

The Thermocouple consists of copper and aluminum wires that are covered to protect from any entanglement.

The copper and aluminum wire are used to read the temperature of the device. Due to the different characteristics of the metals, make sure to twist the two wires together for accurate results.

The sheath made in the shape of a circle widens the contact area with different metals such as pipes, making it harder for the thermocouple to loosen. When pulled, it serves as a buffering to minimize the twisted part from deviating from the cycle point.

When the copper and aluminum wires get twisted, it could potentially cause the wires to fall apart from the temperature measuring device and most likely cause inaccurate results. When the sheaths are fully removed, possible entanglement could occur, causing unintended contact between the wire and the pipe to happen. This could potentially lead to incorrect data.

Place the thermocouple on the cycle point to be measured. Wrap the aluminum tape tightly. Wrapping the pipe with aluminum tape is one way to ensure accurate reading of the temperature.

Wrap another layer of tape tightly around the aluminum tape. Wrapping the tape increases adhesive strength and protects the aluminum tape from damage.
Tightly bind the cable tie on the bottom. This is to ensure a tight fit of the thermocouple and the tapes that may otherwise loosen easily.

After attaching the thermocouple in the same way as the straight pipes, bind them together with cable ties. Repeat the process twice.

Bended pipes have limited space, thus making it difficult to attach the thermocouple and come into contact. To avoid such difficulties, cable ties should be used to improve contact between the two materials.
When binding the two materials with a single cable tie, the twisted wire can break easily when the thermocouple is pulled.

By adding another cable tie, damage and relocation of thermocouple can be prevented.

The entrance can be easily checked through the distributor of the high-pressure pipe. Number location in a way that is easy to remember regardless of its location top/bottom. Check the course of each path and number the OUTs according to its INs.
*Double-check the path (i.e.: In 1 - Out 1).

The mid point is generally located in the center of the INs and OUTs. There are some products that are in the shape of return bends where the center is not located in the middle. In this case, find an agree upon location with your team and designate a number for that location.
It is recommended to attach the thermocouple on the inside of the unit pipe sensor.

**When necessary, attach thermocouple on the outside unit fan motor, even if it is not a cycle point.

1) Attachment Location : Discharge Pipe, Compressor Top/Body
Purpose : Check OLP (compressor overload protector) operation range and Motor winding temperature.
2) Attachment Location : Compressor Bottom
Purpose : Initial judgment on inflow of liquid refrigerant according to the condenser middle’s temperature and delta T management standards.

Check the INs according to the path of the discharge pipe for the condenser path, and mark accordingly IN - MID – OUT.

The number of INs and OUTs of the path can be the same. There are instances where they are not. In such case, check the intersection point or joining points of the path.
*Example : Starts with 2nd IN and goes out through the 2 OUTs, which are then joined to create the Subcool IN.