Under what condition may metal raceways be manipulated without limitations?

Metal raceways can be manipulated without limitations when joined without welding. This is significant because the National Electrical Code considers the mechanical and electrical integrity of the connections made in metal raceways. When raceways are joined mechanically, such as with screws or other non-welding methods, there is often more flexibility in how they can be bent or altered without compromising their performance or structural integrity.

Welding introduces heat which can change the properties of the metal and may create zones of weakness or stress. Non-welded joints maintain the characteristics of the original material and allow for adjustments as necessary without the potential risks associated with welding, such as deformation or stress fractures.

In contrast, conditions involving installation underground, using approved welding methods, or the absence of electrical conductors don’t apply the same level of flexibility. Underground installations have their own set of limitations regarding methods of manipulation due to environmental factors. Approved welding methods still involve heat and potential issues associated with altering metal properties. Finally, while not containing electrical conductors might reduce some risks, it doesn't inherently allow for unlimited manipulation of the raceways.

Understanding these nuances helps ensure compliance with safety standards and the integrity of electrical systems.