Although all circuit breakers are saddled with the responsibility of ensuring excess current does not find its way into the electrical circuit, there is a variation in how they operate. If an overload, short circuit, or overcurrent occurs, the electric circuit is at risk. An Arc Fault Circuit Interrupter and a Ground Fault Circuit Interrupter offer protection in different ways. Both set of devices have a test button that makes it possible to verify the operational state of the breaker.

A Ground Fault Circuit Interrupter guides against electric shock that may arise as a result of current electricity leaving the path that was created for it to flow through. Usually, the path provided for the flow of current is a conductor such as a wire or electric cable. Anytime a fault occurs, a Ground Fault Circuit Interrupter steps into action immediately. This explains why GFCI’s are used for wet and moist part of a building such as the bathroom or kitchen.

Conversely, an Arc Fault Circuit Interrupter helps to reduce the effect of arcing. There is a misconception that an Arc Fault Circuit Interrupter can help prevent arcing from occurring. This is not only false, it is also impossible. What an Arc Fault Circuit Interrupter does is to reduce the effect of arcing especially because it is capable of triggering fire. It is okay to refer to an Arc Fault Circuit Interrupter as a fire prevention device. Therefore, an AFCI steps into action anytime it senses a spark. The importance of an Arc Fault Circuit Interrupter cannot be overemphasized. Many of the cases of fire outbreaks are due to overheating caused by electrical arcs. Therefore, it is safe to say that if an Arc Fault Circuit Interrupter was in place, a large number of the fire occurrences that took place in the past would have been averted. The operating principle of an AFCI is very similar to that of a GFCI. However, unlike GFCI’s that are strategically positioned in certain parts of a house, Arc Fault Circuit Interrupters can be used in any part of a house.

Apart from Arc Fault Circuit Interrupters and Ground Fault Circuit Interrupters, there is another category of circuit breaker capable of producing a combined effect. This type of circuit breaker is advantageous because it can prevent an electric shock and reduce arcing. The name for this type of circuit breaker is Dual Function Circuit Interrupter. Apart from the test button, Ground Fault Circuit Interrupters have another button called the reset button. This button provides another level of control to the device. As the name suggests, the reset button ‘resets’ the breaker to its default state after it has been tripped.


Sensors are intelligent devices that are frequently used to detect optical or electrical signals. A sensor converts a physical object or variable to signals that can be measured electrically. Usually, certain factors determine a good sensor: reliability, accuracy, repeatability, range, calibration and resolution. There are many types of Smart Sensors. The University of South-Brittany’s team of scientists at the STICC Research Center has been hard at work at an upgrade for smart sensors used in warehouses and harbours. These particular Smart Sensors are safety devices for fire detection, smoke detection, intruders, hazardous gas and other harmful substances. The sensors had been difficult to maintain as owners had battled with battery problems, issues which developed from harsh environmental conditions, etc. The team at USB made it their goal to remodel the device to suit the warehouse environment and better detect the harmful substances around.

The team set about to create a sort of “self-help” program for the device to be able to detect hardware failure of the wireless sensor node. This node is made up of a processor, RAM, an Interface for Actuator and Sensors (IAS), a Radio Transceiver Module (RTM) and a battery with DC-AC converters. The IAS would interface with the environment while the RTM receives and transmits data. Also within the node is a Power and Availability Manager (PAM) which merges with the FPGA-configurable zone. The PAM is seen to be the best part for use of energy and fault-tolerance while FPGA-configurable zone improves sensor node availability.

The FPGA contains a softcore 8051 CPUwhich is activated when performance-enhancement is needed or is used as a replacement for the main processor. It is also an Actel type IGL00V2 selected especially for its reliability and low power consumption. Other components of the node include a PIC processor, two Oldham OLCT 80 gas detectors, RAM, LM3100, MAX618 power switches, a battery and a Miwi radio transceiver module.

In their explanation, the team said the device possesses a node which identifies the exact point at which something has failed within the device and takes immediate action to correct failure and improve machine efficiency and reliability thus relieving one of maintenance cost.

The new design treats former limitations such as limited processing and storage resources, battery autonomy and the like. Furthermore, we were told the node has in built sensors; one for capturing environmental data and the other for user activation to verify data obtained by the first sensor. It was noted that at the failure of the first sensor, reliability of the device’s reduced drastically and the second sensor was rendered redundant. Nonetheless, one the node disconnects the first sensor instead, the second sensor would be activated for use and machine efficiency would be assured.

In conclusion, researchers and manufacturers are responding to the need for smart sensors the improvements made to the smart sensors are selling them they are now small, cheap, low power and flexible enough to be coveted and exported everywhere. Factories, warehouses, etc. will now use these sensors without worry of internal failure, thanks to the node fitted inside.

How many IoT (Internet of Things) sensors are there?

In the fast paced world we live in today, there is a high demand for increased automation in systems that concern our businesses, industries and everyday life. The Internet of Things also known as IoT devices provides a perfect solution to this problem by its ability to collect, analyse, respond to and transfer or share large amounts of data, all of these often carried out without the need for any form of human interaction or interference.

These devices carry out these functions by means of sensors embedded in them. Sensors are devices that have the ability to detect or measure certain physical properties or conditions in the environment, collect the data present, indicate them, transfer them for additional processing or internally analyse and respond to them. The data collected by these sensors is used to make informed decisions about certain environmental conditions, systems and/or processes and businesses.

The Internet of Things (IoT devices) is a wide range of automated machines and electronic devices integrated for use in our everyday life, businesses, industrial work and so on. As the need for this sort of devices increase, many more sensors are utilized to aid in the collection, analysis and exchange of data.

Types of IoT Sensors

The type of function a device is designed to carry out would determine the type of sensor it utilizes. For optimum effect, some devices consist of more than one sensor. Sensors are designed to be sensitive to physical conditions such as heat, light, pressure, or the presence or absence of specific conditions like gas or water. They have the ability to detect these conditions, measure their magnitude or impact and transfer the data acquired by means of electrical signals. Some commonly used sensors are pressure sensors, proximity sensors, temperature sensors, optical sensors, infrared sensors, level sensors, motion sensors, image sensors, humidity sensors, water quality sensors, chemical sensors, gas sensors, smoke sensors, acceleration sensors and gyroscopic sensors. Below is a general description of each of these sensors as used today.

  1. Pressure Sensors

A pressure sensor is a device that can detect and measure the pressure of a liquid or gas expressed in force per unit area. It transforms  pressure to a form of electrical signal or wave which it indicates and shares. The most types of pressure measured by these sensors are Gauge pressure, Absolute pressure and Differential pressure. 

  • Proximity Sensors

Proximity sensors are used to detect the presence of a nearby object without actually touching it. They do this by emitting a beam of electromagnetic energy or an electromagnetic force field into the surrounding environment and then they detect changes in the beam on its return. The most common types of proximity sensors are capacitive, inductive, photoelectric and ultrasonic proximity sensors.  They are differentiated by the medium through which they detect the presence of nearby objects.

  • Temperature Sensors

Temperature sensors determine the temperature level of an environment or object and convert the data to an electrical signal which can indicate the exact temperature value. They are used widely in agriculture to determine and maintain the right temperature for good crop yield, industrial processes, amongst other functions.

Common examples of temperature sensors are thermometers, thermocouples, thermistors, etc.

  • Optical Sensors

Optical sensors are used to detect the presence of light in an area. They are able to convert light rays into electromagnetic signals that can easily be read and understood. They work in two ways:

  • By sensing the interruption of a beam of light by an object or
  • By sensing the reflection of that beam of light by the object.

Thus, they can also be used to detect the presence of a nearby object. There are three basic types of optical sensors namely Through-beam sensors, Retro-reflective sensors and Diffuse Reflection sensors. Each of these optical sensors works differently and can be applied in different ways. Generally, optical sensors are used in the mining industry and chemical factories and refineries.

  • Infrared (IR) Sensors

Infrared sensors are used to detect and measure the amount of infrared radiation emitted by an object or in an area. Some IR sensors also emit infrared radiation into an environment in order to detect changes in certain environmental or physical conditions. They can be used to detect and measure the heat emitted by an object, detect motion and measure distance, all without having close contact with the object. In the health sector, they are used to determine and analyse the blood flow and blood pressure of patients. They are also used in gas detection, determination of water quality, climatology, night vision, etc.

  • Level Sensors

These are sensors that measure the level or quantity of a liquid or fluid substance in relation to a normal benchmark value, and then convert the data required into a signal that can easily be understood. They are found mostly in automobiles where they are used to provide the driver with information on the quantity or level of fuel in the fuel tank via the fuel gauge. Some vehicles even have indicator lights that go off when the fuel level is very low to alert the driver to the fact that the fuel tank is almost empty.

  • Motion Sensors

Motion sensors are used to detect the movement of a physical object. They are used widely in security systems to alert property owners to any strange movement on their property. They are also used in the automation of devices and appliances such as air conditioning and heating systems, showers, control of doors, etc.

The major types of motion sensors are Ultrasonic motion sensors, Passive Infrared (PIR) motion sensors and Microwave Detection motion sensors.

  • Image Sensors

Image sensors are sensors used to take images that are stored digitally for future processing. They can also detect images stored previously. Image sensors are commonly used in facial recognition systems and are also used to capture licence plate numbers, etc. They can be found in smartphones, licence plate readers and other systems that require high quality imagery and storage.

  • Humidity Sensors

Humidity sensors are used to detect and measure the humidity of air and other gases in an area. The data collected are used in industrial and chemical industries and processes that require controlled environmental or physical conditions.

  1. Water Quality Sensors

Water quality sensors are very important in the control and maintenance of certain factors and parameters that affect the quality of water. This is especially important because water is used for everyday activities like cooking and drinking and other industrial processes, and a change in the quality of the water can create adverse effects.

In determining water quality, these sensors take the following into consideration:

  • Chemical presence or levels
  • Oxygen levels
  • Turbidity
  • Salinity
  • pH level
  • Electrical conductivity, etc.
  1. Chemical Sensors

Chemical sensors are used to detect the presence and quantity of certain chemical substances in a space. They are commonly used in chemical industries and refineries to control leakages and provide good safety conditions for workers.

  1. Gas Sensors

These are similar to chemical sensors highlighted above. They are used to detect the presence of combustible and toxic gases in the air, especially those that cannot be easily detected by man’s ordinary senses. Examples of gases that gas sensors can be used to detect include Carbon monoxide (CO), Hydrogen (H2), Hydrogen Chloride (HCl), Bromine (Br2), Formaldehyde (HCHO), Ozone (O3), Hydrogen Peroxide (H2O2), etc.

  1. Smoke Sensors

Smoke sensors are used to detect the presence of smoke in an environment. They are used commonly in fire alarm systems to prevent and curtail fire outbreaks. The two major types of smoke sensors are the Ionization smoke sensors and the Photoelectric or Optical smoke sensors.

  1. Acceleration Sensors

Acceleration sensors are also known as Accelerometers, and they are used to detect and measure the linear velocity of an object or its change in speed over time. There are several types of acceleration sensors and their application depends on the conditions surrounding the change in the rate of velocity. They are Half-effect acceleration sensors, capacitive acceleration sensors and Piezoelectric acceleration sensors.

  1. Gyroscopic Sensors

Also known as Gyroscopes, these sensors are used to detect the rotation of an object around an axis and measure its angular velocity. They differ from accelerometers by their ability to calculate the velocity of an object in relation to the earth’s gravitational pull. Gyroscopes are used in airplanes and the aviation industry in general.

As stated earlier, these sensors are integral parts of devices used in several areas of life. They contribute significantly to the advancement of automation in the world today.


Identifying a Combination Arc Fault Circuit Interrupter isn’t as straightforward as it seems. This is because of the huge similarities and striking semblance it has with other types of circuit breakers. For instance, looking out for a test button is not enough to conclude on what type of circuit breaker you are looking at. This is because test buttons are not peculiar to Combination Arc Fault Circuit Interrupters only. Conventional Arc Fault Circuit Interrupters that are capable of mitigating arcing in an electrical enclosure also have test buttons. Ground Fault Circuit Interrupters (also called GFCI Circuit Breakers) are not left behind in this regard. So, trying to dichotomize between a Ground Fault Circuit Interrupter (GFCI) and a Combination Arc Fault Circuit Interrupter is actually an uneasy and tricky puzzle to solve.

Some circuit breaker producing companies (such as Siemens, General Electric, Eaton/Cutler Hammer) try to lessen this burden by writing an inscription on the face of the breaker. On reading this label, an individual is able to identify what type of circuit breaker he or she is about to buy. The major problem with this is that more often than not, this inscription is not conspicuous. It is usually written in lower case and it takes a closer look to understand what has been written.

Some companies vary the colour of the test button to make it easier for users to distinguish between a Combination Arc Fault Circuit Interrupter and a Ground Fault Circuit Interrupter (GFCI). One of such companies is Square-D/Homeline. They adopt this method because the outer layer of the breaker is shielded by a metal coating. For a Ground Fault Circuit Interrupter (GFCI), the test button is usually painted in yellow. On the other hand, the test button of an Arc Fault Circuit Interrupter is usually painted in white. For other brands, the convention is to paint the test button in yellow or blue.

The idea of using labels and colour conventions to differentiate between circuit breaker types makes it possible to identify this type of device even at the point of purchase or installation. Another thing is that it helps to avert the dangers that may arise as a result of usage of a particular type of circuit breaker. It is improper to use a Ground Fault Circuit Interrupter (GFCI) in an electrical enclosure that is best suited to an Arc Fault Circuit Interrupter. It is highly consequential and this has increased the need for meticulousness when trying to identify a circuit breaker type.


Primarily, the role of a circuit breaker in an electrical enclosure is to stop the flow of current electricity whenever an overload or short-circuit arises. In other words, protection is the first thing any type of circuit breaker should offer.

There are different categories of circuit breakers and each of them has unique qualities and properties. The categorization of circuit breakers is based on the method of use and operating principles of each device. Basically, we have Standard Circuit breakers, Ground Fault Circuit Interrupters (also called GFCI Circuit Breakers), and Arc Fault Circuit interrupters. However, our focus will be on Arc Fault Circuit Interrupters (AFCI) and its comparative advantage over the Combination Arc Fault Circuit Interrupter (CAFCI).

What is an Arc Fault Circuit Interrupter?

This type of circuit breaker offers effective protection from arcing that may occur in an electrical wiring system. Whenever an arc fault is spotted, the Arc Fault Circuit Interrupter interrupts the passage of electrical energy into the circuit. An Arc Fault Circuit Interrupter can only reduce the effect of arcing; it does not have the capacity and ability to stop arcing. This type of circuit breaker shares a lot of similarity with a Ground Fault Circuit Breaker apart from the presence of a test button. If you use an AFCI, ensure it is tested frequently to confirm the efficiency of the device and keep it in good condition.

What is a Combination Arc Fault Circuit Interrupter?

The Combination Arc Fault Circuit Interrupter is an upgrade on the conventional Arc Fault Circuit Breaker. They are both capable of mitigating the effect of arcing which can cause electrical fire.

Before a Combination Arc Fault Circuit Interrupter was invented, there was really no way of offering both Arc Fault and Ground Fault protection in an electrical enclosure. However, the CAFCI has the ability to protect against both parallel arcing conditions and series arcing conditions. For the avoidance of doubt, series arcing is when there is a chasm in an electrical conductor such as a wire or cable.

Furthermore, a Combination Arc Fault Circuit Interrupter shields feeder wirings and branch circuits. It offers overload protection, short circuit protection, parallel arc protection, series arc protection, and ground protection. To identify a Combination Arc Fault Circuit Interrupter, you may have to look behind the front cover of the panel box. This label isn’t particularly conspicuous because it is written in small letters. Another cool trick is to watch out for a white-colour test button.

All in all, the Combination Arc Fault Circuit Interrupter is a dual function device.

Let’s look at some of the things that can lead to an arc fault.

  1. An arc fault may occur if an electrical wire isn’t properly installed. It is important to avoid piercing and compressing wires when installing an electrical device.
  2. An arc fault may occur when outlets and switches are loosely connected.
  3. An arc fault may occur when a cable is constantly extended or stretched beyond its original length.
  4. Heat and a constantly increasing temperature can lead to an arc fault.

Quick review of Sensors used in the Internet of Things and their Application

The Internet of Things also known as IoT Devices refers simply to a range of devices that can collect, analyse and transfer data. They carry out these functions by means of unique sensors embedded inside them. They include alarm clocks, smart phones, fire alarm systems, etc., and their application cuts across different sectors – health, transport, home living, sports, agriculture, safety and environment, etc.

One of the major things responsible for their ability to carry out these functions is the sensor embedded in them. The type of function to be carried out determines the type of sensor found in a device. For instance, a device such as a camera would possess an optical sensor which would help it convert the light rays it receives into a high quality image.

Knowing and understanding these sensors and their uses or applications would help you to know how best to maximize their potentials in your use of IoT devices. Some common sensors used in IoT devices include gas sensors, proximity sensors, temperature sensors, optical sensors, pressure sensors, smoke sensors, infrared (IR) sensors, and accelerometer and gyroscope sensors and so on.

  1. Gas Sensors – Gas sensors or detectors are used to detect changes in the gaseous state of an environment. They can also be used to detect and measure the presence of certain gases in an area. They are used mostly in health and safety systems. For instance, a carbon monoxide gas detector can be used to detect the presence and quantity of carbon monoxide which is not easily detectable by man and is very dangerous and injurious to health. Gas detectors can be embedded in smartphones, ventilation systems, etc.
  2. Proximity Sensors – Proximity sensors help you verify the presence of physical matter without having any physical contact with them. They are found mostly in smartphones and other mobile devices, cars (parking sensors), conveyor systems, rollercoasters, etc. Some very common types of proximity sensors are capacitive sensor, magnetic sensor, inductive sensor, ultrasonic sensor, Doppler Effect sensor and the fibre optics sensor. In smartphones, they can detect when someone’s body or face is close to the phone while in cars, there are very useful while reversing or navigating areas with other vehicles around.
  3. Temperature Sensors – These are sensors used to measure and detect changes in temperature and then convert the data to electronic signals. They are used frequently in safety and environmental systems, agriculture and industrial systems. An instance of the application of the temperature sensor is its use in detecting soil temperature. The data collected is used to maximise crop yield and production. Common examples of temperature sensors are thermocouples and thermopiles, thermometers, NTC thermistors, Resistance Temperature Detectors (RTDs) and the commonly used DHT 11 which also doubles as a humidity sensor.
  4. Optical Sensors – Optical sensors are used to convert light rays into electronic signals that are readable and easy to understand. In cameras, they convert light rays to images. They also commonly found in computers, Xerox machines, alarm systems and other systems that can detect the presence of nearby objects using the light rays captures by the optical sensors embedded in them. They are commonly used in the mining industry, and chemical factories and refineries.
  5. Pressure Sensors – A pressure sensor is used to detect and measure the pressure or force applied per unit area and then converts the data collected to electronic signals. Pressure sensors are commonly used in environmental and safety systems. They are useful in weather forecasting systems and tools used to measure pressure in case of leakages in water systems.
  6. Smoke Sensors – A smoke sensor detects and measures the quantity of smoke in an area. In recent times, manufactures have added a voice alarm system which can be connected to a smartphone or other home safety systems such as a fire alarm system or smoke alarm. There are two basic types of smoke sensors; the ionization smoke detector which uses radioisotopes to ionize the air and detect differences in air quality, and the photoelectric or optical smoke detector which makes use of the principle of scattering light. They are used primarily to detect and curtail fire outbreaks. The photoelectric smoke sensors are generally considered to be more responsive than the ionization smoke sensors. Some alarm systems even come with a combination of the two for optimum effect.
  7. IR Sensors – Infrared sensors are sensors that emit infrared radiation into an environment in order to detect and measure changes in certain environmental parameters. They are used to measure the heat emitted by an object and also to detect motion and measure distance. Infrared sensors can be active or passive. Apart from their industrial uses, infrared sensors are used by common home appliances like the Television which interprets signals sent from a remote control by using an infrared sensor or detector. Their other applications areas include night vision systems, flame monitoring, infrared tracking, art history and restoration, climatology and meteorology, gas detection, water analysis amongst other areas.
  8. Accelerometer and Gyroscope Sensors – These sensors are used to determine the position and orientation of an object. The accelerometer is used to detect and measure linear acceleration while the gyroscope is used to determine the orientation or angular position of an object. Even though they perform different functions, they can produce a large amount of information when combined together in one device.

The major difference between an accelerometer and a gyroscope is that the accelerometer can only measure the acceleration of an object in relation to the earth’s surface. Once there is acceleration due to gravity, it cannot differentiate between this and linear acceleration. Thus, it loses its effectiveness. The gyroscope, on the other hand, is best for such situations.

Accelerometers are used widely in the transport system, engineering, hardware monitoring, navigation, amongst other areas and systems. They are also commonly found in smartphones and are used to detect the orientation of the phone. Gyroscopes are used widely in the aviation industry and the use of drones. Depending on the sort of information required, both sensors can be used separately or combined in a single device.


Also referred to as distribution board, an electrical panelboard is used to distribute electrical energy to various parts of a residential or commercial facility. Its role in an electrical distribution system is very similar to that of a router in a typical networking system. Basically, it divides electrical power into different branches so that every part of the house can be powered by electrical energy. Every branch has a fuse or circuit that offers protection from overload, over-current, and short-circuit. It is impossible to access a panelboard from the back this is basically they are usually mounted to the wall. In addition, there will be no control over the light and power circuits in a facility if a panelboard is not installed. Panelboards

Is there any difference between a panelboard and a switchboard?

The role played by a switchboard and a panelboard in a power distribution system are very similar. The major difference is in the way they are mounted or positioned. While panelboards are typically mounted on a surface, switchboards are capable of standing in an erect position. A panelboard can permit up to 1200A of electric current while a switchboard may only permit up to 5000A of current electricity.

Is there a difference between a loadcenter and a panelboard?

The similarity in functionality between a panelboard and loadcenter is so much that it is very difficult to dichotomize between them. In some part of the world, people refer to a smaller version of a panelboard as a loadcenter. A loadcenter is not designed to accept all types of circuit breakers. If it is not a plug-in breaker, it cannot be used on a panelboard. On the other hand, a panelboard can accept different types of circuit breakers whether it is a plug-in circuit breaker or bolt-on circuit breaker. As said earlier, panelboards can accept electric current up to 1200A. This magnitude of current is too much for a loadcenter to handle and as such, loadcenters are usually limited to a maximum current of 400A.

Is there a difference between lighting and appliance panelboard and a power panelboard?

While the lighting and appliance panelboard consists mainly of single-phase load, the power panelboard consists of three-phase loads irrespective of how it is connected.

What are General Purpose Panelboards?

A general purpose panelboard is a panelboard that offers more flexibility in its method of use. This type of panelboard is not restricted to a particular pattern of application. There are different types of special purpose panelboards.

  1. Branch circuit monitoring panelboard: This type of general purpose dashboard monitors the magnitude of incoming electrical power and that of all branches. It is used in commercial facilities to determine the amount to be paid by tenants or occupants of each room based on the number of load they have. It is also used in industries and data centres.
  • Column width panelboards: This type of general purpose panelboard is used in many warehouses. It has a good design that makes it fit between support columns. The dimension of a conventional column width panel board is 8.63’’ X 6.0’’. However, the value of the height may vary between 69” and 90”.
  • Fusible lighting panelboard: This one is used in industries and commercial places where abnormal current is very prevalent.
  • Lighting control panelboards: This is a multipurpose panelboard. It has the ability to provide protection from over-current. It is used when there is a need to ensure strict compliance to local energy codes.
  • Elevator control panelboards: This one has the ability to house a standard fire alarm system, an elevator control mechanism, and power distribution system. It can control and distribute electrical power to up to four different elevators at a time.

Also, there is another category of panelboard referred to as hazardous rated panelboards. This type of panelboard is designed for use in a locality where the atmospheric and environmental conditions are not great. If you reside in a place where vapour and dust is prevalent, the hazardous rated panelboard may be the best bet. Before investing in this type of panelboard, you must consider factors like the voltage rating and short-circuit rating. Hazardous rated panelboards are further subdivided into two. There is the factory sealed type and the non-factory sealed type.

Factors to consider before choosing a panelboard

Before choosing a panelboard, make sure you consider the following:

  1. The maximum amount of current that each branch circuit or feeder device permits.
  2. Voltage rating of the panelboard.
  3. The current rating of the mains.
  4. The short-circuit rating that is desired.

What makes up a panelboard enclosure?

A panelboard has three distinct components – the five-sided enclosure, chassis or inner part, as well as the trims.

The enclosure: This is the outer cover. It has a box shape. This is the part that is mounted to the wall and it is made from galvanized steel.

The chassis: This is usually joined to the main box by means of a screw. Also called the interior, it holds the circuits and fuses.

The trims: This is also called the front because it provides access to the main part of the panel board. It is usually a door that can be opened and close based on what is to be done. The trims or front usually has a lock that helps to prevent unauthorized access to the panelboard.

Apart from the aforementioned parts, a panelboard also has a filler plate which helps to cover or shield any space within the device that is not yet in use. In addition, all panelboards have a label that tells us more about the electrification specification and rating of the device. This gives the user of what to do and what not to do with the panelboard.

 The installation of a panelboard should be done by an expert. However, if you feel confident and know how to go about it, there is no problem. Otherwise, reach out to a certified electrical engineer.


What is a miniature circuit breaker and what does it do?

A miniature circuit breaker is an electromagnetic device that offers prevention and protection from current overflow. When it senses an overload or a magnitude of current that is beyond normal, it acts to automatically turn off the circuit or electrical enclosure. Before now, people use fuses a lot. However, due to a perceived inefficiency and a lack of cover from electrical faults and shocks, miniature circuit breakers have taken over.

A miniature circuit breaker opens when there is an overload or when the current exceeds the set threshold. However, it is designed to return to its default state automatically when the magnitude of current electricity normalizes. This is a major advantage as there are a few other circuit breakers that require manual reset. Typically, miniature circuit breakers have a low current rating.

How does a miniature circuit breaker work?

Just like a thermal circuit breaker, miniature circuit breakers use the principle of temperature difference in their operation. A typical miniature circuit breaker has a bimetallic strip. We know that constant flow of current brings about a rise in temperature of an electrical conductor. When excess current passes through, massive heat is generated and this raises the temperature of the bimetallic strip. As a consequence, the bimetallic strip will deflect to control a metal bar connected to it. It is the movement of this metal bar that brings about the opening and closing of the miniature circuit breaker for current control. This means that a miniature circuit breaker takes advantage of the thermal effect and properties of current electricity. This simple explanation is what guarantees the protection of your electronic appliances from faults that may be caused by unusual current delivery or power surge.

Usually, when a miniature circuit breaker develops a fault, it is replaced. This means it is a maintenance-free device. Its design is simple and sturdy and its case is usually moulded.

 It is not common to see people trying to repair a miniature circuit breaker. Miniature circuit breakers can be divided into Type B, Type C, and Type D based on the magnitude of electric current they are able to permit. While the Type B miniature circuit breaker is suitable for resistive inductive loads, the Type D is ideal for load with high inductive capability. The Type C miniature circuit breaker is in the middle because it is able to handle loads with a moderate inductive capacity.  Let’s take a look at some constructional parts of a miniature circuit breaker.

  1. The Frame: This is the outer shield of the miniature circuit breaker and it is usually a moulded component. It is strong, sturdy, firm, and rigid because it houses and covers other parts of the miniature circuit breaker.
  2. The trip unit: This is the part that acts when there is an upsurge in the magnitude of current electricity. This is the heart of the miniature circuit breaker, the main part. The major constituents of the trip unit are the bimetallic strip and electromagnet with each of them having a role to play.The bimetallic strip offers protection from excess current while the electromagnet takes care of short-circuits.

Let us take a more detailed look at the types of miniature circuit breakers we outlined earlier.

  1. Type B miniature circuit breaker: This type of circuit breaker is best suited for domestic use. It can also be used in commercial places if the load is not too much. The type B miniature circuit breaker has a tolerance of three times to five times its standard current rating and it is not ideal for massive loads as in an industrial setting.
  2. Type C miniature circuit breaker: The Type C miniature circuit breaker is an upgrade on the Type B miniature circuit breaker. While the Type B has allows electric current three times to five times its default rating to flow through it, the Type C has a tolerance of fives times to ten times which is an appreciable upgrade. One common area of application of a Type C miniature circuit breaker is in fluorescent lighting. This type of miniature circuit breaker can comfortable handle load with a moderate inductive capacity.
  3. Type D miniature circuit breaker: When the rate of flow of electric charges is very high, the Type D miniature circuit breaker is the most ideal. It has a minimum trip current rating of 10Ir and a maximum trip current rating of 20Ir. It is best suited for load with high inductive capability. In industries and production factories, this type of miniature circuit breaker is common. Equipments such as x-ray machines, welding machines, and UPS systems are typical examples of areas of application of Type D miniature circuit breakers.

How do I select the right miniature circuit breaker?

Selecting the appropriate miniature circuit breaker for a specific application requires carefulness and deliberateness. If not carefully done, the final aim of protection from abnormal current delivery will be compromised. Asides that, if the chosen circuit breaker is not equivalent to the requirement of the electrical enclosure or circuit, irregular tripping will occur.  

Furthermore, it is important to use the right type of miniature circuit breaker for the right purpose. For instance, using a Type B miniature circuit breaker for heavy duty equipments or an industrial purpose is highly inappropriate. In the same vein, it isn’t proper to use a Type D miniature circuit breaker for domestic or residential purposes since only small inductive loads are involved. It is also important to note the current carrying capacity of a circuit, wiring system, or electrical enclosure. Under no circumstance should the current rating of a miniature circuit breaker be greater than the maximum permissible current in a wiring system when it is not at full load. However, when all electrical appliances are fully operational and the wiring system is at full load, it is okay if the current rating of the miniature circuit breaker is higher or exactly equal in magnitude.


Why do I need a circuit breaker?

Electric shock and fire can happen anywhere and anytime. Home, office, bank, or cinema, electric shocks and fire can be triggered if the appropriate measures are not put in place. Electric appliances and equipment can expose you to electric hazard.

The damages caused are sometimes massive and irreversible especially when a part of the human body is affected. Some persons have suffered injuries and burns from electrical faults and these injuries will live with them for the rest of their lives. By simply investing in a circuit breaker, this situation can be arrested and effectively prevented. Just so you know, a circuit breaker is an electronic safety device. It is placed in an electrical circuit to control and manage the flow of electric current whenever an overload or a short-circuit occurs. It also helps to regulate the temperature of electronic appliances especially when it is rising continuously. In such scenario, the circuit breaker will automatically discontinue the flow of current through the circuit or electrical enclosure.

It is nearly impossible to do without the protection offered by circuit breakers in the world that we live in today especially if you consider that there are electronic appliances everywhere. Asides protecting these appliances from damage, a circuit breaker shield you and your family from electrical exposure that may arise from improper grounding, damaged insulation, voltage fluctuations, faulty wiring, and sort-circuit.

How long should a circuit breaker last?

The answer to this question is relative and it depends on a host of other factors like frequency of use, environmental factors and maintenance. However, it is estimated that under ideal conditions, a circuit breaker should serve for more than thirty years. It is advised that you replace any circuit breaker that has lasted for this long amount of time regardless of their working condition. Therefore, if a circuit breaker has served for up to forty years and it is still functional, make sure you change it so that your family can benefit from renewed protection from electric shock, and fire.

Climate and prevailing environmental conditions have an effect on the lifespan of a circuit breaker. For instance, exposure to chemicals and moisture can lead to a reduction in the lifespan of a circuit breaker due to corrosion and rust. On the other hand, when a circuit breaker is used under moderate and dry weather conditions, it will last longer. This explains why a circuit breaker that is used indoors tends to develop less faults than one used in an outdoor location.

Just as human beings benefit from physical exercise, a circuit breaker also does. To prolong the lifespan of a breaker and to make it more durable, make sure you flip the switch between the on and off position from time to time. By doing this, stiffness and hardness of the switch can be avoided.

What affects the lifespan of a circuit breaker?

So many things have an effect on how well a circuit breaker performs and how long it lasts for. Let’s discuss a few of them.

  1. Environmental factors: Temperature is a major determinant of how long a circuit breaker. When a circuit breaker is placed under harsh atmospheric conditions, its lifespan is shortened. Also, exposure to certain chemicals such as sulphur hexafluoride have a huge impact on how well a circuit breaker performs and how long it will last. It is also important to note that circuit breakers perform better when they are not exposed to fluid or moisture.
  2. Maintenance: They say prevention is better than cure. In similar fashion, it is less stressful to maintain a circuit breaker than to repair a faulty one. From time to time, make sure you inspect the breaker and lookout for defective parts. If any fault is spotted, ensure it is fixed and the part replaced before it becomes a big deal. There is enough evidence to support the fact that devices and electrical appliances last longer when little things are addressed quickly and timely. This principle applies to thermal circuit breakers, standard circuit breakers, hydraulic circuit breakers, magnetic circuit breakers, and all other types of circuit breakers that exist today.
  3. Frequency of use and amount of breaking current: When a device is used often, wear and tear is inevitable. The same can be said of a circuit breaker. The magnitude of current it handles has a huge bearing on its lifespan. Although, its primary role in an electrical circuit is to disrupt the flow of current electricity when there is a short-circuit or an overload, the device may develop a fault or drop in efficiency if this happens too often. This is not unusual especially if you consider the fact that human beings are subject to fatigue when they are overworked or put through their paces. The higher the amount of faulty currents they handle, the more circuit breakers are worked, and the more they are exposed to mechanical failure (since they are electromechanical devices). This applies to all types of circuit breakers.


Circuit breakers must be cared for because of the vital roles they play in securing the lives of human beings and electrical gadgets. Although, they have different operating principles, every type of circuit breaker essentially does the same thing and this explains why there is so much similarity in the way they are maintained. Regardless of the circuit breaker type, poor performance and a short lifespan is inevitable if they are exposed to harsh conditions are badly used/maintained.

As said ab initio, circuit breakers should last for a long time (thirty years to forty years is the estimated range). In fact, some people only have to buy this electromechanical device once in their lifetime as long as it is well utilized.


What is a starter motor?

The only way to kick an engine into gear is through a starting system. The starting system is essentially a combination of different parts aimed at setting a vehicle in motion. One integral part of a starting system is the starter motor. A starter motor is known by other names. It is also called a self-starter or an electric starter motor. Some people also refer to it as a cranking motor. The importance of a starter motor in an automobile cannot be overflogged. If it develops a fault or it is completely absent, it is literally impossible to move a car. Caring for your starter motor means caring for the life and health of your car. Without a starter motor, no internal combustion engine can be ignited.

The other components of a starting/ignition system are the battery, safety switch, cables, ring gear, and ignition switch. Electric starter motors have become very popular among vehicle manufacturers. Before now, manual starter motors were the most popular. However, due to its inefficiencies and the fact that it posed a huge accident-risk, it had to give way. With an electric starter motor, the need for manual cranking is eliminated.

The major components of an electric starter motor are the pinion drive (which is placed on top of the shaft), starter solenoid, and electric motor.

How does a starter motor work?

Without a starter motor, it becomes difficult to crank up an internal combustion engine. To crank up the engine of a vehicle, a starter motor collaborates with the battery and starter solenoid which is responsible for shutting the circuit when electric current flows through the motor. The starter solenoid is also responsible for the transmission of kinetic energy from starter motor to the flywheel.

When a vehicle is ignited, it is the starter relay that first gets activated through current emanating from the battery. The starter relay is responsible for conveying current with higher magnitude to the starter solenoid. The starter solenoid then plays its part as explained earlier. It is after this that the motor will begin to rotate.

After the flywheel receives enough energy from the starter motor, it spins at a very great speed and triggers the engine to start. All these steps occur within a very short time frame, usually within few seconds.

A brief overview of the parts of a starting system

Battery: The battery is the primary source of electrical energy in a vehicle. It can be recharged. Most cars run on a 12V battery.

Ignition Switch: The ignition switch is like a router. Without it, the electrical energy supplied by the battery cannot be distributed to the necessary parts. The ignition switch must be in the START position before the starting system can be activated. Without putting on the ignition switch, there will be no flow of electric current.

Neutral safety switch: It is only found in an automatic transmission system. Its counterpart in a manual transmission system is the clutch switch. The neutral safety switch ensures there is no flow of current unless the gear is in the neutral or park state.

Starter solenoid: It provides the energy required to set the pinion gear in motion. The solenoid is made up of a combination of wires which it uses to induce a magnetic field. It also houses two coils – the pull-in coil and hold-in coil. The primary role of the hold-in coil is to regulate the movement of the pull-in coil while it applies considerable force to the solenoid plunger.

Types of starters

There are different types of starter motors and the classification is based on how they are driven. While some are electrically powered, others are manually or mechanically powered. We also have starter motors that are powered by air and hydraulics.

  1. Electrical starter systems: They are very easy and convenient to use and they offer a lot of comparative advantages. Almost all cars manufactured in recent years make use of electrical starter motors. With an electric starter motor, there is no need for cranking up an engine manually. All that is required is the supply of electric current from a primary source (usually a battery) and the car engine will be set in motion upon rotation of the flywheel.
  2. Fuel starter systems: In this type of starting system, the force required to activate the engine of the vehicle is derived from the movement of the pistons. Usually, the fuel starting system is used in large engines or engines that have up to fourteen cylinders.
  3. Pneumatic starter systems: The components of a pneumatic starter system are rotating turbines, compressor pump, and pressure tank and it is driven by compressed air. It is the force of compressed air after it is discharged from the steel pressure tank that is used to set the rotating turbine in motion. In turn, the rotating turbine sets the flywheel in motion since they are connected by reduction gears. There is a lot of similarity between this type of starter motor and the electric starter motor. The major thing about pneumatic starter motors is that they are mostly used in diesel engines such as trucks, and ships. The design of a pneumatic starter motor is not complicated and it offers a high degree of reliability.

How do I troubleshoot a starter motor?

It is not uncommon for a starter motor to have problems or develop a fault. Having an idea of what to do and how to troubleshoot would be very useful in such situations. Let’s discuss some key moves that you could make when you need to fix such problems.

  1. Try to find out what the problem is. It is not rocket science. No starter motor will pack-up completely without giving any previous signs.
  2. Remove the starter and disassemble it. Inspect the parts and check if it is something you can handle. If you can’t handle it, reach out to an expert.