Pad-mounted transformers are widely used in residential communities, hospitals, docks and other places that require centralized power supply.

If you want to learn more, please visit our website.

What makes it so popular?

Safety, high cost performance, energy saving and high efficiency have become the name for it.

More and more buyers need to buy it?

But, What are Pad-mounted transformers?

What inside a pad-mounted transformer？

What are the pad-mounted transformer health risks？

How to choose a good Pad-mounted Manufacturer?

… …

We have many questions about the pad-mounted transformer, but we can not get them from the Sales Company’s product page.

But for purchasers or engineers, we need to know more about pad-mounted transformers in order to better buy and use it.

In this post, I will disassemble the pad-mounted transformer for you. I will also share some tips on how to choose a pad-mounted transformer.

1.What is Pad-mounted Transformer?

The pad-mounted transformer is an important power supply equipment in the cabled distribution network.

The pad-mounted transformer adopts a double-fuse full-range protection method. This greatly reduces the loss.

There are mainly two types: Single-phase Pad-mounted transformer and Three-phase Pad-mounted transformer.

The pad-mounted transformer has the performance advantages of a lightweight, low noise, small size, and low loss.

An excellent pad-mounted transformer is mainly composed of high-voltage control, protection, substation, and power distribution equipment.

The pad-mounted transformer adopts the principle of parallel operation of the high-voltage side bus.

Its low-voltage side bus is mainly responsible for circuit breaker transfer.

It has good safety performance.

Pad-mounted transformers are widely used in large-scale business centers, railway stations, mines, and other large-scale event venues.

2. What's inside the pad-mounted transformer?

Pressure Relief Valve of the Pad-mounted Transformer

1. The automatic pressure relief valve (Fig 3) is standard on all Daelim transformers.
2. It is designed to slowly release the pressure to prevent the transformer tank from rupturing.
3. These valves have been adjusted to 5 ±2 PSI when they leave the factory.
4. The normal operation of the transformer will make the resulting in pressure fluctuations in the gas-filled headspace of the tank.

automatic pressure relief valve for pad-mounted transformer

• Caution: Before performing any type of service, the pressure in the fuel tank must be safely vented manually.
• Caution: Do not open the Pad-mounted transformer in a high-humidity environment. Moisture can cause short circuits in the device.

Opening the valve (Fig3) will drain the oil in the tank.

It will release the pressure in the fuel tank.

Fill Valve/Valve Cock

Daelim’s pad-mounted transformer contains two types of valves.

One is filling the plug with the Schrader valve (Fig 4A).

The other is the filling valve with the Schrader valve (Fig. 4B).

It is used for the introduction of nitrogen and dielectric fluid.

A filling plug with Schrader valve

a filling valve with Schrader valve

Drain Valve and Fluid Sampler of the Pad-mounted Transformer

fluid sampler for pad-mounted transformer

1. The discharge valve and fluid sampler (Fig 5) is used to facilitate the sampling of dielectric fluids.
2. It is mainly used for testing.
3. A 1/2″ to 2″ plug can help this valve speed up the discharge of the dielectric fluid.
4. The valve can be sampled without removing the end plug.

Liquid Level Gauge of the Pad-mounted Transformer

1. The amount of dielectric in the pad-mounted transformer tank can be observed with a level gauge (Fig 6).
2. It is magnetically coupled to the indicator needle in the gauge.
3. The magnetic coupling maintains the liquid seal between the inside and the outside.
4. It can minimize potential leakage.

level gauge for pad-mounted transformer

Daelim uses a variety of different brands and models of level gauges according to the application.

Daelim can be equipped with standard instruments as required. If the environment is complex, more complex models can also be provided. It can facilitate external monitoring.

Under normal operation, the liquid level may change according to temperature and pressure.

Temperature gauge of the Pad-mounted Transformer

Daelim pad-mounted transformer provides a thermometer (Fig 7).

Its function is to observe the temperature of the top dielectric fluid in the fuel tank.

It includes two hands, one white and one red.

The white pointer indicates the current oil temperature of the pad-mounted transformer.

The red pointer indicates the maximum reset value of the dielectric fluid temperature.

The long thermocouple is its main component.

In order to facilitate the replacement of the gauge. The thermocouple and the dielectric fluid are isolated from each other.

Temperature gauge for pad-mounted transformer

There are one or two SPDT alarm points on the thermometer.

It has the function of remote monitoring.

These alarms for electric shock can be set according to factory requirements.

Unscrew the small hexagonal fixing screw in the center of the meter.

It can help you adjust the contact.

Set the contacts to the required temperature. You can complete the operation.

Pressure Vacuum Gauge of the Pad-mounted Tranformer

The pressure gauge (Fig 8) indicates whether the headspace pressure in the tank is positive, negative, or neutral.

The pressure change factors in the fuel tank:

1. The load of the device;
2. The temperature of the oil;
3. The temperature of the external environment；
4. The load of the device.

Pad-Mounted transformers usually have positive or negative voltage.

Continuous low temperature will cause continuous negative pressure. It is normal.

However, if the temperature rises, the meter reading is still zero.

This means that there is a leak.

The leakage of equipment needs to be checked.

pressure gauge for pad-mounted transformer

Daelim can equip the pressure gauge with SPDT alarm contacts according to your requirements.

It can remote monitoring of positive and negative pressures.

The pressure/vacuum gauge can also be equipped with a decompression or regulator.

When used in combination with an external nitrogen supply, the tank can maintain a positive pressure (2.5 to 3.0 PSI).

The valve of the regulator can be used to collect gas samples.

Fault Pressure Relief Device (FPRD) for the Pad-mounted Transformer

Fault Pressure Relief Device (FPRD) for Pad-Mounted Transformer

1. People often called an explosion-proof device (Fig 9).
2. The function of this device is to quickly release the gas pressure due to internal failure.
3. The APRD lid with a spring-loaded diaphragm installed will open at a predetermined pressure level of 10 PSI.
4. And it will be closed again when the pressure is restored.
5. FPRD has a yellow alarm button. It will stand out when the pressure is abnormal.
6. FPRD is equipped with SPDT alarm for the convenience of remote monitoring.

Rapid Pressure Rise Relay (RPRR) for the Pad-mounted Transformer

1. The RPRR (Fig 10) is a device that detects sudden pressure events based on the transformer pressure rise rate.
2. RPRR will issue a trip signal when the pressure suddenly rises.
3. It will greatly reduce the damage of the Pad mounted transformer.

Rapid Pressure Rise Relay (RPRR) with Seal-in relay for Pad-mounted transformer

Winding Temperature Indicator for the Pad-mounted Transformer

Winding Temperature Indicator for Pad-Mounted Transformer

1. Daelim uses a digital winding temperature monitor (Fig 11).
2. It consists of thermocouples wound in each coil at strategic locations in the Pad-mounted transformer.
3. It can accurately monitor the temperature inside the coil.
4. The digital reading and control device is located in a separate NEMA4 enclosure.
5. It is usually installed on the side of the tank.

Forced Air Cooling Fans for the Pad-mounted Transformer

1. The forced air cooling fan (Fig 12) can be optionally used in a device equipped with a radiator.
2. It increases the KVA capacity of the pad-mounted transformer by 25% without overheating or adverse effects.
3. Daelim can increase or decrease the number of fans according to user needs.
4. The fan can be controlled by a gauge oil thermometer with contacts or a winding temperature indicator.

Forced Air Cooling Fans for Pad-Mounted Transformer

CT for the Pad-mounted Transformer

Daelim can equip pad-mounted transformers with different types and levels of CT according to user requirements.

The following are three types of CT:

1. CT on the casing (Fig 13A).
2. CT inside the transformer (Fig 13B).
3. CT on the meter socket (Fig 13C).

bushing mounted CT

internally mounted CT

internally mounted CT

Switching and Protection Devices for the Pad-mounted Transformer

Tap Changers

An externally operated no-load tap changer (NLTC) (Fig 14 A and B) is suitable for all kinds of pad-mounted transformers.

The rated voltage of the tap under normal conditions is -5%~5%.

This means that the output voltage of the Pad-mounted transformer is adjusted in increments of 2.5%.

The tap switch is designed as an operable handle.

It is available in two styles.

Each of which requires a slightly different method to change tap settings.

Load Break Oil-Immersed Rotary Switches (LBOR)

• WARNING: If the load disconnecting device is used in a fault condition, it can cause an explosion.
• WARNING: Pad-mounted transformer load-breaking equipment can only be operated with hot rods.
• WARNING: After the load is disconnected, confirm whether the voltage at the terminals of the Pad-mounted transformer returns to the expected value.
• WARNING: Before servicing the equipment connected to the secondary side of the transformer. Please make sure that all terminals on the secondary side of the pad-mounted transformer have zero voltage and ground the secondary side terminals of the pad-mounted transformer. Grounding the secondary terminal can prevent the occurrence of the standby generator supplying power to the pad-mounted transformer from the secondary circuit, etc.

Four - Position LBOR Switch “Sectionalizing Switch”

1. The four-position LBOR segment switch (Fig 16 A and B) is optionally provided in the loop feeder Pad-mounted transformer.
2. It can select the feed source.
3. It can turn on or off the feed through the loop.
4. The spring-loaded activation mechanism ensures rapid load disconnection.
5. Only hot rods can be used for switching.

T blade 4 - Position LBOR Switch

V blade 4 - Position LBOR Switch

Dual Voltage Switch

Dual Voltage Switch for Pad-mounted Transformer

The Dual Voltage Switch (Fig. 17) can facilitate selecting one primary voltage from another.

Delta-Wye Switch

1. Due to the special needs of customers, the Delta-Wye switch can be installed on the Pad-mounted transformer (Fig 18).
2. It can help switch between Wye and Delta voltage.

Delta-Wye Switch for pad-mounted transformer

Surge Arresters for the pad mounted transformer

1. Lightning arresters (Fig 16) are optionally installed in the base pad-mounted transformer.
2. If there is a voltage surge, Surge arresters can provide protection for the transformer.
3. Under normal circumstances, the arrester terminals will withstand line-to-ground voltage.
4. When a voltage surge occurs, the arrester will be grounded in order to keep the voltage normal.
5. The arrester will automatically recover after the surge ends.

Grounding requirements for lightning protection in Pad-mounted Substations

Bay-O-Net Fuses for pad-mounted transformer

Bay-O-Net Fuses

1. Bay-o-net fuses (Fig 20 A) can be replaced without opening the transformer tank.
2. It is used in series with the ELSP spare fuse to achieve over-current protection.

Bay-O-Net fuse replacement instruction (Fig. 20 B):

1. Pull out the pressure release valve for 30 seconds until the hissing sound of the valve stops, thereby releasing the pressure in the Pad-mounted transformer tank;
2. Repeat step 1 to ensure that any residual pressure is released;
3. Connect the hot rod to the eye of the fuse holder and twist to unlock;
4. Rotate the fuse holder 90° to damage the sealing gasket and Bay-O-Net housing;
5. Pull the fuse holder out 8-10 inches quickly to interrupt the load;
6. Wait a few seconds for the fluid to drain from the fuse holder and remove it from the housing;
7. Use a ¾” wrench to remove the fuse box from the fuse box holder;
8. Use ¾” and ½” wrenches to remove the end plug;
9. Replace the fuse.

Bay-O-Net fuse replacement instruction

Dry-Well Canister Fuses

Dry-Well Canister Fuses for pad-mounted transformer

1. The fiber-wound glass tube is the main component of the dry-well housing.
2. Its surface is covered with resin.
3. This is to prevent oil from penetrating the pipe wall.
4. Because oil enters the fuse, the fuse will be abnormal.

3.What Connection Methods are Used for Pad-mounted Transformers?

Daelim's pad mounted transformer installed in Venezuela

External Connection

1. Clean the bushing and terminals before making pad-mounted transformer connections.
2. Remove dirt, grease, or foreign matter. Contamination can cause the bushing to fail.
3. The cables connected to the transformer terminals should have sufficient flexibility .
4. Make sure it can allow normal pad movement due to ground freezing/thawing.

Ground Connection

1. Daelim will provide customers with two solutions based on the size of the transformer mounted on the pad. Grounding pad (Fig 1) or boss (Fig 2).
2. One is on the primary side and the other is on the secondary side.
3. Transformer oil tank needs to be connected to low resistance ground. If the connection is not strong enough, this will cause the oil tank to become live and cause casualties.

primary side

secondary side

High Voltage Connection

The connections must be made in accordance with the diagrams and information provided on the nameplate.

There are two typical high voltage connections:

a.Live front transformer connections

External/internal clamping porcelain bushings are usually used for high-voltage connections to pad-mounted transformers.

Daelim was provided with eye bolts or spade terminals suitable for copper and aluminum conductors.

b.Dead front transformer connections

Cased wells or one-piece bushings are usually used for high-voltage connections to pad-mounted transformers

It is suitable for elbow connections.

Low Voltage Connection

Equipped with spade terminals with 2 to 20 holes.

It can take a low voltage connection to pad-mounted transformers.

Connection Mode of Working Winding of Three-phase Transformer

4.How to Residential a Pad-mounted Transformer?

Pre-service inspection

• WARNING: Only professionals can operate the link of the Pad-mounted transformer.

Before the work starts, a full inspection of the pad-mounted transformer is required.

Confirm that all its accessories are normal. There was no damage.

The following are the inspection steps:

1. Confirm the liquid position of the oil tank.
2. Perform transformer turns ratio and DC insulation tests.
3. Ensure that the outer surface of the Pad-mounted transformer is complete.
4. Check the condition of all seals and gaskets.

Location Consideration

pad-mounted transformer installation diagram

Pad mounted transformer needs to be placed in an open place. This will facilitate a comprehensive inspection.

Outdoor Installations Pad-mounted Transformer

The correct placement of the pad-mounted transformer should be far away from the structure that restricts the airflow around the equipment.

Indoor Installations Pad-mounted Transformer

Special precautions should be taken.

The venue must be ventilated.

Confirm that the vent is open. This is to prevent accidental overheating of the transformer.

If good natural ventilation is not possible, a fan can be used to make the transformer out of the ventilated environment.

The pad-mounted transformer must be prevented from being on a level ground.

The ground must be concrete.

The location must prevent the pad-mounted transformer from tilting more than 2 degrees from the horizontal.

The pad-mounted transformer oil tank and the cabinet base provide provisions for installing splints to secure the transformer to the mat.

There must be no gap between the gasket and the cabinet.

Add permanent mortar to seal the gaps.

5.How to Store Pad-mounted Transformer？

Storage for 3 months or less

1. The transformer has been dried before leaving the factory.
2. There was no leakage of oil during shipment.
3. The place is open and dry.
4. There will be no significant temperature changes in the placement location.
5. Place on the concrete floor or steel plate floor.

Storage for more than 3 months

1. In order to maintain the nitrogen and oxygen content in the fuel tank, dry nitrogen in the fuel tank at 2 psi.
2. Confirm that the condensing heater is in a state where it can work normally.
3. The transformer must be placed in a dry and constant temperature place.

6.How to Ship the Pad-mounted Transformer?

1. The Pad-mounted transformer is in a complete state when it leaves the factory.
2. The Pad-mounted transformer will be completely placed on the pallet and fixed.
3. The detachable radiator will be shipped separately and wrapped in a protective cover.
4. The radiator will be packaged in a dry state.

7.How to Move the Pad-mounted Transformer?

• WARNING: The accessories of the Pad-mounted transformer need to be kept carefully. Can not be used for other purposes.
• CAUTION: Cranes and forklifts with a load capacity greater than the weight of the Pad-mounted transformer must be used.

Move the Pad-mounted Transformer

Moving Pad-mounted transformers shipped on pallets

Single phase pad mounted transformer ready to move

1. The wooden pallet holding the Pad-mounted transformer is recommended to be moved with a forklift.
2. When using a forklift, make sure that the fuel tank of the transformer is on the side close to the driving position. Place it overturned.
3. If you don’t have a forklift, you can use a crane to move it.

Moving Pad-mounted transformers by hoist or crane

Lifting three-phase pad-mounted transformer

1. Before starting the lifting work, check whether all the equipment used for lifting can work normally.
2. There are lifting eyes on both sides of the fuel tank. If a wire rope is used, the lifting angle must not be greater than 60.
3. The Pad-mounted transformer must be in an upright state when being lifted.
4. If necessary, use cross bars to support the wire rope to avoid any deformation of the box structure or the lifting hook.

Skidding/Rolling Pad-mounted Transformers

1. When the use of the crane is restricted, the pad-mounted transformer can be moved using a rolling device.
2. During the movement, the transformer should be kept in a vertical state and moved horizontally.
3. The rolling equipment must be able to provide a pulling force higher than the weight of the transformer.
4. The multi-roller design can help the transformer move more smoothly.

Transformer conveyor belt

Haoshuo are exported all over the world and different industries with quality first. Our belief is to provide our customers with more and better high value-added products. Let's create a better future together.

Using Jacks to move Pad-mounted Transformers

Using Jacks to move Pad-mounted Transformers

1. The jack must be placed under the fuel tank base.
2. The lift provided by the jack must exceed the weight of the Pad-mounted transformer.
3. More than two jacks must be used to work at the same time.

8.How to Check the Pad-mounted Transformer?

1. Daelim Pad-mounted transformers are thoroughly tested and rigorously inspected before shipment from the factory to ensure the highest quality.
2. Whether the exterior of the Pad-mounted tranformer is complete and free of scratches.
3. Check whether all transformer accessories are complete and in normal condition.
4. According to the material list provided by Daelim, confirm that all link accessories are in complete condition.
5. Check whether the pointers of each meter on the high-voltage side are normal; ,
6. If the terms of the transaction are FOB, Daelim will deliver the transformer to the FOB delivery point as required.
7. If there is a subsequent loss, you can file a claim with the carrier.

9.How to Maintain Pad Mounted Transformer?

Spare Parts

1. Daelim can provide you with customized Pad-mounted transformers according to your specific needs.
2. We only produce a limited number of Pad-mounted transformers. designed by anyone.
3. It is best to deal with replacement parts according to the specific situation.
4. If you need to add or replace parts for any Daelim device. Please contact Daelim. Daelim will provide all available nameplate data.

Tap Changer

Pressure Relief valve

Pressure Indicator

Parking Stand

Oil Level Indicator

Load Break Switch

Drain Valve

Bay-O-Net Fuse

Routine Inspection

Routine inspections of the outside of the equipment should be carried out regularly.

1. The inspection interval should consider the environmental conditions on-site.
2. Salty, humid or other corrosive environments require shorter inspection intervals.
3. Regularly check whether there are debris and obstacles between the radiators (equipped).
4. If the device is equipped with forced air cooling, please use the switch in the control panel to manually circulate the fan to ensure normal operation.

Remove any dirt from the base and cabinet area to prevent premature rust and deterioration.

Check whether the surface paint of the pad-mounted transformer is complete.

If there is paint peeling on the surface, you can take a specific picture and tell Daelim.

Daelim staff will inform you of the type of paint used on specific parts.

This will help you improve the paint touch-up efficiency.

Regularly confirm whether each instrument is working properly.

1. The level gauge is out of the normal fluctuation range. If there is a large drop in buoyancy, it means that the oil drum is leaking.
2. Whether the fluctuation range of the thermometer is within the normal range.
3. Whether the thermometer can fluctuate normally with changes in temperature and load conditions.
4. If the pressure gauge stays at 0 for a long time, it means that the oil drum is leaking.

Dielectric Fluid Sampling

1. Samples of the media fluid should be collected at least once a year. The collected samples must be analyzed by DGA (Dissolved Gas Analysis).
2. The most important way to measure the state of the transformer during DGA testing.
3. Conventional oil testing can usually indicate a harmful internal condition before it damages the device.

Maintenance procedures for pad mounted transformers

10.Pad-mounted Transformer Diagram

There are five main parameters for a Three-phase Pad-mounted transformer:

1. Input current;
2. Input voltage;
3. Output current;
4. Output voltage;
5. Operating frequency range.

Three-phase Pad-mounted Transformer

Bird's eye view

Side view

Dead Front Radial Feed

1. HV BUSHING
2. BAY-O-NET FUSE
3. TAP CHANGER
4. DIAL TYPE THERMOMETER
5. FILLING PLUG
6. PRESSURE VACUUM GAUGE
7. OIL LEVEL GAUGE
8. PRESSURE RELIEF VALVE
9. LV BUSHING
10. NAMEPLATE
11. WARNING LABEL

12.DRAIN VALVE WITH SAMPLER

13.DOOR HANDLE

14.LIFTING LUG

15.HAND HOLE&SECURITY COVER

16.TANK

17.RADIATORS

18.JACKING PAD

19.JACKING PROVISIONS

20.DOOR

21.GROUNDING PAD

22.HV-LV BARRIER

Radial Feed Pad mounted Transformer Data

Single-phase Pad-mounted Transformer

Single Phase pad mounted transformer

1. Lock Mechanism;
2. NEMA safety labels;
3. Externally accessible expulsion fuse with drip cup;
4. Parking stand for elbow connectors;
5. High-voltage bushing wells;
6. Tank ground provisions;
7. Padlock provision;
8. Flip-top hood opens 180º;
9. Laser engraved nameplate;
10. Pressure relief valve;
11. Fill plug;
12. Low-voltage threaded stud bushings;
13. Removeble ground strap;
14. Drain plug;
15. Removable sill;

Core

three-phase transformer winding

1. Daelim uses a silicon steel sheet shearing machine to create a stepped, three-legged miter core structure.
2. The miter core structure is completely cut from high-quality silicon steel (magnetic core steel).
3. High-quality raw materials can greatly reduce the loss of the magnetic core.
4. The mitered core structure eliminates the gap in the seam so that the transformer can obtain maximum efficiency.
5. Use star connection to install three-phase pad-mounted transformers.

If you have any questions for the pad mounted transformer or you are looking for a pad mounted transformer manufacturer, welcome to contact me by : and :+86 .

Power transformers are one of the most important equipment in the electrical power system. If you have any questions regarding power transformers, you'll find all of the answers you're looking for here.

Daelim is a professional power transformer manufacturer in China. The voltage level is up to 230kV, and the capacity is up to 240MVA. Pad-mounted, substation transformer and single phase have UL/cUL, CSA, IEEE, and other certificates. The transformers designed and produced by Daelim comply with various international standards such as ANSI/IEEE, CSA, DOE, AS, and NEMA.

Table of contents 1. What is a power transformer in a substation?
2. What's the purpose of using a power transformer?
3. How does a power transformer differ from a distribution transformer?
4. How many power transformer types are there?

• Step-up power transformers
• Step-down power transformers
• Three-phase power transformers
• Single-phase power transformers
• Distribution power transformers
• Instrument power transformers
• Indoor power transformers
• Outdoor power transformers
• Oil-type power transformers
• Dry-type power transformers

5. How does a power transformer work?
6. What are the different uses and applications of a power transformer?
7. What is a 66kv transformer?
8. What is a 138kv transformer?
9. What is a 220kv transformer?
10. In conclusion

What is a power transformer in a substation?

A power transformer is an industrial-grade electromagnetic device that harnesses the power of inductive coupling to transfer energy from one electrical supply circuit to another. It is the most important component in an electrical substation.

An electrical substation is a place where electricity is generated, transmitted, and distributed to consumers. A power transformer is used to increase (step up) or decrease (step down) the voltage of an AC electrical supply.

Learn more: Electrical Power Transformer Basic Guide

Transformers typically use two or more coils of wire, called "windings," to transfer energy from one circuit to another. The windings are wrapped around a common iron core where the primary and secondary windings are connected to the power source and the load, respectively.

As the alternating current in the primary winding changes direction, it creates a changing magnetic field. This magnetic field produces the necessary energy for the secondary winding. The transformer's job is to transfer energy from the primary circuit to the secondary circuit with as little loss as possible.

What's the purpose of using a power transformer?

The main purpose of a power transformer is to convert high-voltage electricity into lesser and more manageable electric sources for both commercial and residential use. A transformer lowers the voltage rate from the power grid to a safer and more manageable level where the secondary winding can use this converted electricity to power businesses and homes.

The load might be a light bulb, a motor, or some other type of equipment. The transformer converts and maintains the proper voltage to ensure continuous use without potentially damaging the appliance.

The transformer can also increase the voltage if the load requires more juice than the current power available from the power grid. This is often the case with equipment that uses a lot of electricity, such as electric furnaces and large air conditioners.

In addition, power transformers can be used to change the voltage from one level to another. This is often done to transmit electricity over long distances.

Power transformer manufacturers hone their craft by designing transformers that minimize energy loss while providing the necessary voltage conversion.

Try for free: How To Buy Power Transformers In Australia?

How does a power transformer differ from a distribution transformer?

Both terms are commonly used interchangeably, but there is a technical difference between the two types of transformers. The clear difference between a power transformer and a distribution transformer is that the former is used during the load period while the latter operates in both load and no-load periods.

Distribution transformers are meant to step down the voltage from the power grid to a safe level for both commercial and residential applications.

In addition, distribution transformers are usually smaller in size than power transformers. This is because distribution transformers typically have a lower capacity than power transformers.

Read my article on How to choose the best distribution transformer?

How many power transformer types are there?

There are ten power transformers types:

Step-up power transformers

Step-down power transformers

Three-phase power transformers

Single-phase power transformers

Distribution power transformers

Instrument power transformers

Indoor power transformers

Outdoor power transformers

Oil-type power transformers

Dry-type power transformers

Step-Up Power Transformer

A step-up transformer is used to convert low-voltage (LV) and high-current (HC) electricity into high-voltage (HV) and low-current (LC) electricity. It transfers the power transformer's high-current, low-voltage primary side to the low-current, high-voltage value secondary side.

Step-up transformers increase the primary voltage to secondary voltage. As a result, the step-up power transformer's secondary winding will have more turns. This increases the transformers' capability to transfer energy and power.

Step-Down Power Transformer

Step-down transformers are the exact opposite of step-up transformers. It transforms high-voltage (HV) and low-current (LC) electricity into low-voltage (LV) and high-current (HC) electricity.

Simply put, step-down power transformers do the exact opposite of a step-up power transformer. Power transformers in substations have the ability to both increase and decrease voltages. However, its capacity will depend entirely on the purpose and situation.

The step-down transformer also has a secondary winding that has fewer turns than the primary winding. This results in the transformer having a lower capacity to transfer energy and power.

Keep reading: Step-up vs Step-down Transformer

Three-Phase Transformer

A three-phase transformer is a type of power transformer that's commonly used for projects that features a compatible three-phase power system. It's a more efficient way to transmit electricity compared to a single-phase power system.

Three-phase systems are often used in industrial and commercial settings where large amounts of electricity are needed. This is because three-phase systems can transmit more power than single-phase ones while using less conductor material.

One of the benefits of using a three-phase system is that it can provide a steadier and more constant flow of power. This is due to the fact that three-phase systems have three alternating currents that are offset by one-third of a cycle. This offset minimizes any gaps in the power supply, which results in a steadier flow of power.

Read on: 3 Phase Pad Mounted Transformer

Single-Phase Transformer

A single-phase transformer uses a single-phase alternating current. So it's heavily dependent on an operational voltage cycle that's generated by a single alternating current in a unified time phase.

Single-phase systems are often used in residential settings where lower amounts of electricity are needed. The primary to the secondary windings' electric ratio will determine the transformation the single-phase transformer can provide.

Daelim's single transformer has two types: single phase pole transformer mounted and single phase pad mounted transformer. A large number of exported to North America and Central and South America, mainly for power distribution in residential areas.

You may enjoy: 167 kVA Transformers: The Ultimate FAQ Guide

Distribution Transformer

A distribution transformer decreases the voltage of an electric power distribution system to the level that's compatible with the voltages that the customer uses. Various power transformer manufacturers typically use it for commercial or domestic purposes.

A distribution transformer usually has excellent voltage regulation levels that maintain a steadier voltage. This is because it typically features a tap changer that can automatically adjust the turn ratio of the transformer's primary and secondary windings.

This feature results in the distribution transformer having the ability to maintain a steadier voltage even when there are load changes. The tap changer is usually located on the secondary side of the distribution transformer.

Read more about distribution transformer: What Is Distribution Transformer?

Instrument Transformer

An instrument transformer is a type of power transformer that's used to isolate and change certain attributes of an electric circuit. These attributes can include voltage, current, or impedance. Instrument transformers are often used in industrial settings where electricity is measured or monitored.

One of the benefits of using an instrument transformer is that it decreases high currents and voltages to mitigate the values to a safer level. This is done by using either a current transformer or a voltage transformer.

A current transformer changes the high primary current into a lower secondary current. This is done by wrapping the primary conductor around a magnetic core and passing the resulting current through the secondary winding.

A voltage instrument power transformer converts the high-voltage primary side into low-voltage secondary side. This is done by placing the primary and secondary windings on different cores and passing the current through the primary winding. The newly converted voltage will then travel from the primary winding and through the secondary winding.

Indoor Transformer

An indoor transformer is a type of power transformer that's installed indoors. Indoor transformers are typically used in settings where there's a lower risk of fire or explosion. This is because indoor transformers are less likely to be damaged by weather conditions.

Indoor transformers are also often used in settings where aesthetics are important. This is because indoor transformers can be hidden from view more easily than outdoor transformers.

Outdoor Transformer

An outdoor transformer is a type of power transformer that's installed outdoors. Outdoor transformers are typically used in settings where there's a higher risk of fire or explosion. In addition, outdoor transformers are more likely to be damaged by weather conditions.

Outdoor transformers are also often used in settings where space is limited. This is because outdoor transformers take up less space than indoor transformers.

Oil-type Transformer

As the name suggests, an oil-type transformer is a type of power transformer that uses oil (transformer or mineral oils) as a coolant. Oil-type transformers are often used in settings where there's a need for a high degree of protection. This is because oil-type transformers are less likely to catch fire than air-cooled transformers.

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Dry-type Transformer

A dry-type transformer is a type of power transformer that uses air as a coolant. Dry-type transformers are often used in settings where there's a need for a lower degree of protection. This is because dry-type transformers are more likely to catch fire than oil-type transformers.

In addition, dry-type transformers are more affordable than oil-type transformers. This is because dry-type transformers don't require the use of expensive oil as a coolant.

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How does a power transformer work?

A power transformer converts the voltage of an electrical power supply. The primary winding of a power transformer connects to the AC power source, while the secondary winding is connected to the load.

The transformer uses the principles of electromagnetic induction to convert winding voltages from the primary winding to secondary. This concept creates a magnetic field, producing the optimal voltage.

Without a power transformer, electronic equipment would not be able to function properly. At the same time, power transformers help to protect electronic equipment from damage by regulating the voltage of the power supply.

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What are the different uses and applications of a power transformer?

Power transformers are used for the following applications:

Power generation and distribution.

It is increasing the voltage of an electrical supply to transmit electricity over long distances.

Decreasing the voltage of an electrical supply to make electricity safe for use in homes and businesses.

Isolating two electrical circuits from each other to safeguard sensitive electronic equipment.

Providing sufficient power to electronic equipment that requires a lot of electricity.

Sustaining the voltage of an electrical supply during power surges and brownouts.

Converting the voltage of an electrical supply from one country to another.

Reducing power losses during the transmission and distribution of electricity.

Used in cases where the load is required to have a different voltage than the supply.

There are numerous applications for power transformers, which is why they are essential components of the electrical grid.

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What is a 66kv transformer?

A 66kv transformer is a power transformer that's designed for low-loss, high-efficiency power transfer at 66,000 volts. The transformer is made of two or more windings wound around a common magnetic core.

A 66kv transformer usually has the lowest kilovolt ampere rating (kVA) of any standard transformer. This is because the transformer is designed for lower losses and higher efficiency.

Some of the key features of a 66kv transformer include:

Dielectric strength of 66kv.

A frequency range of 50 to 60 Hertz.

A maximum power rating of 500 kVA.

A maximum voltage rating of 66,000 volts.

A minimum impedance of 0.25%.

Daelim 66kV transformers have been exported to Australia, Canada, Myanmar, and other countries. Daelim 69kV transformer and substation projects are numerous in Ecuador.

69KV Series Substation, Latin America

What is a 138kv transformer?

A 138kv transformer is an optimized transformer that's designed to absorb and utilize advanced reactive power compensation techniques. The optimized transformer core, body, coil, and fuel tank, among other components, help to make the 138kv transformer one of the most efficient and reliable power transformers available.

Some of the key features of the 138kv transformer include:

Reduced no-load and eddy current losses.

Higher impedance design for superior voltage regulation.

Lower sound levels.

Windings are made of copper or aluminum for better conductivity.

Enhanced mechanical strength and durability.

Read on: How To Choose The Suitable 110KV Power Transformer?

What is a 220kv transformer?

The 220kv transformer is a power transformer that's designed for high-voltage, long-distance power transmission. The 220kv transformer is made of two or more windings wound around a common magnetic core.

A 220kv transformer usually has a higher kilovolt ampere rating (kVA) than other standard transformers. This is because the transformer is designed for high-voltage power transmission.

Some of the key features of a 220kv transformer include:

High security and reliability during operation

High economic efficiency to reduce power losses

A wide voltage regulation range

High insulating and short-circuit strength

Customize transformers to meet your specific needs

Excellent short delivery times

No-load and eddy current losses are low

Daelim 220kV transformers are exported to many units in Ecuador, and there is a local after-sales installation team. Daelim 230kV transformers are exported to the United States, and 115kV transformers are exported to Mexico and other countries.

In conclusion

Every transformer produced by Daelim has to go through strict quality control. Including routine tests before leaving the factory, routine tests, and some special test items according to customer requirements. Pursuing high-quality products is the philosophy of the Daelim transformer enterprise. If you have any technical and price questions about the transformer, please contact the Daelim team, Daelim will reply within 8 hours.

Contact us to discuss your requirements of Transformer Tank Produce Machine. Our experienced sales team can help you identify the options that best suit your needs.

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