Current

The standard describes FMEA and Failure Mode, Effects and Criticality Analysis (FMECA), and gives guidance as to how they may be applied to achieve various objectives by providing the procedural steps necessary to perform an analysis; identifying appropriate terms, assumptions, criticality measures, failure modes; defining basic principles; and providing examples of necessary worksheets or other tabular forms. All the general qualitative considerations presented for FMEA will apply to FMECA, as latter is an extension of the other.

This International Standard describes fault tree analysis and provides guidance on its
application as follows:
definition of basic principles;
describing and explaining the associated mathematical modelling;
explaining the relationships of FTA to other reliability modelling techniques;

description of the steps involved in performing the FTA;
identification of appropriate assumptions, events and failure modes;
identification and description of commonly used symbols.

The standard is intended to be a basic functional safety standard applicable to all kinds of industry. It defines functional safety as: “part of the overall safety relating to the equipment under control (EUC) and the EUC control system which depends on the correct functioning of the E/E/PE safety-related systems, other technology safety-related systems and external risk reduction facilities.”

The standard provides fire prevention and protection requirements for safeguarding life and physical property for buildings or facilities that employ stationary fuel cell systems of all sizes. Criteria cover design, construction and installation requirements, including general equipment configuration, siting and interconnections, fuel supplies and storage arrangements, ventilation, exhaust and fire protection. Specific provisions for fuel cell power systems 50 kW or less are also included.

This standard covers performance requirements for emergency and standby power systems providing an alternate source of electrical power in buildings and facilities in the event that the normal electrical power source fails. Systems include power sources, transfer equipment, controls, supervisory equipment, and accessory equipment needed to supply electrical power to the selected circuits.

NFPA 55 facilitates protection from physiological, over-pressurization, explosive, and flammability hazards associated with compressed gases and cryogenic fluids. Criteria provide fundamental safeguards for the installation, storage, use, and handling of compressed gases and cryogenic fluids in portable and stationary cylinders, containers, and tanks in all occupancy types.

1 Scope
1.1 These requirements apply to controls that employ solid-state devices and are intended for specified safety-related protective functions.