All of the following are excluded in the equipment breakdown basic policy EXCEPT?

The correct choice highlights that the explosion of steam boilers is not excluded in the equipment breakdown basic policy. This is significant because equipment breakdown coverage is designed to protect against various operational risks, including mechanical failures and specific accidental damages that can occur with equipment like steam boilers.

In many policies, damage resulting from an explosion of steam boilers is typically covered since such incidents can pose serious risks to property and business operations. Therefore, this coverage is crucial for businesses relying on steam boilers in their processes.

In contrast, the other options represent common exclusions in basic equipment breakdown policies. For instance, ordinance or law coverage pertains to the need to comply with building codes or regulations following a loss, which generally isn't included because it's seen as a separate risk. Similarly, business interruption is often excluded as it deals with lost income rather than the physical damage to equipment, while loss of power, lights, heat, steam, or refrigeration signifies operational issues that come from external factors rather than breakdowns of equipment itself. Thus, these exclusions reflect the specific focus of the basic policy on the actual breakdown and damage of equipment rather than ancillary effects or compliance issues.