Facility Lighting Protection

DOE-HDBK-1092-2004

9.11.3 FACILITY LIGHTNING PROTECTION

Lightning protection is required for facilities which will house enclosed electrical/electronic

equipment while such equipment is involved with radioactive, explosive, and similarly hazardous

materials or for facilities that are considered valuable or house valuable contents.

9.11.4 SURGE PROTECTION

In addition to facility lightning protection, the effects of surges resulting from lightning strikes to

power distribution systems may be lessened by the use of lightning arrestors and suppressors

installed at strategic points in the supply system to the facility. An assessment is necessary,

addressing the consequences of lightning-induced surges, in order to determine the degree to

which protection should be provided.

For additional information see Section 9.6.1.

9.12 ENCLOSED POWER ELECTRONICS

Power electronics equipment is equipment that uses electronic components and subsystems to

control significant amounts of electrical energy. Examples of power electronics systems include:

1. Power supplies and modulators for laser systems;

2. Accelerators, magnets, x-ray systems, and other research equipment;

3. Radio and radar transmitters;

4. Variable speed motor drives; and

All applicable portions of this section should be addressed due to the hazards involved with this

type of equipment.

9.12.1 ENCLOSURES

Power electronics equipment should be constructed in all-metal enclosures for containment of

fire, high energy, and electromagnetic radiation hazards.

The enclosures should support the housed equipment, provide strength to brace conductors

against short circuit forces, and protect housed equipment against physical damage.

It is usually easier to provide barriers to protect the electronics enclosure from collision and

missile hazards rather than strengthening the enclosure itself.

9.12.2 COMPONENT CLEARANCES

Enclosures must provide adequate clearance from energized parts. The required clearances

depend on the shape of the conductor, the surface characteristics of the conductor and

enclosure, the voltage characteristics, environmental conditions, and creepage. The breakdown

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