Metal Clad Switchgear vs Metal Enclosed: Selection Guide

Metal clad switchgear vs metal enclosed switchgear is one of the most critical decisions engineers and procurement teams face when designing medium-voltage power distribution systems, and selecting the wrong type can directly compromise personnel safety, increase maintenance costs, reduce operational uptime, and create long-term reliability risks across the entire electrical infrastructure, which is why a thorough technical understanding of both types is essential before any specification or procurement decision is made.

What is Metal Clad Switchgear?

Metal clad switchgear is a medium-voltage assembly where every major component is fully isolated in its own grounded metal compartment, governed by IEEE C37.20.2 for equipment rated from 4.76 kV to 48.3 kV with bus current ratings up to 4000 A.

Why Full Compartmentalization Matters?

Full compartmentalization is the defining feature separating metal clad from all other switchgear categories.

1. Fault containment — Internal faults and arc flash events are physically contained within the originating compartment, preventing propagation to adjacent sections.
2. Safe maintenance access — Individual breaker compartments are accessible without exposing adjacent live components.
3. Draw-out breaker — Circuit breaker can be racked out while the bus remains energized, enabling maintenance without full system shutdown.
4. Separated instrument compartments — Metering and relay work proceeds independently of switching operations.

Typical Applications of Metal Clad Switchgear:

Metal clad switchgear is the standard specification across the following high-criticality environments where safety and uptime are non-negotiable.

• Utility substations and power generation facilities handling large available fault current levels.
• Heavy industrial plants including oil refineries, chemical processing facilities, and steel manufacturing operations.
• Data centers and mission-critical facilities where any unplanned downtime carries severe financial consequences.
• Primary and secondary unit substations serving large commercial complexes, airports, and hospitals.

Read More: What Is Switchgear and Its Types for Industrial Projects?

What is Metal Enclosed Switchgear?

Metal enclosed switchgear is a broader category where all components are housed within a grounded metal enclosure without mandatory full compartmentalization, defined by IEEE C37.20.3 covering equipment rated above 1 kV up to 48.3 kV AC where certain components may share compartments.

Construction and Design Characteristics:

Metal enclosed switchgear balances cost efficiency with adequate protection across a wide range of applications.

1. Shared compartments — Bus bars and switching elements may share internal spaces without mandatory grounded metal barriers.
2. Breaker configurations — Both fixed-mounted and draw-out options available depending on specification and budget.
3. Voltage range — Covers medium-voltage distribution at 1 kV to 48.3 kV, overlapping significantly with metal clad.
4. Enclosure protection — Provides physical protection against accidental contact, dust, moisture, and environmental exposure.

Typical Applications of Metal Enclosed Switchgear

Metal enclosed switchgear is widely deployed in environments where the highest level of compartmentalization is not required by code or project-specific risk assessment.

• Commercial office buildings, retail centers, schools, and educational campuses.
• Light to medium industrial facilities operating at lower available fault current levels.
• Municipal water treatment plants, pumping stations, and public infrastructure projects.
• Distribution substations serving residential developments or smaller commercial loads.

Metal Clad Switchgear vs Metal Enclosed:

The core of the metal clad vs metal enclosed switchgear comparison lies in four dimensions : compartmentalization, safety performance, maintenance flexibility, and total cost of ownership, and the global market for these two equipment categories was valued at USD 4.8 billion in 2025 and is projected to reach USD 7.9 billion by 2034 at a CAGR of 5.6%, reflecting the critical role both types play in powering industrial and commercial infrastructure worldwide.

The following table provides a structured side-by-side evaluation across all critical technical and operational parameters.

Read More: What Is Arc Flash Resistant Switchgear and Its Types?

Design Arc Flash & Standards Compared Metal Clad Switchgear vs Metal Enclosed:

 NFPA 70E 2024 establishes equipment selection as a primary engineering control for reducing incident energy before reliance on PPE, and this is where the difference between metal clad switchgear vs metal enclosed becomes most consequential for personnel safety.

Arc Flash Performance: Metal Clad vs Metal Enclosed:

When comparing metal enclosed vs metal clad switchgear arc flash performance, full compartmentalization contains fault energy within the originating compartment, and field studies indicate metal clad designs typically achieve lower incident energy than metal enclosed designs, though the degree of reduction depends on multiple system-specific factors, while the draw-out mechanism supports remote racking to keep personnel at a safe distance during the highest-risk operations.

Applicable Standards Summary:

1. IEEE C37.20.2 — Governs metal clad design, testing, and compartmentalization up to 48.3 kV.
2. IEEE C37.20.3 — Governs metal enclosed switchgear, permitting shared compartments.
3. NFPA 70E 2024 — Mandates arc flash risk assessment, engineering controls take priority over PPE.
4. NEMA SG-6 — Additional guidance on compartmentalization and fault withstand performance.

Read More: Switchgear Maintenance Procedure: A Complete Guide.

How to Choose Between Metal Clad and Metal Enclosed Switchgear?

Selecting between metal clad switchgear vs metal enclosed requires evaluation of four key factors before any procurement decision is finalized.

1. Available Fault Current — High fault current demands metal clad’s superior arc containment and compartmentalization.
2. Maintenance and Uptime — Critical facilities should specify metal clad to leverage draw-out breaker capability and compartment-level isolation.
3. Initial vs Lifecycle Budget — Metal enclosed costs less upfront, but lifecycle analysis over 20 to 30 years often favors metal clad.
4. Regulatory Requirements — Verify which IEEE standard and local code applies, as certain industries may mandate metal clad regardless of fault current.

How Green Origin Manufactures Metal Clad and Metal Enclosed Switchgear?

Green Origin designs and manufactures both metal clad and metal enclosed switchgear to the highest international standards across utility, industrial, and commercial projects — contact Green Origin today to discuss your project requirements and receive a tailored switchgear solution built to perform.

Need expert guidance in choosing the right equipment for your facility? Visit our Contact Us page, message our engineering team directly on WhatsApp, or email us at contact@greenorigin-elec.com for tailored solutions and project quotations.

FAQs:

Can metal enclosed switchgear be retrofitted for arc flash protection?

Yes, retrofit options include arc flash detection relays and remote racking systems, but full metal clad compartmentalization cannot be replicated through retrofitting alone.

Metal Clad vs Metal Enclosed: which needs less downtime for maintenance?

Metal clad requires significantly less downtime because its draw-out breakers can be removed and serviced without de-energizing adjacent compartments or the full bus section.

Do Metal Clad and Metal Enclosed use the same breakers and parts?

No, metal clad exclusively uses draw-out breakers with dedicated disconnect contacts, while metal enclosed may use fixed-mounted breakers that are not interchangeable with metal clad equipment.