Product Overview

The Schneider MT20H2 Circuit Breaker is an industrial power distribution protection device associated with Schneider Electric’s Masterpact MT air circuit breaker family. Designed for use in high-current electrical distribution systems, this type of circuit breaker helps protect electrical installations against abnormal current conditions, including overloads and short circuits.

Air circuit breakers (ACBs) are commonly installed in main distribution boards, switchgear assemblies, industrial power panels, and other high-capacity electrical systems. They provide a means of connecting and disconnecting electrical circuits while supporting protective functions that help limit damage caused by electrical faults.

The MT20H2 designation is associated with a 2000 A Masterpact MT configuration. However, the complete technical specification of an individual breaker depends on its frame, pole arrangement, mounting style, trip unit, and installed accessories. These details should be checked against the equipment nameplate and the original product documentation before replacement or installation.

In industrial facilities, a correctly selected air circuit breaker is an important part of the electrical protection architecture. It works alongside upstream and downstream protective devices to help isolate faults and maintain the safe operation of the distribution network.

The supplied product listing information gives dimensions of 352 × 422 × 297 mm and a weight of 50 kg. These values are retained below as listing parameters. Because dimensions and weight can vary between fixed and drawout versions and between breaker configurations, they should be confirmed against the actual unit before panel design or shipment.

Technical Specifications

Important: MT20H2 alone is not sufficient to establish every electrical and mechanical specification. Confirm the full catalog or reference number, nameplate, pole arrangement, trip unit, and mounting configuration before using this information for engineering or procurement.

Function and Working Principle

The Schneider MT20H2 circuit breaker is intended to protect electrical distribution circuits by interrupting current when specified abnormal operating conditions occur. Its protective operation is based on detecting electrical faults and activating the opening mechanism to separate the main contacts.

1. Overload Protection

An overload occurs when a circuit carries more current than its intended operating capacity for a sustained period.

Overload protection helps prevent excessive heating of cables, busbars, and connected electrical equipment. Depending on the installed trip unit, the breaker can provide an adjustable long-time protection function.

The actual pickup current and delay settings must be selected according to the electrical installation design and applicable protection-coordination requirements.

2. Short-Circuit Protection

A short circuit can cause a rapid increase in current. If the fault is not interrupted promptly, the resulting thermal and electrodynamic stresses can damage electrical equipment.

The circuit breaker’s short-circuit protection function detects fault conditions and initiates interruption. The breaker must have an appropriate interrupting capacity for the prospective fault current at its installation point.

The H2 designation is associated with a particular breaking-capacity class within the relevant product family. The actual interrupting rating must be verified for the exact model, voltage, and applicable standard.

3. Switching and Isolation

An air circuit breaker also provides a switching function. Depending on its configuration, it can be used to connect or disconnect a main distribution circuit.

This is important during equipment maintenance, electrical system modification, and controlled shutdown procedures.

However, the circuit breaker should not be treated as a substitute for every form of maintenance isolation. The installation must follow the applicable electrical safety procedures and isolation requirements.

4. Arc Interruption

When a circuit breaker opens under load or fault conditions, an electrical arc may form between its contacts.

Air circuit breakers use an arc-control and arc-extinguishing arrangement to interrupt the current. The design helps manage the arc and restore electrical insulation between the separated contacts.

The ability to interrupt fault current safely depends on the breaker design, rated voltage, interrupting capacity, and condition of the internal components.

5. Protection Coordination

In a complex distribution system, circuit breakers work together with other protective devices.

Correct coordination helps ensure that the protective device closest to a fault operates when possible, reducing unnecessary interruption to other parts of the facility.

Protection coordination requires engineering analysis of current ratings, fault levels, trip curves, time delays, and the characteristics of upstream and downstream equipment.

Role in Industrial Power Distribution Systems

The MT20H2 circuit breaker can serve as a major switching and protection component in industrial electrical distribution equipment.

Main Distribution Protection

In a main distribution board, a high-current air circuit breaker can protect the incoming supply or a major distribution section.

It helps provide a controlled point for switching and fault interruption. The actual position of the breaker depends on the facility’s electrical architecture and protection design.

Busbar Protection and Distribution

Industrial switchgear uses busbars to distribute electrical power among multiple feeders and loads.

An appropriately selected circuit breaker helps protect a busbar section or outgoing feeder. Its current rating, short-circuit performance, and coordination settings must match the electrical design.

Generator and Transformer Distribution

Air circuit breakers are commonly used in power systems involving transformers, generators, and large distribution panels.

In these applications, engineers must consider the available fault current, operating voltage, grounding arrangement, and protection requirements. A breaker should never be selected based only on its nominal current rating.

Industrial Electrical Maintenance

The breaker can also be relevant to maintenance and replacement work in existing electrical installations.

When replacing an older unit, maintenance teams should verify the complete reference number, mechanical dimensions, mounting arrangement, control voltage, trip unit, and accessory configuration.

A breaker that fits physically may still be electrically or mechanically incompatible with the original installation.

Industrial Applications

1. Manufacturing Facilities

Manufacturing plants use high-capacity electrical distribution systems to supply production machinery, motor control centers, lighting, and auxiliary equipment.

An air circuit breaker can provide protection and switching for a main distribution section or a large feeder, depending on the system design.

2. Industrial Switchgear Assemblies

Switchgear assemblies contain circuit breakers, busbars, protection devices, metering equipment, and control components.

A compatible Masterpact-type breaker may be installed in a suitable switchgear compartment to support power distribution and fault protection.

3. Power Distribution Rooms

Large commercial and industrial buildings often use main distribution equipment to distribute incoming electrical power to different sections of the facility.

A high-current air circuit breaker can serve as a main or feeder protection device where its electrical ratings and installation configuration are appropriate.

4. Transformer Secondary Distribution

Transformer secondary circuits may require high-current protection depending on transformer capacity and system design.

The circuit breaker’s current rating and interrupting capacity must be selected according to the transformer characteristics and calculated fault current.

5. Infrastructure and Utility Installations

Electrical distribution systems in infrastructure facilities may require robust switching and protection equipment.

Air circuit breakers can be used in suitable low-voltage distribution assemblies, subject to applicable standards, environmental conditions, and engineering requirements.

Installation and System Integration

Correct installation is essential for the safe operation of a high-current circuit breaker.

1. Verify the Complete Model

Before installation, check the complete product reference and the information on the nameplate.

Important details include:

• Rated current.
• Rated operational voltage.
• Number of poles.
• Breaking-capacity class.
• Trip-unit type.
• Fixed or drawout mounting arrangement.
• Control and operating voltage.
• Installed auxiliary accessories.

Do not assume that every breaker carrying an MT20H2 designation has identical specifications.

2. Confirm Panel Dimensions

The supplied dimensions are 352 × 422 × 297 mm.

Before designing or modifying a switchgear compartment, compare these measurements with the actual breaker and the manufacturer’s dimensional drawing.

Check the required mounting space, connection clearances, operating mechanism access, and space for maintenance.

3. Inspect Electrical Connections

Inspect the main terminals, contact surfaces, busbar connections, and conductor supports before installation.

Connection surfaces should be clean and free from damage. Tightening torque must follow the manufacturer’s instructions.

Improper connections can cause localized heating, voltage drops, and equipment damage.

4. Check the Trip Unit

The trip unit is an essential part of the breaker’s protection system.

Verify its model, protection functions, current settings, and time-delay settings. These parameters must be coordinated with the facility’s electrical protection scheme.

Never copy protection settings from another breaker without confirming that the electrical installation and equipment ratings are equivalent.

5. Verify the Operating Mechanism

Depending on the breaker configuration, the operating mechanism may include manual or electrical operating functions.

Inspect the charging mechanism, closing and opening functions, interlocks, and position indicators. For drawout versions, check the racking mechanism and connected, test, and disconnected positions where applicable.

6. Perform Commissioning Tests

Before energizing the equipment, qualified personnel should perform the required inspection and commissioning tests.

These may include:

• Visual and mechanical inspection.
• Contact resistance testing.
• Insulation resistance testing.
• Trip-unit functional verification.
• Opening and closing operation tests.
• Auxiliary contact verification.
• Interlock and position-indicator checks.
• Protection coordination review.

Testing must follow the manufacturer’s procedures and applicable electrical safety standards.

Compatible System Components

The MT20H2 is normally part of a wider electrical distribution assembly. Its compatibility with other components depends on the actual breaker configuration and switchgear design.

The components listed above are examples of equipment used in industrial switchgear systems. They are not necessarily included with the MT20H2 breaker.

Alternative Models and Replacement Considerations

When replacing an MT20H2 circuit breaker, the correct substitute must match both the electrical requirements and the mechanical arrangement of the existing switchgear.

Before selecting a replacement, compare:

• Rated operational voltage.
• Rated current.
• Short-circuit breaking capacity.
• Pole arrangement.
• Fixed or drawout installation.
• Physical dimensions and mounting points.
• Busbar and terminal connections.
• Trip-unit functions and settings.
• Auxiliary contacts and electrical accessories.
• Operating mechanism and control voltage.
• Applicable IEC, UL, or other certification requirements.

A replacement breaker may require changes to the switchgear compartment, busbar connections, control wiring, or protection coordination. Engineering approval should be obtained before substituting a different product family.

Key Advantages

High-Current Distribution Protection

The MT20H2 designation is associated with a high-current Masterpact MT breaker configuration, making exact rating verification essential for main distribution and feeder applications.

Overload and Short-Circuit Protection

With the appropriate installed trip unit, the breaker can provide protection against abnormal current conditions.

Industrial Switching Capability

Air circuit breakers provide a switching and isolation function within suitably designed low-voltage distribution assemblies.

Integration with Switchgear Systems

The breaker can form part of a larger switchgear installation containing busbars, protection equipment, metering, and control components.

Configurable Protection

The protection functions and settings depend on the installed trip unit, allowing the electrical protection arrangement to be matched to the system design.

Maintenance and Replacement Support

Accurate identification of the MT20H2 reference can help maintenance teams locate compatible spare equipment for existing installations.

Technical FAQs

1. What is the Schneider MT20H2?

The Schneider MT20H2 is an air circuit breaker designation associated with the Masterpact MT family. It is used in industrial power distribution applications requiring high-current switching and protection.

2. What is the rated current of the MT20H2?

The MT20H2 designation is associated with a 2000 A configuration. The exact rated current must be confirmed from the unit’s nameplate and complete product reference.

3. What does H2 mean in the model designation?

H2 identifies a breaking-capacity class within the relevant circuit breaker family. The actual interrupting capacity depends on the product version, rated voltage, and applicable standard.

4. Is the MT20H2 a molded case circuit breaker?

It is associated with an air circuit breaker product designation rather than a conventional small molded-case breaker. Its physical construction and switching arrangement are intended for larger electrical distribution systems.

5. What is the difference between a fixed and drawout air circuit breaker?

A fixed breaker is mounted directly into its installation position. A drawout breaker is installed in a compatible chassis and can be moved between defined operating positions, making inspection and maintenance arrangements different.

The exact MT20H2 configuration must be checked before determining which installation arrangement applies.

6. Can the MT20H2 be used as a main incoming breaker?

It may be used in a main distribution application when its rated current, voltage, interrupting capacity, trip-unit configuration, and switchgear compatibility meet the system requirements.

7. What should be checked before replacing the breaker?

Confirm the full product reference, nameplate ratings, pole arrangement, mounting type, trip unit, accessories, terminal layout, and switchgear dimensions.

8. Can an MT20H2 be replaced by an MTZ2 model?

Not automatically. The MT and MTZ2 families have different product designs and may have different dimensions, accessories, and mounting arrangements. A replacement requires a detailed engineering compatibility assessment.

9. What maintenance is required?

Maintenance may include inspection of main contacts, terminals, operating mechanisms, trip-unit functions, auxiliary circuits, and mechanical interlocks. The schedule and procedures should follow the manufacturer’s instructions and site maintenance requirements.

10. What are the dimensions and weight of this listing?

The supplied listing dimensions are 352 × 422 × 297 mm, with a weight of 50 kg. Confirm these measurements against the actual unit because breaker dimensions and weight can vary with mounting style and accessories.

Procurement and Maintenance Recommendations

When purchasing the Schneider MT20H2 circuit breaker, verify the complete product reference rather than relying solely on the abbreviated model designation.

Request clear photographs of the nameplate, front panel, terminals, operating mechanism, and any installed trip unit. These details help confirm the breaker’s electrical rating and mechanical configuration.

For used or refurbished equipment, check the condition of the main contacts, insulation components, operating mechanism, auxiliary contacts, and trip unit. Where possible, request test records covering mechanical operation and electrical protection functions.

The supplied dimensions and weight should also be checked against the actual equipment before arranging transportation or planning a switchgear replacement.

For maintenance, qualified personnel should follow the manufacturer’s inspection and testing procedures. Protection settings should be documented and coordinated with the facility’s electrical protection study.

Conclusion

The Schneider MT20H2 Circuit Breaker is associated with the Masterpact MT air circuit breaker family and is intended for industrial power distribution and circuit protection applications. It can provide switching and protective functions in high-current electrical systems when correctly configured with suitable protection equipment.

The complete technical characteristics depend on the specific breaker version, including its rated current, voltage, breaking capacity, pole arrangement, trip unit, and mounting style. Accurate identification is therefore essential when purchasing, installing, or replacing this equipment.

For industrial maintenance and spare-parts procurement, verifying the nameplate and mechanical configuration helps reduce the risk of selecting an incompatible circuit breaker.