Demand for electricity has increased over the past decade due to urbanization, data centers, and the increase in electronics availability. The expectation is that the lights will always be on. When distribution is interrupted even temporarily by a branch falling on a line, lightning strike, or animal contact, consumers expect the outage to be temporary.
These temporary faults can be cleared by a recloser on a pole automatically opening and then reclosing the circuit after the fault. The pole mounted recloser will attempt to clear the fault up to three times at predetermined intervals. Once the fault has been cleared, the power is restored automatically. The purpose of pole reclosers is to reduce outage times and provide reliable power.
Reclosers are pole mounted on distribution systems or are installed on distributed energy renewable systems (DERs) at intertie connections, either in an overhead application or a padmounted application. Overhead reclosers on poles are used in areas where undergrounding lines is difficult due to terrain or environmental considerations.
Why is a Recloser Pole Important in Distribution Networks?
Many distribution networks with voltage ratings from 15.5kV to 38kV consist of overhead power lines. To increase reliability and resiliency, pole reclosers are installed to reduce the duration and number of outages.
System average interruption duration index (SAIDI) and system average interruption frequency index (SAIFI) are reliability indexes used by power utilities. Reclosers on a pole reduce outage durations (SAIDI) by clearing temporary faults quickly without having to send workers out to locate and fix the fault. By automatically restoring power quickly after temporary faults, pole reclosers reduce the number of prolonged outages experienced by customers. These modern reclosers are designed to meet industry standards for reliability and outage reduction.
Reclosers are typically mounted on the utility pole. G&W Electric’s pole reclosers are offered in a variety of configurations to fit specific applications.
- Center mount – positioned with the recloser frame centered on the pole
- Alley arm – – Ideal for overhead applications where all three-phase conductors are on the same side of the pole or for congested installations with minimal phase spacing.
- Cross arm – two of the reclosers are mounted on one side of the pole while the third recloser is mounted on the other side.
- Cluster – each of the three reclosers is on a different side of the pole.
Understanding Pole Mounted Reclosers
From distribution networks to renewable energy integration, pole mounted reclosers deliver precise protection and control. Pole reclosers continually monitor electrical lines using sensors, such as current transformers (CTs) and voltage sensors to detect abnormalities caused by lightning strikes, branches on the line, or animal contact. When a fault is detected, the recloser automatically opens the circuit, interrupting the fault current and stopping the power flow to the fault area. The recloser waits briefly before re-energizing the circuit.
In contrast, load break switches or circuit break switches are not designed for current interruption during fault conditions but are used to isolate specific loads for maintenance or repair work.
Pole mounted reclosers typically use either internal or external current transformers (CTs) and voltage sensors. The sensors provide current and voltage readings to the recloser control, where the control system processes this data for automatic switching and protection. The control uses this analog information to provide real time measurement and monitoring of the distribution network. Other options available are automation-ready controls with features that allow for advanced protection, programmability, integration with SCADA or other distribution automation systems, and site-ready assemblies which reduces the pole mounted recloser installation time in the field. Potential transformers (PTs), arresters, aerial lugs, terminal/junction boxes, wildlife protectors, and all associate wiring may be included, reducing installation time in the field.
Types of Reclosers on Poles
To protect the electrical components in reclosers either oil or solid dielectric insulation is used. Each insulation method has pros and cons.
- Oil filled reclosers offer long-term reliability and require periodic maintenance, can be prone to contamination, and are more expensive.
- Solid dielectric reclosers are environmentally friendly, require less maintenance, but require more design considerations.
G&W Electric’s Viper recloser family utilizes a time-proven epoxy polymer system that encapsulates the vacuum interrupters, providing excellent insulation properties and ensuring long-term performance. Solid dielectric recloser on a pole are more compact and lightweight compared to oil reclosers.
Pole reclosers are available in single-phase, three-phase or single triple-phase. There are recloser manufacturers like G&W Electric who offer all three types of pole reclosers. The Viper-S solid dielectric pole recloser is rated up to 38kV. The Viper-SP pole recloser is designed for automatic or manual operation providing overcurrent protection for single-phase systems. The Viper-ST pole recloser offers three distinct mechanical operating modes.
- Three phase trip with three phase lockout
- Single phase trip with three phase lockout
- Single phase trip with single phase lockout
Benefits of Installing Reclosers on Utility Poles
- Reliability – engineered to withstand faults and ensure continuous operation
- Maintenance-Free – less maintenance lowers total cost of ownership
- Compact and Lightweight – suitable for various applications with configurations that meet space constraints
- Safety – dead-front construction enhances worker safety and reduces wildlife contact
- Automation Compatibility – integration with distribution automation systems, enabling remote control and monitoring
- Cost-Effective – longer lifespan, ease of installation, and reduced maintenance contribute to lower cost of ownership
Why Choose G&W Electric for Your Recloser on Pole Needs?
G&W Electric has been a leader and innovator in the power industry for more than 115 years. The Viper line of reclosers on a pole incorporates the latest technology to deliver reliable, maintenance-free overcurrent protection for power systems up to 38kV. The time-proven reliability of the electronically controlled, vacuum fault interrupters with the maintenance-free and environmentally safe benefits of the solid dielectric Viper pole reclosers makes G&W Electric is a leader in reclosers.
Ready to enhance your grid with pole mounted reclosers? Contact G&W Electric today for expert consultation and support
FAQ
What is the main purpose of a recloser on a utility pole?
- The main purpose of a recloser on a utility pole is to automatically detect and interrupt temporary electrical faults, such as those caused by lightning or tree branches, and then quickly restore power by reclosing the circuit, minimizing power outages and improving grid reliability.
How does a pole mounted recloser differ from a traditional circuit breaker?
- Unlike traditional circuit breakers that stay open after tripping, a pole mounted recloser can automatically reclose after opening to test if the fault has cleared. This automatic reclosing helps restore power faster for temporary faults without requiring manual intervention.
Can a recloser utility pole handle permanent faults?
- Yes, a recloser utility pole will attempt to reclose several times after detecting a fault. If the fault is permanent and not cleared after a preset number of reclosing attempts, the recloser locks open to isolate the faulted section, requiring manual repair.
