630 kVa Mini Substation and Miniature Substation

Mini Substations also consist of different electrical equipment that serves other purposes, which is why it is considered a versatile electric device. Miniature substations are considered as one of the most underrated electrical devices out there. But why? Are they not worth it or are they not as effective compared to regular substations?

In this article, DAELIM, one of the top mini substation and miniature substation manufacturers in China, will provide you with information about mini substations for you to have a better understanding of them.

The Mini Substation is a small, portable, and compact power generator for automobiles. It can be used in cases when the main engine of the car is not producing enough power to run most of the car’s accessories and systems. Daelim is one of the best 630 kVa Mini substation manufacturers in the market.

The advantage of using a Mini Substation with an engine that isn’t running at full capacity is that it can act as supplemental power to keep all systems running properly while also providing emergency backup power to charge your mobile devices or other battery-powered devices. With its sleek design, portable nature, and user-friendly interface, this device would make a great addition to any vehicle.

One of the main benefits of this device is the ability to charge your devices when you have an empty car battery or just need some extra power. The Mini Substation can also be used to power up most of your accessories in case your engine isn’t running at full capacity. Since it is a fully functional power generator, it’s great for those camping trips or long road trips when you need some additional power to make sure all of your essential electronics stay on.

The Mini Substation is designed to be robust, compact, and weatherproof, allowing users to use them in any environment or landscape. They are constructed from a high-impact structural polymer and can be bolted onto freestanding legs for an elevated installation. The structure allows hot air from inside the unit to escape without letting in dust or moisture, allowing for extended safe use in harsh environments such as deserts or hostile external weather conditions.

This is to help you understand better what they are and to help you formulate a purchase decision of whether you should or should not purchase one for your next project.

230KV Class Three Phase Two Winding DETC Power Transformer
220KV Class Three Phase Two Winding NLTC Power Transformer
Class Three Phase Three Winding OLTC Power Transformer
OLTC 1000kva Mini Miniature Substation

Mini Substation and Miniature Substation: The Ultimate FAQ Guide

What Is A Substation?

To begin with, you should be able to tell the difference between what substations and miniature substations are. Miniature substations are basically the smaller version of substations.

For substations, they are commonly used to step down (decrease) high voltage electricity from the transmission system. This lowers the voltage electricity into a more compatible level for easy electricity distribution to houses and other establishments through their distribution lines.

In short, substations convert power system voltages from transmission levels to distribution levels. This is for safe and efficient distribution.

Miniature Substation Mini Substation

What is a mini substation?

A substation is a component of a system that generates, transmits, and distributes electricity.

Substations convert high to low voltage – or vice versa – and conduct a variety of other critical duties.

Electricity may travel through many substations at varying voltage levels between the generating station and the customer.

Transformers may be used in a substation to convert voltage levels between high transmission and low distribution voltages or to connect two separate transmission voltages.

A utility company or a major industrial or commercial customer can own and operate a substation. Substations are typically unattended, with remote supervision and control provided by a control system.

Mini substations are prefabricated electrical equipment units that include medium voltage and medium voltage switchgear, power and distribution transformers, low voltage switchboards, connection busbars, and other accessories.

A small substation is a self-contained substation; it is a safe, portable, and space-saving design concept.

Get the lastest How to ground the pad-mounted substation now

What is the Function of a mini substation?

Smaller transformers and less secondary distribution equipment (breakers, switchgears, etc.) are typical features of a miniature substation, which is basically a regular substation with a lower kVA rating and less sophisticated systems to protect the transformer and feeder(s) and metering and other controls.

Get the lastest
Dry-type Transformer Model List

How to Install a mini substation?

Install a mini substation
Install a mini substation

There have been instances where installations have been halted owing to insufficient preparation between the consumer and manufacturer, which is why planning should be the first step in the process of acquiring a substation or micro substation.

The layout should be in the form of a one-line diagram, which is the simplest form of switching.

Additionally, it safeguards the arrangement.

This includes all incoming supply or distribution lines, as well as all leaving feeders.

Electrical businesses adhere to this protocol when creating one-line diagrams that include all major components such as lines, transformers, fuses, and circuit breakers.

These are arranged on the page similarly to how other electrical devices are constructed.

Incoming lines are typically comprised of a disconnect switch and a circuit breaker. There are rare instances where a line will lack both.

Because disconnect switches are incapable of interrupting load currents automatically, their role is to isolate.

These can be used as a protective device to interrupt fault currents or to switch loads.

Additionally, it has the ability to disconnect a line if power is being transmitted in the wrong direction.

When a large fault current flows through the circuit breaker, it is easily identified using current transformers, which are transformers designed expressly for this purpose.

The magnitude of the current transformer output will be used to trigger the circuit breaker; this will result in the circuit breaker disconnecting the load it supplies from its feeding point.

This effectively separates the failure site from the rest of the system, allowing the remainder of the system to run with minimal disruption.

These two switches and circuit breakers can be controlled locally or remotely via a supervisory control center.
Overhead transmission lines and the propagation of lightning and switching surges may cause the small substation’s insulation to fail, causing significant damage to the electrical device.

Surge arrestors at the line entrance are frequently employed to protect substations from this type of destructive element.

After passing through the switching components, the lines are given a voltage connection to one or more buses.

These are common busbar sets that are normally three in number, as the electrical power distribution devices used in this application are all three-phase.

The power consumed by switches, buses, and circuit breakers has an effect on the cost and dependability of the small substation.

Additionally, substations and substations make use of a variety of buses, including twin buses and ring buses.

A circuit breaker failure has no effect on the operation of other circuits.

De-energized sections of the substation can be used for maintenance and repairs.

Mini substations that provide a single industrial load may have fewer switching capabilities, particularly for installations that require little time and effort.

Having buses that are capable of operating at a range of voltage levels. Additionally, transformers can be connected between voltage levels.

A circuit breaker and transmission wires are typically included in the arrangement.

This is for safety reasons in the event that a transformer develops a fault or short circuit.

Substations and mini-substations are always equipped with a control circuit that initiates the opening of numerous breakers.

This is true in the event of a component failure.

Transformer three-phase dual power supply automatic switching

What are the different parts of a mini substation?


There are numerous above-ground mini and conventional substations available in the market. For example, a utility pole and a metal tower can be included.

In exchange for the low-cost supports for the transmission lines and apparatuses, this build demands greater area. The location of some substations and mini-substations is a determinant in whether or not they are purchased.

It’s possible that gas-insulated switchgear could be used in indoor mini-substations (depending on what you prefer). There will be metal-enclosed switchgear used for low voltages.

To blend in with their surroundings, urban and suburban substations and mini-substations are often built outside.

It’s best to use a small outdoor substation, which is usually enclosed in metal to keep the public away from the electrical equipment and devices. Because of the lower footprints, each electrical device can be placed next to each other.

Compared to outdoor small substations, indoor micro substations have a simpler design and construction.

For this reason, indoor small substations are equipped with additional safety and security measures.

Detailed explanation of the difference between dry-type transformers and oil-immersed transformers

Voltage Levels

Indoor mini substations can install voltage levels up to 66kV, whereas outdoor mini substations can install voltage levels up to 66kV and beyond.

Thus, outdoor small substations have a greater voltage range.

Assigned Area

On the basis of the designations assigned to them, indoor and outdoor mini substations are only meant to be used indoors and outdoors.

Smaller substations are easier to fit into smaller places than their larger counterparts, making them ideal for smaller areas.

In order for it to be safe, however, there are still a number of requirements that must be met.

For example, the micro substation installation process necessitates a suitable amount of land area. Large electrical devices, such as transformers, should also have a path or method to go to their destinations.

You can save a lot of money by using gas-insulated switchgear. Substations located along the coast are more susceptible to flooding and other natural disasters caused by high winds, heavy rain, and other factors.

These features necessitate a raised construction to protect the instrument from malfunction. There must also be room for expansion in the small substation’s area, due to increased demand or more transmission lines.

Disruptive components such as floods, debris, and so on should be taken into account, too. The small substation can be severely impacted by this.

The location of the small substation must be in close proximity to the distribution area as well as the customers it serves.

To keep people away, the property must be surrounded with dangers and barriers. Placement of barriers surrounding the region is highly suggested to prevent electrical shock or arc injuries, which can be extremely severe and even life-threatening.

Calculation Formula of Transformer Transformation Ratio

Space Consumption

Both are tiny substations in terms of space consumption, although outdoor mini substations are slightly larger than indoor micro substations.

Nonetheless, they are rather standard-sized small substations in comparison to their larger counterpart, the standard substation.

Three-Winding Transformer | Three-Phase Transformer | Daelim

Installation Expansion

Both types of installations can be expanded.

However, it is difficult to expand inside small substations.

Outdoor small substations, on the other hand, are considerably easier to expand.

2021 A Complete Guide to Power Plant Transformer

Cost Expenses

Indoor mini substations are much less expensive than outside mini substations.

This is because outside small substations must be protected, as they are exposed to weather, natural calamities, and other phenomena.

Principle of resolver (signal transformation)

Fault Cleaning

Indoor small substations, on the other hand, are a breeze to clean of faults. It’s also difficult to cope with outside small substations when it comes to fixing their flaws.

The main factors affecting the insulation performance of transformers


Despite the fact that indoor small substations are securely installed within buildings, they nevertheless require periodic monitoring and maintenance. Indeed, they are a high-maintenance electrical equipment.

While outdoor mini substations are subject to the elements, their structure makes them resilient enough to require little maintenance.

Wiring method of Dry-type Transformer


Apart from monitoring, you’ll need to consider replacements and repairs.

In comparison to outdoor mini substations, indoor mini substations are more difficult to repair and replace.

Occasionally, parts are also unavailable.

Protection Grade

Because they are housed in a protected facility, indoor mini substations necessitate less protection than outdoor mini substations.

Outdoor small substations are vulnerable to a wide range of threats.

Anything and everything can be found in the atmosphere.

Although it is possible to protect the outdoor small substation from outside interference by erecting a protective cage or shield, there are many more options.

Fire Code

Indoor mini substations can be installed within buildings because they comply with most building’s fire codes, however outdoor micro substations are deemed too risky to be placed near buildings.

They are just not appropriate or compatible with this level of exposure.


They typically consist of wood poles, metal structures, and lattice metal towers for outdoor small substation constructions.

However, this may vary depending on the variant.

Steel lattice towers are an economical way to support transmission lines.

They can be characterized as low-profile small substations in suburban regions where appearance is more important.

Indoor mini substations can be gas-insulated for high voltage applications or metal-enclosed for low voltage applications.

Miniature indoor substations in urban and suburban areas can be finished externally to mix in with their environment.

The majority of compact substations are outdoor substations enclosed in a metal cage.

Each item is substantially closer to the other in this configuration, resulting in a reduced footprint for the substation.

Preventive measures for tripping of three-side switch of 110kV main transformer


When planning a substation or micro substation layout, the initial step is to create a one-line diagram. The simplicity with which switching and protection are implemented is clear in this example.

There are other costs associated with supplying and exchanging electricity.

The lines, circuit breakers, switches, breakers, and transformers are presented on the page in one-line schematics prepared by the electrical utilities.. that is akin to how a micro substation’s equipment should be arranged.

Commonly, incoming lines have both a disconnect and a circuit breaker installed. In some cases, there will be no lines at all.

The disconnect switch serves as an isolation device because it cannot interrupt the current flowing through the load.

As a device for protection, the circuit breaker interrupts fault current automatically. In the event that power is flowing in the wrong direction, they can be used to turn on and off switch loads on a line.

Circuit breakers have current transformers that may detect abnormally high fault currents.

Current transformer outputs are used as triggers for circuit breakers, which results in the disconnection of loads supplied to the circuit breaker by means of its feeding point being disconnected..

An isolated fault spot can be found by doing this. The remainder of the system is less affected as a result of this. Local and remote control is possible for switches and circuit breakers.

Connection Mode of Working Winding of Three-phase Transformer

What is the Function of a mini substation?

Step-down Mini Substation

According to its name alone, this small substation’s purpose is to specifically reduce high voltage or transmission levels to distribution voltages.

Alternatively, it can be decreased to what are known as sub-transmission voltages, which are frequently employed in industrial applications.

On the contrary, the output will be sent to a tiny distribution substation or a normal distribution substation.

You may have heard of step-down mini substations; this is a popular form of mini substation available on the market.

Typically, step-down mini substations are positioned at various points along an electrical network. Additionally, they can connect various components of the network that serve as a source of distribution lines or sub-transmission.

Miniature step-down substations are capable of converting transmission voltages to sub-transmission voltages.

Additionally, these modified voltage lines can be used to power micro distribution substations. Additionally, there are instances where power is drawn from the transmission line to utilize industrial capacity.

Mobile Transformer | Mobile Substations | Mobile Substation Manufacturers

Mini Step-up Substation

In contrast to step-down transformers, step-up substations are the most popular type of transformer. As a result, the cost of this small substation is expected to be more.

This mini-substation is designed to improve the voltage levels of generators at power plants so that electricity can flow more easily.

Calculation Method of the Number of Turns of Power Transformer Core

Underground Distribution Mini Substation

Although tiny substations are already compact, there are rare instances where specific places lack the space required for mini substations.

Installing the micro substation underground is one of the most effective solutions to combat this. This reduces the required amount of space and allows for the utilization of the tiny open area above for other construction reasons.

The primary objective of subterranean distribution mini substations is to deliver the best conventional mini substation possible without obstructing above-ground area.

What is the no load losses of transformer?What is the short-circuit loss of the transformer

Mobile Mini Substation

A transformer, breakers, bus work, and a transformer are all contained in a mini substation that is wheeled and contains this type of substation.

On a semi-trailer that can be towed by a car or truck, the bus work is installed.

In the event of a power outage due to a natural disaster, a tiny substation like this can serve as a backup power source.

Also called as mobile mini substations, they can be erected in many units to accommodate mobility restrictions.

How to calculate the power losses of the transformer, the calculation method of the transformer iron losses and copper losses power

Mini Distribution Substations

The price of a tiny substation of this kind is greater than the prices of the previous two types since this substation is capable of lowering sub-transmission voltage. Miniature step-down substations may be capable of lowering voltage levels to sub-transmission levels, but only to a certain extent.

This is to ensure that electricity is supplied to all structures within the area that it is capable of reaching (long distances).

Mini distribution substations are frequently used in conjunction with distribution transformers prior to the transfer of power to the load.

The majority of these electrical equipment are frequently buried.

What Is A Miniature Substation?

This leads us to the next topic; what is a miniature substation? Basically, a miniature substation is a smaller version of the regular substation with a lower kVA (kilovolt ampere) rating.

Although small with a less rating, miniature substations are still part of an electrical generation, distribution system, and transmission as well. As mentioned, miniature substations are used to step down high voltages to distribution levels for electrical distribution.

But they can be used to step up (increase) low voltages as well for transmission levels.

Furthermore, miniature substations can perform other important functions, which you will get to know as we go deeper in this article.

Electrical power can flow through several substations at different voltages as well between generating stations and the consumers (houses and other buildings).

Although not necessary, substations can include transformers to change or adjust voltage levels between high transmission voltages and lower distribution voltages. In addition to that, it is also applicable at the interconnection of different transmission voltages of up to two levels.

Substation and miniature substations are primarily operated and controlled by an electrical utility. They are usually unattended, and they rely on a control system that is made for remote supervision and control.

To begin with, the most appropriate element to understanding what mini substations is knowing what it is.

A mini substation is basically a smaller version of the regular substation with a lower kVA (kilovolt ampere) rating. They are part of distribution systems, electrical generations, and transmissions.

Mini substations are also considered as transformers because they transform voltages from high voltages to low voltages and vice versa. 

Electric power flows through several substations or mini substations at different voltage levels between the power generating station and the buildings connected, A mini substation can include transformers to adjust voltage levels both at high transmission voltages and lower distribution voltages.

Moreover, adjusting voltage levels at the interconnection of two different transmission voltages is also possible.

Substations and mini substations are usually owned by electrical companies and big industries, but they can be used by a commercial customer as well. These substations rely on a control system for remote supervision and operation.

Understanding Live Front Three Phase Pad-Mounted Transformer

What Are Mini Substations For?

They serve different kinds of purposes. But it is primarily used to step down (decrease) high voltage electricity so that it would be easier to supply houses and other buildings with electricity through their distribution lines.

Mini substations are usually associated with a power transformer and they are commonly used for areas that do not have much space or applications that only require low kVA ratings.

They operate with the same functions as regular substations, such as stepping up and down voltage levels, distributing electricity, system protection, switching capabilities, and other functions.

This is why they are considered small but versatile electrical devices.

Mini Miniature Substation

Miniature Substation Working Principle

Again, miniature substations work with the same principles as regular substations do. The electricity will be transmitted at high voltages and low current, this is to reduce the eddy currents, heat, and other transmission losses.

The substations are where the voltages are increased to high values by using step-up transformers or transformers that are capable of increasing voltage levels.

After the transmission, they are then stepped down for distribution.

Classification and function of transformer’s dielectric loss

The Difference Between Mini Substations and Substations

To better understand the differences between the two, DAELIM included this section for you to know the distinct features, similarities, and characteristics of each substation.

For starters, mini substations are just like regular substations. However, when it comes to size and rating, they are very different. It also is less in the way of the secondary distribution equipment.

Chances are, it will have less sophisticated systems to protect the transformer, feeders, metering, and other controls.

Basically, a mini-substation is like a regular substation, only the transformer is usually smaller (lower kVA rating), and it has less in the way of secondary distribution equipment. Mini-substations commonly consist of power transformers, fuses, tap changer, and metering.

Mini Substation Electrical Functions

Mini substations may be small, but they are packed with several electrical types of equipment that perform different functions.

Below are some of the electrical equipment in it.

Circuit Switches

Circuit switches are responsible for directing the flow of electricity. For instance, the switch you use to turn on and off the lights.

Circuit switches can be considered a direct guide for the flow of electricity. An example of this is turning on or off the lights in your kitchen.

Maintenance Procedures for Pad Mounted Transformers


Capacitors are responsible for helping the miniature substation to improve the quality of the electricity that is being supplied to houses and other buildings.

There are two ways this can be done, and it can be either by smoothing out voltage depressions or filtering out voltage distortions.

Capacitors help improve the quality of the electrical supply to the houses and buildings. This can be done in two ways:

  1. Smoothing out voltage depressions 
  2. Filtering out voltage distortions


Miniature substations have the ability to step up or step down voltage levels for proper use, which is why substations are in high demand for electrical companies because they are highly efficient in distributing electricity safely and smoothly. 

As aforementioned, mini substations can step down or decrease high voltage electricity entering the transmission lines to a lower voltage that is more suitable for distribution wires.

The Complete Guide to Ground Mounted Transformer

Parts of a Mini Substation

Below are just some of the parts of a mini substation, parts will depend on the mini substation’s brand or manufacturer.

But since mini substations are smaller, there is a possibility of having fewer parts or less efficient parts in them compared to regular substations.

Miniature substations have various parts in them, but because they are smaller, there is a chance that they may have fewer pars in them compared to regular substations

Regardless, they are still effective in what they are made to do.

Below are parts of a miniature substation.

Power Transformer

A mini substitution consists of a power transformer. This is located at the heart of the substation. The function of the power transformer is to step down voltages.

Miniature transformers have a power transformer that enables them to step up or step down voltage levels to a specific level. This is usually located at the center of the miniature substation but it could vary depending on the manufacturer.

Primary Fuses

Power fuses are used to protect the power transformers in distribution substations and mini substations. But its primary purpose is to provide interruption of permanent faults.

The use of power fuses is to protect the power transformers in miniature distribution substations and distribution substations.

It is primarily used to provide interruption of faults as well, specifically permanent ones.
Power fuses are used to protect the power transformers in distribution substations and mini substations. But its primary purpose is to provide interruption of permanent faults.

Lightning protection for 10 KV distribution transformers 10 KV


Circuit breakers are utilized to open and close circuits. These can be operated manually to perform maintenance on it. It has the option to automatically trip if a short circuit occurs. The breakers of the power system are quite the same as the fuses or circuit breakers of your house.

Breakers disrupt the flow of electricity in events that unexpected electrical surges or faults occur. This prevents the system from receiving any damage,

This function is similar to the main service panel at your house.

Circuit breakers play a vital role in miniature substations since they are used to both open and close circuits. They are operated manually to do maintenance.

One of the useful functions of it is that it trips a circuit if a short circuit is ever to happen. The breakers of the power system are similar to fuses or circuit breakers that are in your house.

Miniature Substation packaging

Tap Charger

The purpose of tap chargers is to regulate or balance the output voltage of the power transformer in a substation. This is done by altering the number of turns in one winding, which changes the turns of the transformer.

Tap chargers regulate the output voltage of the power transformer in miniature substations. The process of this is that it alters the number of turns in one winding, which changes the turns of the transformer.

Secondary Metering

Secondary metering refers to the meter that asserts the quantity of the gas.

Secondary metering is the meter that asserts the quantity of the gas that is applied to the miniature substation.


Types Of Mini Substations

In this list, you can find these types normally in regular substations, but there are manufacturers that manufactured these types of substations to mini substations as well for the convenience of those who require it in small spaces and low kVA rating operations.


Mini Switching Station

Switching stations are substations or mini substations that do not have transformers. Moreover, they are only operating at a single voltage level. They are commonly used by collector stations and distribution stations.

There are certain situations as well that are used for switching the current to backup lines or parallelizing circuits. This is added security just in case there is a failure.

Switchings stations can also be considered as switchyards, as mentioned, there are located near a power station. Generators from power stations supply power to the yard then to the generator bus on one side of the yard.

The transmission lines get their power from a feeder bus on another side of the yard.

Switching is actually one of the important functions of substations, this connects and disconnects transmission lines or other components to/from the system. This can be planned or unplanned.

A transmission line may need to be de-energized for its maintenance, or construction.

For instance, adding or removing a transmission line. To maintain the reliability of its supply, industries focus on keeping the system up and operating while performing the necessary maintenance.

Miniature Substation

Mini Transmission Substation

The short definition of this mini substation is that it connects transmission lines. This is for transmission lines that have the same voltage, such as substations that have high-voltage switches that keep the lines connected for fault clearances and as well as maintenance.

A transmission station does not necessarily have a transformer but it can have one too to convert two transmission voltages, reactors, etc.

This is to control power flow between adjacent power systems. Transmission substations can be easy and hard to operate because they range from simple to complex. For easy-to-operate transmission substations, you can inquire at DAELIM.

Mini Distribution Substation

Mini distribution substations transfer power from the transmission system to the distribution system of a certain area. It is simply uneconomical to directly connect electricity consumers to maintain the network, except for using it in large amounts of power for the distribution station to reduce voltage levels at a compatible level.

Mini distribution substations transfer power from the transmission system, to the distribution system. It is not recommended to directly connect electricity consumers to the main transmission network unless they use it for purposes that require large amounts of power.

The input for distribution substations is two transmissions or sub-transmission lines. The input voltage will depend on the area. The input consists of a number of feeders. Distribution voltages usually range from 2.4 kV and 33 kV.

This also depends on the size of the area that practices the local utility. The feeders along the streets overhead and power the distribution transformers.

Furthermore, mini distribution substations can also isolate faults in the transmission or distribution systems. They are the points of voltage regulation.

Miniature Substation

Mini Collector Substation

A collector mini substation resembles a mini distribution substation, but its power flows in the opposite direction.

They are commonly used in wind farms or photovoltaic power stations. In the economy of constructions, the colleter mini substation operates at 35kV, but there are collector systems that run 12kv.

This mini substation provides power factor corrections if needed. There are also certain situations that can contain HVDC converter stations.

Cooling method of 500kV transformer

Mini Converter Substation

Converter substations can also be associated with HDVC converter plants, interconnected non-synchronous networks, and traction currents.

These stations contain power electronic devices to adjust the frequency of its current or to convert from alternating to direct current.

Common Faults and Routine Maintenance of 220kv Transformer

69kV Transformers and Mini Substations

DAELIM 69kV Power Transformers are transformers that use oil as their cooling medium, and they are commonly used in mini substations. This transformer is highly efficient which is why it is commonly used in mini substations and substations.

Their design is also built by domestic and foreign technologies to enhance its durability. They are also designed to convert energy from one voltage to another. This is why you can find DAELIM 69kV Power Transformers at mini substations because of their effectiveness and easy-to-operate design.

Selection of Voltage Regulation Mode of 1000kV Transformer and Operation and Maintenancer

How Are Miniature Substations Classified?

Similar to transformers, miniature substations are also classified into different categories, and this depends on what their purpose is. Basically, they are classified the same way as with substations.

Miniature Substation

Miniature Primary Grid Substations

These are recommended for load centers with long primary transmission lines.
Miniature Mobile substations
These are used for short-term projects or purposes only.


Miniature Step up substations

This type of miniature substation is associated with generating stations at low voltages.

Indoor Minature Substations VS Outdoor Miniature Substations

Other than the classifications of miniature substations and substations, there are substations that are specifically made for indoor purposes only, and for outdoor purposes as well. So, what is the difference?

Miniature substations only require low voltage and that can be safely installed inside building constructions are called indoor miniature substations. Indoor substations usually do not exceed the standard of most fire codes inside establishments.

On the other hand, miniature substations that you see outside building constructions are called outdoor miniature substations. Although small, the high voltage level requirements that it is installed are simply just too dangerous for indoor applications.

Three-Phase Transformer: The Ultimate FAQ Guide

Are Mini Substations Necessary?

Mini substations are a part of the electrical generation and distribution system, in which they transform voltages from low to high vice versa, and they have other important functions as well.

Are Mini Substations Dangerous?

Mini substations are not considered dangerous or hazardous because they are surrounded by electromagnetic fields that equipment and cables they contain produce, so, they have to be treated with caution.

There is no scientific evidence that supports the claim that standing near mini substations will cause health risks.

Miniature substations and substations are not considered hazardous because their build is designed to be safe for the public. 

Miniature Substation

What Is The Safe Distance For Minature Substations?

There is no exact measurement for a safe distance when it comes to close or far should you be around miniature substations. To measure the safe distance, there must be an accurate magnetic field measurement that is taken from various locations in the area.

Generally, to save you the math, safe distances from the miniature substation usually range from 3 to 30 meters from it.

Step-Up Substation and Its Significance In Power Distribution

How Are Mini Substations Classified?

They are classified the same way with substations, depending on what their purpose is, the category that it belongs to will vary.


  • Mini Primary Grid Substations are suitable for load centers long primary transmission lines.
  • Mini Mobile substations are only temporary, they are used to meet a short-term application.
  • Mini Step up substations are associated with generating stations as the voltage is not high.

What is the Mini Substation Advantages and Disadvantages?

In this section, you will know the main advantages and drawbacks of miniature substations. This can greatly help you with making a better purchase decision.

But if you have any questions or concerns, DAELIM’s team of professionals will be happy to accommodate.

In this section, you will learn the key advantages and drawbacks of using mini substations which will help you with your purchase decision.


Below are the following main advantages of miniature substations

Easy To Operate

They are fairly easy to operate, but if you have any concerns or confusion, you can directly contact DAELIM’s team to help you.

With their smaller build and components, this makes them easier to operate. But chances are, you might have some confusion along the way.

You can directly contact DAELIM’s team for immediate assistance.

But for transformer purposes, you can easily step up or increase voltage levels and step down or decrease voltage levels to your needs. Just make sure that you are doing the right adjusting because it is easy to commit mistakes that might put you and the people around you in danger.

8+FAQ About the CSP Transformer


They may be small but there is without a doubt that their attributes make it a versatile electrical device. At first glance, miniature substations may not look as complicated as other electrical devices, but do not let their appearance fool you.

As mentioned, they can be used for several functions because it contains a lot of electrical equipment in it. With that said, do not let appearance be a basis for your purchase decision.

Mini substations may not look like they cannot do much, but do not let their appearance trick you, because as mentioned, they are capable of doing many things because they contain a lot of electrical equipment.

It Supports The Transmission Grid

Mini substations can support transmission grids in moving power from generation sources to customer loads, while the electrical utilities use them for protection purposes, switching capabilities, and voltage transformation.

Miniature substations are capable of supporting transmission grids in moving power from different generation sources to customer loads. Electrical utilities at the same time will use them for protection purposes, voltage transformation, etc.


Since they are the smaller version of a regular substation, you can expect it to be cheaper than normal substations. But depending on the manufacturer, the price can vary. For fair quotes with the best services, DAELIM offers the best value deals.

Due to their small size, build, and low kVA rating, they are considered a cheaper option for regular substations. But again, prices may vary depending on the manufacturer.

If you are looking for fair quotes along with the best services for a satisfying customer experience, you may check DAELIM’s best offer deals.


Below are the drawbacks of the miniature substation.

Less Rating

Due to their size, mini substations are known to have significantly lower kVA ratings compared to regular substations. If this is something that affects the purpose of your project, then you might want to reconsider your purchase decision.

Due to their size, and components with limited capabilities, miniature substations lower kVA ratings compared to regular substations.

If this is something that you find not compatible with your purpose of purchasing a substation, then this product is not for you.

Less Protection

Mini substations have less protection as well because of their non-sophisticated systems that protect transformers and feeders, including metering and other controls. The protection that it provides is limited and less resistant compared to regular substations.

Miniature substations have less protection due to their basic systems that mediocrely protect transformers and feeders, including metering and other controls.

The protection that it provides is limited and less resistant compared to regular substations.

Can Easily Shut Down

In the event that a bus or a circuit breaker malfunctions, the entire miniature substation will shut down as well.

Hard To Maintain

The maintenance of a miniature substation is high and difficult to maintain due to the various components in it that require regular monitoring, especially single bus scheme substations.

8+FAQ About the Power Pole Transformer

Limited Usage

Substations and miniature substations can only be used in loads that can be interrupted or have another form of supply arrangement. This is for a single bus scheme miniature substation.

Are Miniature Substations Noisy?

Yes, miniature substations can be noisy due to their components. They have three sources of where the noise usually comes from with each having different characteristics. Transformer noise gives a low-frequency hum, while miniature substation auxiliary plants like diesel generators and air compressors give a different noise. 

8+FAQ About The Generator Transformer

Why Do Miniature Substations Create Noise?

Miniature substations generate noise due to the stray magnetic fields that are causing the enclosure and parts to vibrate, Magnetostiction is another source of vibration that causes the components to make noise.

The Complete Guide to a Generator Step-up Transformer

What Is A 630 kVa Mini Substation?

The 630 kVa Mini Substation is a standalone substation and it is modularized. It can be installed at any site and does not depend on other equipment for its functioning. The 630 kVa Mini Substation can provide power at a voltage of 6.3kV for both residential as well as commercial applications. The maximum capacity of the 630 kVA Mini Substation is 6,300 kilovolts amps (kVA). This mini substation generates 415 volts to provide protection against short circuits and ground faults. Daelim is one of the best 630 kVa Mini Substation manufacturers in the world.

It can be installed indoors or outdoors and can be used in wet environments as well. The unit is easy to install using the provided components and can be upgraded with additional accessories as per the requirement of the customer.

630 kVa Mini Substation

How does 630 kVa Mini Substation work?

The 630 kVA Mini Substation generates rated power up to 6.3kV and it is capable of providing the necessary voltage levels to thousands of residents and commercial establishments. It has perforated distribution tubing (PFT) connected to an underground conduit system. The 630 kVa Mini Substation is designed in a modular manner so that it can be installed at any point of sale without any intrusions into the existing electrical system and can easily be installed at existing sites as well as in new developments.

The 630 kVa Mini Substation has horizontal polyvinyl chloride (PVC) insulation on the outside components and the inside feeder cables are insulated with natural rubber-coated polyethylene. It is also designed in compliance with international safety standards and provides fire protection against fire at a 771 degrees Celsius temperature. The 630 kVa Mini Substation is active power factor corrected and supported by a GFCI circuit breaker. It is hermetically sealed against leakage of any kind making it both dustproof and rainproof. It is also waterproof, which gives it increased reliability under any condition.

The Complete Guide to 500 kVa Mini Substation

What is on the inside of the 630 kVa Mini Substation?

Every power substation has a switchboard, which typically includes a number of circuit breakers to isolate faulty electrical and protect equipment. The 630 kVa Mini Substation is no exception. This mini substation has a 480 V 3-phase 15 kA power system along with three transformers; one 115/230 V 3 phase 30 kVA transformer and two 115/230 V single phase 5 kVA transformers. The single-phase transformers serve as backup to the main transformer in case it fails or goes offline during an outage event caused by severe weather, for example. The arrow in the picture indicates the main switch. The alternate positions are located further back in the substation to improve safety and reduce the risk of electrical damage.

The Black Box on the switchboard is a 20 kV-rated DC generator used for testing purposes and to provide a supply of DC power to electrical transformers which can’t operate from AC current. In this case, it provides voltage levels for 115/230 V, 15 kA, 600 V 3 phases with a frequency range of 50 – 60 Hz. The blue box is called an Air Duct or Blower Room which is used to get air circulation under the switchgear housing without having to open every closet door into it.

The metal boxes between the substation transformer room and the transformer are called Remote Controllers or Voltage Controllers. These are used to adjust voltage levels during maintenance activities such as adjustments when replacing transformers or when testing equipment in the substation. 

Why should you have a 630 kVa Mini Substation?

The main reason is that the 630 kVa Mini Substation has a range of full-load capacities, from 600 to 900 kW. Daelim is one of the best manufacturers for 630 kVa Mini Substation. 630 kVa operating voltage ranges from 115 to 138 kV, which means that the utility company can use either high-voltage lines or low-voltage lines in order to avoid any overloading. It is also possible for these substations to have both single and three-phase connections. The switching configuration can be done from remote terminal units.

A 630 kVa Mini Substation also comes with a number of power configurations which include AC, DC, and VFD modules. This allows for maximum efficiency on every installation project due to the size and nature of each site request. In addition, the 630 kVa Mini Substation also comes with a K-Wave co-generation module that assures energy optimization and power supply. Another great feature of the 630 kVa Mini Substation is that it can be used for subwoofer installation in auditoriums, concert halls, and theaters. It is possible for these to be used as musical instrument amplifiers or sound reinforcement systems. The installation size for the 630 kVa Mini Substation can also measure up to 100% of the available space.

And finally, it also comes with an enclosure that houses all necessary hardware and components inside its container. This ensures that all of the installed components are safe for human contact and for outdoor purposes. The enclosure can also be converted to a standard enclosure with all necessary hardware being provided. The 630 kVa Mini Substation is one of the smallest substations in the market today, thus proving a clear advantage to those looking to add power without adding size and weight.

Advantages of 630 kVa Mini Substation

A 630 kVA mini substation is a small sub-station that is mainly used to feed 415 V distributed power to the load center. The primary advantages of the 630 kVA mini substation are:

  • 1) It has an inherent fault tolerance, which means that if any part of the distribution circuit becomes disconnected from the main supply, it will still work and keep supplying power.
  • 2) 630 kVA Mini Substation is easy to install and maintain. It can be quickly installed by just plugging its transformer into a wall outlet socket or other places with 220V voltage where there is no load center for connection.
  • 3) The 630 kVA mini substation can be installed in any place without the need for any civil works.
  • 4) It is small and light
  • 5) There are no complicated maintenance requirements since there are not many parts to worry about and maintain.
  • 7) No main power supply is needed so its installation cost is low.
  • 8) It is easy to set up because of its small size and flexible configuration
Transformer Manufacturers In Canada (Toronto and Mississauga)

What frequency can the 630 kVa Mini Substation work with?

The 630 kVA Mini Substation works with frequencies of 380-415Hz, 400-450Hz, and 1,000Hz. There are 3 different ranges available for this substation. Keep in mind that if you have a power transformer that is rated at 230V then this item will need to be upgraded before it can go up to 415V as well.

So let’s get started and talk about what the 630 kVA Mini Substation is. A substation is basically used to transfer power from a high voltage source to multiple indoor and outdoor circuits that are typically located within the same area that you are in. These circuits tend to be small mostly because they have a very limited amount of space available for them so a transformer is needed. This 660 Watt Substation is designed for use with the following power sources: 230VAC, 460VAC, 420VAC, and 415VAC.

The 630 kVA Mini Substation is a substation that can transfer 630 Watts of power at 220 Volts up to 215 Amps. The 330 kVA Mini Substation can transfer 475 Watts at 230 Volts up to 70 Amps however so make sure you know what you’re getting before buying it. This unit has a mechanical fuse but also has an electronic fuse in case the mechanical fuse blows or is damaged by muddy or dirty conditions.

The Complete Guide to a Three-phase Combined Power Transformer
Miniature Substation

What voltage can the 630 kVa Mini Substation work with?

The 630 KVA Mini Substation can be powered by AC or DC mains power supply. AC mains supplies operate on a nominal 230 V voltage level and the range varies from region to region. AC power supplies are also used to provide cheaper electrical requirements for households in remote locations such as farms, which may require less than 100 kW of output. DC mini-subs also offer higher voltages, up to 800 V DC type converters with an output range from 500V-1 MW (annual baseload), and are capable of supplying electrical demands for industrial applications like data centers or hydroelectric generation facilities respectively.

The purpose of the 630 KVA Mini Substation is to provide a wide range of power supply options for users. It can be used to save money in the long run by not having to buy multiple separate power stations at different capacities. The 630 Kva models are also ideal for emergency situations where there is no main mains power supply available. A small diesel or gas generator could only be set up to deliver enough energy for a single small converter, but the mini-sub station already has multiple converters built into one unit, and with this comes a variety of on-off switches that can control some or all of them as required.

How do I know if my Mini Substation is the correct model?

The 3-phase Mini Substation is the most common unit. The 5-phase unit is more commonly found in industrial applications because it has a larger capacity and can be used with multiple zones.

The 3-Phase units are considered the most common installation due to their lower cost, but they lack cooling power for very large or multiple zones. The 5 Phase units are considered more useful in industrial settings due to their high capacity, but they have larger dimensions which makes them harder to install in smaller spaces. To determine if you have a 3 Phase or 5 Phase unit, look at the label on the left side of the Mini Substation

The Complete Guide to Medium Voltage Transformers

How Much Copper Is Inside 630 kVa Mini Substation?

A 630 kVa mini substation is used to provide a switchgear and bus connection in sub-transmission systems. It can be an integral part of a line crossing several distribution transformers or may be installed in the back yard of a high voltage power station. The main function of this substation is to transfer the voltage level down from 132 kV to 66 kV, which is suitable for transmission over distances of up to 45 kilometers. The metal parts with which it is constructed are also capable of withstanding lower voltages and currents than those used in the 132kV circuits for switching purposes.

The 630 kVa metal enclosures and bus structures are designed to provide an uninterrupted supply of power in all situations. The availability of the power source prevents power outages and enables distribution load capacities to be increased, thus reducing capital expenditures. The 630 kVa Mini substation is made up of two main components: the metal enclosure and the bus structure. The enclosure, referred to as housing, is made up of die-cast aluminum components that are bolted together to form a housing for the high voltage equipment.

It provides protection against moisture, mechanical damage, and vandalism. The bus structure is housed within this housing. The bus structure is made of steel-reinforced concrete and consists of a set of poles, temporary conductors, and conductors that make up the circuit to and from the customers. The high voltage equipment itself is housed within the enclosure. The equipment includes transformers, switchgear, circuit breakers, and other components that are used in high voltage transmission systems.

The Complete Guide to Telephone Pole Transformer
Miniature Substation

WHY CHOOSE DAELIM 630 kVa Mini Substation?

If you are a contractor, you need to be equipped with an ample power supply for your job sites. The DAELIM 630 kVa Mini Substation unit is a compact and portable solution, which can serve as an emergency backup power source in the event of a blackout or disaster. This unit can also be used for camping trips and in other outdoor activities. Its compactness and portability make it one of the most efficient products in the market today.

The DAELIM 630 kVa Mini Substation unit is a portable power station that is built around an inverter. It also comes pre-configured with an automatic transfer switch (ATS), voltage and frequency sensors, and has a remote control panel equipped with LED readouts showing voltage, frequency, and ATS status.

It is also equipped with an electronic display that indicates the amount of power still available for use. This portable unit can be used not only for blackouts but also for off-grid power solutions in remote areas or disaster zones. It can be easily transported, as it is made of lightweight materials and has its own dolly for easy movement.

The DAELIM 630 kVa Mini Substation unit is a smart solution to your power needs especially in times when daily work becomes difficult because of a blackout. You can even use it as an emergency backup power source during natural disasters such as typhoons, earthquakes, and floods. Its compactness makes it ideal to cater to your home requirements or even your small office and business setup. It can also be used in your construction sites and during camping trips.

The Complete Guide to Industrial Transformer Manufacturers

Final Thoughts

Miniature transformers are a good and cheaper option for the regular substation. However, there are limits to its capabilities since it is only the smaller version of the normal substation. Nonetheless, if you are looking for a substation that is cheap, effective, and versatile, then this product is definitely for you.

It is highly recommended that you only purchase electrical devices from reliable manufacturers. But you do not have to worry about finding one because you can easily get high-quality miniature substations at DAELIM.

About Daelim

Recent Posts

padmounted transformer

Padmounted Transformer in Construction Work The pad mounted transformer is widely used in electrical engineering

About Bin Dong

Hello, I am Bin, General manager of Daelim which is a leading transformer manufacturer. If you have problems when you are looking for the equipment, what you need to do is tell us.