What type of bonding is necessary if the source and first disconnecting means are in separate enclosures?

When the source and the first disconnecting means are housed in separate enclosures, a supply-side bonding jumper is necessary to ensure that the grounding system is properly integrated. This requirement exists because a bonding jumper ensures an effective grounding path between the disconnecting means and the electrical supply. It prevents voltage differences that could arise between these separate enclosures, which may occur due to ground potential rise during a fault condition.

By installing a supply-side bonding jumper, the electrical system maintains bonding integrity and ensures that all equipment operates safely and effectively. This reflects a fundamental principle in grounding and bonding practices, which is to minimize the risk of shock and maintain system stability.