Electrical Transformer Box - Modern Power Distribution

By R.W. Hurst, Editor

An electrical transformer box, often referred to as a "big green box" or "green metal box," is a critical component in modern power distribution systems. These boxes, commonly found in front yards or near sidewalks, play a vital role in ensuring the efficient and safe delivery of electrical service to homes and businesses. This article will explore the primary functions, key components, safety measures, types, and maintenance of these essential pieces of electrical equipment.

Primary Functions

The primary function of an electrical transformer box is to step down high voltages from power lines to lower, safer voltages suitable for residential and commercial use. These transformer boxes, known as pad mounted transformers, are connected to the electrical grid via underground cables. They ensure a stable and reliable supply of voltage electrical power, facilitating the delivery of electricity from the utility company to individual service points.

Key Components

Inside an electrical transformer box, several key components work together to achieve its functions:

Core: The core is typically made of laminated steel and serves as the magnetic pathway for the transformer.
Windings: These are coils of insulated wire wrapped around the core, where the primary winding receives high voltage, and the secondary winding delivers lower voltage.
Insulation: Ensures electrical isolation between different components and prevents short circuits.
Cooling System: Often involves oil or air to dissipate heat generated during operation.
Protective Devices: Include fuses and circuit breakers to safeguard against overloads and faults.

Ensuring Safety

Safety is a paramount concern when dealing with transformer boxes that handle high voltages. Several measures are in place to ensure their safe operation:

Robust Enclosures: The green metal boxes are designed to be weatherproof and tamper-resistant, protecting the internal components from environmental damage and unauthorized access.
Grounding: Proper grounding of transformer boxes helps prevent electrical shock hazards.
Regular Inspections: Utilities perform routine inspections to identify and address potential safety issues, such as leaks or corrosion.

Common Types and Their Applications

There are several types of transformer boxes, each suited to different applications:

Distribution Transformers: These are the most common type, used in residential areas to reduce high voltage from power lines to usable levels.
Power Transformers: Used in substations to transfer electricity between different voltage levels in the transmission network.
Pad Mounted Transformers: Installed at ground level and enclosed in tamper-resistant, green metal boxes, they are ideal for areas with underground cable systems.

Maintenance and Troubleshooting

Proper maintenance is crucial for the longevity and reliability of transformer boxes. Maintenance tasks typically include:

Visual Inspections: Checking for signs of wear, damage, or leaks.
Thermal Imaging: Detecting hotspots that indicate potential problems.
Oil Testing: For transformers with oil-based cooling systems, oil quality and contamination levels are regularly tested.

Troubleshooting involves identifying and resolving issues that may arise. Common problems include:

Overheating: Often caused by overloading or inadequate cooling.
Insulation Failure: Can lead to short circuits and requires immediate attention.
Mechanical Damage: Such as dents or cracks in the enclosure, which could compromise safety and performance.

Electrical transformer boxes, or big green boxes, play an indispensable role in modern electrical distribution systems. By stepping down high voltages from power lines, these boxes ensure that electrical equipment receives safe and reliable power. Understanding their primary functions, components, safety measures, types, and maintenance is essential for ensuring their efficient operation. With regular maintenance and proper safety protocols, transformer boxes can continue to provide reliable electrical service to homes and businesses, keeping our modern infrastructure running smoothly.

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03/12/20

Evluma Launches Line of Post Top Globes to Complement LED OmniMax

March 12, 2020, Renton, WA…Street and area lighting manufacturer Evluma, announces the release of a new globe accessory line, OmniMax Lighting Solutions (OLS) to complement their OmniMax family of LED replacement lamps. OLS is a custom, curated selection of spherical and acorn style globes for decorative streetlights. The OmniMax is a Bluetooth-connected, screw-in replacement lamp for use in decorative post top globe and acorn lights. The release of a globe line to complement the OmniMax is designed to make the HID to LED conversion and maintenance process easier for Evluma customers.

Customers executing a retrofit project can conveniently purchase a replacement globe at the same time they purchase the OmniMax. “The wide variety of styles and materials offered means that we can typically provide a customer with a globe that matches an older style,” said Marketing Director, Cathleen Shattuck. “Customers can refresh globes simultaneously with OmniMax installation to save on labor, or if they suddenly discover damage to individual light fixtures, we can quickly provide them with a solution. Our high level of customer service means we are well-adapted to quick turnaround on orders of any size, keeping the process convenient and low cost.”

Using OmniMax, municipalities, utilities and electric departments converting post top fixtures from HID to LED can do so in under 5 minutes a fixture. The OmniMax is available in both Premium and Standard models. Premium models are Bluetooth-enabled and are compatible with Evluma’s wireless control application, ConnectLED. Both models carry a ten-year warranty and offer Evluma’s signature low-glare illumination.

About Evluma

Formed in 2008, Evluma is committed to developing affordable, long-lasting and environmentally low-impact LED lighting solutions that fundamentally change the landscape of the outdoor utility lighting market. Evluma’s high standard of customer service and background in innovative lighting technologies, automation and software design creatively ideate and inform its utility-grade products. Evluma is located in Renton, WA, USA.

09/24/20

Evluma's Build-Your-Own Acorn is an Affordable Answer to Decorative Streetlight LED Upgrades

Street and area light manufacturer Evluma announces the release of Build-Your-Own Acorn; a full-fixture, decorative streetlight replacement solution that includes the customer’s choice of acorn globe, finial and capital fitter. This solution is designed for utilities, municipalities, facilities and property managers looking to upgrade their existing decorative lighting from HID to LED and features the OmniMax™ LED lamp as its light source.

“Build-Your-Own-Acorn is a tailored solution that puts control in the hands of the customer,” said Evluma Product Manager Jason Dobbs. “With the value-driven OmniMax at the center of quality, cost-effective options, this is an affordable approach to complete head replacements. Build-Your-Own-Acorn offers the freedom to replace and repair fixtures without being locked into a proprietary OEM solution that may be hard to change later and typically costs more. It’s everything but the pole.”

Build-Your-Own Acorn includes multiple styles of acrylic and polycarbonate globes, in addition to a cast aluminum capital fitter. The capital fits 3 inch and 4 inch poles and is offered in black or green. The 70W OmniMax LED lamp is offered in six different color temperatures ranging from 2000K-5000K in either the Premium or Standard. OmniMax Premium includes Evluma’s patented, maintenance-saving Photocontrol Failsafe™ and compatibility with Evluma’s Bluetooth lighting app ConnectLED™. OmniMax Standard ships without connectivity features or Photocontrol Failsafe built-in.

“Photocontrol Failsafe means never having to replace a failed photocontrol ever again,” said Janine Soper, Evluma’s Regional Sales Manager. “With ConnectLED, the OmniMax Premium can be quickly dimmed or programmed with a dimming schedule, offering additional aesthetic and energy saving opportunities,” said Janine.

Both OmniMax models are supported by robust 20kV/10kA surge protection and the OmniMax’s four layers of thermal management for extended operation in enclosed environments. The capital has a 5 year warranty on the finish. Acrylic globes are warrantied for 5 years against yellowing. The OmniMax and all electronics, including the capital’s optional photocontrol are warrantied for 10 years.

About Evluma

02/22/21

Parallel Resonant AC Test Sets

High Voltage, Inc. is an American test equipment manufacturing company located in rural Copake, NY. We are known for high quality, easy to use equipment and for our commitment to providing the best customer and product support in the industry.

As we matured we expanded into larger products. Cable fault locators (thumpers) as well as higher power ac (HPA) dielectric testers as might be used in a factory environment. Our HPA line of ac testers are available with outputs up to 300 kV ac and power levels up to 40 kVA and can be customized with various levels of control sophistication.

Our new PAR line of ac dielectric testers are designed to meet the needs of those who need power levels up to 250 kVA, to be able to test their highly capacitive test loads. Using ac resonant technology outputs of 50 kV at 5A (for example) are possible with an input of only 230 v, 90 A. That is an input of 20 kVA for an output of 250 kVA. (Model PAR-50250FC5)

The PAR models consist of a control section and a high voltage section. While large, they are transportable by van or trailer for field work. The control section includes the input breaker, variable (motorized) input control, a PLC controller, and connections for controlling the hv section. The high voltage section is a steel tank with a phenolic output bushing. Inside this tank is a variable-core reactor in an insulating oil bath with an air space at the top to allow for thermal expansion.

The variable reactor looks similar to a transformer but has a moveable core that allows the inductance value to vary to match the capacitance of the load, thereby achieving resonance. This effectively cancels the load capacitance, as far as input power requirements are concerned. Once in resonance, the input voltage is increased until the desired output voltage level is achieved. For a capacitive load that must be tested at power frequency the PAR reduces power requirements, as well as test equipment size by one tenth to one thirtieth, compared to a test transformer.

The HVI PAR family of resonant as dielectric testers are perfect for power frequency testing of power cables, rotating machinery, bushings, instrument transformers, transformers, shunt reactors, and many other products.

For more info please contact sales@hvinc.com to discuss your application.
For more information on these and other high voltage test products, contact High Voltage, Inc. at www.hvinc.com, sales@hvinc.com, or call 518-329-3275.

03/07/22

Evluma Launches Low-Glare LED Roadway Luminaire

LED lighting manufacturer Evluma announces the launch of a new roadway lighting product RoadMaxTM. The RoadMax series will include three sizes: small, medium and large and a range of wattages designed to replace legacy HID 100w, 250w and 400w cobraheads. The first model in the series, the RoadMax RX1, with wattages ranging from 30W-70W and an estimated output range of 3,000 to 9,000 lumens, is estimated to start shipping at the end of April 2022.

This sleek and stylish luminaire was designed with RP-8-18 roadway requirements in mind. The unique optical design offers a combination of roadway performance and glare control unprecedented in the industry. “RoadMax is an advancement of Evluma’s reputation for low-glare, visually-pleasing outdoor lighting,” says Taisha Bezzo, National Sales Director. “RoadMax addresses contemporary concerns regarding disability glare and light trespass from roadway lighting while maintaining exceptional pole spacing.”

Multiple luminaire configurations for Type II, Type III and Type V, all with zero-uplight (U0), are offered. Additional features such as a field adjustable wattage selector (FAO), light trespass shields and a choice of photocontrol sockets are available. RoadMax can be customized to include Evluma’s Photocontrol FailsafeTM, a patented technology that solves photocontrol failures on street and area lights. Compatibility with ConnectLEDTM, Evluma’s Bluetooth app for wireless lighting controls, enables dimming and dimming schedules without the need for a network. Evluma’s comprehensive 10-year warranty and signature 20kV/10kA surge protection comes standard with every model.