c556c467_egal__Cleaning___Sterilization_Pre_Anesthesia_Checklist_2008_Rationale
[Step] Turn on anesthesia delivery system and confirm that AC power is available. [Rationale] 
Anesthesia delivery systems typically function with backup battery power if AC power fails. Unless the presence of AC power is confirmed, the first obvious sign of power failure can be a complete system shutdown when the batteries can no longer power the system. Many anesthesia delivery systems have visual indicators of the power source showing the presence of both AC and battery power. These indicators should be checked and connection of the power cord to a functional AC power source should be confirmed. Desflurane vaporizers require electrical power and recommendations for checking power to these vaporizers should also be followed.
Anesthesia Gas Machine- Machine checklist, Medicolegal, Cleaning & Sterilization
Rationale