If you're looking for the answer to the difference between a ring main unit and switchgear, then you've come to the right place!
Now, you can easily find the answer to this question.
In this post, we’ll walk you through the differences between the two.
Are you ready?
But first, let's discuss the definitions of each.
What is Ring Main Unit?
A ring main unit is a compact, sealed, and enclosed type of switchgear.
These are used for medium voltage power distribution.
It’s a complete switchgear system in itself.
You see,
A complete switchgear system means an assembly of the necessary switching devices.
It also includes a protection device and a metering device.
Ring main units with various voltage and current ratings are also available.
Both outdoor and indoor types of ring main units are offered.
RMU is composed of:
You see,
The incomer feeder is either:
with associated earth switch and disconnect switch
Take note that this incomer feeder is presented with the establishment of bushing bulging from the enclosure of RMU for supply cable connection
Now, what is switchgear?
In an electrical power system, switchgear is a combination of:
- disconnect switches
- circuit breakers or fuses
to control, safeguard, and isolate electrical equipment.
Switchgear is utilized both to de-energize equipment,
which allows work to be performed, and to clear faults downstream.
This kind of equipment is directly related to the reliability of the electrical supply.
What is the Function of RMU?
Normally, an RMU is utilized to enable a supply feed from two directions and to connect to a transformer.
One of these supplies might have several ring main units in series, creating a ring.
When a section of the feeder needs to be isolated due to work or failure, a ring main unit at each end of this section can be opened without interrupting the supply.
What is the Function of Switchgear?
Meanwhile,
The essential functions of switchgear are:
**Control of circuits:**
It controls the circuit for functional switching.
**Isolation:**
It isolates the faulty equipment from the rest of the circuit.
**Protection:**
It safeguards the electrical circuit from earth fault currents, short circuit faults, and overload.
Advantages of Ring Main Unit
A ring main unit is undoubtedly a groundbreaking solution.
It makes it much easier to handle the various challenges of electrical distribution.
You see,
An RMU is considered an all-in-one solution.
It’s also a safe, simple-to-install, and maintenance-free switchgear.
It helps utilities enhance the uptime and reliability of the network.
It also reduces operational expenses.
**Smart Capabilities:**
If fitted with Intelligent Electronic Devices, a ring main unit is easy to integrate.
**Safety & Performance:**
In case you didn’t know yet, the latest technology and compact design of the ring main unit ensure total efficiency, reliability, connectivity, and safety.
**Cost & Time Savings:**
A ring main unit is switchgear that is easy to install.
If you use this, you can expect to save on commissioning and installation time.
What's more,
A ring main unit is also independent of climate.
They are resistant to various environmental conditions.
The maintenance and operational costs of such units are also low.
**Feature-Rich Compact Designs:**
Ultimately, an RMU is an SF6-insulated compact switchgear.
It is equipped with a vacuum circuit breaker and an SF6 switch disconnector.
Its compact design requires the least possible space to set up and operate.
In the modern power distribution system, RMUs are widely utilized across the globe.
They are used to meet the growing necessity for reliable energy.
It is a solution with comprehensive capabilities.
Advantages of Switchgear
Some of the essential features of switchgear include:
- Provision for manual control
- Quick operation
- Complete reliability
- Certain discrimination
Below, we will discuss each of them:
**Provision for manual control:**
Switchgear should have provision for manual control.
In case the electrical control fails, the necessary operation can be performed manually.
**Fast operation:**
If a fault occurs in any part of the power system, the switchgear should operate quickly.
This ensures that no damage is done to transformers, generators, and other equipment.
If the fault isn’t cleared quickly, it is likely to spread to healthy areas.
This could endanger a total system shutdown.
**Certain discrimination:**
When a fault occurs in any area of the power system, the switchgear should discriminate between the healthy and faulty sections.
It must isolate the faulty area from the system without affecting the healthy area.
This will ensure continuity of supply.
**Total reliability:**
The demand for reliable switchgear has become of utmost importance along with:
- the rising capacity of generating stations and;
- the continued trend of interconnection.
This isn’t surprising anymore, as it’s included in the power system to enhance reliability.
If a fault occurs in any part of the system, it must operate to isolate the faulty area from the remaining circuit.
At this point, we hope you have identified the major differences between RMU and switchgear.
In short:
A ring main unit is utilized in a substation for high voltage distribution.
An example of this is 11kV or above.
It is a ring system where if one line is interrupted or fails, the other will continue to operate.