Nfpa 79; Ansi B11 - Siemens Sinamics S110 Function Manual

Safety Integrated Functions
8.1 Standards and regulations
8.1.3.3

NFPA 79

NFPA 79 (Electrical Standard for Industrial Machinery) applies to the electrical equipment of
industrial machines with rated voltages of less than 600 V (a group of machines that operate
with one another in a coordinated fashion is also considered to be a machine).
NFPA 79 contains basic requirements for programmable electronics and communications
buses that specify that these devices must be listed if they are used for executing safety-
relevant functions. The devices must be listed. When these requirements are fulfilled,
electronic controllers and communications buses can also be used for EMERGENCY STOP
functions in stop categories 0 and 1 (see NFPA 79 9.2.5.4.1.4).
Like EN 60204-1, NFPA 79 no longer specifies that the electrical energy must be
disconnected by electromechanical means for EMERGENCY STOP functions.
The core requirements regarding programmable electronics and communication buses are:
system requirements (see NFPA 79 9.4.3)
1. Control systems that contain software-based controllers must:
2. The following suitable standards IEC 61508, IEC 62061, ISO 13849-1/-2, and IEC 61800-
Underwriter Laboratories (UL) has defined a special Category for "Programmable Safety
Controllers" for implementing this requirement (code NRGF). This category covers control
devices that contain software and are designed for use in safety-related functions.
A precise description of the category and a list of devices that fulfill this requirement can be
found on the Internet at the following address:
http://www.ul.com --> certifications directory --> UL Category code/ Guide information -->
search for category "NRGF"
TUV Rheinland of North America, Inc. is also an NRTL for these applications.
8.1.3.4

ANSI B11

ANSI B11 standards are joint standards that were developed by various committees, such as
the Association for Manufacturing Technology (AMT), and the Robotic Industries Association
(RIA).
The hazards of a machine are evaluated by means of a risk analysis/assessment. Risk
analysis is an important requirement in accordance with NFPA79, ANSI/RIA 15.06, ANSI
B11.TR-3 and SEMI S10 (semiconductors). The documented findings of a risk analysis can
be used to select a suitable safety system based on the safety class of the application in
question.
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– In the event of a single fault
(a) cause the system to switch to a safe shutdown mode
(b) prevent the system from restarting until the fault has been rectified
(c) prevent an unexpected restart
– Offer the same level of protection as hard-wired controllers
– Be implemented in accordance with a recognized standard that defines the
requirements for such systems.
5-2 are specified in a note.
Function Manual, 10/2008, 6SL3097-4AB10-0BP0
Drive functions