What is the primary duty of an Energy Management System (EMS) installed in a coach?

An Energy Management System (EMS) in a coach is primarily designed to monitor and manage the electrical power consumption within the vehicle. The function of switching off various components in a prearranged pattern when amperage draw exceeds the maximum allowable amount is essential for preventing overload conditions that could damage electrical systems or components.

When the amperage exceeds a certain threshold, the EMS acts to maintain optimal operating conditions by selectively shutting down non-essential appliances or devices. This is crucial in recreational vehicles where power availability can be limited, especially when relying on battery systems or generators. By managing the power load in this manner, the EMS helps ensure that critical systems remain operational while avoiding circuit breaker trips and potential electrical hazards.

The other options, while they mention aspects of RV management, do not capture the primary function of an EMS as effectively. The correct answer focuses directly on the system's role in managing amperage loads to protect the coach's electrical system, making it the best choice.