A 4-position load break switch is an electrical device designed to safely interrupt or connect circuits under load conditions, meaning it can be operated while the circuit is energized. The "4-position" designation indicates the number of distinct operational settings that the switch can achieve, allowing for various electrical pathways or connections to be selected.

Key Features:

1. Four Operational Positions: These positions typically correspond to different circuit configurations, such as connecting to different power sources or isolating specific sections of the circuit.
2. Load Break Capability: The switch can interrupt or connect circuits while under load, meaning it can handle the electrical current without causing arcing or damaging equipment, which is essential for maintaining safety and reliability in electrical systems.
3. Use in Transformers and Switchgear: These switches are often employed in pad-mounted transformers or distribution switchgear, particularly in medium-voltage systems. They are installed in oil-filled environments (like transformer oil) for insulation and cooling purposes.
4. Applications: Commonly used in underground residential distribution networks, commercial and industrial installations, and other systems requiring the ability to switch between different power sources or isolate parts of the network.
5. Rotational Mechanism: Many 4-position load break switches, such as those in Eaton’s Cooper Power™ series, feature a rotational mechanism that allows the switch to rotate 360° in either direction, providing flexibility in selecting the desired operational position.
6. Hotstick Operable: These switches are often designed for operation using a hotstick, an insulated tool that allows linemen to operate the switch from a safe distance.

Typical Positions:

Source 1 Connected: Power is supplied from the primary source.

Source 2 Connected: Power is supplied from an alternative source.

Loop or Tie Position: The switch connects two or more sources together.

Isolated Position: The circuit is disconnected or isolated, ensuring a safe condition for maintenance or emergencies.

In summary, a 4-position load break switch is a versatile and essential component in medium-voltage electrical systems, providing safe, reliable control over power distribution.

What is the difference between M and B of Eaton 4-Position Load Break Switch?

Eaton's Cooper Power™ series four-position sectionalizing load break switch is designed for transformer (mineral) oil, Envirotemp™ FR™ fluid, or other approved equivalent fluid-filled pad-mounted transformers or distribution switchgear. These switches meet the latest revisions of both IEEE® and IEC standards, making them suitable for single- and three-phase grounded wye or delta systems.

Primarily used in underground residential applications with loop feed, these switches are also ideal for three-phase commercial and industrial installations requiring an alternative power source. They can switch a primary cable tap on or off on a transformer, and when installed near the transformer core/coil assembly, the minimized cable capacitance reduces the risk of ferroresonance.

Eaton's Cooper 4-position load break switches have different model codes that represent various configurations. The first three digits represent the product series; the fourth digit indicates the mounting method, with "R" for Ring-Mount System, "B" for Bolt-Mount System, and "Q" for Quick-Mount System. The fifth digit represents the mounting direction: "H" for Horizontal and "V" for Vertical. The sixth digit denotes the number of poles, while the seventh digit indicates the switch type, such as "V" for V-Blade and "T" for T-Blade. The eighth and ninth digits specify the contact rating, and the tenth digit has two codes: "B" for Break Before Make and "M" for Make Before Break.

Make-Before-Break (MBB) Switches:

• Improve system reliability by eliminating momentary interruptions during switching operations, which are typically associated with Break-Before-Make (BBM) sectionalizing switches.
• Replace 2 or 3 two-position load break switches depending on the application (Choose V-Blade or T-Blade type).
• Simplify operational procedures.
• The Make-Before-Break design is only available for V- and T-Blade switch types.

The Make-Before-Break (MBB) switches ensure uninterrupted power during switching operations.