Power supplies often have protection from short circuit or overload that could damage the supply or cause a fire. Fuses and circuit breakers are two commonly used mechanisms for overload protection. Overload protection can be automatically enabled in response to high pressure or high temperature situations. Circuit breakers may be manually activated to interrupt the flow of electricity for the purpose of planned equipment maintenance or serviceable repair.
A vacuum breaker is an attachment commonly placed on a bibcock valve or toilet or urinalflushvalve, that prevents water from being siphoned backward into the public drinking water system. This prevents contamination should the public drinking water.