Vacuum Contactor
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Shaanxi huadian electric co., Ltd. It is located in Baoji high-tech development zone, Shaanxi province. A modern high-tech enterprise specializing in integrating research and development, manufacturing, and sales of vacuum circuit breakers.
Shaanxi huadian has nearly 10,000 square meters of circuit breaker production workshop, and has a fully automated control assembly line and a full set of imported circuit breaker testing equipment, with an annual production capacity of 10,000 units.
Why Choose Us?
High Quality
Our products every tiny part is made of the most suitable material，every single product comes out with strict inspection.
Advanced Equipment
Our has a fully automated control assembly line and a full set of imported circuit breaker testing equipment.
Good Service
We have complete pre-sales and after-sales service, professional team, 24 hours to serve you.
Technical Support
We has a professional research, and development team and a new product laboratory.
What is Vacuum Contactor？
A vacuum contactor is a device that contains electrical contacts inside a sealed “vacuum interrupter” Called a vacuum bottle. This sealed environment in which the switching takes place allows for a fast, clean “make/break” Action of the contacts in harsh, dirty environments.
Benefits of Vacuum Contactor
Reliability
Vacuum connectors provide consistent performance in the harshest and dirtiest applications because they work in enclosed environments.
Extended lifecycle
Reduced contact with other components inside the chamber limits the contactor’s mechanical wear, resulting in a longer lifespan.
Quiet operation
The contained environment also allows vacuum contactors to operate with significantly less noise than air brakes or circuit breakers.
Space-saving
Vacuum contactors are much smaller in size than larger-horsepower contactor devices and their panel housings, maximizing space.
Application of Vacuum Contactor
01
Motor Control
Vacuum contactors are commonly used for controlling motors in industries such as manufacturing, mining, and oil and gas.
02
Capacitor Switching
They are suitable for switching and controlling capacitors in power factor correction systems.
03
Power Distribution
Vacuum contractors play a crucial role in power distribution systems, enabling the switching and control of medium voltage circuits.
Important information:
●Vacuum contactors are used for motor control in various industries.
●They are suitable for switching capacitors in power factor correction systems.
● Vacuum contactors are essential for power distribution systems.
Components of Vacuum Contactor
Electromagnetic System: Electromagnetic system includes electromagnetic coil and core, which is an important part of vacuum contactor, relying on it to drive the closing and breaking of contacts.
Contact System: Contact is the executive part of vacuum contactor, including main contact and auxiliary contact. The role of the main contact is to connect and break the main circuit and control the larger current, while the auxiliary contact is in the control circuit to meet the requirements of various control modes.
Arc Extinguishing System: The arc extinguishing device is used to ensure that when the contact breaks the circuit, the resulting arc is reliably extinguished, reducing the damage of the arc to the contact. In order to quickly extinguish the arc when disconnected, usually vacuum contactors are equipped with an arc extinguishing device, generally using a half-sealed longitudinal seam ceramic arc extinguishing cover, and equipped with a strong magnetic arc blowing circuit.
Other Parts: Insulated shell, spring, short circuit ring, transmission mechanism, etc.
The vacuum contactor requires no adjustment. Preventative maintenance is recommended on a routine basis, once every twelve months, dependent upon the environment that the contactor is exposed to. In general, maintenance consists of keeping the device free of dirt and dust and ensuring the power and control terminals are tight.
Maintenance should verify the mechanical operation of the device for freedom of movement. Clean dirt from the surfaces. Pay particular attention to molded parts and tracking surfaces. Foreign materials on these surfaces should be removed by vacuum or wiping. Do not use compressed air to remove foreign materials.
A basic contactor switches electrical circuits within a mechanism as needed. Where vacuum contactor operating principles enter the picture is in the contactor’s housing. By initiating circuit switches in a vacuum, the switches can happen much more frequently. This makes the technology ideal for higher loads that involve more circuits.
Current flowing through a vacuum can break much quicker than one moving through air. This principle contributed to the rising popularity of vacuum contactors in the last several decades.
Air vs. Vacuum Contactors
While air contactors (also known as air break contactors) are the most widely used switching devices in motor control starters, vacuum contactors offer notable benefits for certain power system environments.
The switching action that occurs in an air contactor takes place in the open air, allowing the atmospheric pressure to extinguish the arc that resulted from the switch. A vacuum contactor, however, utilizes a vacuum bottle to create a sealed environment for the switching to take place in, allowing for fast and clean action in a harsh or dirty workplace environment. Not only does this prevent external factors from affecting the switching action, but the controlled vacuum bottle also helps to extinguish the arc quickly in medium-high voltage applications – leading to reduced downtime and better overall contact reliability.
Air contactors are a common choice for low voltage applications, as they are reliable and cost-effective. They use air to extinguish the arc that is created when the contacts open, and are able to handle high continuous currents. However, they can be large and require regular maintenance to ensure proper functioning.
Vacuum contactors, on the other hand, use a vacuum to extinguish the arc and are a great choice for medium to high voltage applications. They are smaller in size, have a longer lifespan, and require less maintenance than air contactors. They are also more energy-efficient and can provide better control over the flow of electricity.
However, vacuum contactors can be more expensive than air contactors and may not be suitable for all applications. It’s important to work with an experienced electrical engineer who can help you determine which type of contactor is best for your system based on its specific needs and requirements.
In some cases, a combination of air and vacuum contactors may be the best option. For example, air contactors can be used for the main power control and vacuum contactors can be used for secondary control.
No matter which type of contactor you choose, it’s important to select a high-quality product that is reliable and fits your system’s needs. Proper maintenance and regular testing can also help ensure the contactors continue to function properly over time.
What Is the Difference Between a Vacuum Contactor and a Vacuum Circuit Breaker?
|
Characteristic |
Vacuum Breaker |
Vacuum Contactor |
|
Continuous Current |
High (1,200 A, 2,000 A, 3,000 A or 4,000 A) |
Moderate (200 A) |
|
Switching Capability |
Switch currents from very low (magnetizing) values to full system short-circuit current |
Switch currents from very low (magnetizing) values to interrupting capability of vacuum contactor without fuses (at least 10 x continuous rating) Fuses operate for currents higher than the interrupting capability of the vacuum contactor alone, up to the interrupting capacity of the fuse |
|
Endurance – Mechanical |
High (typically 10,000 operations) (refer to ANSI/IEEE C37.06) |
Very high, up to 1,000,000 operations for up to 630A |
|
Endurance – Electrical |
High For vacuum, typically 10,000- 50,000 operations at rated continuous current For vacuum, typically 30 to 100 operations at full shortcircuit rating |
Very high Switching continuous current, 450,000 to 1,000,000 operations for up to 630 A Switching short-circuit current, endurance data not established in NEMA or UL standards; short-circuit current interruption requires replacement of currentlimiting fuses |
|
Application Limitations |
Not appropriate for very high endurance applications |
Well suited for very frequent switching operations |
|
Operation |
Electrically operated (manual operation for maintenance or emergency |
Electrically operated only |
|
Control Scheme |
Mechanically latched – circuit breaker remains closed on loss of system voltage |
Usually electrically held – vacuum contactor opens on loss of system voltage; vacuum contactor will close automatically on system voltage return Latched contactors are available |
|
Overcurrent/ Short-Circuit Protection |
Requires protective relays |
Requires protective relays for overload protection and current- limiting fuses for short-circuit protection |
|
Remote Operation |
Well suited |
Well suited |
|
Construction |
Drawout, if metal-clad (ANSI/IEEE C37.20.2) Stationary, if metal-enclosed (ANSI/IEEE C37.20.3) |
Stationary |
|
Space requirements |
Larger enclosure |
Smaller enclosure |
|
Purchase Cost |
Relatively high |
Moderate |
|
Maintenance |
Medium (long maintenance intervals, need to clean insulation) |
Low (simple mechanism, need to clean insulation, replace fuses) |
How to Test the Vacuum Contactor?
Vacuum interrupter integrity
Vacuum contactor reliability is dependent on the integrity of its sealed vacuum. The vacuum interrupter provides excellent dielectric strength to interrupt high currents to the vacuum contactor. While vacuum interrupters are known for being low maintenance with long life, it is important to ensure the interrupter is completely sealed for proper vacuum contactor performance. Check the dielectric strength of a vacuum interrupter using a High Potential test set.
High potential test
High Potential, or Hi-Pot, tests should be performed using a 50/60 hertz test set with a continuously variable voltage up to 20kV RMS. X-radiation is negligible at this level; however, personnel should not be closer than 6 feet to the interrupter under test to avoid electrical high voltage shock hazards. The contactor should be free of dust and other contaminants before conducting this test.
Connect output leads of the test set across the interrupter terminals with the contactor in the OPEN position. Slowly raise the test voltage from 0 to 10kV RMS and hold for 15 seconds. During this time, ignore any discharges or test set tripping unless it becomes impossible to reach test voltage and keep for 15 seconds. Throughout the test, leakage current should not exceed five milliamps. If the auto ramp Hi-Pot tester cannot raise voltage slowly, repeat the test 10 times or until it reaches the desired voltage level.
A successful withstand of the Hi-Pot test indicates that the interrupter is properly vacuum sealed. If a break-down occurs during the Hi-Pot test, remove the vacuum contactor housing a defective interrupter immediately.
A defective or unsealed vacuum in a vacuum contactor causes improper and unreliable motor starting operation, creating an unsafe environment for operators.
Contact resistance
With the switch closed, use a micro-ohmmeter to measure the resistance across the terminals. The contact resistance should be less than 200 micro ohms. If higher contact resistance values are measured, then the high potential test should be performed. If the contactor passes Hi-Pot test, recondition the interrupters by cycling the contactor on/off up to 20 operations. If the resistance still exceeds 200 micro ohms post cycling, replace the contactor.
Latching Mechanisms of Vacuum Contactors
Electrically Latched Vacuum Contactors
Electrically held vacuum contactors require a continuous control power source for the contacts to be closed. If you lose power or have a weak electrical system with sever voltage sag, the contacts could automatically spring open. Due to fewer components, electrically held contactors have a smaller footprint.
Mechanically Latched Vacuum Contactors
Mechanically latched vacuum contactors do not require a continuous control power source. A short control power signal is needed to close a contact and become latched. If a mechanically latched vacuum contactor loses control signal, the contacts will stay closed. A separate, short power signal is required to release mechanically latched contacts. This type of contact mechanism will take up slightly more space in the cabinet due to the extra components needed.
Mechanically Interlocked Reverser
To get the most out of your vacuum contactor, you should also consider whether your application requires a mechanically interlocked reverser. Applications that require forward and reverse motion from the motor will most likely need a mechanically interlocked reverser. The mechanically interlocked option offers one contactor dedicated to the forward motion while another is dedicated to reverse direction. You can implement this option by a mechanical “latch” or lever that prevents both contactors from closing at the same time. In this type of application, proper motor function depends on only one contactor operating at a time.
Our Factory
Shaanxi huadian electric co., Ltd. It is located in Baoji high-tech development zone, Shaanxi province. A modern high-tech enterprise specializing in integrating research and development, manufacturing, and sales of vacuum circuit breakers.
