---
title: "Metal-clad vs. metal-enclosed switchgear: how to choose | Entogo"
description: "Metal-clad switchgear uses drawout breakers and grounded metal barriers between every compartment; metal-enclosed interrupter switchgear is simpler and…"
url: https://entogo.ca/insights/metal-clad-vs-metal-enclosed-switchgear/
lang: en
type: article
image: https://entogo.ca/_astro/entogo-solution-electrical-substation-power-distribution-dusk.DeCEie2C.jpg
datePublished: 2026-06-25
dateModified: 2026-06-25
site: https://entogo.ca/
llms: https://entogo.ca/llms.txt
---

Home › Insights › Metal-clad vs. metal-enclosed switchgear: how to choose

Power & Distribution

# Metal-clad vs. metal-enclosed switchgear: how to choose

Entogo June 25, 2026

![Medium-voltage metal-clad switchgear lineup in an electrical substation and power distribution facility](https://entogo.ca/_astro/entogo-solution-electrical-substation-power-distribution-dusk.DeCEie2C_Z14yBsG.webp)

In short

Metal-clad switchgear uses drawout breakers and grounded metal barriers between every compartment; metal-enclosed interrupter switchgear is simpler and built for lower fault duty. Here is how North American buyers match construction class, voltage, and fault duty to the application.

## Why does switchgear come with so many “metal-something” labels?

A specifier comparing bids for the same feeder will often see three construction classes quoted at three different prices — and the single-line diagram looks identical on all three. The labels **metal-clad**, **metal-enclosed**, and **switchboard** are not marketing terms. Each maps to a distinct North American standard, a distinct level of internal compartmentalization, and a distinct expectation about fault duty, maintenance, and service life. Choosing the wrong class either overpays for a duty the site will never see or, worse, under-builds protection on a bus that needs it. The distinction matters most in [substation and power-distribution](https://entogo.ca/solutions/substations-power-distribution) line-ups feeding critical load.

## How do metal-clad and metal-enclosed switchgear differ?

The cleanest way to read a medium-voltage quote is by the governing standard.

### Metal-clad switchgear

**Metal-clad** switchgear is governed by **IEEE C37.20.2**, the Standard for Metal-Clad and Station-Type Cubicle Switchgear. Its defining feature is compartmentalization. Major parts of the primary circuit — the interrupting device, the main bus, the instrument transformers — are each enclosed by **grounded metal barriers**, and the main interrupting device is a removable **drawout circuit breaker** that self-aligns and self-couples as it racks between the connected and disconnected positions. IEEE C37.20.2 covers ratings from **5 kV through 38 kV**, with main-bus continuous-current ratings of **1200 A, 2000 A, and 3000 A**. The grounded barriers make an internal fault more likely to stay in one cubicle, and the drawout design lets a breaker be withdrawn and serviced without working on an energized bus. [Metal-clad switchgear](https://entogo.ca/products/metal-clad-switchgear) is the default where fault duty is high or the protection scheme is sophisticated.

### Metal-enclosed interrupter switchgear

**Metal-enclosed interrupter** switchgear is governed by **IEEE C37.20.3**, whose 2023 edition is titled the Standard for Metal-Enclosed Interrupter Switchgear Rated above 1 kV AC up to and Including 48.3 kV AC. It typically combines **interrupter switches** and **power fuses** rather than drawout breakers, and it does not require the full grounded-barrier compartmentalization of a metal-clad design. That makes [metal-enclosed switchgear](https://entogo.ca/products/metal-enclosed-switchgear) lighter, more compact, and lower in cost — a sound fit for feeders that switch infrequently and sit below the fault levels that justify drawout breakers. Where space or environmental sealing drives the design, [gas-insulated switchgear](https://entogo.ca/products/gas-insulated-switchgear) compresses the same function into a far smaller footprint.

## Is low-voltage switchgear the same as a switchboard?

No — and the confusion is common because both sit at 1000 V or less. Two different UL standards apply.

**Low-voltage switchgear** is built to **UL 1558**, the Standard for Metal-Enclosed Low-Voltage Power Circuit Breaker Switchgear, covering equipment rated 1000 V ac nominal (1058 V ac maximum). It uses **drawout power circuit breakers** tested to **UL 1066**, which can be racked out and serviced while the structure stays in place. A **switchboard** is built to **UL 891**, which applies to switchboards rated 1000 V or less, and normally uses fixed-mounted **molded-case circuit breakers** tested to **UL 489** — a standard that covers devices rated 6000 A or less.

The practical split is one of role. [Low-voltage switchgear](https://entogo.ca/products/low-voltage-switchgear-mcc) is primary distribution, often bolted to the secondary of a service transformer, where high short-circuit withstand and drawout serviceability earn their cost. A [low-voltage switchboard](https://entogo.ca/products/low-voltage-switchboard) is secondary distribution — feeding panelboards and loads downstream — where compactness and installed cost matter more than racking out a breaker live.

## What about arc-resistant construction?

Any of these classes can be specified as **arc-resistant**, tested to **IEEE C37.20.7** for switchgear rated up to 52 kV. The test verifies that an internal arcing fault is contained and its energy redirected away from personnel rather than blowing out the front of the enclosure. Accessibility ratings describe where that protection applies — **Type 1** at the front only, **Type 2** at the front, sides, and rear. Arc-resistant construction is increasingly specified for [data center](https://entogo.ca/solutions/data-centers) and [industrial EPC](https://entogo.ca/solutions/industrial-epc) line-ups where personnel work close to energized equipment.

## Where does each class make sense?

| Class | Standard | Interrupting device | Best fit |
| --- | --- | --- | --- |
| Metal-clad | IEEE C37.20.2 | Drawout breaker | High fault duty, frequent switching, critical feeders |
| Metal-enclosed interrupter | IEEE C37.20.3 | Switch and power fuse | Lower-duty MV feeders, infrequent switching |
| Low-voltage switchgear | UL 1558 | Drawout breaker (UL 1066) | Primary LV distribution, high withstand |
| Switchboard | UL 891 | Fixed molded-case breaker (UL 489) | Secondary distribution to loads |

## What should a buyer specify?

Anchor the specification to the standard, not the label. State the **rated maximum voltage** and the **short-circuit and short-time withstand** the bus must survive, because that pair usually decides metal-clad versus metal-enclosed. Call out whether breakers must be **drawout** for live serviceability. Specify the **accessibility type** if arc-resistant construction is required, and confirm it against the locations where staff will actually work. Finally, confirm coordination with upstream and downstream protection so the chosen class supports the relay scheme the site needs.

## How this maps to Entogo’s lines

Entogo builds the full range in its own Toronto factory — metal-clad and metal-enclosed switchgear, gas-insulated switchgear, and low-voltage switchgear and switchboards — each designed and built to the governing IEEE and UL standards above; UL (cULus)/CSA certifiable on request. Because the line-ups are engineered and manufactured in-house, construction class, ratings, and arc-resistant options can be matched to the application and to the [substation and power-distribution](https://entogo.ca/solutions/substations-power-distribution) scheme rather than to whatever a distributor happens to hold in stock. For sizing or a class recommendation against a specific single-line, [contact](https://entogo.ca/contact) the engineering team.

- Switchgear
- Power & Distribution
- Medium Voltage
- Substations
- Standards & Compliance

Glossary: [Metal-enclosed](https://entogo.ca/glossary#metal-enclosed-switchgear) [Metal-clad switchgear](https://entogo.ca/glossary#metal-clad-switchgear) [Switchboard](https://entogo.ca/glossary#switchboard-ul-891) [Gas-insulated switchgear](https://entogo.ca/glossary#gas-insulated-switchgear) [Low-voltage switchgear](https://entogo.ca/glossary#low-voltage-switchgear-ul-1558)

FAQ

## Common questions

- **What is the difference between metal-clad and metal-enclosed switchgear?**: Metal-clad switchgear uses drawout circuit breakers and grounded metal barriers between every major compartment under IEEE C37.20.2, while metal-enclosed interrupter switchgear under IEEE C37.20.3 is simpler and built for lower fault duty and less frequent switching.
- **What voltage range does metal-clad switchgear cover?**: IEEE C37.20.2 covers metal-clad switchgear rated from 5 kV through 38 kV, with main bus continuous-current ratings of 1200, 2000, and 3000 A.
- **Is low-voltage switchgear the same as a switchboard?**: No. Low-voltage switchgear under UL 1558 uses drawout power circuit breakers tested to UL 1066, while a UL 891 switchboard normally uses fixed-mounted molded-case breakers tested to UL 489 and is built for downstream distribution.
- **What is arc-resistant switchgear?**: Arc-resistant switchgear is tested to IEEE C37.20.7 so an internal arcing fault is contained and its energy redirected away from personnel; Type 1 protects the front and Type 2 protects the front, sides, and rear.
- **When should a buyer choose metal-clad over metal-enclosed switchgear?**: Choose metal-clad where fault duty is high, protection is sophisticated, or breakers must be serviced without de-energizing the bus; metal-enclosed interrupter switchgear fits lighter, less frequently switched feeders at lower cost.

Keep reading

## Related insights

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Project inquiry

## Turn the brief into a specified system.

[Talk to engineering](https://entogo.ca/contact)

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_Markdown twin of https://entogo.ca/insights/metal-clad-vs-metal-enclosed-switchgear/ — generated at build time from the same content as the HTML page. Company facts, catalogue index and contact: https://entogo.ca/llms.txt_