Understanding air conditioning: Knowledge of AC PCB

Table of Contents

PCB stands for “printed circuit board”. Its layout is similar to computer’s motherboard.

The green board we generally see with some wires soldiered is PCB actually we can find it on old TV, Radio or every electronic devices has preinstalled PCB board that connects all the semi conducting devices and other devices like PCB resistors, transistors and diodes, speakers etc.

We can find AC PCB in air conditioners that supports multiple operations.

What does AC PCB mean?

It is a green board that performs the wiring for different components mounted in it. Different component include transistors, capacitors, resistors, etc. The conductive track is present there that combines different components after assembly on the board.

They are made with a layer of copper and masked with a fiberglass silkscreen. Made with the layer of copper they are generally covered with fiberglass silkscreen.

A AC PCB is designed to add many components in a board in order to perform data communication also controlling the output of an AC.

There are connections between various components called as conductive track. AC PCB are usually made with a layer of copper and is masked with fiberglass silkscreen. Its main function includes allowing components to get connected in a cheaper and easier way to perform their specific operations jointly.

In air conditioning device we can find air conditioner Printed circuit board (AC PCB).

PCB are the most important part of airconditioner. PCB can control many settings like compressor on or off, temp. 

PCB are divided into two parts first display pcb and other power pcb. Display pcb shows the temp. On display, fan speed, timer settings. Power pcb operate the AC compressor with the using the Relay. Both pcb are fix- display pcb located of AC grill.

And power pcb back the display pcb. PCB can control the all things of air conditioner.


How many kinds of PCB are there?

The different types of PCBs commonly available are

What is AC PCB design?

PCB designing for air conditioner:

As the picture shows, the air conditioner collects hot air from the space it is located in and transfers the collected air to its interior with the help of refrigerants. The designing of a board for air conditioning system with assembly of several components like capacitor, relay, resistors etc is called AC PCB design.

After we turn on the air conditioner and set the desired temperature, the room temperature sensor in the air conditioner can sense the indoor air temperature and adjust to the temperature we set.The AC PCB can control the all settings like compressor on or off, & temp Change.

Hot air enters through the grille, and the refrigerant flows through the coil. There’s a refrigerant liquid.Refrigerant liquid is present there that helps to absorb the heat and it then becomes a hot gas itself.

The evaporator coil basically not only absorbs heat, but also filters moisture out of the air, which helps to remove moisture from the room.It is specially designed by including different components to:

◐perform the data communication
◐a specific command
◐or allows calculation of the output
for controlling the AC.

This is how AC PCB does supports in cooling warm air.

What are the uses of AC PCB?

(i)It joins all the conductors or semiconductor components.

(ii)It helps in dividing the complex circuit into a one common board.

(iii)It helps in preventing damage to motors and other components as it cause the device to be made of desired size.

(iv)AC PCB helps in controlling of different settings like compressor on or off, & temp Change.

(v)The commonly used High-frequency AC PCB boards can withstand diffrent cycles without being subjected to any strain

What is the role of PCB in AC?

Role of PCB in AC

(i)PCB use different components to communicate data, execute specific commands, or control air conditioning by calculating output.

(ii)Pcb are control to the all of settings like compressor on or off, & temp Change.

(iii)Parts on those PCBs can be small digital microchips to follow the rules and light the displays, larger semiconductors, possibly a mechanical relay and other higher power control devices.

(iv)Different cycles can be handled without being vulnerable to any effects and damage by the help of PCB’s.

What causes PCB failure in AC?


Defects are the primary cause of PCB failure. Often, defects occur during the PCB assembly process.
Defects can cause PCB failure. Often, defects can occur during manugacturing or during the industrial assembly too of different components.

They are sensitive to Electrostatic Discharge and, component defect can take place because of smallest discharge.

Some other defects can be:
◐Misalignment of the layers
◐Short circuits & Crossed signals

(ii) Burned components:

Component burning one of major cause of PCB defect, it is one of major reason for failure of PCB. Burned components can cause whole system function to halt and can lead to system damage or burning of whole AC system and thus lead to the loss of property.

(iii) inappropriate spacing of components:

If the components on the circuit are too close together, it may cause heat and affect the performance of different parts. So the best way to avoid heat-related defects is to design the PCB with the best amount of space.

(iv) External factors:

PCB board is very sensitive and can be affected by external factors. If exposed to excessive temperature and humidity, PCB boards will expand and warp, causing potential damage to welded joints. In order to protect the PCB from the external environment, PCB manufacturing should be carried out in a mild climate area.

Foreign sources debris collected there may cause harm and different issues.

i.Problems related to soldering:

For PCB design solder is most essential process and it is compulsory to build a board with best functioning of components and vital for assembly process ultimately. It maintains the contact between a component and circuit, but it may frequently become contaminated.

Thus, board failure may take place. Too much moisture in the solder, causes to solder joints to becomes very conductive and then it causes over power delivery leading short circuiting.

It can cause harm in AC PCB boards if not looked into thus moisture should be avoided nearby the boards.

ii.human error:

Human resource involved in the design process can make mistakes during the processes. There are many assemblers who are involved in the production cycle. So it is clear that human error plays a great role in PCB quality improving as well as PCB failures. Some common causes related with human error are:

◐Misreading schematics
◐Incorrectly installing components
◐Placing the traces nearby or close, so it may cause a short there
◐Poor soldering


PCBs can age more as human beings do. As they become older per day, they may be suffering break down or become much defective.
Components generally don’t work properly after a certain point of time is reached so they require a replacement.

The soldering of pcb

How do I know if AC PCB is working?

The conditions occur from which we can get gesture of PCB failure and whether it is working some of examples of such conditions are:

◐Motor Running Capacitor performance can justify its working:

The Fan Capacitor is responsible for the operation of the fan motor. If the capacitor is broken, the fan will not start or operate slowly, and cannot be cooled. It will also lead to overheating of other parts and damage of air conditioning devices.

◐Failure of compressor (turning OFF) :

In this case, the room temperature sensor is in contact with the coil, and the coil is much colder than in the room. Therefore, when the obtained readings are transmitted to the microcontroller, it thinks that the room is cool enough and then turns off the compressor.

◐The Start Capacitor that is inside the Outdoor unit blows off:

The starting of the capacitor caused by the start capacitor and that is generally burnt up. It may cause the compressor unable to start and thus hot gas cannot cool down. The AC cannot cool therefore and this may lead to possible damages.

How to resolve the PCB failure?

Resolving PCB failure includes different vital methods to be followed.

PCBs are made according to designer’s specifications and suggestions from engineering experts. But, errors can occur during the construction process, or accidents may be happened that may cause physical loss along the way that render them faulty.

In such cases, it is sometimes essential to repair faulty board.

PCB are manufactured according to designer specifications. However, error can occur during the construction process too or accidents may happen proving them as faulty. In either case, it is necessary to repair a manufacturing board and performing any other maintenance is also nearly impossible.

The various steps include:
◐Inspection with a microscope
◐Troubleshooting of specific parts
◐Testing their different functions

◐Testing components
◐Regular cleaning of air conditioner
◐Avoiding moisture and humid areas
◐Using voltage protection and UPS systems

Most of commonly available electrical boards, use the name “printed circuit board” or “PCB” in abbreviated form. In previous decades, PCBs were developed by a complex process that consists of specific points detailed wiring.

During the process, the circuits left exposed and were very vulnerable to damage. The best method was with development of much safe, and advanced design methods that the process so it has reached the standards of security that are being used in PCB design and development nowadays.

Components present commonly in modern day boards are:
◐fiberglass substrate,
◐solder mask

In the earlier years , PCBs were comprised of one layer. But, commonly used PCBs usually usually have multiple layers, which are used in accommodating and meeting today’s requirements with the complex circuitry.

Troubleshooting The Old PCBs
Techniques followed for troubleshooting older one PCB’s:

◐Review of solder joints
◐Identifying of the related problem with the board
◐Inspecting the integrated circuits and connected motors properly
◐Inspection of the semi conductors
◐Cleaning the doubted portions and soldiered points

◐Checking the conductivity and power input supply

Whether PCB can be repaired?

Repairing of faulty PCB is complex and a technician commonly available are usually unable to fix this so tests are also not enough in order to troubleshoot the different issues occurring and found in newly Printed boards.

So, in response to these challenges PCB receives complex analysis in order to tackle the problem.

In the modern PCBs, different high-pitch parts may have been included but have not been identified on the boards.

The methods required to troubleshoot modern days, commonly available common PCB is much complicated, On circuit boards used in the previous decades the repair could be done with testing tools automated, but it doesn’t works on today used Printed Circuit Boards which are highly advanced.

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