Does service equipment, listed as suitable for use only as service equipment, always include a main bonding jumper?

Service equipment that is specifically listed as suitable for that purpose does not always include a main bonding jumper. The main bonding jumper is a crucial component that connects the grounded (neutral) conductor to the grounding electrode system. Its purpose is to ensure a low-resistance path to ground, which helps protect against electrical shocks and ensures the proper operation of overcurrent protective devices.

However, not all service equipment installations require a main bonding jumper as a factory-installed component. The requirement for a main bonding jumper can depend on a variety of factors, including the specific installation parameters, local code requirements, and the type of service equipment being utilized. For instance, some equipment may be designed to operate in a manner where a separate bonding jumper is not necessary because the grounding and bonding requirements have been adequately fulfilled through other means.

Therefore, when considering whether service equipment always includes a main bonding jumper, it's important to recognize that while many installations will require it for safety and compliance, there are scenarios where this may not be the case. This understanding is essential for ensuring that electrical systems are safely and effectively grounded and bonded according to appropriate standards and practices.