How to Source Replacement Molded Case Circuit Breakers (MCCBs)

Need a replacement molded case circuit breaker (MCCB) for an older system? The fastest way to source the right breaker is to capture the correct nameplate details, confirm true compatibility (not just amps), and work with a supplier that has tested inventory on the shelf.

Specs to capture | How to match compatibility | Why tested/refurbished often wins | Lead times & availability | Quality, standards & warranty | FAQ

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1) Capture the MCCB nameplate details (this prevents wrong orders)

Before you call, quote, or search online, document what’s on the breaker label. These details are what your supplier needs to match a correct replacement quickly. 

• Manufacturer + model/catalog number
• Voltage rating (system voltage must match)
• Amp rating (and frame/series if shown)
• Trip type / characteristics (thermal-magnetic, electronic trip unit, etc.)
• Poles (1 [single] / 2 / 3)
• Interrupt rating (AIC / kAIC) (critical for safety & compliance)
• Mounting + terminals (bolt-on vs. plug-in, lugs, load-side accessories)
• Physical dimensions (space/enclosure fit)

Fast-track tip: If anything is unclear, take a clear photo of the label (and the breaker installed in the panel) and send it to your supplier. That’s often the fastest path to the right match.

2) Match true compatibility (not just amps)

Two breakers can share the same amp rating and still be wrong for the application. For a safe, fit-for-purpose replacement, confirm these high-impact items:

• Voltage class and interrupt rating (AIC/kAIC)
• Frame/series (especially on legacy gear)
• Trip unit type and settings compatibility
• Mounting style and terminal/lug configuration
• Accessories (shunt trip, aux contacts, alarm switch, etc.) if your system requires them

Best practice: When in doubt, have a qualified electrician/engineer verify compatibility with your panelboard/switchboard and application requirements.

3) Consider tested/refurbished MCCBs when new is expensive or unavailable

For discontinued or hard-to-find MCCBs, used and tested inventory can be a practical solution—often faster and more cost-effective than chasing new old stock.

Why many facilities choose tested/refurbished

• Lower total cost versus new replacements
• Shorter lead times when the exact model is obsolete
• Confidence when parts are inspected/tested and backed by a warranty

If you’re sourcing for critical uptime, ask your supplier what testing/inspection is performed and what documentation is available.

4) Lead time matters: prioritize “in-stock and ready” inventory

Downtime is expensive. Partnering with a supplier that maintains a large, organized breaker inventory can dramatically reduce delays.

EMSCO’s Minneapolis facility includes a 250,000-square-foot warehouse with a large selection of tested MCCBs ready to ship, helping contractors and facilities teams get replacements faster.

5) Verify quality controls, standards, and warranty

Replacement MCCBs must fit correctly and perform safely. Ask about inspection/testing practices and warranty coverage. Suppliers referencing recognized standards (such as PEARL) are signaling an emphasis on process and quality.

Quick buyer checklist:

• What testing is performed (electrical + mechanical)?
• Is the unit cleaned/refurbished or simply “pulled and shipped”?
• Is a warranty included?
• Can you provide photos and/or test documentation?

Common mistakes to avoid

• Ordering by amp rating only (ignoring frame/series, terminals, or mounting)
• Skipping interrupt rating (AIC/kAIC) verification
• Not confirming required accessories (shunt trip, aux contacts, etc.)
• Assuming “close enough” is acceptable on legacy gear

FAQ

What info do I need to match an MCCB replacement?

At minimum: manufacturer, model/catalog number, voltage, amps, poles, trip type, interrupt rating (AIC/kAIC), and mounting/terminal configuration.

Can I replace an MCCB with a different brand or model?

Sometimes—but it must be a verified equivalent that matches the electrical ratings, mounting, and the equipment’s requirements. When in doubt, have a qualified professional confirm compatibility.

Are refurbished/used MCCBs safe?

They can be, when sourced from a reputable supplier that inspects/tests units and backs them with a warranty. Always ask what testing is performed and what documentation is available.

What if I can’t find the model number?

Send clear photos of the breaker label and how it mounts/installs. That often provides enough information for a knowledgeable supplier to identify the correct replacement or equivalent.

Next step

Browse EMSCO’s inventory of molded & insulated case circuit breakers, or contact our team with your breaker photos/specs to get a fast match.

Browse Molded Case Circuit Breakers

Introduction

In today’s industrial environments, efficient and flexible power distribution is key. Bus plugs are crucial components in ensuring reliable power delivery through busway systems. Whether you're expanding your facility or maintaining an older system, choosing the right bus plugs can greatly impact your operation's safety and performance. At EMSCO, we specialize in providing used and reconditioned bus plugs, offering solutions from trusted brands like GE, Square D, and Cutler-Hammer, ensuring cost-effective and reliable options for all industrial power needs.

What Are Bus Plugs and Why Are They Important?

Bus plugs connect electrical equipment to busway systems, distributing power efficiently across facilities. Bus plugs offer flexibility in power distribution, allowing for easy reconfiguration as industrial layouts change. In addition to their adaptability, they provide essential circuit protection, ensuring equipment is safeguarded against overcurrent and electrical faults.

EMSCO is proud to offer reconditioned bus plugs that meet or exceed industry standards, giving you access to reliable equipment from trusted manufacturers at a fraction of the cost of new components.

Benefits of Choosing Used and Reconditioned Bus Plugs

Opting for used or refurbished bus plugs offers numerous benefits, especially for businesses looking to optimize costs without sacrificing quality:

1. Cost Savings: Purchasing used bus plugs can save up to 50% compared to new products. With reconditioned options from brands like Square D and Siemens, you get the same quality at a reduced price.
2. Access to Obsolete Parts: If you're working with an older busway system, finding parts that are no longer manufactured can be a challenge. We offer a wide selection of obsolete bus plugs, including those from legacy brands like Westinghouse and ITE.
3. Faster Lead Times: At EMSCO, we maintain a large inventory of reconditioned bus plugs, which allows us to deliver products faster than competitors who rely on factory orders for new parts.
4. Environmental Sustainability: Reusing and refurbishing electrical equipment reduces waste, supporting your company’s sustainability goals while keeping your operations running smoothly.

Types of Bus Plugs Available

At EMSCO, we stock a wide range of bus plugs to meet various industrial needs, including:

• Fusible Bus Plugs: These provide built-in circuit protection using fuses that disconnect the power in the event of an overcurrent, helping prevent equipment damage.
• Non-Fusible Bus Plugs: These use circuit breakers instead of fuses, allowing for quick resetting in case of a fault, reducing downtime for your operations.

We offer configurations for both high- and low-voltage systems, including 3-phase bus plugs, 10-amp bus plugs to 1600-amp bus plugs in three and four wire configurations.

Why Choose EMSCO for Your Reconditioned Bus Plugs?

With over 70 years of experience in the electrical distribution industry, EMSCO is a trusted provider of used and reconditioned electrical equipment. We offer:

• The largest inventory of used bus plugs in the country, ensuring that you get the equipment you need quickly.
• Expertise in refurbishing electrical components to meet PEARL standards, ensuring the reliability and safety of all our products.
• A one-year warranty on all reconditioned bus plugs.
• Competitive pricing on reconditioned equipment from top brands, such as GE, Square D, and Eaton, helping you reduce costs without compromising on quality.
• Dedicated customer support to assist in selecting the right bus plug for your specific needs.

Key Considerations for Selecting Bus Plugs

When choosing the appropriate used bus plug for your system, there are several important factors to keep in mind:

• Current and Voltage Ratings: Ensure that the bus plug you choose is compatible with your busway system and the equipment it powers. Our team at EMSCO can help guide you through this process.
• Installation Requirements: Depending on your facility's layout, you may need horizontal or vertical configurations. We offer both, along with expert advice to ensure a smooth installation.
• Compatibility with Legacy Systems: If your facility uses an older busway system, finding obsolete bus plugs can be difficult. We carry a wide range of hard-to-find parts from manufacturers like Cutler-Hammer / Westinghouse to keep your system running smoothly.

Conclusion

Bus plugs are integral to maintaining efficient, reliable, and safe power distribution in industrial settings. Whether you're looking to expand your existing system, replace outdated equipment, or find cost-effective solutions, EMSCO is here to help. With our vast inventory of refurbished bus plugs from trusted brands like GE and Square D, we ensure your facility operates at peak performance without breaking the bank.

For more information or to explore our selection of reconditioned bus plugs, visit our Bus Plugs Category Page today. Let us help you find the right solution to keep your power distribution system running smoothly and efficiently.

Upgrading or replacing your existing busway and bus plugs with Bulldog Busway and Bus Plugs—whether new, reconditioned, or used — brings benefits to your facility.

Reconditioned used or inspected and safety-tested Bulldog bus plugs can significantly lower your investment compared to purchasing new ones. These options provide the reliability and efficiency of new equipment at a fraction of the cost, allowing you to allocate budget to other critical areas of your operations.

Bus Plug Testing and Quality Assurance:

EMSCO Reconditioned used and inspected, safety-tested bus plugs undergo testing processes to meet industry standards and your specific operational requirements. This means you can trust that these components will perform reliably, maintaining the safety and integrity of your electrical system.

Bulldog Bus Plugs In Stock for Reduced Lead Times:

Used and reconditioned Bulldog Busway and Bus Plugs are often more readily available than new ones, which can have long lead times due to manufacturing processes and supply chain delays. This means you can upgrade your busway system faster, minimizing disruptions and keep your business moving.

Buyers Checklist Questions for ITE/Siemens Bulldog Bus Plugs

☑️ Amperage

Knowing the available amperage for bus plug options ensures you choose a bus plug that can handle your specific electrical load, preventing overloading and ensuring efficient operation. Selecting the correct amperage rating matching the bus plug's capacity to your system's leads to safety and optimal performance.

☑️ Ground

Review the grounding options provided by ITE Bulldog Bus Plugs. Proper grounding options are essential for electrical safety and system stability, preventing potential hazards and ensuring compliance with safety standards.

☑️ Fusible or Breaker Style Bus Plugs

Choose between fusible and breaker style: Fusible Bus Plugs are ideal for applications where cost is a primary concern, and where high fault current handling capability is needed. Breaker Style Bus Plugs are better suited for applications where minimizing downtime is critical, and where power options are important.

☑️ Voltage

Correct voltage ratings to ensure that the bus plug can handle the electrical potential of your system, preventing mismatches that could lead to equipment failure or safety issues.

☑️ Bus Plug Wiring

Wire compatibility ensures that the bus plug can be securely and effectively connected to your existing wiring, which is critical for maintaining system integrity and performance. This also reduces the risk of faults and improves overall system performance.

ITE/SIEMENS Bulldog Series Busway Voltage and Amperage

5 Questions to Ask When Choosing Bus Plug Replacements

1. What factors should I consider when selecting the amperage rating for my bus plugs?

Answer:

When deciding on an amperage rating for your bus plugs, keep in mind your system's electrical load requirements, the maximum current the bus plug can carry, and the possibility of future extension. Using the proper amperage rating reduces overloading, improves safety, and extends the life of your electrical components.

2. Should I choose fusible or breaker style bus plugs for my system?

Answer:

Your special needs will determine whether you use fusible or breaker style bus plugs. Fusible bus plugs are inexpensive and can take greater fault currents, but they require fuse replacement after usage. Breaker style bus plugs are resettable and have customizable trip settings, which reduces downtime and increases operating flexibility; still, they are often more expensive upfront.

3. How important is proper grounding for bus plugs, and what options are available?

Answer:

Correct grounding is necessary for electrical safety and system performance. It protects against electrical faults and surges, lowering the risk of equipment damage and providing compliance to safety regulations. To maintain a safe and stable electrical environment, be sure that the bus plugs you purchase have sufficient grounding options that meet the requirements of your system.

4. What voltage ratings should I consider when selecting bus plugs for my electrical system?

Answer:

Check your electrical system's voltage needs for safe compatibility with bus plugs. To guarantee safe and efficient operation, the bus plug's voltage rating must be equal to or greater than the system operating voltage. Common voltage ratings include 120V, 208V, 240V, 480V, and 600V. To avoid malfunctions or safety issues, check whether the bus plugs you choose are capable of handling the voltage in your system.

5. Are there benefits to using reconditioned or inspected and safety-tested bus plugs compared to new ones?

Answer:

These options can provide significant cost savings while still offering reliability and performance equivalent to new components. Reconditioned bus plugs undergo thorough testing to make certain they meet industry standards, making them a practical and economical choice for maintaining and upgrading your electrical system.

Request help online or call a product specialist at 800-328-1842.

Reconditioned, used busway and bus plugs that are inspected and safety tested offer a viable option for your electrical needs. These products go through our evaluation and testing processes to certify they meet safety standards for safety and performance.

In any industrial or commercial setting, ensuring the safety of personnel and equipment is paramount. One critical aspect of electrical safety is the proper implementation of safety switches and disconnects. These devices play a crucial role in protecting against electrical hazards, preventing accidents, and facilitating maintenance work on electrical systems and machinery. In this blog post, we'll delve into the basics of safety switches and disconnects, exploring their functions, types, and importance in maintaining a safe working environment.

Understanding Safety Switches and Disconnects

Safety switches, also known as disconnect switches or isolators, are devices designed to quickly and safely disconnect electrical power to a circuit or piece of equipment. They serve as a means of isolating electrical circuits, machinery, or appliances to prevent electric shock, fire, or damage to equipment during maintenance, repair, or emergency situations.

Functions of Safety Switches and Disconnects

Isolation: Safety switches provide a physical break in the electrical circuit, ensuring that no power is supplied to the connected equipment or circuit when in the off position. This isolation is essential for preventing accidental contact with live electrical components.

Emergency Shutdown: In case of electrical faults or emergencies, safety switches offer a quick and reliable means of shutting off power to affected circuits or equipment, minimizing the risk of further damage or injury.

Lockout/Tagout (LOTO): Safety switches are often used in conjunction with lockout/tagout procedures to ensure that equipment remains de-energized during maintenance or servicing, preventing unauthorized activation and safeguarding personnel working on the equipment.

Types of Safety Switches and Disconnects

Fused Disconnect Switches: These devices incorporate fuses into the disconnect switch mechanism, providing overcurrent protection when excessive current flows along with the ability to disconnect power, preventing damage to equipment and minimizing safety risks.

Non-Fused Disconnect Switches: Non-fused disconnect switches offer a means of isolating power without the inclusion of fuses. They are commonly used in applications where overcurrent protection is provided elsewhere in the circuit.

Circuit Breaker Disconnects: Circuit breaker disconnects combine the functions of a disconnect switch and a circuit breaker, allowing for both disconnection and overcurrent protection.

Importance of Safety Switches and Disconnects

Electrical Safety: By providing a means of isolating power, safety switches and disconnects help prevent electric shock and electrocution hazards, safeguarding personnel working on electrical systems.

Equipment Protection: Disconnecting power during maintenance or repair activities helps prevent damage to equipment and extends its operational lifespan.

Fire Prevention: Properly functioning safety switches can mitigate the risk of electrical fires by quickly disconnecting power in the event of a fault or overload.

Compliance with Regulations: Many regulatory standards and codes mandate the use of safety switches and disconnects in industrial and commercial settings to ensure compliance with safety requirements and prevent accidents

Key Considerations When Choosing Safety Switches

Voltage and Amperage Rating: Select safety switches that match the voltage and amperage requirements of the electrical system they will be protecting.

Enclosure Type: Consider the environmental conditions (e.g., indoor, outdoor, hazardous locations) when choosing the appropriate enclosure type for the safety switch and select the appropriate NEMA rating for the disconnect switch.

Fused or Non-Fused: Ensure that you select the correct type for the applications of your electrical system.

Conclusion

Safety switches and disconnects are indispensable components in electrical systems, serving to protect both personnel and equipment from electrical hazards. Understanding their purpose, types, and key considerations is essential for ensuring a safe and compliant electrical environment. By prioritizing safety and selecting the right safety switches for your application, you can mitigate risks and create a secure work environment. Remember, when it comes to electrical safety, there's no room for compromise.

Shop the largest selection of used and reconditioned safety switches

Westinghouse TAP, ITAP and ZTAP bus plugs can look very similar, but they are designed for different busway systems and are not interchangeable.

If you're trying to replace an existing Westinghouse or legacy Cutler-Hammer bus plug, don't identify it by enclosure shape alone. The part-number prefix, stab arrangement and hanger width can help determine which series you have.

TAP vs. ITAP vs. ZTAP: Quick Identification

The biggest trap is TAP vs. ZTAP. Both can have aligned stabs, and a ZTAP plug may even have a part number beginning with TAP. That's why the label alone isn't always enough.

How to Identify a TAP Bus Plug

TAP bus plugs are used with Westinghouse Standard-Design busway rated from 225A through 1000A. They were available in both 3-wire and 4-wire configurations.

The easiest clues to check are:

• Stabs: The phase stabs are aligned in a row.
• Neutral: On a 4-wire TAP plug, the neutral is offset from the phase stabs.
• Part number: The product label typically begins with the prefix TAP.
• Hanger width: TAP hanger brackets measure approximately 9-5/8 inches wide.

That last measurement becomes especially important when distinguishing a TAP plug from a ZTAP plug.

How to Identify an ITAP Bus Plug

ITAP bus plugs are used with Westinghouse Pow-R-Way I and Pow-R-Way II busway rated from 225A through 4000A. They were also available in 3-wire and 4-wire configurations.

ITAP is usually the easiest of the three families to identify:

• Stabs: ITAP stabs have a distinctive staggered or offset arrangement.
• Part number: The product label should use an ITAP prefix.

If the stabs are aligned rather than staggered, you're likely looking at a different Westinghouse bus plug family.

How to Identify a ZTAP Bus Plug

ZTAP bus plugs are used with Westinghouse Low-Impedance busway rated from 1000A through 4000A. ZTAP plugs can be more difficult to identify because of their similarity to TAP plugs.

Look for these clues:

• Stabs: The phase stabs are aligned.
• Neutral: On a 4-wire ZTAP plug, the neutral stab is also aligned with the other stabs.
• Hanger width: ZTAP hanger brackets measure approximately 11-5/8 inches wide.
• Part number: Don't rely on the prefix alone. ZTAP plugs may also have part numbers beginning with TAP.

The wider hanger brackets are one of the best physical clues. Compared with the 9-5/8-inch TAP hanger, the ZTAP hanger measures approximately 11-5/8 inches and extends farther beyond the enclosure.

TAP or ZTAP? Check These Two Details

If you're stuck between TAP and ZTAP, focus on hanger width and the neutral stab position.

Do not order a replacement based only on seeing "TAP" on the label. Check the physical configuration as well.

What to Send EMSCO for a Replacement Bus Plug

If you're still not sure which Westinghouse bus plug you have, don't guess. Send us enough information to verify the series before ordering.

For the fastest match, send:

• A clear photo of the bus plug nameplate
• A photo showing the stab configuration
• A photo of the busway nameplate, if available
• The hanger width if you're trying to distinguish TAP from ZTAP
• Amperage and voltage
• 3-wire or 4-wire configuration
• Ground requirements
• Breaker or fusible configuration

EMSCO stocks used, surplus, obsolete and professionally reconditioned bus plugs, including legacy Westinghouse and Cutler-Hammer equipment. Not everything in our inventory is listed online, so contact us if you don't see the exact plug you need.

Shop Bus Plugs   |   Busway & Plugs   |   Ask EMSCO for Help Identifying Your Bus Plug

It's been a while since we discussed one of our main product categories in an overview post. In the past, we've covered topics like bus plugs to provide general information about the products EMSCO offers. In this post, we'll delve into the basics of Motor Control Centers (MCC).

Shop MCC Buckets and Structure

A bus plug is a removable tap-off unit that connects to a compatible busway or bus duct system and provides a protected power feed for equipment, machinery, panels, or other downstream loads.

Bus plugs are commonly used in industrial and commercial facilities because they make it easier to add, relocate, or replace power drops without rebuilding large conduit runs.

The important part is compatibility: bus plugs are not universal. The plug must match the manufacturer and series of the busway, as well as the system's voltage, amperage, wire configuration, and other physical requirements.

How a Bus Plug Works

Busway distributes electrical power through enclosed conductors running through a facility. Plug-in busway includes designated openings where compatible bus plugs can be installed.

When a bus plug is installed, its internal contacts engage the conductors inside the busway. The unit then provides a protected connection point for conductors feeding equipment below or downstream.

Depending on the system, a bus plug may use either a circuit breaker or fuses for overcurrent protection.

Breaker vs. Fusible Bus Plugs

Breaker Bus Plugs

Breaker-style bus plugs contain a circuit breaker inside the enclosure. They provide a resettable means of overcurrent protection and are common across many industrial busway systems.

When identifying a replacement, details such as the breaker type, frame size, trip rating, and interrupting rating may all matter.

Fusible Bus Plugs

Fusible bus plugs use replaceable fuses for overcurrent protection. These units are common in both current and legacy systems and may be selected based on the system design, coordination requirements, or busway family they are designed to fit.

Neither style is inherently better. The correct choice depends on the existing system and application.

Why Facilities Use Bus Plugs

The main advantage of plug-in busway is flexibility. Instead of running a dedicated conduit path every time equipment is moved or added, facilities can install compatible bus plugs at available tap-off points along the busway.

This can be especially useful for:

• Production-line changes
• Machinery moves
• Plant expansions
• New equipment installations
• Temporary or changing power requirements
• Replacement of existing tap-off units

For facilities with established busway systems, keeping compatible bus plugs available can also reduce downtime when an existing unit needs replacement.

Bus Plug Compatibility: What Actually Has to Match?

This is the part that matters most when identifying a replacement. Two bus plugs can have the same amperage and voltage ratings and still be completely incompatible.

Before sourcing a replacement, identify as much of the following information as possible.

1. Manufacturer and Busway Series

Start with the manufacturer and exact busway family. Common examples include:

• Square D I-Line and I-Line II
• Siemens Sentron
• General Electric Spectra
• Westinghouse / Cutler-Hammer Pow-R-Way
• General Electric Armor-Clad
• Siemens XL-U

The manufacturer alone usually isn't enough. A manufacturer may have produced several different busway families with completely different plug-in designs.

2. Voltage

Confirm the voltage rating of the existing busway and required bus plug. Industrial systems commonly include ratings such as 240V, 480V, and 600V, but the correct rating should always be verified from the equipment nameplate.

3. Amperage

Identify the required amp rating for the load and confirm that the bus plug configuration is appropriate for the busway system.

Bus plugs are available across a wide range of amperages, from relatively small branch circuits to large industrial loads.

4. Wire Configuration and Ground

Determine whether the system is:

• 3-wire or 4-wire
• Equipped with a neutral
• Equipped with an integral or separate ground

These details can affect both electrical compatibility and the physical configuration of the bus plug.

5. Breaker or Fusible Style

If replacing an existing unit, note whether it uses a circuit breaker or fuses.

For breaker units, record the breaker manufacturer, frame, trip rating, and any visible catalog numbers. For fusible units, note the fuse class and amp rating where available.

6. Physical Configuration

Mechanical details matter just as much as electrical ratings. Depending on the busway system, relevant details may include:

• Plug-in connection design
• Mounting orientation
• Enclosure configuration
• Cable exit direction
• Operating handle
• Interlocks
• Grounding provisions

These details are one reason photos can be extremely helpful when identifying older or obsolete equipment.

The Fastest Way to Identify a Replacement Bus Plug

If you're trying to identify an existing bus plug, start with the nameplates and photos.

Useful photos include:

• The busway nameplate
• The existing bus plug nameplate or label
• The front and sides of the bus plug
• The plug-in connection or opening
• The circuit breaker or fuse information
• Any catalog numbers or series markings

Also provide the voltage, amperage, and wire configuration if known.

For example, asking for a "100-amp Square D bus plug" may not provide enough information to identify the correct replacement. Knowing the exact Square D busway family and providing photos of the equipment can significantly narrow the search.

When Should a Bus Plug Be Inspected or Replaced?

Bus plugs operate in industrial environments where heat, dirt, vibration, age, and repeated operation can affect components over time.

Potential signs that a unit should be evaluated include:

• Discoloration or evidence of overheating
• Burnt odor
• Damaged or worn stab contacts
• Loose hardware
• Cracked or damaged enclosure components
• Corrosion or contamination
• Broken handles or interlocks
• Repeated nuisance tripping
• Visible damage around the plug-in connection

Inspection, removal, installation, and service should be performed by qualified electrical personnel following applicable safety procedures and manufacturer instructions.

Bus Plug vs. Tap Box

Bus plugs and tap boxes are both used with busway systems, but they generally serve different purposes.

A bus plug is typically installed at a plug-in opening along a busway run to provide a protected power feed to downstream equipment.

A tap box is generally used as a connection point within the busway system rather than as a removable branch tap for individual equipment.

Terminology and applications can vary by manufacturer and busway family, so the specific equipment should always be verified.

Looking for a Replacement Bus Plug?

EMSCO stocks a large inventory of new, used, and reconditioned bus plugs for current, legacy, and obsolete busway systems.

If you know the manufacturer, series, voltage, amperage, and wire configuration, start by browsing our bus plug inventory.

If you're not sure what you have, photos of the busway and bus plug nameplates can help our team identify the system and narrow down compatible options.

Browse Bus Plugs | Browse Bus Duct & Busway | Browse Tap Boxes & Accessories

Frequently Asked Questions

Are bus plugs universal?

No. Bus plugs are designed for specific busway manufacturers and series. Voltage, amperage, wire configuration, grounding, and mechanical fit must also be compatible.

Can I use a bus plug from a different manufacturer?

Bus plugs should not be assumed interchangeable across manufacturers or busway families. The plug must be designed and rated for the specific busway system.

What information do I need to replace a bus plug?

Start with the busway manufacturer and series, voltage, amperage, wire configuration, breaker or fuse information, and clear photos of the busway and bus plug nameplates.

What is another name for a bus plug?

Depending on the manufacturer and system, bus plugs may also be referred to as tap-off units or plug-in units.

Can an obsolete bus plug still be replaced?

Often, yes. Many industrial facilities continue operating legacy busway systems after the original equipment has been discontinued. Replacement may involve locating compatible used, surplus, or reconditioned equipment.

Browse EMSCO's Bus Plug Inventory