Electrical Equipment Criteria

DOE-STD-1066-99

10.6.3 Exit requirements for toxic and explosive environments should be as determined by

the AHJ. In addition, for explosives environments, exits should reflect the criteria

contained in the DOE Explosives Safety Manual (DOE M 440.1-1).

11. ELECTRICAL EQUIPMENT CRITERIA

11.1 In addition to the applicable requirements of the National Electrical Code, NFPA Standard 70,

transformer installations should comply with FM Data Sheet 5-4/14-8.

11.2 Where there is no "listed" equipment or materials of the type, special one-of-a-kind equipment

can be accepted if the AHJ can verify that all components meet high quality control standards.

Installation methods should be in accordance with the manufacturer's instructions, NFPA 70,

and other applicable requirements.

11.3 Where multi-tiered cable trays are installed in configurations that represent a significant fire

hazard (as determined by the FHA), they should be provided with fire protection/suppression

as determined by the AHJ.

11.4 Where required by the SAR, critical facilities should be served by dedicated, redundant

electric circuits. The two services should be separated by 4-hour fire-rated construction and

should be served from separate sources. In lieu of providing two separate services, a single

service supplied from a loop-type transmission or distribution system having sectionalizing

features may be provided when the reliability of the single service proves adequate when

considered in conformance with IEEE 399 and IEEE 493. Locations where fire can damage

both normal and emergency power should be protected by redundant fire protection systems.

12. PROTECTION CRITERIA FOR GENERAL PROCESS HAZARDS

12.1 Compressed gas cylinders that represent a significant fire hazard (as determined by the FHA)

should be isolated outside of facilities or housed in a special hazardous materials storage

room, exhausted gas cabinets, or similar types of containment.

12.2 When a process uses or produces combustible gases or vapors, the design should include

features such as inert gas purging, premixing the gas to a nonflammable mixture with inert

gas, or increasing the air flow within process confinement barriers to provide the dilution

required to maintain the concentration of gases or vapors below the lower limit for

flammability.

12.3 Lightning protection systems should comply with NFPA 780. Such systems should be

considered for buildings containing facilities for the use, processing, and storage of

radioactive, explosive and similarly hazardous materials; for buildings over 50 feet in height;

and for buildings containing valuable equipment. A risk assessment using the guide in

Appendix I of NFPA 780 should be made of these buildings to determine the risk of loss due

12.4 Process furnaces should be provided with a system for automatically shutting off the gas and

purging with inert gas in the event of power failure, loss of coolant water, loss of exhaust

ventilation, overtemperature, or detection of hydrogen in the vicinity of the furnace. (See FM

Data Sheets for additional guidance.)