Definition:
Electrical/Electronic/Programmable Electronic Systems (E/E/PE) is a broad term which refers to systems based on electrical or electronic components that may be programmable and are used to perform safety functions.
- E – electric – with a contact – an old-school pressure switch or basic relay
- E – electronic – with solid state circuity – a simple 4-20 mA pressure transmitter
- PE – programmable electronic – with software – a 4-20mA pressure transmitter +HART + diagnostics.
You cannot have a SIF without E/E/PEs.
Key Points:
- Term defined in IEC 61508 Part 4.
- Forms the basis for all safety instrumented functions and logic solvers.
See also: logic solver, logic module, instrument
Example:
A safety PLC connected to sensors and shutdown valves is an E/E/PE system. A mechanical pressure relief valve is not an E/E/PE
Cited Source:
- IEC 61508-4:2010.