INTRINSICALLY SAFE SYSTEM ASSESSMENT USING THE ENTITY CONCEPT

Available format(s)

Hardcopy

Language(s)

English

Published date

01-01-1995

Publisher

International Society of Automation

1 Introduction
2 The intrinsic safety protection technique
3 Intrinsically safe systems
4 Intrinsically safe system control drawings
5 Entity concept
6 Entity parameters
7 Entity concept control drawings
8 Assessing the intrinsic safety of simple loops
9 Loop operation considerations
10 Special considerations for multi-channel associated
   apparatus loops
11 Assessing the intrinsic safety of complex loops
12 Intrinsically safe apparatus that adds energy to the
   loop
13 Considerations for intrinsically safe bus systems
14 Conclusion
15 References
Figures
1 - Example of a typical control drawing
2 - Control drawing for an intrinsically safe apparatus
     examined under the entity concept
3 - Control drawing for an associated apparatus examined
     under the entity concept
4 - Two-wire loop with neither conductor connected to
     ground using two single-channel associated apparatus
5 - Two-wire loop with neither conductor connected to
     ground using one dual-channel associated apparatus
6 - Control drawing for two-channel associated apparatus
     with Vt and lt parameters
7 - Complex loop with two intrinsically safe apparatus and
     three two-channel associated apparatus
8 - Control drawing for three two-channel associated
     apparatus with Vt and lt
9 - Control drawing for intrinsically safe apparatus with
     multiple circuits
10 - Control drawing for intrinsically safe apparatus
11 - Control drawing for hand-held communicator
12 - Typical intrinsically safe bus configuration

Gives information and examples for assessing intrinsic safety of a wide variety of control loops using the control drawings and the entity concept.

Committee	SP12
DocumentType	Standard
Pages	27
PublisherName	International Society of Automation
Status	Current

C22.1-15 PACKAGE	Consists of C22.1-15, Canadian electrical code, part I (23rd edition), safety standard for electrical installations; C22.1HB-15, Canadian electrical code handbook - an explanation of rules of the Canadian electrical code, part I and the 2015 Electrical quick reference
C22.1HB-18	Canadian Electrical Code Handbook - An Explanation of the Rules of the Canadian Electrical Code, Part I
CSA C22.4 No. 1 : 2009(R2018)	OBJECTIVE-BASED INDUSTRIAL ELECTRICAL CODE
CSA C22.4 PACKAGE : 2009	CONSISTS OF C22.4 NO. 1-09, OBJECTIVE-BASED INDUSTRIAL ELECTRICAL CODE AND C22.4 NO. 2-09, OBJECTIVE-BASED INDUSTRIAL ELECTRICAL CODE - SAFETY MANAGEMENT SYSTEM REQUIREMENTS
C22.1-18	Canadian Electrical Code, Part I (24th Edition), Safety Standard for Electrical Installations