Outdoor vacuum circuit breaker

Outdoor Vacuum Circuit Breaker: The Ultimate Guide

Well, one thing that you ought to know is that circuit breakers generally play a significant role in the medium-voltage network.

The essence of the instrument is to ensure that it breaks all currents within the scope of its ratings.

On the other hand, it is also necessary to know what this particular unit is in details especially if you want to buy or import.

And if you’re looking for or planning to purchase this type of instrument sooner or later, then you’re certainly in the right place.

In this guide, I want to take you through various aspects of outdoor vacuum circuit breaker.

And therefore, without wasting much time, let’s get straight to the point;

Chapter 1: Vacuum Circuit breaker Definition: What is Vacuum Circuit Breaker (VCB)

A vacuum circuit breaker refers to an instrument which ordinarily is designed to interrupt an electric circuit.

In many occurrences, many articles and other materials refer to it as VCB. Apparently, this is merely an abbreviation for Vacuum Circuit Breaker, which is also imperative to know.

The essence of causing interruption is merely to prevent unwarranted current which arises from short circuit resulting from overload.

In other words, VCB function is to ensure that it interrupts the current flow immediately after the detection of a fault.

From the basic VCB definition, you can realize that this instrument has an arc quenching activity which takes place in a vacuum medium.

And as you’ll later learn more about the working principle of this device, you’ll notice that operation of switching and closing of currents.

Now, a bit of history of VCB indicates that the introduction of vacuum interrupter technology was in the year 1960.

However, it is still a growing technology, and the size of this instrument has really reduced over the years due to technical developments.

Now what happens with this device is that they come in different sizes.

https://youtu.be/XKzcrckw9Dk

Some are designed for relatively small devices which help to protect a number of household appliances and low current circuits.

On the same note, some are comparatively large switchgear designed to prevent high voltage circuits supplying an entire city.

So you’ll find that this device contains a vacuum which plays a significant role in providing the arc quenching system.

The vacuum also provides the highest insulating strength which is also an indication that it has a superior arc quenching properties.

For instance, if contacts of a breaker are opened in a vacuum, there’s an interruption which occurs at first current zero.

This interruption has a dielectric strength between contacts that accumulate multiple times higher than that achieved with other breakers.

From the description of what id VCB circuit, breaker, it’s evident that it plays an essential role in the overall electric circuit efficiency.

And it’s for that reason that you have to be meticulous when it comes to purchasing the different or specific type of VCB.

As you’ll come to see, later on, this device incorporates quite a lot of components which make its efficiency apparent.

But you should also not forget that it plays several roles which include the following;

Enhancing Safety

What happens is that the moment there can be an interruption on an electric circuit, it shows that you and your properties are safe.

In most instances, you’ll find that failure of interrupting or preventing the short circuit, can cause significant destruction and related risks.

So once you have this device, you can be confident that chances of damaging your properties or harming you are close to zero.

Provides Silent Operation and Produces Non Pollutant Gases

Additionally, an outdoor vacuum breaker also provides silent operation and non-pollutant gas.

What this statement implies is that in as much as it an outdoor VCB appears large, you will hardly hear any form of noise emanating from it.

And now this is important because in many instances the operations people undertake hardly require noise pollution.

Furthermore, it becomes a vital component given that it does not emit any form of gases that would necessarily pollute the surrounding.

So in a nutshell, a VCB is more important both in safeguarding the electric circuit system and the environment as well.

Durable and Easy to Maintain

Another appealing aspect of outdoor vacuum circuit breaker is the fact that it is easy to maintain and also durable.

Trust me! Once you buy this unit, you’ll rarely think of replacing it as long as you maintain it accordingly, which is also easy.

So what all these mean is that once you have this particular device, you’re sure that cases of fire will be rare.

In fact, unless there is a particular fault resulting from the poor fitting of other electrical components, VCB guarantees you of no cause of the fire at all.

And that is one of the most important things because it gives you confidence when it comes to having peace of mind.

Nonetheless, you should also be mindful of the fact that the designs and types of VCB tend to vary.

Therefore, as you’ll later learn about the same, it will become easy to make an ideal choice or pick when looking for this device.

In the second chapter, we will look at how this particular unit works.

At least it will give you an idea of understanding what often happens or what it takes for the VCB to provide its efficiency.

So let’s shift focus and find out more regarding the working principle of this unit.

Chapter 2: Vacuum Circuit Breaker Working Principle: How Does a Vacuum Circuit Breaker Work?

Now, this is one of the most important sections of this guide that you have to really understand.

Like I did mention before, an ordinary VCB has quite a lot of parts and components.

And all of these components also play significant roles in the overall functionality, efficiency and working principle of this unit.

So primarily, this instrument depends much on the arc that is struck between the contacts.

Production of the arc is as a result of ionization of metal ions, and this is entirely dependent on material contacts.

What often happens is that vacuum usually provides the highest insulating strength. It thus implies that its arc quenching principles are far much superior to any other medium.

https://youtu.be/z3F-Vpk7eMw

For instance, the moment contacts of breaker open up in a vacuum, there will be an interruption at first current zero.

The dielectric strength between the contacts tends to build up at the rate of a thousand time more than what other circuit breakers obtain.

As you’ll realize, the technology will only be ideal for medium voltage application.

And as the arc is produced in a vacuum, the dielectric strength in vacuum also recovers so fast hence leading to first extinguishing of the arc.

Now let’s find out the working principle of a vacuum circuit breaker;

Ideally, the vacuum circuit breaker consists of three major components;

• Moving contact
• Fixed contact
• Vacuum interrupter

So the connection of the moving contact is to the device mechanism by stainless steel bellow.

The insulating housing supports the arc shields in such a manner that the cover shields and prevent them from condensing on the insulating enclosure.

The permanent sealing of a vacuum chamber also eliminates any possibility of leakage since the glass or ceramic vessel provides the outer insulating body

Typically, as I’ve mentioned above, the arc interruption in vacuum interrupters is entirely different from other circuit breakers.

And it is the separation of the contacts that results to release of vapor which is apparently filled in the contact space.

This vapor contains positive ions which are liberated from contact material.

What you also ought to understand is that the density of the vapor is dependent on the current available in the arc.

And for that matter, any moment the current decreases, the rate of vapor release also decreases.

But after current zero, the medium recovers its dielectric strength the moment there is a reduction in the vapor density.

The arc also takes several paths when the current for interruption is negligible in the vacuum.

What happens is that the total current is divided into several parallel arcs which tend to repel one another and spread over contacts surface.

This is what is commonly known as a diffused arc. The salient feature of this arc is that it is extremely easy to interrupt it.

In most instances, the concentration of the arc appears in a small region at high current values. Apparently, this leads to rapid vaporization of the contact surface.

Additionally, the interruption of the arc only happens when the arc remains in a relatively diffused state.

But should you remove it from the contact surface there’s a possibility that the arc will re-strike.

The material, contacts shape and mechanism of considering metal vapor are some of the significant aspects which influence the arc extinction in vacuum breakers.

And so it happens that the path of the arc is kept on a constant motion to prevent the rise of temperature at any one point.

So once there’s a final arc interruption, a rapid build-up of dielectric strength occurs which incidentally is quite strange of a vacuum breaker.

This, therefore, implies that it is ideal for capacitor switching given that it shall provide a re-stick free performance.

Interruption of small current before zero may result in chopping whose level evidently is dependent on the material of contact.

So as you can see from this description, the working principle of an outdoor vacuum circuit breaker is quite impressive.

Several aspects revolve around the same, but it is always fundamental to understand it from at least to enable you to have an idea of how it works.

Once you have a basic understanding of VCB circuit breaker working principle, you’ll realize why it is preferable or suitable for specific applications.

And talking if applications, let’s now look at some of the areas where the use of outdoor circuit breakers appears to be common;

Applications of Vacuum Circuit Breaker

Well, the truth is that the vacuum circuit breaker is regarded as the most dependable current interruption technology for medium voltage switchgear.

Of course, this is as a result of several elements, and one being that it is comparatively easy to maintain it than other circuit breaker technologies.

That alone is a clear indication that many industries would obviously prefer using this circuit interruption technology.

And in most cases, it is common and suitable in medium voltage application.

One aspect which you also ought to realize is that this unit is mainly employed for outdoor applications which range from 22Kv to 66Kv.

And that is probably the reason why you would mostly find them suitable for various applications in several parts of rural areas.

Some of the outdoor applications for this type of vacuum circuit breaker include the following;

a) Electric Transmission

It is probably one of the applications where the use of this unit is seemingly common.

Electric transmission stations use various components to ensure that all the aspect of transmitting electricity is feasible and efficient.

So as the central power station, the use of outdoor vacuum circuit breakers becomes inevitable.

The vacuum breakers help in protecting these transmission lines as well as controlling them to attain the necessary rating.

Of course, the type of outdoor vacuum circuit breaker to use varies depending on various factors.

However, the configuration of these units on electric transmission stations and power lines may depend on the arrangement of the poles.

On the same note, the outdoor vacuum circuit breakers are also useful in the electric transmission systems, especially in interconnecting HVDC transmission systems.

b) Electric Transformers

This is also the other area where the application of outdoor vacuum transformers seems to be very common.

An electric transformer is designed to transfer electrical energy between two or more circuits via electromagnetic induction.

Therefore, it clearly shows that the use of the outdoor circuit breaker in these devices is essential as it helps to regulate the electrical energy transferred.

And for that reason, the circuit breakers in these devices make it possible to prevent incidents such as fire and destruction of electronic items.

c) Electrical Boxes

In various industries, you’ll realize that the use of electrical enclosures is becoming common.

The ideal reason is primarily that these boxes are useful in storing and protecting various electrical components and instruments.

And given that they house a wide range of electric instruments and components, there is a need for making sure that they work effectively.

One way of attaining this, definitely, is by integrating vacuum circuit breaker as a way of ensuring that they do not short-circuit.

In this instance, the vacuum circuit breaker helps significantly in regulating the transfer of electric energy from each of the instruments.

Furthermore, the VCB also prevents the electrical cabinet from exploding which often is as a result of high temperature within the box.

Additionally, this unit also protects the electrical boxes from damaging especially from lightning and other related aspects.

These are some of the most common applications of outdoor VCB.

Again, I’m hopeful that you now have a better understanding of the concept of working principle of VCB as well as its applications.

Now in the next chapter, we want to discuss more regarding the standard testing procedure for vacuum circuit breaker.

Indeed, it is crucial because it shall also help you to grasp the idea of what it takes to have an efficient outdoor circuit breaker.

Chapter 3: Vacuum Circuit Breaker Testing Procedure

Here’s the truth,

The moment there is a fault on any electrical system, the essential factor to consider is the fast and reliable protection.

You see, like in the case of a circuit breaker failure to clear the fault at the crucial moment, the ensuing damage can be disastrous.

And remember the extent of the disastrous damage can affect both the equipment and personnel handling the same.

What I’m trying to say here is that in as much as outdoor VCB can be dependable, there are instances when they gather dirt, contaminants, and moisture.

And those breakers which are used in hostile environments are prone to exposure to a wide range of corrosive contaminants.

Eventually, you’ll realize that these contaminants end up damaging the metal components like the main contacts as well as the insulation system.

The bottom line here is that there is a need for testing the circuit breakers from time to time. The essence for this is to guarantee proper operation in case of electrical faults.

But before you consider doing the tests, it is important to know the procedures to enable you to carry out the respective assessment.

Typically, the procedures for carrying out such tests are different depending on a wide range of factors.

But in this case, I will let you know the three standard procedures which you may choose to undertake when testing outdoor circuit breakers.

1) Contact Resistance Test

Well, this test revolves around the periodical assessment of the main contacts and primary stabs. The essence is to detect abnormal wear, loose pivot points and inadequate lubrication inside the VCB.

What usually happens is that the damaged contacts which are poorly maintained or the broken contacts often cause electrical fires and arcing.

So when carrying out this test, you should always ensure that you use low voltage DC power supply to transmit current from line to load.

At the same time, the circuit breaker should always remain in a closed position.

When testing, the current must always be equal to the circuit breaker’s rating of 100 amperes.

Incidentally, it is also acceptable to use a test current which is less than 100A. However, you should know that manufacturers never recognize warranty claims on the basis of 10-ampere DLRO test.

Moreover, the values for measuring resistance should be within 50% of every adjacent phase.

It is also unacceptable for the resistance to exceed the manufacturer’s test level by more than 200%.

And the moment the maintenance testing is over, the contact resistance needs to be as low as possible across all the three circuit breaker’s phases.

Nevertheless, the actual contact resistance will be dependent on the continuous current rating of the circuit breaker.

2) Insulation Resistance Test

This is also the other fundamental test procedure that you may choose to undertake in the testing vacuum circuit breaker.

To say the least, the insulation system of a circuit breaker is vitally critical hence requires thorough and regular evaluation.

In many instances, the insulation system often weakens as a result of heat that the arc interruption creates, especially if not maintained.

So a thorough evaluation would reveal that weak insulation leads to catastrophic failure, particularly during arc interruption.

Therefore, when you undertake an insulation resistance test, it enables you to detect fundamental defects in the insulation system.

Nonetheless, you can as well use it as the ultimate safety check before you restore the breaker to service.

When performing this test, always ensure that you use a megohmmeter phase-to-phase and phase-to-ground.

At the same time, the circuit breaker must always remain in a closed position.

You also need to ensure that you use the manufacturer’s acceptance values and ideal test voltage when carrying out this test.

And in any case, you come across one that doesn’t have manufacturer’s recommendations, ensure that you use NETA maintenance specifications.

Still, on the insulation resistance test, there is an aspect of control wiring, which also requires testing. This is vital because often, it can easily be cut on sharp edges particularly when moving the circuit breaker inside and outside of its cell.

Remember that it only takes a single wire shorted inside the VCB to prevent it from clearing a fault.

And since this can lead to failure of the trip coil protective relay and in other instances the trip coil.

When performing this test, you need to connect all the secondary disconnect pins points and measure the resistance from wire to chassis.

When conducting this test, never apply a high voltage to solid state instruments or spring charging motor.

Ensure that you isolate all the devices before you choose to carry out the insulation resistance testing.

3) Dielectric withstand voltage test

This particular test merely refers to a hipost test. It actually picks up where the insulation resistance left off.

It happens that this particular type of test becomes essential when you need to detect deterioration, tracking, and moisture in the insulation system.

When testing medium vacuum circuit breakers, it is ideal to use an AC high potential test set.

But in any case there are no specific recommendations available, always make sure that you use NETA maintenance specifications.

When performing this particular test, you must always make sure that the circuit breaker is open.

And you have to undertake this test from the line side of every phase while all of them are tied and connected to the ground.

Performing this test on a vacuum circuit breaker indicates a vacuum bottle integrity.

At the same time, you should also understand that the vacuum bottle integrity test only indicates the current state of the vacuum bottle.

And for that matter, it cannot necessarily predict the remaining life or determine the vacuum level inside the interrupter.

So these are the major outdoor vacuum circuit breakers testing procedures which you can use to determine the effectiveness of the unit before using it.

Therefore, you can choose any of them depending on the particular one that you would vitally wish to test and set.

Also, you should be aware of performing another functional testing of the trip and close circuit via the manual controls.

Furthermore, once you complete performing the particular test, you should never forget to affix the correct field testing label.

The importance of this label is to indicate the last maintenance date. It also serves the purpose of showing the overall condition of the instruments which have been tested and maintained.

And so talking of maintenance, we want to look at the various aspects revolving around vacuum circuit breaker maintenance in the next chapter.

Hopefully, it’ll provide you with an idea of what it takes to have a fully maintained VCB all the time as a way of enhancing efficiency.

Chapter 4:  Vacuum Circuit Breaker Maintenance

Now, the most critical question that you need to ask yourself, in this case, is how frequently you need to perform VCB maintenance.

Well, something which you ought to understand is that circuit breakers are components you can find in nearly all electrical systems.

You may think that these units are only applicable in the large outdoor electrical applications. The truth, however, is that you use the circuit breakers even in residential dwellings.

And now that you know the circuit breaker construction and operation, it should also be fundamental in realizing appropriate usage.

Now, there are basic concepts which you must have at your fingertips before even thinking of starting the maintenance process.

The first fundamental thing which you must always do is switching off the circuit breaker. This is an underlining safety measure which you must never take for granted.

Secondly, after switching off the breaker, you then must isolate it from both sides by opening the relevant electrical isolator.

So let’s now get straightaway to the main points pertinent to the maintenance of outdoor circuit breaker;

You need always to ensure that you operate the circuit breaker electrically from local and remote then mechanically from local.

The essence of this type of operation is to make the breaker relatively reliable since it helps in removing coatings that are between sliding surfaces.

Check the contact burning and get rid of the burn beads and polish the surface, in any case, the burning is light.

And if the burning is massive, make sure that you replace, and reset the tips and arcing ring.

When replacing the new set, ensure that you first loose and tighten the tips a few times before doing the final tightening.

The other element regarding the maintenance of this unit is checking the extinguishing chamber. Ensure that you remove it from the breaker, wash the chamber.

In any case, there is any part which indicates severe burning, makes sure that you dismantle the chamber and replace the damaged parts.

Also, you need to always clean and lubricate the VCB mechanism to remove the ruts on it and from the metal mechanism.

And when you think of lubrication, it is necessary to use high-grade grease, and you must lubricate even the friction clutch accordingly.

After every six months, make sure that you check the locking pins of tie rods. Properly tighten all the foundation bolts electrical terminal connections at the circuit of the VCB once you remove oxide coating.

Still, you must also adjust the auxiliary switch by ensuring that there are correct NC contacts at the breaker ON and OFF after every six months.

You must as well clean and lubricate the spring charging motor mechanism and the associated bearing after every six months.

Check for any leakage and should you find one make sure that you plug it. On a monthly basis, check the grading capacitors.

As you can see the overall maintenance of an outdoor vacuum circuit breaker requires quite a lot of interventions.

You need to be particular when it comes to maintaining this unit because it is the element that will make it safe, efficient and durable.

What I can assure you is that should you fail to properly maintain your VCB the ultimate results might not be appealing.

And for that matter, it is merely inevitable to carry out all the mentioned and other forms of maintenance on the circuit breaker.

The bottom line, however, is that having a standard maintenance program for your vacuum circuit breaker is ideal.

It enables you to attain the necessary consistency as a way of making sure that the equipment functions appropriately.

Regular maintenance is also vital because it enables you to reassess and the reliability and condition of you VCB. And therefore, it makes it easy for you to adjust the frequency accordingly.

Orecco: Your best Vacuum Circuit Breaker Manufacturer for Industrial Applications

Now, what you need to take note of is that nowadays, several types of VCB from different manufacturers are hitting the market.

Indeed, this is a bit tricky because it confuses you as the user especially if you’re not aware of the best model to go for.

Therefore, it would be unfair to inform you will all these elements regarding best VCB and fail to give you an idea of a highly recommended manufacturer.

In fact, the best bet when purchasing an outdoor vacuum circuit breaker is always by obtaining it from a reputable manufacturer.

Remember that outdoor vacuum circuit breaker is somewhat an expensive investment which you can always keep on purchasing.

And that’s the reason you indeed, require to get a manufacturer that has an established name in this industry for producing high-quality units.

So Orecco is the company that fits all these descriptions.

This company should be your ultimate choice if you’re looking for high quality and reliable circuit breaker for various types of industrial applications.

It has a marvelous reputation when it comes to manufacturing high quality and efficient circuit breakers for numerous applications.

Orecco gives you the many options to choose from especially when you’re looking for a particular type of VCB.

And this is important since you will be confident of using the specific VCB for that particular application and not improvising.

At the end of the day, all you need to attain from a VCB is quality service and all-around safety.

So when you choose to buy any type from Orecco, you can be guaranteed of nothing short of quality and reliability.

In fact, this company has been around for several years now. And this has made it possible for it to understand and incorporate various technologies in a bid for making its products better.

And the most important thing about the same is that it provides you with all the relevant advice and recommendation you’d need.

Therefore, possibly as a newbie in this industry, the mistake you should ever avoid when shopping for VCB is buying from an unknown manufacturer.

And for that reason, I highly recommend Orecco for any of your outdoor vacuum circuit breaker solutions.

Conclusion

As we conclude this guide, I believe that it has opened your eyes by giving some of the great ideas regarding outdoor VCB.

I’m hopeful that at least for now, you understand what an outdoor vacuum circuit breaker entails and some of its aspects.

I also know that you can now tell how the VCB works given that this guide has elaborated more on its working principle.

Nevertheless, you now know some of its common industrial applications as well as the testing procedures for this unit.

This guide has also enabled you to know the most important elements regarding the maintenance of the outdoor vacuum circuit breaker.

And importantly, you now know the best manufacturer to purchase this equipment from in any case you’re looking for one.

So in a nutshell, this guide gives you the ultimate reason for buying or importing a high quality and reliable vacuum circuit breaker.

But should you have any question, concern or suggestion, feel free to share with us and our team will gladly get back to you.

Also, you can share this guide on your social media handles. Perhaps it may come in handy to help your friend or acquaintance in need of the same information.