Single Phase Pole Mounted Transformers

High Voltage Bushing and Terminal – The HV Bushing is the connection point the incoming high voltage cables are attached feeding power to the transformer.

• Location: On the Top of the transformer tank
• Layout: 1 or 2 Porcelain Insulators with copper connectors on top for connection to the high voltage cables
• Function: Provides a safe and insulated connection point for high- voltage conductors into the transformer’s primary winding.

Tap Changer –  A Tap Changer on a single-phase pole-mount transformer is a device that allows adjustment of the transformer’s turns ratio to more closely match the incoming voltage and help regulate output voltage.

• Location: Usually mounted on the side of the transformer tank.
• Layout: Typically, a rotary or handle-operated switch with marked positions corresponding to different tap settings.
• Function: Adjusts the transformer winding ratio to compensate for variations in input voltage or load, ensuring consistent delivery of required voltage to customers.

Hanger Bracket – A hanger bracket on a single-phase pole-mount transformer is the structural component that secures the transformer to the utility pole.

• Location: Welded or bolted to the transformer tank’s side.
• Layout: Heavy-duty steel or alloy bracket with bolt holes designed for pole attachment.
• Function: Provides mechanical support, allowing the transformer to be mounted safely on a pole and remain stable during operation and all weather conditions.

Lifting Lug – A lifting lug on a single-phase pole-mount transformer is a
reinforced attachment point used for safe handling during installation or removal.

• Location: Positioned near top edges of the transformer tank.
• Layout: Heavy steel hooks welded to the tank.
• Function: Allows cranes or lifting equipment to safely raise and
  position the transformer on the pole without damaging the
  tank or components.

Pull Ring – Also known as Pressure Relief Device, it maintains stable internal pressure through the normal operation of the transformer.

• Location: Mounted on tank wall. Mounted above the oil level to prevent spillage during normal operation.
• Layout: Installed in threaded fitting with pull ring for manual and/or automatic operation.
• Function: Releases pressure in case of fault – Self sealing operation preserves oil quality by preventing contamination for outside atmosphere.

Nameplate – Also known as Data Plate is installed on all transformers for
identification

• Location: The metal Nameplate is permanently affixed to the surface of the polemount transformer or hanger bracket.
• Function: Provides all essential specifications and electrical data required for safe installation and operation of the polemount transformer.

Ground Boss – (change to Grounding Provisions) Provides various acceptable safety grounding points

• Location: Grounding provisions are placed in various places around the transformer tank.
• Layout: Grounding Provisions are always welded to the steel parts of the transformer.
• Function: Used to bond the transformer to a system ground and system neutral for personnel and operational safety.

Grounding Provisions – Provides various acceptable safety grounding points

• Location: Grounding provisions are placed in various places, both
  inside the cabinet in the High Voltage and Low Voltage
  compartments and on the external tank surfaces.
• Layout: Grounding Provisions are always welded to the steel parts of the transformer.
• Function: Used to bond the transformer to a system ground, system neutral and/or insulated conductor drain wires for personnel and operational safety