1000 kVA Pad Mounted Transformer-13.2/0.48 kV|Usa 2025

The three-phase three-column core consists of three vertically arranged columns, each corresponding to a phase of electrical power. These columns are connected by horizontal beams, forming a rigid structure that provides good mechanical strength and stability. This design ensures that the transformer can withstand various mechanical stresses during operation while maintaining optimal magnetic performance. The three-phase three-column core forms a closed magnetic circuit, effectively concentrating the magnetic flux and reducing leakage magnetic flux. The core is made of low-loss silicon steel sheets that are stacked together. These silicon steel sheets have excellent electromagnetic properties that effectively reduce eddy current losses and hysteresis losses.

The low-voltage bushing retainer for pad-mounted transformers is a critical structural component designed to secure and stabilize bushings in configurations exceeding ten openings. By providing robust mechanical support, it ensures the alignment and integrity of multiple bushing installations, effectively mitigating the risks of damage from vibration, thermal cycling, or external force, thereby enhancing the long-term safety and reliability of the transformer.

The transformer oil tank should provide facilities for installing the instruments, as shown in Appendix 2. At the same time, a 1-inch conduit installation facility from the interior of the low-voltage compartment to the location of the electricity meter should be provided. All doors must be able to be fully opened without any obstruction (such as the electricity meter, etc.). When the fixed type low-voltage compartment provides a minimum size of 16 1/2 inches x 33 1/4 inches of space and at the height specified in Appendix 2, no instrument installation facilities are required.

Insulation Fault Detection (IFD) for transformers is an online monitoring system that serves as an early warning device by continuously monitoring hydrogen gas (H₂) dissolved in the insulating oil. It detects the initial stages of internal insulation faults, such as partial discharges or overheating, which generate hydrogen, allowing for proactive maintenance before these issues escalate into major failures. Essentially, IFD acts as a preventive health screening for transformers, enhancing reliability and preventing catastrophic damage by identifying latent faults at their earliest and most manageable stage.

Pad-mounted compartmentalized transformers shall include the transformer tank and high and low voltage cable terminal compartments. The transformer tank and compartments shall be assembled as a unit for installation on a pad. There shall be no exposed screws, bolts or other externally removable fastening devices on the exterior. There shall be no openings through which foreign objects such as branches, metal rods or wires could come into contact with live parts. Appropriate means shall be provided for locking the compartment doors. A 1/2-inch hex head lock bolt with NC 2 thread class and separate from the locking device shall also be provided as shown in the attachment. The structural design shall limit the entry of water (except for floods) into the compartments to avoid affecting the normal operation of the transformer.

The transformer shall be equipped with six (6) ESNA, Permali, Components, Cental Maloney or Westinghouse high-voltage bushing holes (ANSI C119.2), externally clamped, for accepting load-break plugs to operate the transformer from a ring main type primary system. Fixtures for the Elastimold Style 164BA hoisting ring assembly shall be provided at the locations shown in Attachment 1. Corprene, Nitrile or other municipally approved gasket material shall be provided with limiting devices. The gasket material shall be installed properly to ensure that the high-voltage bushing holes are always in contact with the grounded tank. The length of the high-voltage leads shall be sufficient to facilitate on-site replacement of the bushing wells.