Metal Clad vs. Metal Enclosed Switchgear: A Detailed Comparison

Are you struggling to decide between metal-clad or metal enclosed switchgear? Selecting the wrong option can compromise safety, cause costly damage and repairs, as well as can cause unexpected outages.

This article aims to provide adequate information regarding the differences, benefits, and best uses of both types so that you can make a wise decision without any financial loses. Let’s get started!

1) What Is Metal Enclosed Switchgear?

“Metal enclosed switchgear is classified under the protective equipment for power systems, which brings together a switchboard, fuses, circuit breakers and several other devices into a single metal cabinet.”

Its main function is safe electrical power distribution while ensuring personnel and equipment safety from possible electrical faults.

This switchgear type prioritises compactness as well as provides convenience. All components are encased within strong metals, which minimise chances of contact or electrical shocks as well as irrelevant fires. Dust, moisture, and physical harm to the equipment are also reduced due to the robust case enclosing them.

A unit where each of the electrical components is mounted within a grounded metal enclosure is referred to as switchgear by the IEEE C37.20.3 standard. This enclosure houses all control equipment and switching devices, and it is built with protective features so that users do not have bare live parts.

Another authority, the International Electrotechnical Commission (IEC), also covers metal-enclosed switchgear under various standards, including IEC 62271. These focus on ensuring the switchgear operates correctly in different environments while maintaining safety, reliability, and effectiveness.

Typical Structural Features

The entire set of functional units, like switches, relays, fuses and so forth, has a single common casing which is one of the most crucial design attributes of metal-enclosed switchgear.

All these components are stored inside a singular metal cabinet called a comparted unit or shared compartment. There are no solid barriers between them except air space separating these wires from physical contact with one another.

The shared compartment design minimises the size and costs of equipment. However, due to the lack of dividers between components, an issue in one section may propagate to adjacent sections. That is why metal-enclosed switchgear is optimally used in lower-risk areas.

• Additional features will often include:

• Front access, which allows technicians to operate or maintain the switchgear from one side.
• Clear design enabling quick installation and smooth operation.
• Fixed mounted breakers, which, unlike draw-out breakers in metal clad switchgear, are not intended to be removed for maintenance.
• Focus on practicality and cost efficiency makes it suitable for numerous standard applications.

Common Applications Of Metal-Enclosed Switchgear

These types of switchgear are found wherever there are electrical systems that need efficient controlling and safeguarding. Here are seven known applications where you can find these types of switch-gears employed.

• Industrial Plants

Metal-enclosed switch gear is employed by industrial plants such as factories and manufacturing units to control power supply to machines, illumination devices, and conveyor systems. It enhances operational safety and the prevention of downtimes associated with power anomalies.

• Commercial Buildings

Offices, shopping centres, and supermarkets use the switchgear to control lighting, air conditioning, escalators, and other power loads. Well, it makes certain that business activities are conducted without electrical interruptions during the day.

• Hospitals and Clinics

Medical facilities require a stable power supply for vital medical devices, lighting, ancillary systems and emergency equipment. In addition, metal-enclosed switchgear provides safe power distribution across the tight zones of the facility in medium-load areas.

• Residential Complexes

Metal enclosed switchgear is utilised on large housing projects in the utility rooms or basements. It helps in controlling and safeguarding electricity distribution for multiple units in large blocks of flats or apartments.

• Small Substations

For small towns or remotely located structures with medium voltage requirements, metal-enclosed switchgear is incorporated into compact substations for safe management of electricity flow within them.

• Data Centres (Non-critical Zones)

In less important regions of data centres where the highest levels of redundancy are not necessary, metal-enclosed switchgear distributes electricity to cooling systems, peripheral lights and backup servers.

2) What Is Metal Clad Switchgear?

“Metal Clad Switchgear is used in protecting high-voltage power systems and isolating them. It has components separately encased in heavy metals that offer protection, hence increasing safety and ease of maintenance.”

This switchgear type finds application primarily in sites where electrical security is mandatory. Metal-clad switchgear's pivotal role is to prevent people and equipment from serious electrical malfunctions like shorts or overloads. With this device, you can manage electrical resources without much hassle, amidst minimal damage probabilities.

Okay, as explained by the IEEE C37.20.2 standard, a metal-clad switchgear can be classified as one containing circuit breakers, bus bars and control wiring. It constitutes all major parts of the primary section, in which each of them is placed into separate cells provided with grounded metal walls divided by boxes meant to shield them from arcs.

These protective divisions permit arc flaming, fault propagation cessation, and allow maintenance work to be performed independently at parts of the whole system without requiring systemic shutdowns.

Moreover, for international markets, however, metal-clad switchgears also fall under the IEC 62271 series. These ensure that these switchgears achieve maximum standards during construction, focusing on safety, reliability, alongside quality of the bolts used while testing them electrically.

Key Features

• Metal barriers

The use of metal barriers between each function is the one big distinction that separates metal-clad from metal-enclosed switchgear. These barriers will help prevent individual live parts from interacting with each other. This form of design improves upon the spread of faults and creates a safer operating system while minimising risks during maintenance.

• Draw out breakers

Another key feature is draw-out circuit breakers. Unlike fixed breakers in metal-enclosed switchgear, draw-out breakers can be removed and replaced easily. Therefore, maintenance work such as testing or replacing parts does not require shutting down the entire unit.

• Grounding mechanisms

Grounding mechanisms are also built into metal-clad switchgear. As the breaker is to be removed, the system automatically grounds the circuit first.

By doing this, there will be zero potential for electric shock, making it safe for workers to carry out maintenance on the device and touch equipment without risk, ensuring that no accidents or injuries occur alongside unnecessary delays at work.

• Other common features include:

• Individual chambers for control wiring, busbars and breakers.
• Arc-resistant designs in many models.
• Stronger doors and locks for safety.
• Increased voltage + current ratings compared to metal-enclosed

These characteristics allow the construction of devices where human safety considerations must also be critical, along with power reliability, which is a critical aspect.

Higher level of safety and maintainability

The strategically designed compartments enable metal-clad switchgear to reduce overall downtime and service life. Technicians can service one compartment while the other parts of the system remain energised and fully operational, reducing the total time needed for maintenance.

In addition to improving the efficiency of servicing, metal-of barriers greatly improve the safety of operating switchgear. Operating this equipment doesn’t require concern regarding accidental contact or arc flashes. This is quite handy for systems that require interaction regularly.

For these reasons, industries prefer purchasing this type of metal-clad switchgear even if it means spending more than cheaper versions. In these critical environments, advanced protective features ensure uncompromised protection and peace of mind that justifies additional costs.

Common Applications of Metal-Clad Switchgear

Metal-clad switchgear is renowned for its robust safety features, strong protection mechanisms, and simple maintenance routines. It’s frequently deployed in critical areas where power permanence is essential and safety concerns dominate. Below are seven frequent examples:

• Power Stations

In power generation stations, metal-clad switchgear plays a vital role. It safeguards generators, transformers and other high-voltage equipment. The strong barriers and safety features supplied reduce failure risks while ensuring power output stability.

• Electrical Substations

Substations utilise metal-clad switchgear to control the flow of power between transmission lines and distribution lines, as well as manage the portioning of electricity for each network segment.

• Data Centers

Functionality in data centres relies on uninterrupted operations around the clock; hence, numerous heavy machines are utilised on a 24/7 basis without powering down.

Metal switchgear helps guarantee a consistent power supply while shielding sensitive equipment from overloads or outages. Thus, it is against malfunctions due to volatile operational conditions.

• Hospitals

Efficient life-saving devices demand constant energy supplies without voltage fluctuations, crucial during patient operations or post-surgical procedures.

• Underground Power Rooms

In urban areas, it is common to place switchgears in basements or underground rooms. Besides being compact, easy to maintain, and safe, metal-clad units provide additional protection, which makes them best for these locations.

3) Metal enclosed vs metal clad switchgear: Key Differences

4) Common Advantages and Disadvantages

Metal Clad Switchgear Advantages

+ High Safety Standards: Metal-clad switchgear consists of individual sections divided by metal partitions. This limits the spread of arc flashes and electrical faults.

+ Easy Maintenance: All draw-out circuit breakers enable quick disconnection of power without switching off the entire system. Well, this makes the testing, inspection, and other processes safer and faster to execute, even during critical power cycles.

+ Automatic Grounding: The system grounds itself before a breaker is removed. This mechanism guarantees safe maintenance work by minimising electric shock hazards.

Metal Clad Switchgear Disadvantages

- Costly: The metal-clad switchgear is more expensive to buy or install compared to its metal-enclosed counterparts due to complicated systems with increased safety features within them.

- Larger Size: Due to added compartments dedicated to additional safety mechanisms, these devices require more room, which could present issues in cramped spaces.

Metal Enclosed Switchgear Advantages

+ Compact Design: Having all components located within a single enclosure with shared compartments means that this unit can be installed in space-constrained areas, making it less troublesome than other models.

+ Lower Cost: This switchgear is more accessible from a price perspective. Well, it makes it best suited for smaller companies, educational institutes, and light industrial applications.

+ Quick Installation: The installation and setup of metal-enclosed switchgear are comparatively easier and faster because they need fewer planning as well as fewer components.

Metal Enclosed Switchgear Disadvantages:

- Limited Maintenance Options: Due to the fixed breakers with a shared compartment design, this cubicle style may require the entire system to be taken offline, which increases downtime.

- Lower Safety in sensitive Areas: Due to the lack of grounding systems or the absence of metal barriers, this type of switchgear exposes critical areas to arc fault explosions.

5) Application Scenarios: Which One Should You Choose?

• When to Choose Metal Clad Switchgear:

• Located in data centres or working in power plants and substations, you are situated in a mission-critical environment.

• Business operations depend on operational continuity without unplanned outages or drawdowns.

• All repairs have to be done safely without bringing the entire system offline.

• The load remains high, thus taking precautions regarding the system’s safety becomes vital.

• When to Choose Metal-Enclosed Switchgear:

• You are overseeing a system located within commercial complexes, schools, residential buildings, or light industrial zones.

• Your requirements are simple; they involve power distribution at low to medium voltage levels.

• An easily installed compact unit that requires minimal design work is what you need.

• Your equipment can bear short shutdowns during maintenance because the breakers are fixed.

6) Conclusion

A decision between metal-clad and metal-enclosed switchgear will always depend on your safety requirements, cost considerations, and the severity of the power system in question. Metal-clad switchgear has better protection and maintenance, which makes it suitable for mission-critical operations.

Alternatively, metal enclosures are compact and economical, good for standard commercial or light industrial environments. Knowing their distinguishing factors enables one to safeguard their facility in terms of reliability and protective performance, whilst having low operational costs.

Delixi Electric has provided switchgear solutions that are reliable and up to standard. We focus on your satisfaction and offer satisfactory services. This and more can be explored at www.cn-delixi.com.