Auto Recloser Function And Working Principle In Power System
If you are responsible for the procurement or upgrading of power distribution systems, then automatic reclosing in power systems is a critical issue that directly impacts outage costs, customer satisfaction, and operational and maintenance pressures.
This article explains the function, working principles, and selection criteria of auto reclosers in power systems.
Auto Recloser Function
If you look at automatic reclosers from a procurement perspective, they are not simply “switches that trip,” but rather active system nodes that manage faults. Their function directly determines how your power grid operates.
Fault Interruption And Isolation
When a short circuit or ground fault occurs, the biggest fear isn’t the circuit breaker tripping, but rather the fault being amplified uncontrollably.
Automatic reclosers identify abnormal currents and quickly isolate the faulty section within milliseconds.
This means you can minimize the impact of power outages, preventing a complete blackout.
In a real-world case, after a Midwestern industrial park in the United States installed Beyie Electric’s automatic reclosers, the number of users affected by a single ground fault decreased by over 70%. You’ll find that isolation capability is the first line of defense for reliability.
Automatic Power Restoration
You should know that most power line faults are transient.
Wind-blown branches, bird contact, lightning strikes—these problems often resolve themselves naturally within seconds.
The value of an automatic recloser lies in this:
It automatically recloses the circuit after an interruption, attempting to restore power, instead of waiting for you to send someone, drive there, inspect, and operate the equipment.
For you, this means:
● Less manual intervention
● Fewer customer complaint calls
And all of this is done automatically.
Protection Coordination
If you have already deployed circuit breakers, fuses, and relay protection in your system, you will undoubtedly be concerned about whether they will “conflict” with each other.
A properly designed automatic recloser will establish a clear sequence of operation with the upstream circuit breaker and downstream fuses.
In Beyie Electric’s project practices, the recloser is typically set to attempt to clear the fault before the fuse operates, thus avoiding unnecessary fuse replacements. This coordination significantly reduces maintenance costs in the long run.
Improving Power Supply Reliability
You don’t need complex mathematical models to feel the difference.
When you introduce automatic reclosers, the number of power outages decreases, the restoration speed increases, and customers’ tolerance for power quality issues improves significantly.
Auto Recloser Working Principle
How do reclosers work?Understanding how something works isn’t about enabling you to adjust parameters, but rather to help you avoid being misled by specification sheets when choosing a product.
Fault Detection
Automatic reclosers continuously monitor line current and voltage through built-in sensors. When an abnormal change exceeding a set threshold is detected, it immediately determines whether it is a fault.
The key here is not “whether it detects,” but rather the accuracy of the detection.
Modern reclosers typically support:
● Overcurrent detection
● Ground fault identification
● Directional protection
When purchasing, you should focus on the maturity of the algorithms, not just the rated parameters.
Tripping Operation
Once a fault is detected, the recloser will trip, interrupting the power supply. The recloser reduces arc energy, minimizes equipment damage, and prevents the fault from spreading. You can think of it as “decisive damage control.”
Reclosing Sequence
A circuit breaker trip doesn’t necessarily mean the end of the process.
The automatic recloser will attempt to reclose the circuit one or more times according to a preset logic.
Common logic includes:
● Fast reclosing
● Delayed reclosing
● Lockout after multiple attempts
If the fault is transient, power is restored almost immediately; if it is permanent, the system proceeds to the next step.
Lockout Operation
When multiple reclosing attempts fail, the automatic recloser enters a locked state to prevent repeated reclosing from causing further damage. Locking means the device is in a “protective system” mode, rather than “blindly attempting” to reclose.
Based on field experience, a reasonable locking strategy can significantly extend the lifespan of power lines and switchgear.
What Are Reclosers In Power Systems
What is a recloser? In the entire power system, automatic reclosers are typically deployed in medium-voltage distribution networks, especially in overhead line scenarios.
They are widely used in:
● Urban and rural distribution networks
● Industrial park feeders
● New energy grid connection lines
If you are advancing distribution automation or reducing on-site operation and maintenance pressure, reclosers are almost an indispensable choice.
How To Choose
Choosing an automatic recloser isn’t simply about “picking the cheapest one.”
Truly mature purchasing decisions often revolve around the following key points:
● Rated voltage and system compatibility
● Control and communication capabilities
● Mechanical and electrical lifespan
● Brand engineering experience
● After-sales service and technical support
You’ll find that the differences in automatic recloser prices are often hidden in these unseen details.
Auto Recloser Price Comparison
| Type | Voltage Range | Control Mode | Typical Application | Price Level |
|---|---|---|---|---|
| Basic Hydraulic | 11–15 kV | Mechanical | Rural Lines | Low |
| Electronic Recloser | 15–27 kV | Local Control | Urban Distribution | Medium |
| Smart Recloser | 33 kV | SCADA / Remote | Industrial & Utility | Medium–High |
FAQ
Auto Recloser VS Circuit Breaker?
If you are looking for automatic restoration capabilities at the feeder level, an auto recloser is more suitable; however, for substation main protection, a circuit breaker remains indispensable.
Where Are Auto Reclosers Installed?
They are typically installed on overhead distribution lines, branch nodes, or at the front end of important loads.
What Causes Auto Reclosers To Lock Out?
Permanent faults, multiple reclosing failures, or protection triggered by parameter settings.
Can Auto Reclosers Be Remotely Controlled?
Yes, modern products support SCADA, DTU, and remote monitoring.
What Voltage Levels Are Auto Reclosers Used For?
Commonly 11kV, 15kV, 27kV, and 33kV.
How Often Should An Auto Recloser Be Maintained?
Comprehensive inspection is generally recommended every 3–5 years, depending on the operating environment.
What Is The Typical Lifespan Of An Auto Recloser?
High-quality products typically operate reliably for 20–30 years.
What Factors Affect The Price Of An Auto Recloser?
Voltage level, control system, communication functions, and brand experience all affect the price.
How Many Reclosing Attempts Does An Auto Recloser Have?
Usually 1–4 times, configurable according to system requirements.
Are Auto Reclosers Suitable For 33Kv Distribution Systems?
Absolutely, Beyie Electric has verified stable operation in multiple 33kV projects.
Conclusion
Proper selection of automatic reclosers can significantly reduce power outage time, improve system reliability, and lay the foundation for future smart power distribution.
If you want to achieve a true balance between Auto Recloser price and performance, choosing a manufacturer with engineering experience and system understanding is crucial. Based on extensive project experience, Beiye Electric provides purchasers with stable, scalable, and reliable automatic recloser solutions.
