In the electrical installation of a factory, the length of flexible conduit used for connections between the terminal boxes of the motor and starter, the switches and motor should NOT exceed ________.

Explanation:

In the electrical installation of a factory, the length of flexible conduit used for connections between the terminal boxes of the motor and starter, the switches and motor should NOT exceed 1.25 m.

Importance of Flexible Conduits:

Flexible conduits are essential in electrical installations for providing protection and routing for electrical wiring. They offer flexibility and ease of installation, especially in areas where rigid conduits would be challenging to use. However, the length of flexible conduits needs to be controlled to ensure safety and maintain the integrity of the electrical system.

Reasons for Limiting the Length:

• Voltage Drop: Longer lengths of flexible conduit can contribute to voltage drop, which can affect the performance of electrical equipment. By limiting the length to 1.25 m, voltage drop is minimized, ensuring that the equipment operates efficiently.
• Mechanical Protection: Flexible conduits provide mechanical protection to the enclosed wiring. However, they are not as robust as rigid conduits. Limiting their length ensures that the wiring is adequately protected and reduces the risk of damage.
• Ease of Maintenance: Shorter lengths of flexible conduit make it easier to access and maintain the electrical wiring. This is particularly important in factory settings where regular maintenance is necessary to ensure safe and reliable operation.

Correct Option Analysis:

The correct option is:

Option 4: 1.25 m

This option is correct because it aligns with standard practices in electrical installations. Limiting the length of flexible conduit to 1.25 m ensures safety, minimizes voltage drop, and provides adequate mechanical protection.

Additional Information

To further understand the analysis, let’s evaluate the other options:

Option 1: 1 m

While a length of 1 m would also ensure safety and minimize voltage drop, it may be unnecessarily restrictive. In many installations, slightly longer lengths are permissible without compromising safety or performance. Therefore, 1.25 m is a more practical limit.

Option 2: 1.5 m

A length of 1.5 m may be acceptable in some cases, but it could potentially lead to increased voltage drop and mechanical vulnerability. Therefore, 1.25 m is considered a safer and more reliable limit.

Option 3: 1.75 m

This length is longer than the recommended 1.25 m and could pose risks such as higher voltage drop and reduced mechanical protection. It is not a standard practice to use flexible conduits of this length in factory installations.

Conclusion:

In summary, the length of flexible conduit used for connections between the terminal boxes of the motor and starter, the switches and motor should NOT exceed 1.25 m. This limitation ensures the safe, efficient, and reliable operation of the electrical system in a factory setting. It minimizes voltage drop, provides adequate mechanical protection, and facilitates easy maintenance. While other lengths may offer some flexibility, 1.25 m is the optimal limit based on standard practices and safety considerations.