NEC Commercial Electrical Practice Test

What should be ensured when installing nonmetallic-sheathed cable in walls or ceilings?

1. It should not exceed 10 feet in length

2. It must be installed at accessible heights

3. Bends should be gradual to prevent damage

4. They should be painted to prevent corrosion

The correct answer is: Bends should be gradual to prevent damage

When installing nonmetallic-sheathed cable in walls or ceilings, it is essential that bends are made gradually to prevent damage to the cable. Sharp bends can cause stress on the insulation and conductors within the cable, potentially leading to compromised integrity or failure of the cable. Gradual bends help ensure that the cable maintains its shape and functionality while protecting it from wear and tear during installation and in its operational lifespan. The other options present considerations that might come up in electrical installations, but they do not apply specifically to nonmetallic-sheathed cable installations. There is no specific limit on the overall length of nonmetallic-sheathed cable that mandates it must not exceed 10 feet; rather the total run should consider installation practices and local code requirements. Accessibility is important for maintenance but does not dictate an explicit height requirement for all cable installations. Additionally, nonmetallic-sheathed cables do not typically require painting for corrosion prevention, as they are inherently resistant to corrosion due to their design and materials.