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You're probably aware that EMSCO is a top provider of used, reconditioned, and surplus industrial electrical equipment. However, you might not know that beyond just being the largest supplier, we also can tailor our products to your exact needs. Let's discuss one aspect of this customization: trip units, specifically the AC Pro and AC Pro II trip units.

Before and after refurbishment, ready for shipment to our customer in Kentucky.

Square D I-Line Distribution Lineup:
🔹 2000A Main Breaker Section (LSIG)
🔹 1200A Distribution Breaker Section (LSI)
🔹 Surgelogic Surge Protective Device

Distribution Section:
🔹 2 x 400A Breakers
🔹 10 x 200A Breakers
🔹 1 x 60A Breaker

All used circuit breakers are load-tested with test reports.

One of the most common challenges in our industry is accurately distinguishing between the different series of vintage Westinghouse/Cutler-Hammer busway systems. Despite their nearly identical appearances, the TAP, ITAP, and ZTAP series are entirely distinct and cannot be interchanged.

Fortunately, there are quick and straightforward methods for correctly identifying the specific vintage series you require. In the following discussion, we will explore these differences, highlighting easy-to-spot clues on the plugs to help you correctly identify the type you need.

 
Identifying the types:

TAP

In any industrial power distribution system, safety and reliability are of paramount importance. To protect electrical circuits and equipment from potential hazards such as overcurrents and short circuits, engineers and electricians often employ protective devices like fuses and circuit breakers. These devices play a crucial role in safeguarding the entire system, but they differ in design, operation, and response to electrical faults. In this blog post, we will explore the key differences between fuses and circuit breakers in industrial power distribution.

1. Function and Operation:

   • Fuses: A fuse is a one-time, non-resettable protective device that contains a metal strip or wire designed to melt when exposed to excessive current flow. When the current exceeds the fuse's rated value, the metal inside the fuse will melt, opening the circuit and stopping the current flow. Fuses are inexpensive and simple in design, making them suitable for basic protection.
   • Circuit Breakers: Circuit breakers, on the other hand, are resettable protective devices designed to interrupt the current flow upon detecting an overcurrent or short circuit. They consist of an electromechanical switch that opens the circuit when an abnormal condition occurs. After tripping, circuit breakers can be manually or automatically reset, restoring power to the circuit once the fault is resolved.

2. Response Time:

   • Fuses: Fuses generally have a faster response time compared to circuit breakers. When subjected to overcurrent conditions, fuses blow quickly, thereby interrupting the current flow almost instantaneously. This swift response is essential in protecting sensitive equipment from damage due to high currents.
   • Circuit Breakers: Circuit breakers may have a slightly slower response time compared to fuses. The tripping mechanism needs a brief moment to detect the fault and open the circuit. While the delay is minimal, it can be a critical factor when dealing with highly sensitive electronic devices.

3. Protection Accuracy:

   • Fuses: Fuses provide good protection against overcurrent conditions, but their accuracy depends on the type and rating of the fuse. They might not always respond precisely to minor overloads or fluctuating currents, which can lead to undesired nuisance trips or insufficient protection in some cases.
   • Circuit Breakers: Circuit breakers offer more precise protection since they can be equipped with various types of trip units that allow customization of the tripping characteristics. This adaptability ensures that circuit breakers respond accurately to specific overcurrent levels, providing better protection for critical equipment.

4. Maintenance and Resetting:

   • Fuses: Once a fuse blows due to a fault, it must be replaced manually. This process can be time-consuming, especially in large industrial setups with numerous fuses. Additionally, identifying the faulty fuse might require careful inspection, further adding to the downtime.
   • Circuit Breakers: Circuit breakers have the advantage of being resettable, which significantly reduces downtime in the event of a fault. After isolating the faulty circuit, the breaker can be reset with a simple switch, restoring power to the system almost immediately.

5. Cost and Longevity:

   • Fuses: Fuses are generally more cost-effective than circuit breakers, making them a popular choice for lower current applications. However, their one-time use means they must be replaced after each fault, resulting in higher long-term maintenance costs.
   • Circuit Breakers: While circuit breakers may have a higher initial cost, their reusability and longer lifespan offset this drawback. They are an economically viable option for higher current applications and provide better value in the long run.

In conclusion, both fuses and circuit breakers play critical roles in safeguarding industrial power distribution systems. Fuses offer fast response times and cost-effectiveness, while circuit breakers provide more precise protection and are easier to maintain. The choice between these protective devices ultimately depends on the specific requirements of the industrial application and the level of protection needed for the equipment and personnel involved.

The safety of any transformer or other electrical device should always come first. Low Voltage and Medium Voltage Encapsulated Dry Resin Transformers testing is required for safe operation. We can find any potential problems or weaknesses in the insulation of dry resin-filled transformers by performing routine testing. These tests allow us to take preventive action for your secure working environment.

Encapsulated Dry Transformer Components for Safety and the Environment

Electrical transformers that don't need a liquid coolant like oil are known as dry transformers. You may know them as resin-filled transformers, cast resin transformers or solid insulated transformers.

They use air for insulation and cooling. Dry transformers are popular because of their safety, effectiveness, and environmental friendliness in commercial and industrial environments. They are used in manufacturing facilities, renewable energy production, power distribution systems, and other areas.

Dry transformers are made up of a number of essential parts. The primary components consist of a laminated steel core that minimizes energy losses and a copper or aluminum conductor coil. Paper, fiberglass, or epoxy resin are used to insulate these windings, ensuring both electrical insulation and protection from impurities and moisture. For safety and cooling, the transformer is housed in a solid, vented casing.

Let's take a look at Megger test equipment for dry transformers and looking at the test results.

Megger Test Equipment Finds Insulation Weakness, Moisture, Safety Hazards

What is a megger test? Megger test equipment is effective for identifying moisture, insufficient insulation, and other possible problems in transformers. The test procedure includes applying DC voltage to the transformer windings during the test. The Megger test assists in locating any deterioration or breakdown in the insulation material by evaluating insulation resistance.

When looking at your megger test report, keep in mind the resistance reading will be lower than expected if the insulation is damaged, suggesting potential defects or moisture infiltration. With the help of this test, insulation issues like cracks, contaminants, or age can be found that could otherwise result in electrical problems, short circuits, or even catastrophic failures. Early detection of these problems allow necessary repairs or maintenance to be carried out, ensuring peak performance and averting safety risks. If you’re looking to invest in megger test set, check out the Megger Trax 220 Test Set for insulation resistance, winding resistance, turns ratio, dissipation factor, and more.

Transformer Megger Test Step-by-Step Procedures

Safety First:  Make sure the transformer is totally de-energized and you’re wearing appropriate personal protective equipment (PPE).

Setting up the Megger:  Prepare your Megger test device according to manufacturer directions. Verify that it’s calibrated and in good working order.

Disconnect Power:  To prevent incidents from occurring, make sure the transformer's power supply is completely cut off.

Clean your Transformers:  Clean the transformer's terminals and insulating surfaces. Any debris, moisture, or dirt that could compromise the test's accuracy should be removed.

Connect the Leads:  It’s recommended to connect the lead with the higher voltage (often red) to the high-voltage side and the lead with the lower voltage (typically black) to the low-voltage side.

Set Megger Test Duration:  The typical time frame is one minute, but it's always a good idea to check the manufacturer's instructions for any particular specifications.

Launch the Test:  Turn on the testing device. The transformer windings will receive a high-voltage DC voltage, and the instrument will measure the insulating resistance.

Interpret Megger Test Results: Compare insulation resistance with the reference value or the range the OEM specifies.

Based on test results, no urgent intervention may be needed if the insulating resistance is within the manufacturer’s stated range. Do repairs or arrange for maintenance if the reading falls below the designated threshold.

Looking for a Medium Voltage Dry-Type Transformer Testing Service?

This test helps you identify risks and prevent electrical faults or failures by identifying insulation weaknesses, moisture and other potential problems. The Megger test offers useful information about the insulation integrity of the transformer when you’re doing maintenance and repairs to maintain performance and avoid safety risks. Regular Megger testing extends the life and dependability of transformers in a safe environment. Make megger testing a routine and seek professional services if you’re not qualified to use the testing equipment.

Looking for a Medium or Low Voltage transformer or having one tested? A Megger Testing Service for transformers using test equipment like the Megger Trax 220 Test Set is crucial for verifying the effectiveness and safety of transformers.

Contact EMSCO customer service to arrange testing. Ask about EMSCO testing services for dry-type medium voltage transformers. Our new Megger Trax 220 Test Set allows us to perform a wide range of tests, including insulation resistance, winding resistance, turns ratio, dissipation factor, and many others.

In the realm of industrial power distribution, ensuring safety, reliability, and efficiency is of utmost importance. To protect electrical circuits and equipment from overcurrents and short circuits, engineers often turn to molded case circuit breakers (MCCBs). These robust and versatile devices play a crucial role in safeguarding industrial power systems, ensuring smooth operations and preventing potential hazards. In this blog post, we will delve into the features, benefits, and applications of molded case circuit breakers in industrial settings.

The Anatomy of Molded Case Circuit Breakers:
Molded case circuit breakers are named after their housing, which is typically made from molded insulating materials such as plastic or fiberglass. Inside the casing, these breakers comprise essential components like the trip unit, operating mechanism, and current-carrying contacts. The trip unit is responsible for detecting overcurrent conditions and tripping the breaker when necessary, while the operating mechanism ensures the mechanical action of opening and closing the circuit.

Wide Range of Current Ratings:
MCCBs are available in a wide range of current ratings, making them suitable for diverse industrial applications. They can handle currents ranging from a few amps to thousands of amps, allowing engineers to choose the appropriate breaker based on the specific requirements of their power distribution system.

Accurate and Reliable Protection:
One of the primary functions of an MCCB is to provide precise and reliable protection against overcurrent conditions. The trip units in MCCBs are designed to respond swiftly to abnormal current levels, effectively isolating the faulty circuit and preventing potential damage to equipment. With adjustable tripping settings, engineers can customize the MCCBs to suit the unique characteristics of their industrial power systems.

Thermal and Magnetic Protection:
MCCBs offer both thermal and magnetic protection, catering to different types of faults. The thermal trip element responds to overloads caused by long-duration, low-level overcurrents, while the magnetic trip element reacts to short-circuit currents. This dual protection mechanism ensures comprehensive safety coverage in industrial power settings.

Selectivity and Coordination: 
Industrial power distribution systems often have multiple levels of circuit breakers, from the main distribution board down to individual branch circuits. MCCBs provide the advantage of selectivity and coordination, which means that when a fault occurs, only the nearest MCCB to the fault will trip, leaving other downstream breakers unaffected. This feature minimizes downtime and optimizes system performance during fault scenarios.

Ease of Maintenance and Retrofitting:
MCCBs are designed for easy maintenance and replacement. With proper periodic inspection and testing, their lifespan can be extended, contributing to cost savings. Additionally, they are compatible with various accessories and digital communication modules, enabling seamless integration into modern industrial automation systems.

Versatility and Applications:
Molded case circuit breakers find applications across various industrial sectors, including manufacturing plants, data centers, commercial buildings, oil and gas facilities, and mining operations. They provide vital protection for motors, transformers, generators, distribution boards, and other critical electrical components.

In conclusion, molded case circuit breakers are indispensable assets in industrial power settings. Their accurate protection, ease of maintenance, and compatibility with modern automation technologies make them a reliable choice for ensuring the safety and efficiency of power distribution systems. By understanding the benefits and applications of MCCBs, engineers can make informed decisions to secure their industrial power infrastructure effectively.

Find the Molded Case Breaker you need here!

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

Shop Medium Voltage Transformers

Shop Molded & Insulated Case Circuit Breakers