What do you need to know about power pole transformer ?

Pole Mount Transformer Sizes

Pole-mount transformers, designed for installation on utility poles, come with weight requirements, typically not exceeding 1,000 kilograms. If the transformer's weight exceeds 1,000 kg, a bracket should be installed to ensure proper support.

Daelim Transformer offers pole-mount transformers with capacities reaching up to 333kVA. These transformers are engineered to meet stringent standards, providing reliable solutions for decentralized power distribution. The following outlines the available pole-mount transformer sizes from Daelim Transformer.

For information on other sizes or specific requirements for pole-mount transformers, please feel free to Contact Daelim Transformer. Our team is dedicated to providing tailored solutions to meet your unique needs.

Try for free: The Ultimate Guide to Pole Mounted Transformers

What are pole-mounted transformers filled with?

The power pole transformer is mainly composed of an iron core and winding. It is the magnetic path channel of the iron core transformer, and the winding is the circuit part of the transformer, which is made up of enameled wires with a certain number of turns. When it is connected to the power supply, we call it the primary winding, which is also called the primary winding. Connected to the load, we call it secondary winding, also called secondary winding or secondary winding. The basic forms of iron core structure include the core type and shell type. The core column of the transformer with the core structure is surrounded by windings. Simply put, the winding surrounds the iron core, so the structure is simple, and the assembly and insulation are easy, so the transformer often adopts the core structure. The shell structure is that the iron core surrounds the winding. The shell-type transformer has high mechanical strength and exposed teeth, but its manufacturing process is complicated and more materials are used. It is usually only used in low-voltage high-current transformers or small-capacity power transformers.

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How many houses can connect to a power pole transformer?

The answer to this question will vary by country, region, and community type. In the United States, on average, there is about one transformer in every city block, that is, about every 10 households are connected to the same power pole transformer.

However, transformers come in different sizes and capacities. The rated capacity is between 10kVA and 100kVA, and the most common one is around 50kVA. The amperage of the transformer will mislead most people because they will relate the amperage of the household switchboard to the actual average usage. However, the two are completely different. A 50-70 KVA power pole transformer, which can supply about 200/300A current, can meet the needs of 10 families, and each family has a 200A panel. The amperage of the panel is not only nominal but also super-large, while the amperage of the power pole transformer is real.

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The power pole transformer buzzing

The sound of the power pole transformer comes from inside the transformer. The transformer belongs to the principle of electromagnetic induction and is internally provided with a primary winding coil a secondary winding coil, and a silicon steel sheet with high magnetic permeability material in the middle. Under normal circumstances, the coil winding of the transformer is a coil called the "ampere-turns ratio" calculated according to the cross-sectional area of the iron core. Since there is a coil winding, there will be an exciting current when it is connected to the AC 50Hz power supply. There are two losses in the AC core coil. The variable loss is short-circuiting loss, that is, copper loss. It is also divided into two parts, namely the active power part and the reactive power part.

The power pole transformer can judge the running condition according to the running sound. The method is that one end of the listening bar is pressed against the oil tank of the transformer, and the other end is close to the ear to listen to the sound carefully. If it is a continuous "metaphor" sound, it means that the transformer is running normally. If the "metaphor" sound is worse than usual, check the voltage, current, and oil temperature of the transformer to see if it is caused by excessive voltage or overload. If it is the same, it is mostly caused by a loose iron core. When you hear "cheep, cheep", check whether there is a flashover on the surface of the casing. When the "crack" sound is heard, the internal insulation is broken down.

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Power pole transformer fault analysis

The faults of the power pole transformer are as follows:

(1) Winding faults: mainly include turn-to-turn short circuits, winding grounding, phase-to-phase short circuits, wire breaks, joint welding, etc.

(2) Casing damage: dirt is easy to accumulate on the bushing of a power pole transformer that has been running for a long time, and it is easy to cause single-phase grounding or phase-to-phase short circuits on the high voltage side of the Power Pole transformer in heavy fog or light rain.

(3) Oil tank failure: the oil leakage of the power pole transformer during operation will make the oil level gauge unable to display the oil level correctly. There are many reasons for transformer oil leakage, including weld cracking, sealing failure, corrosion, or damage to the oil tank.

(4) Tap-changer failure: including poor tap-changer contact and discharge at the contact point.

(5) Faults caused by overvoltage: When the running power rod transformer is struck by lightning, the high potential of lightning will cause external overvoltage of the transformer, resulting in damage to the transformer.

(6) Iron core failure: the iron core failure is caused by the insulation damage of the piercing screw or clamping screw of the iron core column.

(7)Discharge phenomenon: due to the low oil level of the power pole transformer, the insulation level is greatly reduced, which is easy to cause breakdown discharge.

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Check the power pole transformer

Always check the power rod transformer in operation, to find the abnormal phenomena or faults of the transformer in time and avoid the occurrence of major faults and losses. Items to be checked include:

(1) whether there is abnormal uneven noise, discharge sound, and other sounds in the pole transformer.

(2) Whether the oil level of the transformer is within the normal range and whether there is oil leakage.

(3) Whether the oil temperature in the oil tank is within the normal range.

(4) Whether the bushing of the transformer is cracked or damaged.

(5) Whether each joint of the transformer is hot.

(6) Whether the explosion-proof membrane in the explosion-proof tube of the transformer can be used normally.

(7) Whether the gas relay of the transformer is in normal operation and damaged.

(8) Check the oil level of the oil seal respirator.

(9) Whether the cooling system of the transformer is running normally and whether there is any fault.

(10)Whether the shell grounding wire of the transformer is damaged.Manufacturer of power pole transformer

Learn more: Single Phase Pole Mounted Transformer

Manufacturer of power pole transformer

Beijing Daelim is a transformer manufacturer and exporter located in Beijing, China. Daelim has been producing transformers for fifteen years and has rich experience in producing and exporting power pole transformers. Daelim produces power pole transformers, pad-mounted transformers, power transformers, distribution transformers, and dry-type transformers. The transformers produced by Daelim conform to IEEE, CSA, IEC, UL, and other international standards, and are exported to the United States, Canada, Mexico, the Philippines, Australia, and other countries. Feel free to consult!

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