Electrical Power Distribution
The prevalence of electrical devices for the diagnosis and treatment of patients has made electrical power distribution one of the more important systems in modern medical facilities
(see Chapter 109). The nature of the operating room environment demands a particularly
elaborate set of requirements (NEC, 2003). Electrically powered devices surround
the patient and perform a wide range of vital functions. Therefore, proper design and
maintenance of the electrical power system are essential, to ensure the safety of both the
patient and the clinician. As the need for a continuous power is essential throughout a hospital,
electrical systems must comprise at least two sources of power. The typical primary
power sources are public utility lines. To provide for the continuous supply of power to
the critical areas of the hospital, an alternate, or emergency, source of power is necessary.
In the event of an interruption, hospitals are required to have an in-house alternate source
of power, such as a generator.
The operating room is densely populated with electrically powered devices. Individual
surgical suites must be supplied with enough electrical wall outlets to accommodate the
equipment, and these outlets must be in locations that are conveniently accessible to the
clinician. Wall outlets in a health care facility deliver power to equipment using a threewire
configuration of hot, neutral, and ground wires. The ground wire protects patients
and staff from electrical hazards by providing a low resistance pathway to channel fault
or leakage currents away from an electrically powered device to ground. Some surgical
techniques and instrumentation bypass the patient’s body resistance, thus increasing the.