Magnetic Hydraulic Circuit Breakers and Their Function:

A hydraulic magnetic circuit breaker is designed to protect electrical circuits from overloads and faults. Unlike standard breakers, it uses a combination of magnetic forces and a hydraulic system to provide superior protection.

The working principle revolves around magnetic effects triggered by overcurrents, with an added time delay mechanism that ensures the breaker responds only when necessary.

In the heart of this mechanism, a core moves through a cylinder filled with silicone fluid. This creates a delay in response, allowing short overcurrent spikes to pass without tripping the breaker.

However, if the overcurrent persists, the core continues to move and activates the magnetic field, which eventually causes the contacts to separate, cutting off the current and protecting the system.

The advantage of hydraulic magnetic circuit breakers is that they are quick to reset once tripped, unlike traditional thermal breakers that require time to cool down.

Reliable Protection in AC and DC Circuits:

These breakers are available for both AC and DC applications, providing a reliable and cost-effective solution for overcurrent protection. They are also independent of ambient temperature, making them especially useful in environments with fluctuating temperatures.

Whether you are dealing with high-voltage circuits or sensitive devices, a magnetic hydraulic circuit breaker offers precise protection with a reliable, accurate, and inexpensive design.

What is the hydraulic operating mechanism of a circuit breaker?

The hydraulic operating mechanism plays a critical role in how circuit breakers function, helping them prevent electrical faults. In simple terms, this system uses oil and pressure to manage the breaker’s action.

The process begins when the pump moves oil from the low pressure reservoir or tank to a designated area where energy storage is built up. This stored energy is crucial for the breaker’s operation, allowing it to respond quickly to electrical issues.

As the system builds pressure, it charges the spring assembly inside the breaker, which is responsible for storing the energy needed to trip the breaker.Once a fault occurs, the energy stored in the spring is released rapidly. This released energy activates the circuit-breaker, causing it to operate and disconnect the circuit.

This mechanism ensures that the circuit breakers act swiftly to protect your electrical system from damage, keeping everything safe and running smoothly. The principle behind this operation is all about controlling pressure and using it to control the release of stored energy at the right time, offering both precision and reliability.

Hydraulic-Magnetic Principles of Operation 

A hydraulic-magnetic circuit breaker uses a combination of magnetic force and a hydraulic mechanism to protect electrical circuits. The breaker is designed around a series-connected solenoid coil that is wound around a hermetically sealed tube.

Inside the tube, you’ll find an iron core, a spring, and a dampening fluid. When the load current flows through the solenoid coil, it creates a magnetic force that pulls the core. If the current exceeds safe limits, the breaker trips, and the current is interrupted.

The spring and the dampening fluid play key roles in controlling the movement of the core. They help create a time delay, allowing momentary surges to pass without triggering the breaker unnecessarily.

This system ensures that the breaker responds only when an overcurrent persists long enough to pose a risk, making it an efficient and reliable solution for overcurrent protection in electrical systems.

Normal Overload Operation

When a circuit breaker is operating within its rated current or below, the magnetic flux in the solenoid is insufficient to attract the core towards the pole piece due to the spring force. As a result, the breaker remains loaded, and the circuit stays energized.

However, when an overload occurs and the current exceeds the breaker’s rating, the magnetic flux becomes strong enough to pull the core towards the pole piece. This starts the movement of the core, and the hydraulic fluid helps to regulate the core’s speed of travel, creating a controlled time delay that’s inversely proportional to the magnitude of the current.

If the overload is brief, such as during start-up of motors, the core will return to its rest position once the overload disappears. However, if the overload continues, the core will reach the pole piece, reducing the reluctance of the magnetic circuit.

This causes the armature to be attracted with enough force to collapse the latch mechanism (or toggle) and trip the breaker. This action causes the contacts to separate, cutting off the current, and the flow of electricity ceases.

Short Circuit Operation

When a short circuit occurs, the magnetic flux generated by the coil increases rapidly. This surge of flux is strong enough to attract the armature to the pole face, causing the breaker to trip almost instantly.

Unlike other types of circuit breakers, such as thermal breakers, the hydraulic-magnetic circuit breaker is designed to respond quickly in this instantaneous trip region. The core does not need to move for the breaker to activate, which makes it highly efficient during high overloads or short circuits.

The trip point of a hydraulic-magnetic circuit breaker is unaffected by ambient temperature, meaning that it will function consistently regardless of the surrounding conditions. After the breaker trips, it can be reclosed immediately without needing a long cooling down time.

This characteristic is crucial, as it ensures the breaker is ready to function again without any delay, making it a reliable option for managing electrical faults. Additionally, this type of breaker allows for different variations of time/current characteristics, offering flexibility in different applications.

Reliable Performance and Consistent Operation

Hydraulic magnetic circuit breakers are designed to handle 100% rated current, independent of ambient temperature, ensuring reliable performance without the need for derating. These breakers trip at 125% to 130% of rated current, offering protection against overloads and short circuits. The immediate resetting after a trip adds to their convenience, as no cooling period is necessary, making them ideal for high-demand systems.

Customization and Time-Delay Features

These circuit breakers are highly customizable, offering a wide range of current ratings and time delays. The magnetic and hydraulic design works by using magnetic forces induced through an electromagnetic coil or solenoid, along with a hydraulic fluid-filled tube containing an iron core and actuator. The time-delay feature, regulated by the viscosity of the hydraulic fluid, ensures that nuisance tripping does not occur, especially with devices that briefly draw higher current like motors or HID bulbs.

Advanced Features for Durability and Safety

These circuit breakers are engineered to accommodate various current ratings by adjusting the number of turns in the coil, enabling precise control over the electromotive force. Additionally, they are designed for vertical mounting, as gravity can influence the time it takes for the iron core to move through the hydraulic fluid.

Other features include trip-free operation, silver alloy contacts for extended life in harsh environments, and polymer materials that meet IEC 60947-2 and UL 489 standards. The hermetically sealed sensing mechanism ensures a longer service life with consistent time-delay and tripping characteristics.

Circuit Breaker Components

1. Handle: This is what we use to manually switch the circuit breaker on or off. From experience, the handle’s durability matters a lot; a reliable handle can withstand frequent use without any signs of wear, a feature I’ve come to value during high-demand projects.
2. Mechanism Assembly: This part coordinates the internal operations when the breaker trips. It’s fascinating how precise it has to be; a slight misalignment can throw the entire breaker off, making a quality assembly crucial for consistent protection.
3. Line Terminal: This is where incoming power connects to the circuit breaker. A secure, solid line terminal is essential, as any loose connection can lead to sparking and, potentially, hazardous situations.
4. Fixed Contact: This stationary contact connects to the moving contact when the circuit is closed. The quality of this fixed point is critical for reducing wear and tear, as any deterioration here can affect the entire circuit’s reliability.
5. Contact Tips: These tips ensure solid contact between fixed and moving contacts, minimizing arcing. I always check for wear on these tips because damaged tips can lead to unstable connections, especially during heavy load conditions.
6. Moving Contact: This part physically moves to make or break the circuit. Over time, you learn that durable moving contacts handle frequent switching cycles much better, reducing the chances of mechanical failure.
7. Arc Runner Line Side: This component directs the arc away from the contacts to prolong their life. I’ve noticed that a well-designed arc runner minimizes wear, especially in high-voltage breakers, where arc control is critical.
8. Hermetically Sealed Tube: This tube prevents moisture and air from affecting internal components. In humid environments, a sealed tube is a game-changer, as it keeps critical parts from corroding, ensuring longevity and safety.
9. Magnetic Frame: This directs magnetic force to aid in breaking the circuit during a fault. I’ve seen how a well-built frame can react instantly to high currents, which is essential for protecting sensitive equipment downstream.
10. Solenoid Coil: The solenoid coil creates a magnetic field to move the armature and open the breaker. From hands-on experience, you learn that any issues in this coil lead to unreliable trips, so its integrity is a big deal in ensuring safe operation.
11. Armature: This piece moves within the breaker to trigger the tripping mechanism. Regular maintenance of the armature is key, as it must operate smoothly to avoid delayed responses during faults.
12. Load Terminal: Here, the outgoing load connection is established. Ensuring a tight, corrosion-free load terminal has saved me from frequent downtime, as loose connections here can lead to inefficiencies and overheating.
13. Pole Piece: This part focuses the magnetic force generated by the coil to enhance tripping reliability. A well-aligned pole piece can make a significant difference in the speed and consistency of the breaker’s response.
14. Arc Runner Load Side: It guides the arc away from the load side contacts, protecting them from damage. In high-current applications, having a durable arc runner here can extend the lifespan of the breaker significantly.
15. Arc Grids: These grids help dissipate the energy of the arc during fault conditions. From practical experience, I’ve seen how well-maintained arc grids prevent extensive damage and ensure the breaker resets smoothly after a trip.
16. Clip-in Springs: These springs secure various components within the breaker, keeping them in place. Over time, I’ve learned that sturdy clip-in springs reduce vibrations, which can prolong the life of internal parts and make servicing easier.

Each component plays a crucial role in keeping the system safe and efficient, and regular inspection has always proven essential in avoiding bigger issues down the line.

What is the Weakness of Hydraulics?

Hydraulic systems, while powerful, have certain weaknesses. One major issue is that hydraulic fluid can leak, which affects the performance of the system and can be messy and difficult to clean up.

If the fluid doesn’t function correctly, it can lead to significant leakage issues, especially if there is damage to parts like the piston, rod, or shaft. A damaged steel pipe can also cause oil to spill, worsening the leaks.

In my experience, using well-built cylinders and quality materials can help prevent these issues. A strong shaft and piston rod made from durable steel are essential to avoid unwanted leaks. With proper maintenance, hydraulic systems can minimize problems, though it’s crucial to stay alert to these common weaknesses.

Why is My Hydraulic Breaker Not Working?

If your hydraulic breaker isn’t working, there are a few common reasons that could be causing the problem. First, make sure all shutoff valves are fully open and engaged. Often, a cycle stoppage occurs because one of the valves is closed or a fluid coupler isn’t properly connected.

These couplers must be fully engaged to ensure a smooth flow of fluid through the system, as even a small disruption can prevent the breaker from functioning.

In my experience, another issue might be a quick coupler that isn’t correctly aligned. This common problem often causes unexpected stoppage of the hammer during operation. Double-check to see if any coupler has come loose or if one was not securely attached during setup. Taking the time to inspect these components can save you from unnecessary downtime.

What are the most important hydraulic system testing procedures?

Check fluid level and condition: Regularly checking the hydraulic fluid level and quality is essential to ensure smooth system operation. In my experience, low or dirty fluid can lead to overheating or poor performance. Look for signs of contamination, like changes in color or consistency, which indicate it’s time to replace or filter the fluid.

Measure pressure and flow: Verifying pressure and flow rates helps identify leaks or restrictions in the system. I recommend using reliable gauges and measuring tools, as even small fluctuations in pressure can indicate issues that could grow over time. Maintaining proper pressure keeps the hydraulic system working at peak efficiency.

Inspect hoses and fittings: Periodic inspection of hoses and fittings is crucial to prevent leaks and ensure safe operation. Over time, hoses wear down, and fittings can loosen, especially under high pressure. From my experience, checking for cracks, bulges, or loose connections early can save significant time and expense.

Test valves and actuators: Valves and actuators control the flow and movement in a hydraulic system. Testing these components ensures they respond correctly under different conditions. Sometimes, a valve or actuator can stick or fail, and I’ve found that catching these issues early avoids costly repairs.

Monitor temperature and noise: Monitoring temperature and unusual noise during operation helps detect problems like overheating or excessive vibration. High temperatures or strange noises often indicate friction or pressure problems. In my experience, this step gives valuable clues to system health.

Perform preventive maintenance: Regular preventive maintenance keeps hydraulic systems in optimal condition. I’ve learned that proactive maintenance, such as replacing worn parts before they fail, minimizes unexpected downtime. A structured maintenance plan goes a long way in extending system lifespan.

Here’s what else to consider: In addition to these procedures, check for proper calibration and follow the manufacturer’s guidelines. From my perspective, taking time to review each component’s condition and calibration further ensures reliability and safety. A thorough approach leads to fewer issues and keeps the hydraulic system running smoothly.

What Happens if Hydraulic Pressure is Too High?

When hydraulic systems experience overpressurization, it can lead to serious issues that impact many of the mechanical components involved. For example, high pressure can cause the seal on a hose or fitting to fail.

When this happens, it leads to leaks, which can reduce the system’s performance and, in some cases, shut it down entirely. Additionally, parts like pumps, motors, and cylinders may suffer due to this excessive pressure. These parts are designed to handle specific pressures, and when those limits are exceeded, the risk of damage increases.

In systems with an axial pump, overpressurization can even create a vacuum effect at the inlet. This effect can disrupt the flow, impacting the pump’s ability to function efficiently. Valves also play a key role here, as they are supposed to regulate the pressure.

When pressure becomes excessive, these valves can struggle to keep things in balance, leading to additional strain on cylinders and motors. Each of these components is essential to maintaining the system’s integrity, and the effects of overpressurization can cascade, putting the entire hydraulic setup at risk.

Why do hydraulics get weak when hot?

From experience, I’ve seen hydraulic systems weaken when they get too hot, and it’s usually due to how heat affects the hydraulic fluid. This fluid is designed to work best within a specific temperature range. But as it heats up, it becomes thinner and loses some of its ability to properly lubricate moving parts.

Imagine trying to work with oil that’s as thin as water it just doesn’t protect the parts as well. This loss of lubrication creates more friction between components, which then causes the pump to work harder and overheat even more.

Over time, this heating cycle leads to faster wear and tear on key parts, and you can actually feel the system getting weaker as it loses efficiency. In some cases, you might even notice it struggling to maintain pressure. Proper cooling and regular checks on fluid temperature make a huge difference in keeping hydraulics running smoothly, especially in tough environments.

What is the biggest enemy of a hydraulic system?

the biggest threat to a hydraulic system isn’t always what people think. It’s energy contamination essentially, heat building up in the system. While particle and water contamination can certainly cause issues, most modern systems are equipped with advanced filtration technologies that handle these pretty effectively. However, heat is a more silent enemy that wears down a hydraulic system from within.

When heat accumulates, it changes the viscosity of the hydraulic fluid, making it thinner, which then affects lubrication. Over time, this leads to more friction in the moving parts, which only makes the system run hotter in a vicious cycle. Without the right cooling measures or proper maintenance, this buildup of heat accelerates wear on the components, shortening their lifespan and reducing overall performance.

What is the purpose of a hydraulic breaker?

From my hands-on experience with hydraulic breakers, their main purpose is clear: tackling tough demolition jobs involving concrete and rock. These machines are built for strength and accuracy, so they make breaking through old concrete structures or rock formations surprisingly manageable.

For contractors and operators, a hydraulic breaker brings serious power to the job site, allowing them to efficiently remove thick concrete slabs, foundations, or even solid rock when preparing for new construction.

What I’ve noticed in the field is that these breakers don’t just offer raw force they give you control too, which is critical in precision demolition. Whether you’re clearing out remnants of a structure or creating space in rocky terrain, hydraulic breakers get it done with impressive precision. That’s why they’re indispensable in demolition work and excavation projects.

What is the PSI of a hydraulic system?

In my experience with hydraulic systems, understanding PSI (pounds per square inch) is key to grasping how much force the system is putting out. Typically, most hydraulic systems operate between 3000 and 4000 PSI high enough to power heavy-duty equipment across industries like mining, oil drilling, manufacturing, and even irrigation. This pressure allows hydraulics to perform demanding tasks with both strength and precision.

Another important measure is cubic centimeters (cc), which tells us the volume of hydraulic fluid displaced with each rotation of the pump. It’s a small detail, but crucial, because fluid volume and pressure together define how effectively the system functions.

From managing the right PSI to ensuring the right cc flow, every part of hydraulic control depends on these measurements working together, making the system efficient and safe for various applications.

What is the difference between pressure loss and pressure drop?

From my experience with hydraulic systems, understanding pressure drop and pressure loss can make a big difference in system performance. Pressure drop refers to the change in pressure between two points in the flow, which can occur due to factors like height changes, flow area adjustments, restrictions, or friction. For instance, as fluid travels through pipes, the natural resistance it encounters can create these drops.

However, pressure loss is a different story. Unlike a regular pressure drop, pressure loss is energy that the system can’t recover. This usually happens because of friction or significant restrictions in the flow path. Once this pressure is lost, it can’t be regained downstream, impacting the system’s overall efficiency.

To manage these issues, relief valves come into play. These pressure control valves limit the maximum pressure by diverting excess fluid back to the reservoir. By keeping pressure within safe limits, relief valves prevent potential damage to system components and help maintain smooth, reliable operation.

What will happen if there is air trapped in the hydraulic system?

From working with hydraulic systems, I can tell you that trapped air is a common and frustrating issue. When air gets into the system, it leads to a delay in response and a “spongy” feeling in the actuator. This happens because air is compressible, unlike hydraulic fluid. So, when you try to move the actuator, the air compresses first, causing a lag before the actual movement starts.

As the system cycles, this trapped air repeatedly compresses and decompresses, slowing down the overall performance. Instead of the quick, firm response you’d expect, the actuator reacts more sluggishly, which can be inefficient and even unsafe in precision tasks. Getting rid of that air is crucial for keeping the system responsive and working smoothly.

Which is better pneumatic breaker or hydraulic breaker?

When choosing between pneumatic and hydraulic breakers, it’s essential to understand their strengths to select the right tool for the job. Having worked on various construction projects, I’ve seen firsthand how hydraulic breakers often outshine their pneumatic counterparts, especially when tackling heavy-duty tasks.

The main advantage of hydraulic breakers is their higher impact energy. This means they can break through tougher materials faster and with greater efficiency. Additionally, hydraulic systems are generally quieter than pneumatic ones, which can be a significant plus on job sites where noise levels are a concern.

Another edge hydraulics have is their versatility; they can be used on a wider range of machines, making them more adaptable for different types of equipment. However, they do come with a caveat: they require more maintenance due to the complexity of their components. Pneumatic breakers, on the other hand, are simpler and often more budget-friendly.

They’re great for lighter jobs and environments where cost and simplicity take precedence. In my experience, while pneumatic breakers are reliable for smaller projects, the power and efficiency of hydraulic breakers make them the go-to for demanding construction needs.

Frequently asked questions (FAQ)

What gas is in a hydraulic breaker?

Nitrogen gas

Hydraulic breakers use hydraulic pressure to push the piston, working against the gas pressure stored in a tank or back head. Nitrogen gas is used because it’s safe and doesn’t react.

What is the pressure in a hydraulic breaker?

In my experience, the optimal pressure in a hydraulic breaker typically ranges from 1.4 to 1.6 MPa (14-16 kg), but it can vary depending on the model and external conditions. It’s always best to check the manufacturer’s specifications for accurate settings.

How long can you use a hydraulic breaker?

In my experience, hydraulic breakers can be used for as long as needed if used correctly. However, when used continuously, it’s important not to run them for more than 15 seconds at a time to prevent damage.

What are the three main components of a hydraulic power unit?

• Primary Source – AC or DC motor or an internal combustion engine (petrol or diesel).
• Hydraulic Pump – The most common varieties are gear, piston or vane.
• Oil Tank/Hydraulic Reservoir – The container for the hydraulic fluid.

What is the size of the hydraulic breaker?

From my experience, for tough materials, a hydraulic breaker in the 7,500 to 10,000 ft-lb range usually performs well, while high-demand jobs may need a 13,500 ft-lb breaker. When breaking concrete, the breaker’s job is to penetrate and crack the material so it separates cleanly from any reinforcement.

What is the pressure drop in a hydraulic circuit?

In a hydraulic circuit, pressure drop is the difference between the fluid’s pressure when it enters and exits a hose assembly. From experience, this drop is normal, as pressure naturally decreases along the hose due to resistance.

How do you calculate hydraulic pressure?

To calculate hydraulic pressure, use the formula Pressure = Force / Area. In my experience, it’s crucial to ensure force and area are in consistent units, like Newtons and square meters, to get accurate results.

How long should you use a hydraulic breaker for?

Based on years of hands-on experience, I recommend using a hydraulic breaker for no more than 30 seconds on a single point—any longer risks overheating the hydraulic fluid, which could lead to piston seizure. And remember, hydraulic breakers aren’t designed to move heavy loads with the point or casing; it’s crucial to use them strictly for their intended purpose to avoid costly damage

What is the formula for breaker size?

From my experience, sizing an inverter circuit breaker is simple: multiply the inverter’s maximum continuous output current by 1.25 so, for 40A, you’d get 50A then round up to the nearest standard breaker size for safety and reliability.

How to increase hydraulic flow rate?

Boosting hydraulic flow is achievable by either upgrading to a larger pump or running multiple pumps in parallel. Alternatively, you can raise the system’s pressure by installing a high-pressure pipeline or opting for a more powerful pump to handle increased demand efficiently.

What do p and t stand for in hydraulics?

In hydraulics, “P” stands for pressure (where the fluid flows in) and “T” represents the tank or return line. Over time, I’ve found that mastering these basics is key to understanding the flow dynamics in any hydraulic system.

What is the difference between CD and Cv?

The key difference between Cd and Cv is that Cd (coefficient of discharge) measures the actual discharge from an orifice, while Cv varies slightly, usually between 0.95 and 0.99, depending on the orifice’s shape and size. For sharp-edged orifices, Cv is typically around 0.98.

What are two main causes of failure of hydraulics?

In my experience, air and water contamination are the top culprits behind hydraulic failures, responsible for nearly 80-90% of issues. These problems often stem from faulty pumps, leaks, or temperature fluctuations, all of which can allow contaminants to enter the system.

Why is my hydraulic breaker not working?

If your hydraulic breaker isn’t cycling, in my experience, it’s often due to a simple issue: check that all shutoff valves are open and fluid couplers are fully engaged. Many service calls boil down to one of these being overlooked.

What are the symptoms of hydraulic failure?

Don’t ignore these signs of a failing hydraulic pump.

• Your Hydraulic Pump Makes Noises. Hydraulic pumps make noise as they operate. …
• Your Hydraulic Pump Leaks. Any leaking of hydraulic fluids should give you some concern. …
• Your Hydraulic Pump Gets Too Hot. …
• Your Hydraulic Pump Slows Down.

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