Okay, let's break down this question and the relevant NEC sections to arrive at the answer.

Understanding the Sections NEC 550.15(H)(1) & (2) (Mobile Homes/Manufactured Homes) This section deals specifically with wiring under a mobile/manufactured home. It outlines that wiring exposed to the weather must be protected by a conduit or raceway suitable for wet locations. And also that where wiring is exposed to physical damage it shall be protected by a raceway, conduit or other means. NEC Table 300.5 (Minimum Cover Requirements, 0 to 600 Volts) This table deals with the burial depth requirements for underground wiring. Column 3 refers to wiring under a building.

Analysis & Answer

Here's the critical interpretation:1. Mobile Home as a "Building"

The question correctly states that a mobile home is considered a building.2.

Table 300.5 and Under-Building Wiring

Table 300.5, Column 3, states that wiring under a building has a burial depth of 0 inches (meaning it does not have to be buried).
3.

Conduit on the Ground

Given the above, it would appear that the conduit laying on the ground would be in compliance with Table 300.54.

550.15(H)(1) and (2) Still Apply



HOWEVER Section 550.15(H)(1) and (2) still apply. Weather Exposure

Because the conduit is laying on the ground under the mobile home, it is definitely exposed to the weather (rain, snow, moisture, UV, etc.). Therefore, the conduit must be a type listed for wet locations.

Physical Damage

Because the conduit is laying on the ground under the mobile home, it is definitely exposed to physical damage (People walking, rodents, animals, equipment, etc.). Therefore, the conduit must be protected by a raceway, conduit or other means.

Conclusion

While Table 300.5 allows for a 0-inch burial depth under a building (including a mobile/manufactured home), placing the conduit directly on the ground without any further protection likely violates 550.15(H)(1) and (2), unless the following conditions are met:1. The conduit is listed for wet locations.2. The conduit is protected from physical damage This could be accomplished in several ways, which would need to be evaluated by the AHJ.

Important Considerations & Recommendations Local AHJ (Authority Having Jurisdiction)

Always consult with the local electrical inspector (AHJ) before installation. They have the final say in interpreting the code and ensuring compliance. Their interpretation can vary.

Best Practices

Even if technically permissible, running conduit directly on the ground under a mobile home is generally not considered best practice. It's more susceptible to damage.

Better Alternatives



Slight Burial

Bury the conduit a few inches deep. Even a shallow burial provides a significant degree of protection from physical damage.

Support

Support the conduit above the ground using straps or other approved methods.

Rigid Metal Conduit (RMC)

If physical damage is a major concern, use RMC, which provides the highest level of protection.

Schedule 80 PVC: Schedule 80 PVC is also more resistant to physical damage than Schedule 40.In summary, while Table 300.5 appears* to allow conduit to lay on the ground, the requirements of 550.15(H)(1) and (2) for weather exposure and physical damage protection mean that in practice, simply laying conduit directly on the ground without additional protection is unlikely to be compliant. Consult with your local AHJ for their specific interpretation and approval. Flag for review