Practical Differences Between Rigid Galvanized Conduit (RGC) and Aluminum Rigid Metal Conduit (ARMC)Weight

ARMC is significantly lighter than RGC, making it easier to handle and install. However, it may not be as heavy-duty for some applications.

Corrosion Resistance

RGC has superior corrosion resistance compared to ARMC, especially in outdoor applications where it is exposed to moisture and extreme temperatures.

Thermal Expansion

Aluminum has a higher coefficient of thermal expansion than galvanized steel. This means that ARMC will expand and contract more than RGC, which could be a concern in applications with significant temperature fluctuations.

Strength

RGC is generally stronger than ARMC, but ARMC is still suitable for most electrical applications. However, it may not be suitable for heavy-duty applications or where mechanical protection is critical.

Cost

ARMC is typically more expensive than RGC, but the cost difference may vary depending on the specific project and local market conditions.

Other Considerations



Threaded Joints

RGC and ARMC have different threading requirements, so you may need to use compatible fittings.

Bending

ARMC bends more easily than RGC, which can be advantageous in some situations but may also be a disadvantage if precise bends are required.

Grounding

ARMC requires special grounding methods, such as grounding bushings or bonding straps, which may differ from those used with RGC.*

Fire Resistance

RMC has better fire resistance than ARMC, but both can meet the requirements of most building codes when properly installed.

Conclusion:

Ultimately, the choice between RGC and ARMC depends on the specific project requirements. If corrosion resistance and strength are critical, RGC is a better option. If weight reduction is a priority and thermal expansion is not a concern, ARMC can be a suitable alternative. It's important to consult with a qualified electrician and consider all factors carefully before making a substitution. Flag for review