Basic knowledge about telephone pole transformer

A telephone pole transformer is a single-phase pole-mounted transformer. We can first understand what a single-phase transformer is, that is, a transformer whose primary winding and secondary winding are single-phase.

Daelim Transformer is a professional manufacturer and supplier of telephone pole transformers, with more than 20 years of experience in transformer production and export. Transformers manufactured by Daelim conform to IEEE, CSA, UL, and many other international standards. Daelim's hot-selling products include pole mounted transformers, pad-mounted transformers, power transformers, substation transformers, and distribution transformers. Please feel free to contact me for consultation.

What is a telephone pole transformer?

A telephone pole transformer, also known as a power pole transformer, is a single-phase device mounted on utility poles. It converts high-voltage electricity to lower voltage for distribution to local areas. Key components include the primary coil, secondary coil, and iron core. It is used for voltage adjustment, impedance matching, and safety isolation, playing a crucial role in distributing electricity to meet the demands of residents.

Read more about single-phase pole transformer

What does a transformer on a telephone pole do?

The transformer on the utility pole steps down the high voltage electricity on the power line to a lower voltage suitable for residential or commercial use. This makes the electricity safe and usable for everyday appliances and devices. It plays a vital role in the distribution network by efficiently converting and delivering electricity to the local area. It is usually more common in rural areas.

What is inside a pole transformer?

When you open the oil tank cap of a pole transformer, you will see:

• Insulating Oil: The liquid used for electrical insulation and cooling.
• Iron Core: The core that forms the magnetic circuit.
• Windings: The primary (high-voltage) and secondary (low-voltage) coils.
• High and Low Voltage Leads: Connections for the high and low-voltage circuits.
• These components are essential for the transformer's operation and maintenance.

How many amps is a telephone pole?

The current rating of a telephone pole transformer can vary widely based on its design and application. Typically, residential pole-mounted transformers range from 10 to 167 kVA (kilovolt-amperes), with common ratings being 25, 50, or 75 kVA. To estimate the current in amps, you need to know the transformer’s power rating and the output voltage.

For a typical residential transformer, assuming a standard secondary voltage of 240 volts, here’s how you can calculate the current:

1. Determine the transformer’s kVA rating.

2. Convert kVA to amps using the formula:

   Current (amps)=Power (kVA)×1000Voltage (V)\text{Current (amps)} = \frac{\text{Power (kVA)} \times 1000}{\text{Voltage (V)}}Current (amps)=Voltage (V)Power (kVA)×1000​

Example Calculation:

For a 25 kVA transformer with a secondary voltage of 240 volts:

Current=25 kVA×1000240 V≈104 amps\text{Current} = \frac{25 \text{ kVA} \times 1000}{240 \text{ V}} \approx 104 \text{ amps}Current=240 V25 kVA×1000​≈104 amps

Thus, a typical residential pole transformer might handle currents in the range of 50 to 150 amps, depending on its power rating and voltage.

What does a transformer on an electric pole do?

A transformer on an electric pole usually has two applications
 

1. Improve or reduce the voltage level in the power grid to meet residents' electricity and industrial electricity;

2. Emergency temporary power supply for construction and disaster relief site

The capacity of the transformer installed on the electric pole is usually not higher than 300kva, otherwise, the electric pole will not bear the weight. The side of the transformer will be designed with 2-4 lifting lugs, which are convenient to install on the electric pole.

How does a telephone pole transformer work?

A telephone pole transformer is an electrical device that converts voltage and transmits electric power. Its primary side is connected to the power supply, which provides electric energy to the power network. The secondary side is the output end, which connects to electrical equipment and supplies the electrical energy to the load.

When the primary winding is energized under rated voltage, an alternating current with a frequency of 50/60 Hz flows through it. With a constant voltage, the magnetic flux in the iron core remains steady; this flux is known as the main magnetic flux. When the secondary circuit is open, or the transformer is in a no-load state, the current flowing through the primary winding is called the no-load current. The product of the no-load current and the number of turns N in the primary winding represent the primary magnetic potential of the transformer.

According to the principle of electromagnetic induction, a changing magnetic flux passing through a coil induces an electromotive force (EMF). As the magnetic flux simultaneously passes through both sets of windings on the same iron core, an induced potential EEE is generated in the primary winding and an induced potential EEE is produced across the secondary winding. When the primary winding is connected to a load, a load current flows through the load, enabling the transformer to transfer electrical power from the supply to the load and output electrical energy. This describes the basic working principle of the transformer.

Read my article on How to test a power transformer?

How much copper is in a power pole transformer?

Winding and silicon steels account for about 70%of the total weight of the power pole transformer. The weight of copper in the power pole transformer is about 30%-40%.

For example, a 25 kVA power pole transformer's total weight is 225kg. Then, the total weight of the copper is about 68kg. The 50 kVA power pole transformer, is 320kg, of which the weight of the copper is about 96kg.

How much does a power pole transformer weigh?

Power pole transformer usually has cylindrical and square, with various capacities. Material and capacity are the main factors that affect the weight of the transformer. The larger the capacity, the heavier the transformer. The weight of copper transformer is about 20% heavier than aluminum.

For example, the total weight of a 100 kVA power pole transformer produced by Daelim is about 530kg, 167 kVA power pole transformer is about 680kg.

Read my article on 167 kVA Single Phase Pole Mounted Transformer

How long does it take to replace a power pole transformer?

The time to replace the transformer needs to be disassembled according to the on-site transformer, experimental trials, wiring, etc. In addition, the working load of high, medium, and low-voltage transformers is also different. Small transformers can be completed for several hours. The large ones take a few weeks. The power pole transformer is usually a small transformer. If the preparation work is sufficient, you can complete the replacement installation in a few hours.

What type of transformer is on a utility pole?

The utility pole is a pillar made of composite materials such as wood, metal, concrete, or glass fiber, which is used to support overhead power lines and various other public utilities. Therefore, the load of the utility pole is limited, suitable for installing a small distribution transformer. The capacity of the single-phase utility pole transformer and three-phase oil immersion transformer is not more than 500 kVA.

These transformers are used for two different types of power lines:

1. Perform electrical energy transmission between the substation,

2. Distribute a lower voltage power supply to the terminal customer for direct use.

Keep reading: How Much You Know For The Different Types Of Transformers?

How much does a utility pole transformer cost?

The utility pole transformer's voltage and capacity will not be large, so the cost will be cheaper. Depending on the voltage, capacity, and type, the price is about $ 1500-8000. To get specific prices and technical parameters, please contact the DAELIM team.

How much voltage is in a transformer on a pole?

From the above content, we know that the voltage and capacity will not be very large. DB Transformer can design and produce various types of pole transformer

The standard voltage includes: 12470Y/7200V, 13200Y/7620V, 13800Y/7957V, 34500Y/19920V, 7.2KV, 12.47kv, 13.2kv, 14.4KV, 24.94kv, 34.5kv.

If you need another voltage level of the pole transformer, please send the specific requirements to sales@daelim-electric.com or pingruidan@daelim-electric.com, we will give the quotation within 24 hours.

In conclusion

Daelim Transformer is a leading manufacturer and supplier of telephone pole transformers, with over ten years of experience in transformer production and export. Our transformers comply with international standards, including IEEE, CSA, and UL. Daelim's telephone pole transformers are exported to countries such as Canada, Honduras, Peru, and many others. Our products are renowned for their high quality and quick delivery times, earning widespread praise from customers.

Please feel free to contact Daelim for further consultation.