Electric Pole Transformer | Single Phase Transformer

Learn the fundamentals of Electric Pole Transformers, including What is pole mounted distribution transformer, pole mounted transformer specifications, pole mounted transformer drawing, pole mounted transformer sizes and custom options.

An electric pole transformer is an electric utility distribution transformer. It’s mounted on an electrical service pole made of wood or concrete. Usually, it is attached at the level of overhead cables.

The 16 kVA to 100kVA electric pole-mounted transformers range transforms 11,000 to 33,000 volts down to 400 lower volts.

Electric pole transformers are the standard breadbox transformers. They are used for converting distribution voltage to 120/240-volt power. Homes and low-volume commercial installations commonly use it.

DAELIM is one of the world’s leading professional transformers and electrical equipment manufacturers. For 15 years, DAELIM has been serving the electric industry with inexpensive and quality equipment. They have been following international standards like ANSI, IEEE, IEC, CSA, AS/NZ, etc.

The brand was built around a concept called DAELIM EDGE+ADVANTAGE. An idea aims to deliver multiple standards, cutting-edge service/ speed, and expert-level customization skills.

Electric Pole Transformer: The Ultimate FAQ Guide

What Is A Transformer?

Transformers come in a variety of shapes and sizes with different functions and purposes. Ranging from very large transformers to very small transformers. When it comes to getting the job done, there is not much of a difference between the power transformers and small ones like the single-phase transformer.

Basically, this means that regardless of the size, transformers do the same thing but depending on your project or purpose of purchasing one, you need to first understand its properties in order to get the right type of transformer.

For starters, a transformer is an electrical device or machine that transforms the value of current and voltages; hence, getting the name “transformer”. There are many types of transformers out there, and you will learn several of them in this article.

Step-up Transformer

A step-up transformer is a transformer that changes lower values to higher values. Step-up transformers are usually used for transmission systems. 

Step-down Transformer

Contrary to the step-up transformer, the step-down transformer does the opposite job, wherein it changes higher values to lower values, and they are commonly used in a distribution system.

single Phase Transformer
single Phase Transformer

What Is A pole electrical transformer?

So, what type of transformer is a pole electrical transformer? Is it a step-up or step-down?

pole electrical transformers are actually distribution transformers that are mounted on an electric service pole that could either be wood or concrete. Moreover, they are commonly leveled with the electric wires you see connected with the pole electrical transformer.

pole electrical transformers range from 16 kVA – 100 kVA and they have the capability to transform 11,000 volts – 33,000 volts down to 400 volts, which is very impressive for a transformer that has the size of a barrel.

Calculation Formula of Transformer Transformation Ratio

Daelim Belefic Single Phase Over head Transformer is designed and produced normally for stepping utility distribution voltages (ranging from 2400 to 34500 volts) down to lower utilization voltages. Although some are used for stepping down to commercial and industrial voltages such as 277, 240/480, 2400 and 4800, most are used for stepping down to the single-phase voltage of 120/240. These transformers are also used for small substations, miscellaneous applications and can serve to step up voltages.

The transformer type describes the basic protective devices which are included as an integral part of the transformer package. Table I defines each type as a function of the protective device(s) included. These protective devices and their functions are described later in this section.

Table1
TypeCSPCPSPS
Protective Devices    
High Voltage Surge ArresterYesNoYesNo
Low Voltage Circuit BreakerYesYesNoNo
High Voltage Protective LinkYesYesYesNo
Single Phase Overhead Conventional Electric Pole Transformer

Pole Mounted Transformer Sizes

Product model: SCZ10-50/10 
No-load loss: 270W;
Load loss 120ºC: 990W;
No-load current: 1.9%;
Pole Mounted Transformer Sizes (L X W X H): 970×880×1015;
Installation size (mm): 500×820.

Product model:  SCZ10-80/10
No-load loss: 360W;
Load loss 120ºC:1370W;
No-load current:1.8%;
Pole Mounted Transformer Sizes (L X W X H): 1050×880×1040;
Installation size (mm): 550×820

Product model: SCZ10-100/10 
No-load loss:  400W;
Load loss 120ºC:1570W;
No-load current:1.6%;
Pole Mounted Transformer Sizes (L X W X H): 1100×880×1160;
Installation size (mm): 550×820;

Product model:  SCZ10-125/10 
No-load loss: 470W;
Load loss 120ºC:1800W;
No-load current:  1.5%;
Pole Mounted Transformer Sizes (L X W X H): 1110×880×1190;
Installation size (mm): 550×820;

Product model:  SCZ10-160/10 
No-load loss: 540W;
Load loss 120ºC:2120W;
No-load current:  1.4%;
Pole Mounted Transformer Sizes (L X W X H): 1110×880×1190;
Installation size (mm): 660×890;

Product model:  SCZB10-400/10
No-load loss: 970W;
Load loss 120ºC:3980W;
No-load current:  1.2%;
Pole Mounted Transformer Sizes (L X W X H): 1320×950×1530;
Installation size (mm): 660×950;

How Do Electric Pole Transformers Function?

A transformer trades voltage for current in a circuit while not affecting the total electrical power. It takes high-voltage electricity with a slight current. It changes it into low-voltage electricity with a large current or vice versa. Transformers only work for Alternating Current (AC), such as you get from your wall plugs, not Direct Current (DC).

Transformers increase or decrease the voltage. Transformers use two coils of wire wrapped around a metal core. The first coil is for the incoming electricity. While the other is for outgoing electricity. Alternating Current in incoming coil sets up an alternating magnetic field in the core. This generates Alternating Current in the outgoing coil.

How Does It Work?

First, using a pole mounted distribution transformer, the electricity voltage from a power plant is “stepped up” to the right level for long-distance transmission. Because high-voltage current can arc, step-up transformers called ignition coils. They power spark plugs. Dynamos at power plants generate large currents but not too high voltage. This electricity steps up to high voltage for transmission over wires. As electricity travels more efficiently at high voltage.

After that, the voltage is stepped down. A “step-down” transformer changes the 440-volt electricity in power lines to 120-volt electricity you use in your house. Then, the current can be used at that level for devices like light bulbs. It is converted to DC using an AC/DC adapter for devices like laptop computers.

Pole Mounted Transformer Drawing

This article mainly describes two transformers, Single Phase Overhead Conventional Electric Pole Transformer and Single Phase Overhead Completely Self Protected (CSP) pole mounted distribution transformer. Including this two pole mounted transformer drawing and pole mounted transformer sizes.

Technical Data for Single Phase Overhead Conventional Electric Pole Transformer

Technical Data for Single Phase Over head Conventional Electric Pole Transformer
Technical Data for Single Phase Over head Conventional Electric Pole Transformer
Rated Power (KVA)High Voltage (V)Low Voltage (V)Loss(W)Dimension(mm)Weight(kg)
No-load Loss(W)On-load Loss(W)WDHOil WeighTotal Weight
534500 19920 13800 7957 7957 13200 7620 12470 7200   or others120-240 240-480 34760019754654858551592
103612050052588522150
155019552056590530210
258029056059093545258
37.510536061062593550340
50135500635675103562395
75190650745840103588480
100210850770965113594530
16735014107958901335138680

Note: The above data is only subject to our standard design, special requirements can be customized.

Technical Data for Single Phase Overhead Completely Self Protected (CSP) Electric Pole Transformer

Technical Data for Single Phase Overhead Completely Self Protected (CSP) Electric Pole Transformer
Rated Power (KVA)High Voltage (V)Low Voltage (V)Loss(W)Dimension(mm)Weight(kg)
No-load Loss(W)On-load Loss(W)WDHOil WeighTotal Weight
534500 19920 13800 7957 7957 13200 7620 12470 7200   or others120-240 240-480 347   600357540053096030115
105012043053098045150
1565195480580100055205
25105290500580103066345
37.5140360560640108078335
50180500560640113085370
752506507808001170138505

Note: The above data is only subject to our standard design, special requirements can be customized.

Types of Electric Pole Single Phase Transformer

Type CSP, 5 kV and Below, 10-100 kVA

Type CSP, 5 kV and Below, 10-100 kVAElectric Pole Transformer

Class A: Two fully insulated high voltage bushings, two arresters, two protective links, and external breaker handle. Suitable for application on either wye or delta distribution systems. Single-position pole mounting in accordance with latest ANSI standards.

Class B-1: Two fully insulated high voltage bushings, one arrester, two protective links and external breaker handle. Normally applied on solidly grounded systems.

Class B-2: Not Available.

Class B-3: Not Available.

Type CSP, Above 5KV, 10-100 kVA

Type CSP, Above 5KV, 10-100 kVA Electric Pole Transformer

Class A: Two fully insulated high voltage bushings, two arresters, two protective links and external breaker handle suitable for application on either wye or delta distribution systems. Single-position pole mounting in accordance with latest ANSI standards.

Class B-1: Two fully insulated high voltage bushings, one arrester, two protective links and external breaker handle. Normally applied on solidly grounded systems.

Class B-2: One fully insulated high voltage bushing, one arrester, one protective link and external breaker handle suitable only for application on solidly grounded distribution systems.
Single-position pole mounting in accordance with latest ANSI standards.

Class B-3: Same as Class B-2 except with two-position mounting.

Type CSP, Above 5KV, 10-100 kVA

Type S. 5 kV and Below, 10-500 kVA pole electrical transformer

Class A: Two fully insulated high voltage bushings, suitable for application on either wye or delta distribution systems. Singleposition pole mounting in accordance with latest ANSI standards.

Class B-1: Not Available

Class B-2: Not Available

Class B-3: Not Available

Type S. Above 5 kV, 10-500 kVA

Type S. Above 5 kV, 10-500 kVA pole electrical transformer

Class A: Two fully insulated high voltage bushings, suitable for application on either wye or delta distribution systems. Single-position pole mounting in accordance with latest ANSI standards.

Class B-1: Not Available

Class B-2: One fully insulated high voltage bushing, suitable only for application on solidly grounded distribution systems. Single-position pole mounting in accordance with latest ANSI standards.

Class B-3: Same as Class B-2 except with two-position mounting.

Standard Features

Standard Features pole electrical transformer

1.LIFTING LUGS

2.ARRESTER MOUNTING PADS

3.COVER-MOUNTED HIGH VOLTAGE PORCELAIN BUSHING(S) WITH EYEBOLT TERMINAL

4.LOW VOLTAGE BUSHINGS WITH EYEBOLT TERMINALS

5.LOW VOLTAGE NEUTRAL GROUNDING STRAP (NOT SHOWN) (10-50 KVA CLASS B-2 AND B-3 ONLY)

6.ANSI SUPPORT LUGS (HANGER BRACKETS) WITH LASER INSCRIBED NAMEPLATE ON LOWER BRACKET

7.POLYESTER INSULATED COVER

8.SELF-VENTING AND RESEALING COVER ASSEMBLY

9.CORE

10.COIL

11.CENTERLINE CORE/COIL ASSEMBLY SUPPORT BRACKETS

12.LOW VOLTAGE LEADS

13.OIL FILL PLUG WITH COVER GROUND STRAP

14.TANK GROUND PAD THE FOLLOWING ADDITIONAL FEATURES ARE ALL STANDARD ON SELF-PROTECTED TYPE CSP UNITS ONLY:

15.PRIMARY PROTECTIVE LINK (MOUNTED IN HIGH VOLTAGE BUSHING)

16.SURGE ARRESTER

17.SECONDARY CIRCUIT BREAKER

18.SECONDARY BREAKER OPERATING HANDLE WITH EMERGENCY OVERLOAD RESET AND OVERLOAD SIGNAL LIGHT

Pole Mounted Transformer Specifications

Daelim Belefic pole mounted distribution transformer is designed and produced normally for stepping utility distribution voltages (ranging from 2400 to 34500 volts) down to lower utilization voltages. Although some are used for stepping down to commercial and industrial voltages such as 277, 240/480, 2400 and 4800, most are used for stepping down to the single-phase voltage of 120/240.

The pole mounted distribution transformers are also used for small substations, miscellaneous applications and can serve to step up voltages.

Surge Arrester

Surge arresters are mounted on the outside of the transformer tank. Their function is to intercept and divert to ground various overvoltage transients (such as lightning surges) which originate on the distribution system.

Grounding requirements for lightning protection in Pad-mounted substations

Protective Link

Improper coordination with primary protective devices separate from the transformer could prevent the link from operating properly both for load current characteristics and for fault current characteristics.

Transformer Types SP, CP and CSP have protective links (expulsion type fuses) in them. These are mounted either in the bottom of the high voltage bushing or in a terminal block between the high voltage coil and the high voltage bushing. These protective links must be under oil for proper operation. Upon request DAELIM provides curves giving characteristics of these protective links so their characteristics can be coordinated with protective devices on the primary side of the transformer.

Protective links are oil-immersed high voltage expulsion fuses designed to isolate the transformer from the primary distribution system in the event of a transformer fault inside the tank on the load side of the link. The purpose of this link is to prevent a line lockout when a transformer fails; not to provide overload or fault current protection for the transformer.

What are the main neutral grounding methods of power systems?

Current - Liming Fuse

High voltage current-limiting fuses are designed to limit the flow of current (and energy) to a low impedance fault. When properly applied, they prevent almost all violent failure of transformers. Like protective links, their purpose is to isolate the transformer from the distribution system in the event of an internal transformer fault. Current-limited fuses usually are applied when the system available fault current exceeds the interrupting capability of the protective link. Because partial range type current-limiting fuses are normally applied on overhead distribution transformers, a series protective link is applied with each current-limiting fuse.

Low Voltage Circuit Breaker

Type CSP and CP pole mounted distribution transformer have circuit breakers mounted under oil and connected between the coils’ low voltage winding leads and the low voltage bushings. These are to protect the transformer from severe overloads and short circuits external to the transformers. The low voltage breaker is not intended to protect secondary (low-voltage) circuits and connected apparatus (meters, meter sockets, connectors, service entrance equipment, etc.) from thermal and magnetic effects due to short circuits and overloads. The breaker is calibrated to trip when its bimental reaches a pre-determined temperature. Some breaker sizes have an additional feature that is a magnetic trip element so that breaker can respond quicker to higher fault current.

The breaker is primarily a protective device designed for only occasional switching operations; as such it is not intended for frequent (weekly or daily) switching duty.

The bimetallic element of the breaker is connected in series with the secondary windings of the transformer and responds thermally to the flow of transformer load current through it and to the oil temperature.

The circuit breaker is always used in conjunction with a protective link.

The circuit breaker coordinates with the protective link so it opens first on overloads and faults on the load side of the circuit breaker.

Circuit Breaker Emergency Control

Should it be necessary for a short time emergency situation, the breaker’s calibration can be changed to allow additional overload capacity. The emergency trip setting of the breaker should be used only when absolutely necessary and for as short a duration as possible because extended use of the setting will result in higher winding temperatures before the breaker can trip. These higher winding temperatures cause a reduction in transformer life. When the emergency control setting is made it increases the load at which the signal light will come on and the breaker will trip by about 20%.

leakage protector
leakage protector

The breaker is recalibrated to the emergency position by removing the meter seal and rotating the emergency control handle upward, in a clockwise direction away from the breaker operating handle as shown in Figure 8. After the emergency condition, the emergency control handle should be returned to its normal position. It is recommended that a new seal be applied to the handle when it is returned to the normal position to avoid inadvertent operation of the emergency control.

Signal Light

Type CSP and CP pole mounted distribution transformer can be supplied with an overload signal light. When the signal light comes on it gives a warning that the transformer has experienced a heavy overload. The signal light remains lighted until reset by means of the breaker operating handle. It can be reset by operating the breaker handle to the maximum upward position and then back down to the closed position.

If the breaker handle is operated to the reset position and then to the close position and the signal light remains on, the temperature of the transformer oil is still too hot to allow the signal light to turn off.

If the signal light bulb is burned out, it can be replaced from outside the transformer by unscrewing the signal light lens and then the bulb.

Single Phase Electric Pole Transformer

Protecto-Combo

The Protecto-Combo device consists of a flip open type of fuseholder and a surge arrester. The fuse link is normally supplied by the user. The Protecto-Combo device requires field assembly. This protective device is used only on transformers 50 kVA and below, Class B-2 or B-3 type units with one cover mounted high voltage bushing. This optional device is not shown on the nameplate.

Tap changer

Tap changers are connected into the high voltage coil. The pole mounted distribution transformer output voltage can be increased or decreased by changing the tap changer setting.

The internal tap changer is operated by removing the pole mounted distribution transformer handhole cover, or transformer cover, and turning the tap changer handle to the position desired on the tap position indicator. The tap changer numbers on the position indicator are the same as ones on the transformer nameplate.

To change taps with the externally operated tap changer, loosen the locking screw in the handle, turn the handle to the tap position needed and tighten the locking screw.

Dual voltage switch

Dual voltage switches permit the use of pole mounted distribution transformers on different primary voltage systems. They are externally operated with a handle on the outside of the tank. Voltage ratings are given at the switch handle and on the transformer nameplate.

The switch handle is held in place by a locking screw. Back out the locking screw until it is clear from the locking hole, then rotate the handle. The locking screw should then be put into the locking hole for the new position and tightened.

Tank Pressure Relief

A unique feature of the pole mounted distribution transformer cover is its ability to flex and relieve pressure which can build up from some internal faults. Except in cases of extreme dynamic pressure build up, the cover automatically reseals itself. Whenever the cover needs to be removed, any internal static pressure is relieved automatically as the cover bolt is loosened. When the bolt is being loosened, the cover can vent but the bolt is still held by a nut in the cover beam.

The cover bolt should be tightened to 350 in. lbs. (27 ft. lbs.)+ 10% to insure that the cover vents properly. If there is a handhole cover on the transformer cover, the handhole cover bolt should be tightened to 150 in. lbs. (13 ft. lbs.) + 10%.

All pole mounted distribution transformers are tested in strict accordance with the latest revision of applicable ANSI™, IEEE™, NEMA, and RUS with test reports available by serial number of the transformer
Routine tests are:

•Leak test

•Polarity and phase relation

•Resistance

No-load losses and excitation current

•Load losses and impedance

•Applied voltage

•Induced voltage

•Full wave impulse

•Ratio test

Electrical Pole Transformer Size

There are two common Electric Pole Transformers: Single Phase Overhead Conventional Transformer and Single Phase Overhead Completely Self Protected (CSP) Transformer.

Single-phase transformer size

Width: 465 mm
Depth:485 mm
Height:855 mm
Oil Weight: 15 kg
Total Weight: 92 kg

Width: 500 mm
Depth:525 mm
Height:885 mm
Oil Weight: 22 kg
Total Weight: 150 kg

Width: 520 mm
Depth:565 mm
Height:905 mm
Oil Weight: 30 kg
Total Weight: 210 kg

Width: 560 mm
Depth:590 mm
Height:935 mm
Oil Weight: 45 kg
Total Weight: 258 kg

Width: 610 mm
Depth:625 mm
Height:935 mm
Oil Weight: 50 kg
Total Weight: 340 kg

Width: 635 mm
Depth:675 mm
Height:1035 mm
Oil Weight: 62 kg
Total Weight: 395 kg

Width: 745 mm
Depth:840 mm
Height:1035 mm
Oil Weight: 88 kg
Total Weight: 480 kg

Width: 770 mm
Depth:965 mm
Height:1135 mm
Oil Weight: 94 kg
Total Weight: 530 kg

Width: 795 mm
Depth:890 mm
Height:1335 mm
Oil Weight: 138 kg
Total Weight: 680 kg

single phase transformer Conventional type
single phase transformer Conventional type
Single phase transformer CSP type
Single phase transformer CSP type

Single Phase Overhead CSP Transformer size

Width: 400 mm
Depth:530 mm
Height:960 mm
Oil Weight: 30 kg
Total Weight: 115 kg

Width: 430 mm
Depth:530 mm
Height:980 mm
Oil Weight: 45 kg
Total Weight: 150 kg

Width: 480 mm
Depth:580 mm
Height:1000 mm
Oil Weight: 55 kg
Total Weight: 205 kg

Width: 500 mm
Depth:580 mm
Height:1030 mm
Oil Weight: 66 kg
Total Weight: 345 kg

Width: 560 mm
Depth:640 mm
Height:1080 mm
Oil Weight: 78 kg
Total Weight: 335 kg

Width: 560 mm
Depth:640 mm
Height:1130 mm
Oil Weight: 85 kg
Total Weight: 370 kg

Width: 780 mm
Depth:800 mm
Height:1170 mm
Oil Weight: 138 kg
Total Weight: 505 kg

What are the Features of an Electric Pole Transformer?

All transformers share some standard features regardless of their type:

  • The same frequency of input and output power
  • All pole mounted distribution transformers use electromagnetic induction laws.
  • Primary and secondary coils devoid of electrical connections (except for autotransformers). The power transfer by magnetic flux.
  • No moving parts have to transfer energy. So, no friction or windage losses as with other electrical devices.

On the other hand, an electric pole transformer has a low voltage bushing insulator available in fiberglass reinforced polyester material or porcelain (both eyebolt and spade terminals). Low-voltage neutral grounding strap (furnished on 10 – 50 kVA single HV bushing units)

The cover has 15 kV dielectric insulation and increased resistance to corrosion. In addition, the body is sloped 15°, preventing water from collecting and reducing corrosion and leaking.

What are Common Applications for an Electric Pole Transformer?

pole electrical transformers are used for converting distribution voltage  to the 120/240 power system that are used by houses and also low-volume installations. As aforementioned, these transformers have a kVA range of 16 – 100 kVA and easily convert 11,000 – 33,000 V to 400 V.

Electricity is an integral part of many people’s daily lives. As a result, pole mounted distribution transformers have evolved to play an essential role in generating and distributing electrical power. Besides, pole mounted distribution transformers regulate electricity by modifying current to run from one electric circuit to another. 

Regulates alternating current

All transformers have one primary function: increasing or decreasing alternating current within the electrical system. By regulating the current flow, the transformer allows for increased energy efficiency, which governs and ultimately lowers electricity bills.

Stops and starts the flow of electricity

Pole mounted distribution transformers are also helpful in stopping the flow of electricity and interrupting an electric current. Transformers are commonly present in circuit breakers. They use a switch to automatically interrupt the flow of electricity and prevent damage due to high voltage.

Charging batteries

The functioning of generators fuels battery charging mechanics. Transformers control the voltage that enters the battery during the charging process to prevent any internal battery component damages. It is essential because an unregulated voltage can result in high surges during the charging of batteries.

Manufacturing steel products

Steel manufacturing plants rely on high voltage pole mounted distribution transformers to provide a range of voltages for the manufacturing process. For example, high currents are required for melting and welding of steel, and lower currents are required during the cooling process. It provides this range of voltages for regulating currents within the system.

Electrochemicals

In chemical engineering and manufacturing, electrolysis gets fuelled by the functioning of transformers. Metals such as copper, zinc, and aluminum are typically used for electroplating.

Transformers provide a regulated electrical current to drive the chemical reaction from the beginning stages until completion. The current can therefore be regulated as the reaction proceeds.

30 kVA Single Phase Electric Pole Transformer

Typical configuration of Electric Pole Transformer

The Electric Pole Transformer is small and light. It can be mounted on a pole, which is convenient for installation. Electric Pole Transformer has a small footprint and is economical.

It can reach the load center to the greatest extent, shorten the power supply radius of the low-voltage network, and reduce losses.

According to the installation requirements of distribution transformers, the typical configuration of sElectric Pole Transformer installation is summarized: Electric Pole Transformer, low-voltage switch, reactive power compensation device, distribution load monitoring system and other equipment.

Electric pole mounted transformer Installation

Installation method: Single-pole suspension can be used for Electric Pole Transformer installation, and the poles can be 12 m heavy-duty cement poles or 15 m cement poles.

Selection of installation location: The installation location of Electric Pole Transformer is less restricted by geographical factors and more restricted by load characteristics.

When the power supply radius of the three-phase distribution transformer is too large, resulting in a low end power supply voltage, which affects the normal power consumption of users.

Install an Electric Pole Transformer at the end of the power supply. Then cut the low-voltage network, and shorten the low-voltage power supply radius, which can solve the problem of low voltage for users.

Electric Utility Pole Transformer Installation

When the load of the three-phase distribution transformer is too heavy. According to the characteristics of the load, select the appropriate branch line to install the single-phase distribution transformer, cut and transfer the load, which can solve the problem of capacity increase;

Install Electric Pole Transformer to supply power to residents at locations. It can shorten the low-voltage power supply radius and reduce losses;

Installing single-phase distribution transformers for power supply in locations with low load density, wide distribution. It can save investment and solve the problem of power supply points.

Cost-benefit analysis of Electric pole mounted transformer

The low-voltage line loss has dropped significantly

The power supply radius of a Electric Pole Transformer is only 10-15 m. Compared with a three-phase distribution transformer, the power supply radius is greatly shortened, and the low-voltage line loss is significantly reduced. 7.61% decreased to 2.72%, and the monthly electricity saving was 1810 kWh.

The voltage qualification rate is significantly improved

As the radius of the low-voltage power supply is greatly shortened, the line voltage loss is small, and the qualified rate of household voltage is significantly improved.

The reliability of user power supply has been improved

As the radius of the low-voltage power supply is greatly shortened, the line voltage loss is small, and the qualified rate of household voltage is significantly improved.

Single-phase distribution transformers are used for power supply.

The High-voltage lines can be erected as two lines.The low-voltage lines can be erected as two or three lines.

When three-phase distribution transformers are used for power supply, high-voltage lines must be erected as three lines, and low-voltage lines as four lines.

From the perspective of engineering cost, the engineering cost of using Electric Pole Transformers to supply high and low voltage lines can be saved by 1/5.

From the perspective of the construction cost of the station area.

The cost of building a pad-mounted transformer is 3 times that of an Electric pole transformer.

Are Electrical Pole Transformers Dangerous?

Yes, they can be dangerous and highly flammable. pole electrical transformers could also fall down, which might hit someone that is just near the pole. When it comes to its voltage, the power lines or wires between the areas could cut off and start to spark in an abnormal way, getting hit by live wires can potentially burn our insides and cause other life-threatening injuries.

Power lines are strung between utility poles in urban areas. It goes from 4 to 25 kilovolts or less. At this voltage, touching a power line can already cause severe injuries. At times, the wound left by electricity exiting the body can cause such severe damage.

This electric shock this large can stop your heart. What’s more, tree branches that come in contact with a power line energize the tree and the ground around it. So it creates a very hazardous situation.

That’s why it’s essential to choose a brand of transformer that significantly focuses on quality. It will guarantee that you are safe from any hazardous instance.

At DAELIM, you are guaranteed to get quality transformers that are hazard-free. Being in danger while using an electric pole transformer is the last thing that will cross your mind.

How Close Can A Transformer Be To A House?

First, a pole mounted distribution transformer should be installed with the front (doors) facing away from the building, with no balconies or overhangs above. Second, the transformer must also be accessible to line trucks (The size and weight of a cement truck) for maintenance or replacement.

Generally, a transformer near a building requires 4ft clearance from the vertical building surfaces, assuming no windows from grade to 18ft. In addition, the sides of the transformer must be clear of all objects for 3ft, including landscaping. More so, transformers must be 10ft horizontal from doors, windows, or fire hydrants.

The transformer’s front (door side) shall have a 10 ft. clearance. This ensures line crews safely perform maintenance or repairs on the. This clearance requirement includes landscaping. When it comes to landscaping during emergency repairs, the utility can remove the landscaping or leave and await notice when offending vegetation has been removed.

The utility will not attempt to work on the transformer during routine maintenance until the landscaping has been removed.

Three Outdoor Installation Methods for Power Transformers

Which Type Of Current Makes An Electric Pole Transformer Work?

Suppose you put a secondary coil of wire next to the first and send a fluctuating electric current into the first coil. In that case, you’ll create an electric current in the second wire. The electric current in the first coil is usually called the primary current. At the same time, the current in the second wire is the secondary current.

Note: This trick works only if the electric current fluctuates somehow. In other words, you have to use a constantly reversing electricity called alternating current (AC) with a transformer.

Inside Of A pole electrical transformer

pole electrical transformers contain a magnetic core that is produced from laminations of silicon sheet steel or otherwise known as transformer steel, that are stacked together. There are also primary and secondary wire windings wrapped around them.v

pole electrical transformer Connection

Each house has a pole mounted distribution transformer drum that is mounted to a wooden or concrete pole. For houses that are near each other or suburban neighbourhoods, the distribution wires are located underground with transformer boxes underneath every house.

What these transformers do is reduce 7,200 V to 240 V, this is sufficient for running a normal household with electrical services.

Different Types Of Transformers

Below are the different types of pole mounted distribution transformers you usually hear from other companies who are considering buying premium pole mounted distribution transformers for their inventory stocks. You will have a better understanding about the different types of transformers after reading this section.

Core Type Transformers

Core type pole mounted distribution transformers are commonly used in applications such as for transferring cores, energy and power grids. So, it still has the main function of what transformers do which is the ability to increase and decrease values.

When it comes to their mechanical properties, the core type pole mounted distribution transformer has two limbs with windings contracted to the core material.

Shell Type Transformer

Shell type pole mounted distribution transformers may not be popular but it does not mean that they are not worth considering. They are used for low voltage applications including low voltage power circuits that involve electrical circuits.

Its mechanical components are composed of its core, three limbs, and two windows. For its windings, they are contracted on the center or central limb, in a “one over the other” position. Nonetheless, the arrangement of these windings can be progressed with one limb.

Spiral Core Transformer

The spiral core transformer is considered to be the modern one since it has the latest development in its core construction.

The core is formed in a continuous strip or ribbon form that is somewhat similar to a circular cylinder, hence, getting the “spiral core” for its name. These shape allows its core flux to escort  the grain of the iron

Calculation Method of the Number of Turns of Power Transformer Core

Are pole electrical transformers Necessary?

Yes, pole electrical transformers help regulate and distribute the right amount of voltage to each house smoothly. Without pole electrical transformers. Moreover, this keeps the electricity flowing consistently to provide homes electricity without getting it cut off.

Do pole electrical transformers Contain Oil?

Yes, they do contain oil, distribution transformers like single-phase transformers and pole electrical transformers contain oil for electrical insulation and cooling to the windings inside the transformer.

What Liquid Is In A pole electrical transformer?

There is a specialized oil that is specifically made for pole mounted distribution transformers, thus, claiming its name “transformer oil” that is also referred to as insulating oil. These are used for oil-type transformers, fluorescent lamps, high-voltage switches, and circuit breakers. 

Why Do pole electrical transformers Explode?

When there is a disturbance or interruption that causes the pole electrical transformer to receive too much electricity, the energy and electricity passing through it gets uncontrolled  which results in an explosion and possibly followed by fire.

How Many Houses Are Connected To A pole electrical transformer?

Normally, the range of connection between how many houses connected to a single pole electrical transformer varies but it can be connected to up to 50 houses. But for industrial and commercial applications that require high loads of electricity, it can be as low as only 4 to 5 large infrastructures.

How Much Copper Is Inside A pole electrical transformer?

The amount of copper in a pole electrical transformer contains about 15% to 20% along with steel materials and core laminations including the insulating oil inside the pole electrical transformer.

Advantages and Disadvantages Of pole electrical transformers

In this section, you will learn the advantages and drawbacks of pole electrical transformers. This section helps you give a final verdict on your purchase decision. So, once again, do look into the details that are provided,

If there are any concerns you would like to be assessed, DAELIM is ready to answer them. But before that let us look into its advantages.

pole electrical transformer Advantages

Here are the main advantages of using pole electrical transformers.

Excellent Control of Energy

When it comes to control of energy transmission, there is without a doubt that pole electrical transformers do a decent job. It is simply well-designed and is the only compact transformer that can do energy and electricity transmissions on a pole.

Smooth Voltage Transmission

This is the reason why pole electrical transformers can have a lot of wired connections. It has no problems in distributing electricity to all connected houses because of its effective mechanical components that are behind the smooth voltage transmission from house to house. 

Highly Efficient

By now you could definitely tell that pole electrical transformers do well. In fact, the place you are living in might even be powered with a pole electrical transformer! A lot of companies tend to use two or three of these because large consumption is enough for 4 to 5 huge buildings already.

Low Cost Compared To Other Transformers

Compared to its other big competitors, pole electrical transformers are fairly priced in the middle. It is compact, low maintenance, and highly efficient. What more could you ask for? It is at the top of the league compared to its alternatives.

Low Maintenance

As mentioned, it requires little to almost no maintenance at all! Have you noticed that electricians rarely visit pole electrical transformers? This is because it has no moving parts inside, and its material is so solid that it can withstand changing temperatures, typhoons, and heavy beating.

Solid State Device

There are no moving parts whatsoever in pole electrical transformers which is why it is considered as a solid state device. This means that you have less to worry about, especially random explosions, fire, or electricity cut offs.

Pole Electrical Transformer Disadvantages

Below are the disadvantages or drawbacks of pole electrical transformers.

Has To Be Replaced

Since it has little maintenance and no moving parts inside, you cannot expect that it will stay in pristine condition forever, which means you will have to replace it every 3-4 years or so. Some pole electrical pole mounted distribution transformers even require yearly replacement.

But with high-quality ones, you do not have to worry about constantly replacing your pole electrical transformers. DAELIM has several pole electrical transformers you can choose from.

Might Fall Off

Since it is mounted to a pole, without checking it every once in a while, pole electrical transformers might get loose and fall off, which is why it is very important that it is installed properly by experts who are responsible for strongly clamping it to where it is mounted.

DAELIM offers low cost installations for you to not go through that hassle. Rest assured, your pole electrical transformer will never budge with DAELIM’s low cost installation.

Requires Oil

As mentioned before in a previous section, some pole electrical transformers require oil as an insulation. Oil can be quite costly, and you do have to fuel it up every once and a while as well. If this is something you do not want to apply, do reconsider or contact DAELIM for your concerns.

4 Methods of Transformer Drying Treatment

Dangerous Voltage

As you know, there are a lot of power lines or wires connected to a single pole electrical transformer especially in urban areas. The range could go from 4 to 5 kilovolts. Even at this low voltage, a contact with a power line can seriously cause injuries to those who come in contact with it.

This is the reason why live wires can cause injuries that require amputations, and even death. Electricity that is that large of an amount is capable of stopping your heart from working. Touching a tree branch that is in contact with the wire can still reach you. 

So, whenever there are live wires down connected to a pole mounted distribution transformer, stay as far away from it.

Chemicals

The pole, wood, or concrete that it is mounted to is usually applied with preservatives that contain harmful chemicals that are dangerous to animals, and humans. These preservatives can cause cancer, complications to our systems, and even birth defects.

So, if ever you are in a case wherein your 2nd floor is near to a transformer, keep the windows closed or wear a mask. These preservatives will eventually fade away after a month or so. Depending on how strong it is.

Stray Voltage

When the insulation that is surrounding old power lines underground degrade, the wires become exposed to the ground or soil, in which stray electrical currents can travel through soil.

YES, electricity can travel through soil. Especially, metal objects on the surface including sheets of metals, utility poles, fire hydrants, etc. Coming in contact with flowing electricity in the ground with your bare feet can cause an electric shock that causes severe injuries. 

There have been lots of reports of people and animals dying from stray voltages.

Conclusion

Electrical transformers make it possible for large quantities of electrical loads. It is because they carry on a primary source to a smaller output device.

For a single electric barrel that is capable of passing energy of up to 50 houses, it is very efficient in its job and with little maintenance, it sustains itself very well. 

Should you have further questions and concerns, you may contact DAELIM’s team of professionals who are ready to accommodate.

Custom Pole Mounted Distribution Transformer

When you need to find more than just existing transformers, Daelim’s Transformer Service Center can help you design and produce distribution transformers that meet your unique needs.

We have our own factory and a professional team of engineers, which can design and modify application requirements that meet all your conditions.

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