A three-phase pad-mounted transformer is a type of electrical transformer designed
for outdoor installation at ground level, typically mounted on a concrete pad. These
transformers are commonly used in distribution networks to step down high-voltage
primary power to a lower, more usable voltage for commercial, industrial, and
residential applications.
Key Features and Benefits
• Compact and Secure Design: Pad-mounted transformers have a compact design and are
enclosed in a tamper-resistant cabinet, providing safety and reliability in public areas.
• Outdoor Installation: These transformers are designed to withstand harsh outdoor
conditions, including exposure to sunlight, rain, and temperature variations.
• Low Noise Operation: Pad-mounted transformers are designed to operate quietly,
making them suitable for installation in residential and urban areas.
Components of a Three-Phase Pad-Mounted Transformer
1.Core and Coil Assembly
o Core: Made of high-grade silicon steel to minimize core losses and enhance
efficiency.
o Coils: Typically made of copper or aluminum, these are wound around the core
to create the primary and secondary windings.
2.Tank and Cabinet
o Tank: The transformer core and coils are housed in a steel tank filled with
transformer oil for cooling and insulation.
o Cabinet: The entire assembly is enclosed in a tamper-proof, weather-resistant
cabinet.
3.Cooling System
o Oil Cooling: The transformer oil circulates to dissipate heat generated during
operation.
o Radiators: Attached to the tank to increase the surface area for better heat
dissipation.
4.Protection Devices
o Fuses and Circuit Breakers: Protect the transformer from overcurrent and short
circuits.
o Pressure Relief Device: Releases excessive pressure buildup inside the tank to
prevent damage.
5.High Voltage and Low Voltage Bushings
o High Voltage Bushings: Connect the transformer to the high-voltage primary
supply.
o Low Voltage Bushings: Provide connection points for the low-voltage secondary
output.
Applications of Three-Phase Pad-Mounted Transformers
• Commercial Buildings: Providing power to office buildings, shopping centers, and other
commercial facilities.
• Industrial Facilities: Supplying power to factories, warehouses, and other industrial
operations.
• Residential Areas: Distributing electricity to residential neighborhoods and housing
developments.
• Renewable Energy Projects: Integrating power from solar panels and wind turbines into
the grid.
Advantages of Using Three-Phase Pad-Mounted Transformers
• Ease of Installation: Quick and straightforward installation on a concrete pad without the
need for additional structures.
• Safety: The tamper-resistant enclosure and secure design ensure safe operation in public
and private areas.
• Reliability: Robust construction and protective devices contribute to long-term, reliable
Performance
• Low Maintenance: Designed for minimal maintenance with features like sealed tanks
and durable components.
Conclusion
Three-phase pad-mounted transformers are essential components in modern electrical
distribution networks, offering a reliable and efficient solution for stepping down high
voltage to usable levels in various applications. Their compact design, secure
enclosure, and robust construction make them suitable for outdoor installations in
commercial, industrial, and residential settings. With their ease of installation and low
maintenance requirements, these transformers provide a cost-effective and dependable
power distribution solution.
Detailed Structure
Design
HV Bushing Config.:
• Dead front or live front
o Loop feed or radial feed
Fluid Options:
• Type II Mineral Oil
• Envirotemp™ FR3™
Standard Gauge/Accessory Package:
• Pressure relief valve
• Pressure vacuum gauge
• Liquid temp gauge
• Liquid level gauge
• Drain & sample valve
• Anodised aluminum nameplate
• Adjustment taps
Switch Options:
• 2 Position LBOR Switch 4 Position LBOR Switch (V-blade or T-blade)
• 4 Position LBOR Switch (V-blade or T-blade)
• (3) 2 Position LBOR Switches
Fusing Options:
• Bayonets w/ isolation links
• Bayonets w/ ELSP
Construction:
• Burr-free, grain-oriented, silicon steel, 5-legged core
• Rectangular wound copper or aluminum windings
• Carbon reinforced or stainless steel tank
• Steel divider between HV and LV cabinets
• (4) Lifting lugs
• Penta-head captive bolt
Optional Design Features & Accessories:
• Gauges w/ Contacts
• External drain and sample valve
• Electro-static Shielding
• K-Factor Design K4, K13, K20
• Step-up Design
• Surge-Arresters
Post time: Jul-15-2024