What must service equipment in non-dwelling units be marked with in the field?

In the context of service equipment in non-dwelling units, marking with the maximum available fault current is crucial for safety and operational efficiency. This information is important because it helps electrical professionals assess the fault protection requirements and understand the potential for short-circuit currents within the system. Knowing the maximum available fault current aids in selecting the appropriate protective devices and ensures that systems are designed to handle fault conditions without leading to equipment damage or hazards such as fire or electrical shock.

When service equipment is marked with the maximum available fault current, it allows for better planning and coordination in the installation and maintenance processes. This signifying factor plays a significant role in ensuring that the overall system can operate safely under fault conditions.

The other options, while important in different contexts, do not specifically address the critical need for fault current information in service equipment marking for non-dwelling units. The service rating and maximum voltage are typically related to the operational limits of the equipment, while the equipment type identifies its specific function or use, neither of which substitute the fundamental necessity of indicating fault current capabilities.