Aircraft engines take advantage of different types of fuel induction systems as per an aircraft’s needs. Within small aircraft engines in particular, there are two main types of induction systems, those of which include the carburetor system and the fuel injection system. Today, we will be outlining how fuel induction systems bring in outside air, mix it with fuel, and deliver an optimal fuel-air mixture to the engine cylinders, as well as provide a brief overview of carburetor and fuel injection systems.
Carburetor System
There are two primary types of carburetors, those of which are classified as either float type or pressure type carburetors. The float type is equipped with idling, accelerating, mixture control, idle cutoff, and power enrichment systems, which make it the most convenient option. Meanwhile, pressure type carburetors are not as common and are usually only found in larger aircraft. The main difference between both types of carburetors is the method they utilize to deliver fuel. For instance, pressure type carburetors deliver fuel by harnessing the pressure of a fuel pump.
Within a float type carburetor system, the outside air first flows through an air filter that is located at an air intake in the front part of the engine cowling. This filtered air makes its way into the carburetor and through a venturi, a narrow throat in the carburetor. As the air flows through the venturi, a low-pressure area is created which forces the fuel to flow through a main fuel jet located at the venturi. At this point, the fuel flows into the airstream where it is mixed with flowing air.
The fuel-air mixture is then sucked into the intake manifold and into the combustion chambers where it is ignited. Moreover, the float type carburetor gets its name from a float that rests on top of the fuel within the float chamber. A needle attached to the float opens and closes an opening at the bottom of the carburetor bowl. This measures the proper quantity of fuel in the carburetor. The flow of the fuel-air mixture to the combustion chambers, on the other hand, is regulated by the throttle valve.
A major advantage of float type carburetors is its icing tendency. Since the float type carburetor must discharge fuel at a point of low pressure, the discharge nozzle must be positioned at the venturi, and the throttle valve must be on the engine side of the discharge nozzle. Keep in mind that any drop in temperature due to fuel vaporization takes place within the venturi. As such, ice quickly forms in the venturi and on the throttle valve. If water vapor in the air condenses when the carburetor temperature is near below freezing, ice will form on internal surfaces of the carburetor, including the throttle valve.
Fuel Injection System
In a fuel injection system, fuel is directly injected into the cylinders, or just ahead of the intake valve. The air intake for the fuel injection system is similar to that of a carburetor system, wherein an alternate air source is located in the engine cowling, and this source is typically used when the external air source is obstructed. The alternate air source is generally operated automatically, with a backup manual system that can be utilized if the automatic feature malfunctions.
A fuel injection system consists of six basic components: an engine-driven fuel pump, a fuel-air control unit, fuel manifold, discharge nozzles, an auxiliary fuel pump, and fuel pressure/flow indicators. The auxiliary pump provides fuel under pressure to the fuel-air control unit for engine starting and/or emergency use. This control unit essentially replaces the carburetor and meters fuel based on the mixture control setting, sending it to the fuel manifold valve at a rate controlled by the throttle.
After reaching the fuel manifold valve, fuel is distributed to the individual fuel discharge nozzles. The discharge nozzles, which are found in each cylinder head, inject the fuel-air mixture into each cylinder intake port. A fuel injection system is less prone to icing than the carburetor system, but impact icing on the air intake can still occur in both systems. Impact icing takes place as ice forms on the exterior of the aircraft and blocks the air intake for the injection system.
Disadvantages of this system include the difficulty of starting a hot engine, vapor lock during ground operations on hot days, and issues with restarting an engine that has to quit due to fuel starvation.
Conclusion
Aerospace Purchasing is the leading distributor of aerospace and aviation parts, all of which have been sourced from top global manufacturers that we trust. With over 2 billion new, used, obsolete, and hard-to-find products in our inventory, customers can easily fulfill their operational requirements. Kickoff the procurement procurement process with a competitive quote and see how we can serve as your strategic sourcing partner.
Carburetor System
There are two primary types of carburetors, those of which are classified as either float type or pressure type carburetors. The float type is equipped with idling, accelerating, mixture control, idle cutoff, and power enrichment systems, which make it the most convenient option. Meanwhile, pressure type carburetors are not as common and are usually only found in larger aircraft. The main difference between both types of carburetors is the method they utilize to deliver fuel. For instance, pressure type carburetors deliver fuel by harnessing the pressure of a fuel pump.
Within a float type carburetor system, the outside air first flows through an air filter that is located at an air intake in the front part of the engine cowling. This filtered air makes its way into the carburetor and through a venturi, a narrow throat in the carburetor. As the air flows through the venturi, a low-pressure area is created which forces the fuel to flow through a main fuel jet located at the venturi. At this point, the fuel flows into the airstream where it is mixed with flowing air.
The fuel-air mixture is then sucked into the intake manifold and into the combustion chambers where it is ignited. Moreover, the float type carburetor gets its name from a float that rests on top of the fuel within the float chamber. A needle attached to the float opens and closes an opening at the bottom of the carburetor bowl. This measures the proper quantity of fuel in the carburetor. The flow of the fuel-air mixture to the combustion chambers, on the other hand, is regulated by the throttle valve.
A major advantage of float type carburetors is its icing tendency. Since the float type carburetor must discharge fuel at a point of low pressure, the discharge nozzle must be positioned at the venturi, and the throttle valve must be on the engine side of the discharge nozzle. Keep in mind that any drop in temperature due to fuel vaporization takes place within the venturi. As such, ice quickly forms in the venturi and on the throttle valve. If water vapor in the air condenses when the carburetor temperature is near below freezing, ice will form on internal surfaces of the carburetor, including the throttle valve.
Fuel Injection System
In a fuel injection system, fuel is directly injected into the cylinders, or just ahead of the intake valve. The air intake for the fuel injection system is similar to that of a carburetor system, wherein an alternate air source is located in the engine cowling, and this source is typically used when the external air source is obstructed. The alternate air source is generally operated automatically, with a backup manual system that can be utilized if the automatic feature malfunctions.
A fuel injection system consists of six basic components: an engine-driven fuel pump, a fuel-air control unit, fuel manifold, discharge nozzles, an auxiliary fuel pump, and fuel pressure/flow indicators. The auxiliary pump provides fuel under pressure to the fuel-air control unit for engine starting and/or emergency use. This control unit essentially replaces the carburetor and meters fuel based on the mixture control setting, sending it to the fuel manifold valve at a rate controlled by the throttle.
After reaching the fuel manifold valve, fuel is distributed to the individual fuel discharge nozzles. The discharge nozzles, which are found in each cylinder head, inject the fuel-air mixture into each cylinder intake port. A fuel injection system is less prone to icing than the carburetor system, but impact icing on the air intake can still occur in both systems. Impact icing takes place as ice forms on the exterior of the aircraft and blocks the air intake for the injection system.
Disadvantages of this system include the difficulty of starting a hot engine, vapor lock during ground operations on hot days, and issues with restarting an engine that has to quit due to fuel starvation.
Conclusion
Aerospace Purchasing is the leading distributor of aerospace and aviation parts, all of which have been sourced from top global manufacturers that we trust. With over 2 billion new, used, obsolete, and hard-to-find products in our inventory, customers can easily fulfill their operational requirements. Kickoff the procurement procurement process with a competitive quote and see how we can serve as your strategic sourcing partner.
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A propelling nozzle is a cone-shaped apparatus that aids in generating a propulsive force in aircraft jet engines. It operates to constrict flow and maximize the force of gasses moving through the engine to create a desired propulsive force. Moreover, propelling nozzles can vary from aircraft to aircraft, with each working in different ways.
Various nozzle designs act differently and each is used in its own unique application. To accommodate different engines, the internal structure of nozzles can be either convergent, divergent, or convergent-divergent (C-D) in shape. Operating off of the Venturi effect, propelling nozzles are designed to bring exhaust gasses to ambient pressure and form them into a jet. Venturi effect refers to the fall in fluid pressure caused by fluid moving through a restricted segment of a pipe. When the pressure is high enough, the flow will choke and the jet will become supersonic. The temperature and pressure of the gas provide the energy required to accelerate the stream. The gas expands adiabatically (without losing heat or mass) and hence efficiently. The gas then accelerates to a final exit velocity that is determined by the pressure and temperature at nozzle entry, the ambient pressure it exits, and the expansion efficiency.
During the combustion process within jet engines, exhaust gasses are produced by burning a mixture of air and jet fuel. As gasses are produced, they must then travel through the narrow passage of an engine's propelling nozzle, its shape aiding in providing enough force to drive the plane forward. Additionally, nozzles also play an active role in generating reverse thrust which occurs after the aircraft has landed to assist in rapid deceleration. This is done by reversing the flow of exhaust in the opposite direction required for propulsion.
Types of Propelling Nozzles
There are different types of propelling nozzles, those of which include fixed-area moving nozzles, low area ratio propelling nozzles, and ejector propelling nozzles. However, alternate nozzles also exist to suit various engine applications and their particular demands, including: afterburner nozzles, variable area nozzles, variable geometry nozzles, rocket nozzles, and others. In addition they are also characterized by different sizes and shapes. Although different propelling nozzles may vary in how they work, they are all still generally designed to pressurize the combustion gasses produced by jet engines.
The shape and design of a passageway making up a nozzle is critical because their propulsion output is dependent on such features. Anything other than smooth airflow will reduce engine efficiency and increase the risk of component failure due to excess vibrations induced by eddies or turbulence.
Conclusion
When maintenance requires the repair or overhaul of aircraft parts and components, Aerospace Purchasing is here to serve as your one-stop-shop for all your aerospace product needs. For propelling nozzles and other aviation items, we at Aerospace Purchasing can help you find exactly what you need through the submission of an Instant RFQ form. Upon submission of a completed RFQ form, a dedicated account representative will respond back to you in 15 minutes or less with a competitive quote for your comparisons, and we are always available to help customers via phone or email, 24/7x365.
Various nozzle designs act differently and each is used in its own unique application. To accommodate different engines, the internal structure of nozzles can be either convergent, divergent, or convergent-divergent (C-D) in shape. Operating off of the Venturi effect, propelling nozzles are designed to bring exhaust gasses to ambient pressure and form them into a jet. Venturi effect refers to the fall in fluid pressure caused by fluid moving through a restricted segment of a pipe. When the pressure is high enough, the flow will choke and the jet will become supersonic. The temperature and pressure of the gas provide the energy required to accelerate the stream. The gas expands adiabatically (without losing heat or mass) and hence efficiently. The gas then accelerates to a final exit velocity that is determined by the pressure and temperature at nozzle entry, the ambient pressure it exits, and the expansion efficiency.
During the combustion process within jet engines, exhaust gasses are produced by burning a mixture of air and jet fuel. As gasses are produced, they must then travel through the narrow passage of an engine's propelling nozzle, its shape aiding in providing enough force to drive the plane forward. Additionally, nozzles also play an active role in generating reverse thrust which occurs after the aircraft has landed to assist in rapid deceleration. This is done by reversing the flow of exhaust in the opposite direction required for propulsion.
Types of Propelling Nozzles
There are different types of propelling nozzles, those of which include fixed-area moving nozzles, low area ratio propelling nozzles, and ejector propelling nozzles. However, alternate nozzles also exist to suit various engine applications and their particular demands, including: afterburner nozzles, variable area nozzles, variable geometry nozzles, rocket nozzles, and others. In addition they are also characterized by different sizes and shapes. Although different propelling nozzles may vary in how they work, they are all still generally designed to pressurize the combustion gasses produced by jet engines.
The shape and design of a passageway making up a nozzle is critical because their propulsion output is dependent on such features. Anything other than smooth airflow will reduce engine efficiency and increase the risk of component failure due to excess vibrations induced by eddies or turbulence.
Conclusion
When maintenance requires the repair or overhaul of aircraft parts and components, Aerospace Purchasing is here to serve as your one-stop-shop for all your aerospace product needs. For propelling nozzles and other aviation items, we at Aerospace Purchasing can help you find exactly what you need through the submission of an Instant RFQ form. Upon submission of a completed RFQ form, a dedicated account representative will respond back to you in 15 minutes or less with a competitive quote for your comparisons, and we are always available to help customers via phone or email, 24/7x365.
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For an aircraft engine to kickstart operations for thrust generation, there often needs to be some type of external system or energy source for starting. Starters may come in varying forms, some being more manually operated while others may be automatic and electrically controlled. Air turbine starters in particular are a common option for various aircraft, capable of providing considerable torque for starting processes while being much lighter than their electric counterparts.
Air turbine starters may vary in their design and construction based on the engine that they serve, but typical designs feature an axial flow turbine that turns a drive coupling through the use of a reduction gear train and starter clutch mechanism. True to their name, air turbine starters require the use of air to kickstart operations, and air is generally supplied from an APU, ground-operated air cart, or an operating engine. For ample starting power, most air turbine starters require a source of 30 to 50 psi, and ducts will work to maintain a minimum pressure.
To begin the starting process with an air turbine starter, air is first supplied under pressure through the starter inlet. From there, air will move into the turbine rotor housing where it will collide with a set of rotor blades. With the use of nozzle vanes that direct air at an angle against the blades, the assembly will begin to revolve as the air’s kinetic energy is harvested. Rotating the rotor assembly allows for the reduction gear train and clutch arrangement to be driven, that of which is a complex assembly containing various planet gears, pinions, valves, clutch mechanisms, and more. Through collaborative operation, this assembly can effectively manage air supply, drive systems, and switch off or disconnect parts when the engine is started and air supply is no longer needed.
While air turbine starters are generally reliable for engine starting, there are various instances in which they can run into issues and will require troubleshooting. When issues arise, it is important to determine what is wrong with the assembly so that a probable cause and remedy can be determined. For instance, a starter that cannot rotate or operate is a major problem, and the cause of this can range from a lack of air supply to a damaged starter drive coupling. As such, users should quickly determine the issue and check areas such as the air supply, cutout switch, drive coupling, or starter to ensure that any aging or defective parts are quickly repaired or replaced.
As air turbine starters can make the difference between a reliable aircraft and one that remains on the ground, starters should be given an appropriate amount of attention when conducting maintenance, repair, or other such operations. It is always important to conduct ample research on repair stations before carrying out MRO servicing, and having a reputable distributor to ensure access to spare parts will always make the job easier. Luckily for you, Aerospace Purchasing is your sourcing solution with over 2 billion new, used, obsolete, and hard-to-find parts readily available for purchase.
Aerospace Purchasing belongs to the ASAP Semiconductor family of websites, and we are unmatched in our ability to provide customers time and money savings on even the most hard-to-find parts on the market. Even if you happen to be facing a time constraint, our expansive supply chain network enables us to expedite the shipping process with ease. Take the time to explore our expansive catalogs as you see fit, and our team is always available to assist you however necessary. When you are ready to begin the purchasing process, give us a call or email, and we would be more than happy to assist you however we can!
Air turbine starters may vary in their design and construction based on the engine that they serve, but typical designs feature an axial flow turbine that turns a drive coupling through the use of a reduction gear train and starter clutch mechanism. True to their name, air turbine starters require the use of air to kickstart operations, and air is generally supplied from an APU, ground-operated air cart, or an operating engine. For ample starting power, most air turbine starters require a source of 30 to 50 psi, and ducts will work to maintain a minimum pressure.
To begin the starting process with an air turbine starter, air is first supplied under pressure through the starter inlet. From there, air will move into the turbine rotor housing where it will collide with a set of rotor blades. With the use of nozzle vanes that direct air at an angle against the blades, the assembly will begin to revolve as the air’s kinetic energy is harvested. Rotating the rotor assembly allows for the reduction gear train and clutch arrangement to be driven, that of which is a complex assembly containing various planet gears, pinions, valves, clutch mechanisms, and more. Through collaborative operation, this assembly can effectively manage air supply, drive systems, and switch off or disconnect parts when the engine is started and air supply is no longer needed.
While air turbine starters are generally reliable for engine starting, there are various instances in which they can run into issues and will require troubleshooting. When issues arise, it is important to determine what is wrong with the assembly so that a probable cause and remedy can be determined. For instance, a starter that cannot rotate or operate is a major problem, and the cause of this can range from a lack of air supply to a damaged starter drive coupling. As such, users should quickly determine the issue and check areas such as the air supply, cutout switch, drive coupling, or starter to ensure that any aging or defective parts are quickly repaired or replaced.
As air turbine starters can make the difference between a reliable aircraft and one that remains on the ground, starters should be given an appropriate amount of attention when conducting maintenance, repair, or other such operations. It is always important to conduct ample research on repair stations before carrying out MRO servicing, and having a reputable distributor to ensure access to spare parts will always make the job easier. Luckily for you, Aerospace Purchasing is your sourcing solution with over 2 billion new, used, obsolete, and hard-to-find parts readily available for purchase.
Aerospace Purchasing belongs to the ASAP Semiconductor family of websites, and we are unmatched in our ability to provide customers time and money savings on even the most hard-to-find parts on the market. Even if you happen to be facing a time constraint, our expansive supply chain network enables us to expedite the shipping process with ease. Take the time to explore our expansive catalogs as you see fit, and our team is always available to assist you however necessary. When you are ready to begin the purchasing process, give us a call or email, and we would be more than happy to assist you however we can!
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Metal structural repairs are necessary for the safe operation of an aircraft when damage or wear occurs. Failing to conduct these critical metalworking tasks may pose safety risks by compromising vital parts, so they must be performed according to the best available techniques to ensure plane integrity.
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The average automobile is made up of nearly 30,000 components, many of which are hardware products like nuts and bolts. While many pay the most attention to grander assemblies, it is often the smallest of parts that serve the most important roles. For instance, the rod bearing is an often overlooked component due to its simplicity and size, yet it plays a critical role in the performance of the engine. In this blog, we will discuss rod bearings in more detail, allowing you to better understand their design, comparison to conventional bearings, and application.
In general, bearings are hardware components placed within assemblies to constrain motion and reduce the amount of friction produced between moving surfaces. Bearings can vary in the complexity of their design, and rod bearings are split-sleeve components that feature two separate semicircular shelves. With their use, the crankshaft and connecting rod of the automobile engine can be kept in place while their rotation is facilitated. With a pinhole situated on the top half of the rod bearing, lubrication can be maintained with ease so that the assembly can rotate without an excessive amount of heat being generated.
Rod bearings are often compared to main bearings as the two have similar appearances and are both located near the engine and crankshaft. While rod bearings allow for connecting rods to rotate the crankshaft without breaking, main bearings simply manage the positioning of the crankshaft within the engine block. Additionally, a rod bearing is placed between the crankshaft and connecting rod, while the main bearing is placed between the engine block and crankshaft. The two components share lubrication, as oil flows from the main bearing to the rod bearing to keep the assembly lubricated.
Due to the importance of the connecting rod bearing, it is important that it is well maintained to save time and money that would otherwise be spent on repairs. There are a few common reasons for rod bearing failures, and it can be useful to understand each so that they may be avoided. Low lubrication is the number one reason for connecting rod bearing failures, and it can be caused by a faulty oil pump or low oil levels. Pipe clogging is also an issue, and regular cleaning and inspection can promote reliable operations. It is important that the lubricating oil chosen is compatible with the connecting rod and all other components, as a sub-par oil may lead to bearing failure as a result of increased wear and tear. Alongside such examples, one should keep an eye out for misassembled items, fatigue, dirt build-up, and corrosion.
If issues have already begun to affect rod bearings, it is crucial that one is able to determine if the part is faulty and requires replacement. When a connecting rod bearing begins to become damaged and the clearance between the rod and crankshaft adjusts, there will be a knocking noise. Additionally, oil lights may activate as a result of low oil pressure if the rod bearing is loose, and the engine light may light up as well. Whenever such issues come about, it is important that the automobile is serviced right away to prevent issues from becoming worse.
Aerospace Purchasing is a leading distributor of aerospace and aviation parts, all of which have come from leading global manufacturers that we trust. With over 2 billion new, used, obsolete, and hard-to-find components available for purchase at any time, we invite you to explore our website as you see fit. Once you narrow down the items you are most interested in, you may request a quote for your comparisons through the submission of an RFQ form as provided on our website. Experience the future of part procurement today when you connect with an Aerospace Purchasing representative
In general, bearings are hardware components placed within assemblies to constrain motion and reduce the amount of friction produced between moving surfaces. Bearings can vary in the complexity of their design, and rod bearings are split-sleeve components that feature two separate semicircular shelves. With their use, the crankshaft and connecting rod of the automobile engine can be kept in place while their rotation is facilitated. With a pinhole situated on the top half of the rod bearing, lubrication can be maintained with ease so that the assembly can rotate without an excessive amount of heat being generated.
Rod bearings are often compared to main bearings as the two have similar appearances and are both located near the engine and crankshaft. While rod bearings allow for connecting rods to rotate the crankshaft without breaking, main bearings simply manage the positioning of the crankshaft within the engine block. Additionally, a rod bearing is placed between the crankshaft and connecting rod, while the main bearing is placed between the engine block and crankshaft. The two components share lubrication, as oil flows from the main bearing to the rod bearing to keep the assembly lubricated.
Due to the importance of the connecting rod bearing, it is important that it is well maintained to save time and money that would otherwise be spent on repairs. There are a few common reasons for rod bearing failures, and it can be useful to understand each so that they may be avoided. Low lubrication is the number one reason for connecting rod bearing failures, and it can be caused by a faulty oil pump or low oil levels. Pipe clogging is also an issue, and regular cleaning and inspection can promote reliable operations. It is important that the lubricating oil chosen is compatible with the connecting rod and all other components, as a sub-par oil may lead to bearing failure as a result of increased wear and tear. Alongside such examples, one should keep an eye out for misassembled items, fatigue, dirt build-up, and corrosion.
If issues have already begun to affect rod bearings, it is crucial that one is able to determine if the part is faulty and requires replacement. When a connecting rod bearing begins to become damaged and the clearance between the rod and crankshaft adjusts, there will be a knocking noise. Additionally, oil lights may activate as a result of low oil pressure if the rod bearing is loose, and the engine light may light up as well. Whenever such issues come about, it is important that the automobile is serviced right away to prevent issues from becoming worse.
Aerospace Purchasing is a leading distributor of aerospace and aviation parts, all of which have come from leading global manufacturers that we trust. With over 2 billion new, used, obsolete, and hard-to-find components available for purchase at any time, we invite you to explore our website as you see fit. Once you narrow down the items you are most interested in, you may request a quote for your comparisons through the submission of an RFQ form as provided on our website. Experience the future of part procurement today when you connect with an Aerospace Purchasing representative
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If you spend enough time in or around the world of aviation, you will eventually hear the term TSO used. In an industry with so many highly-specialized parts and practices, the many acronyms and abbreviations can become hard to remember. This blog will cover the TSO in general, as well as the specific TSO-C173.
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Airplane lighting frameworks provide illumination to both outside and inside of an aircraft. Lights on the outside give light during such activities as arriving around evening time, examination of icing conditions, and security from midair impact. Interior lighting provides illumination to instruments, cockpits, lodges, and different areas involved by crewmembers and travelers. Certain unique lighting, for example, markers and cautioning lights, provide the aircraft status of gear. For more information on the aircraft lighting system, read here.
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The Integrated Drive Generator system, or IDG, is a key power system found on aircraft that controls all of the engine hydraulic systems. An IDG consists of a Constant Speed Drive (CSD) and AC generator mounted side by side in a single housing assembly. The CSD uses controlled differential action to maintain the constant output speed necessary to power the generator. Because the IDG has such an important role in powering key components of the aircraft, its reliability is paramount. This blog will explain Integrated Drive Generator systems, how they work, and how to service them properly.
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When designing, manufacturing, and procuring commercial aviation parts, it is helpful to have a referencing standard and cataloguing system to help establish order and ease of learning. The ATA 100 is a numbering system that has established itself as such a commercial aircraft documentation standard, allowing for pilots, maintenance technicians, and engineers to quickly and easily understand various aircraft systems and components.
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A main bonding jumper is a conductor that acts as the link between the equipment grounding conductor and the grounded service conductor. The purpose of the main bonding jumper is to fasten the EGC (equipment grounding conductors) to the neutral conductor of the electrical service. In other words, it carries the ground-fault current from the service enclosure as well as from the equipment grounding system that is returning to the source. You can read more about the main-bonding jumper and its uses below.
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