Safety of machinery―Pressure-sensitive protective devices―Part 2:General principles for design and testing of pressure-sensitive edges and pressure-sensitive bars
GB/T 17454 consists of the following three parts, under the general title Safety of machinery — Pressure-sensitive protective devices:
——Part 1: General principles for design and testing of pressure-sensitive mats and pressure sensitive floors;
——Part 2: General principles for design and testing of pressure-sensitive edges and pressure-sensitive bars;
——Part 3: General principles for design and testing of pressure-sensitive bumpers, plates, wires and similar devices.
This part is Part 2 of GB/T 17454.
This standard is developed in accordance with the rules given in GB/T 1.1-2009.
This part replaces GB/T 17454.2-2008 Safety of machinery — Pressure-sensitive protective devices — Part 2: General principles for design and testing of pressure-sensitive edges and pressure-sensitive bars. In addition to editorial changes, the following main technical changes have been made with respect to GB/T 17454.2-2008:
——The requirements for performance level (PL) have been added to the control system (see 4.20 herein; 4.20 of 2008 Edition);
——The test of performance level (PL) have been added to the control system (see 7.17 herein; 7.17 of 2008 Edition).
This part, by means of translation, is identical to ISO 13856-2:2013 Safety of machinery — Pressure-sensitive protective devices — Part 2: General principles for design and testing of pressure-sensitive edges and pressure-sensitive bars.
The Chinese documents consistent and corresponding with the normative international documents in this part are as follows:
——GB/T 2423.3-2006 Environmental testing for electric and electronic products — Part 2: Testing method — Test Cab: Damp heat, steady state (IEC 60068-2-78:2001, IDT);
——GB/T 2423.5-1995 Environmental testing for electric and electronic products — Part 2: Test methods — Test Ea and guidance: Shock (IEC 60068-2-27:1987, IDT);
——GB/T 2423.10-2008 Environmental testing for electric and electronic products — Part 2: Tests methods — Test Fc: Vibration (sinusoidal) (IEC 60068-2-6:1995, IDT);
——GB/T 2423.22-2002 Environmental testing for electric and electronic products — Part 2: Test methods — Test N: Change of temperature (IEC 60068-2-14:2009, IDT);
——GB/T 3766-2015 Hydraulic fluid power — General rules and safety requirements for systems and their components (ISO 4413:2010, MOD);
——GB/T 4208-2008 Degrees of protection provided by enclosure (IP code) (IEC 60529:2001, IDT);
——GB/T 7932-2003 Pneumatic fluid power — General rules relating to systems (ISO 4414:1998, IDT);
——GB/T 14048.5-2008 Low-voltage switchgear and controlgear — Part 5-1: Control circuit devices and switching elements — Electromechanical control circuit devices (IEC 60947-5-1:2003, MOD);
——GB/T 16855.2-2015 Safety of machinery — Safety-related parts of control systems — Part 2: Validation (ISO 13849-2:2012, IDT);
——GB/T 17626.2-2006 Electromagnetic compatibility (EMC) — Testing and measurement techniques — Electrostatic discharge immunity test (IEC 61000-4-2:2001, IDT);
——GB/T 17626.3-2006 Electromagnetic compatibility — Testing and measurement techniques — Radiated radio-frequency electromagnetic field immunity test (IEC 61000-4-3:2002, IDT);
——GB/T 17626.4-2008 Electromagnetic compatibility — Testing and measurement techniques: Electric fast transient/burst immunity test (IEC 61000-4-4:2004, IDT);
——GB/T 17626.5-2008 Electromagnetic compatibility — Testing and measurement techniques: Surge immunity test (IEC 61000-4-5:2005, IDT);
——GB/T 17626.6-2008 Electromagnetic compatibility — Testing and measurement techniques — Immunity to conducted disturbances induced by radio-frequency fields (IEC 61000-4-6:2006, IDT);
——GB/T 17799.2-2003 Electromagnetic Compatibility — Generic Standard — Immunity for industrial environment (IEC 61000-6-2:1999, IDT).
This part was proposed by and is under the jurisdiction of the National Technical Committee on Machinery Safety of Standardization Administration of China (SAC/TC 208).
The previous edition of this part is as follows:
——GB/T 17454.2-2008.
Introduction
The structure of safety standards in the field of machinery is as follows:
——Type-A standards (basic safety standards) giving basic concepts, principles for design, and general aspects that can be applied to all machinery;
——Type-B standards (generic safety standards) dealing with one safety aspect or one type of safeguard that can be used across a wide range of machinery:
Type-B1 standards on particular safety aspects (e.g. safety distances, surface temperature, noise);
Type-B2 standards on safeguards (e.g. two-hand controls, interlocking devices, pressure-sensitive devices, guards).
——Type-C standards (machine safety standards) dealing with detailed safety requirements for a particular machine or group of machines.
This document is a type-B2 standard as stated in GB/T 15706.
This document is of relevance, in particular, for the following stakeholder groups representing the market players with regard to machinery safety:
——machine manufacturers;
——health and safety bodies.
Others can be affected by the level of machinery safety achieved with the means of the document by the above-mentioned stakeholder groups:
——machine user;
——machine owner;
——service providers;
——consumers (in case of machinery intended for use by consumers).
The above-mentioned stakeholder groups have been given the possibility to participate at the drafting process of this document.
In addition, this document is intended for standardization bodies elaborating type-C standards.
The requirements of this document can be supplemented or modified by a type-C standard.
For machines which are covered by the scope of a type-C standard and which have been designed and built according to the requirements of that standard, the requirements of that type-C standard take precedence.
The safeguarding of machinery (see GB/T 15076-2012, 3.21) can be achieved by many different means. These means include guards which prevent access to the hazard zone by means of a physical barrier (for example, interlocking guards according to GB/T 18831 or fixed guards according to GB/T 8196) and protective devices (for example, electro-sensitive protective equipment according to GB/T 19436.1 or pressure-sensitive protective devices according to this part).
Type-C standards makers and designers of machinery/installations should consider the best way to achieve the required level of safety taking into account the intended application and the results of the risk assessment (see GB/T 15076).
The required solution can also be to combine several of these different means. The machinery/installation supplier and the user examine together carefully the existing hazards and constraints before making their decision on the choice of safeguarding.
Pressure-sensitive edges and pressure-sensitive bars are safeguards of the mechanically-actuated trip device type. General requirements for these safeguards (as well as others) are given in GB/T 15706-2012, 6.3.1 and 6.3.2.
Pressure-sensitive edges and pressure-sensitive bars are used in a wide range of applications with different conditions of use relating, for example, to extremes of loading or electrical, physical and chemical environments. They are interfaced with machine controls to ensure that the machine reverts to a safe condition if the sensitive protective equipment is actuated.
This part is restricted to the design of pressure-sensitive edges and pressure-sensitive bars so that they can be used when the risk assessment carried out by the machine manufacturer and/or relevant type-C standard, when available, shows this to be appropriate.
Pressure-sensitive edges and pressure-sensitive bars can be fitted to a fixed or moving part of a machine or an obstacle to prevent trapping or crushing hazards from another part of a machine. Pressure-sensitive edges and pressure-sensitive bars are designed, selected, installed and/or interfaced with the control system of the machine so that the force/pressure applied to a person or parts of the body do not exceed certain limits.
Pressure-sensitive edges, pressure-sensitive bars, pressure-sensitive bumpers and similar devices have many similarities. Table 1 summarizes the differences which generally apply between the two types of pressure-sensitive protective devices covered by this part and pressure-sensitive bumpers (covered by GB/T 17454.3 and gives guidance for their application).
Table 1 Characteristic features of pressure-sensitive edges, pressure-sensitive bars and pressure-sensitive bumpers
Cross-section Pressure-sensitive edge Pressure-sensitive bar Pressure-sensitive bumper
Regular Regular Regular/irregular
Length/width ratio >1 Any ratio Any ratio
Effective sensitive surface Deforms locally Moves as a whole Deforms locally and/or moves as a whole
Body part(s) intended to be detected Finger Finger —
Hand Hand Hand
Arm Arm Arm
Leg Leg Leg
Head Head Head
Torso Torso Torso
Safety of machinery — Pressure-sensitive protective devices — Part 2: General principles for design and testing of pressure-sensitive edges and pressure-sensitive bars
1 Scope
This part of GB/T 17454 establishes general principles and specifies requirements for the design and testing of pressure-sensitive edges and pressure-sensitive bars used as safeguards and not as actuating devices for normal operation.
This part of GB/T 17454 is applicable to pressure-sensitive edges and pressure-sensitive bars, with or without an external reset facility, used to detect persons or body parts that can be exposed to hazards such as those caused by the moving parts of machines.
It is not applicable to
——determining the suitability of a pressure-sensitive edge or pressure-sensitive bar for a particular safeguarding application;
——selection of an appropriate performance level (PL) for safety-related parts of control systems (SRP/CSs) other than to give minimum values;
——dimensioning or configuring of the effective sensing area of pressure-sensitive edges or pressure-sensitive bars in relation to any particular application;
——stopping devices according to GB 5226.1 used only for normal operation, including emergency stopping of machinery.
Requirements for the information to be provided by the manufacturer are given to assist in the selection of a suitable pressure-sensitive edge or pressure-sensitive bar and its application.
Additional requirements can be necessary where pressure-sensitive edges or pressure-sensitive bars are used in locations accessible to elderly or disabled people or children.
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced documents (including any amendments) applies.
GB 5226.1-2008 Electrical safety of machinery — Electrical equipment of machines — Part 1: General requirements (IEC 602041-1:2005, IDT)
GB/T 7251.1-2013 Low-voltage switchgear and controlgear assemblies — Part 1: General rules (IEC 61439-1:2011, IDT)
GB/T 15706-2012 Safety of machinery — General principles for design — Risk assessment and risk reduction (ISO 12100:2010, IDT)
GB/T 16855.1-2008 Safety of machinery — Safety-related parts of control systems — Part 1: General principles for design (ISO 13849-1:2006, IDT)
GB/T 16935.1-2008 Insulation coordination for equipment within low-voltage systems — Part 1: Principles requirements and tests (IEC 60664-1:2007, IDT)
ISO 4413 Hydraulic fluid power — General rules and safety requirements for systems and their components
ISO 4414 Pneumatic fluid power — General rules and safety requirements for systems and their components
ISO 13849-2 Safety of machinery — Safety-related parts of control systems — Part 2: Validation
IEC 60068-2-6 Environmental testing — Part 2-6: Tests — Test Fc: Vibration (sinusoidal)
IEC 60068-2-14 Environmental testing — Part 2-14: Tests — Test N: Change of temperature
IEC 60068-2-27 Environmental testing — Part 2-27: Tests — Test Ea and guidance: Shock
IEC 60068-2-78 Environmental testing — Part 2-78: Tests — Test Cab: Damp heat, steady state
IEC 60529 Degrees of protection provided by enclosures (IP code)
IEC 60947-5-1:2003 Low-voltage switchgear and controlgear — Part 5-1: Control circuit devices and switching elements — Electromechanical control circuit devices
IEC 61000-4-2 Electro-magnetic compatibility (EMC) — Part 4-2: Testing and measuring techniques — Electrostatic discharge immunity test
IEC 61000-4-3 Electromagnetic compatibility (EMC) — Part 4-3: Testing and measurement techniques — Radiated, radio-frequency, electromagnetic field immunity test
IEC 61000-4-4 Electromagnetic compatibility (EMC) — Part 4-4: Testing and measurement techniques — Electrical fast transient/burst immunity test
IEC 61000-4-5 Electromagnetic compatibility (EMC) — Part 4-5: Testing and measurement techniques — Surge immunity test
IEC 61000-4-6 Electromagnetic compatibility (EMC) — Part 4-6: Testing and measurement techniques — Immunity to conducted disturbances, induced by radio-frequency fields
IEC 61000-6-2 Electro-magnetic compatibility (EMC) — Part 6-2: Generic standards — Immunity forindustrial environments
3 Terms and definitions
For the purposes of this document, the terms and definitions given in GB/T 15706 and GB/T 16855.1 and the following apply.
3.1
pressure-sensitive edge
sensitive protective equipment of the “mechanically activated trip” type comprising a sensor (3.3) or sensors and a control unit and one or more output signal switching devices (3.5) intended to detect contact with a person or body part of a person and where the effective sensing surface (3.9) is deformed locally to actuate the sensor(s)
Note 1: The sensor or sensors generate(s) a signal when pressure is applied to part of its surface. The control unit responds to the signal from the sensor and generates an output signal(s) to the control system of a machine.
Note 2: The length of the sensor(s) is greater than the width. The cross-section throughout the pressure-sensitive area is constant and its width is usually within the range from 8 mm to 80 mm.
Note 3: For the definition of sensitive protective equipment see GB/T 15706-2012, 3.28.5.
3.2
pressure-sensitive bar
sensitive protective equipment of the “mechanically activated trip” type comprising a sensor (3.3) or sensors and a control unit and one or more output signal switching devices (3.5) intended to detect contact with a person or body part of a person and where the effective sensing surface (3.9) moves as a whole to actuate the sensor(s)
Note 1: The sensor or sensors generate(s) a signal when pressure is applied to part of its surface. The control unit responds to the signal from the sensor and generates an output signal(s) to the control system of a machine.
Note 2: The length of the sensor(s) is greater than the width. The cross-section throughout the pressure-sensitive area is constant and its width is usually within the range from 8 mm to 80 mm.
Note 3: For the definition of sensitive protective equipment see GB/T 15706-2012, 3.28.5.
3.3
sensor
part of the pressure-sensitive edge (3.1) or pressure-sensitive bar (3.2) which generates a signal in response to sufficient pressure applied to part of its surface
Note: 3.3 to 3.5 define the functional components of a pressure-sensitive edge or pressure-sensitive bar. These functions can be integrated into a single assembly or can be contained in any number of separate assemblies (see Figure 1). For example, a simple pressure-sensitive edge or pressure-sensitive bar actuating a position switch can be considered to be the sensor, the control unit, and the output signal switching device.
3.4
control unit
part of the pressure-sensitive edge (3.1) or pressure-sensitive bar (3.2) which responds to the condition of the sensor (3.3) and generates output signals to the machine control system
Note: 3.3 to 3.5 define the functional components of a pressure-sensitive edge or pressure-sensitive bar. These functions can be integrated into a single assembly or can be contained in any number of separate assemblies (see Figure 1). For example, a simple pressure-sensitive edge or pressure-sensitive bar actuating a position switch can be considered to be the sensor, the control unit, and the output signal switching device.
3.5
output signal switching device
part of the control unit of a pressure-sensitive edge (3.1) or pressure-sensitive bar (3.2) which is connected to the machine control system and transmits output signals
Note: 3.3 to 3.5 define the functional components of a pressure-sensitive edge or pressure-sensitive bar. These functions can be integrated into a single assembly or can be contained in any number of separate assemblies (see Figure 1). For example, a simple pressure-sensitive edge or pressure-sensitive bar actuating a position switch can be considered to be the sensor, the control unit, and the output signal switching device.
Key:
1——pressure-sensitive edge or pressure-sensitive bar;
2——sensor(s);
3——control unit*;
4——output signal switching device(s)*;
5——part of the machine control system for pressure-sensitive edge or pressure-sensitive bar output signal processing;
a——actuating force;
b——sensor output signal;
c——ON state/OFF state signal;
d——manual reset signal**;
e——reset signal from machine control system (where appropriate);
f——monitoring signals (optional);
g——manual reset signal to machine control system***;
h——machine control system(s);
* Can be located within the machine control system or as part of the machine control system.
** Where appropriate, this may be used as an alternative to g.
*** Where appropriate, this may be used as an alternative to d.
Figure 1 Systematic sketch of pressure-sensitive edge or
pressure-sensitive bar as applied to machine
3.6
ON state
state in which the output circuit(s) of an output signal switching device (3.5) is complete and permits the flow of current or fluid
3.7
OFF state
state in which the output circuit(s) of an output signal switching device (3.5) is broken and interrupts the flow of current or fluid
3.8
actuating force
any force applied to the sensor (3.3) which causes an output signal switching device (3.5) to go to the OFF state (3.7)
3.9
effective sensing surface
part of the surface of the sensor (3.3) or a combination of sensors within the effective sensing angle (3.12) and the effective sensing length (3.10) where the application of an actuating force (3.8) creates an OFF state (3.7) in the output signal switching device (3.5)
Note: See, for example, Figures 2 and 3.
3.10
effective sensing length
length of the effective sensing surface (3.9)
3.11
reference axis
line in the direction of the length of the sensor (3.3), whose position in the cross-sectional view of the sensor is used to define the effective sensing surface (3.9)
Note: See Figures 2 and 3.
3.12
effective sensing angle
angle around the reference axis (3.11) which limits the effective sensing surface (3.9) along the effective sensing length (3.10)
Note: See Figures 2 and 3.
3.13
reference direction
direction of actuation, from a point on the effective sensing surface (3.9) towards the reference axis (3.11), which bisects the effective sensing angle (3.12) and is perpendicular to the reference axis
Note: See Figures 2 and 3.
3.14
dead surface
part of the surface area of the sensor (3.3) outside the effective sensing surface (3.9)
Note: See Figures 2 and 3.
3.15
pre-travel
distance travelled by an object moving in a direction perpendicular to the reference axis (3.11) and in the axis of the applied actuating force (3.8), measured from where this object touches the effective sensing surface (3.9) to where the output signal switching device(s) (3.5) changes to an OFF state (3.7) under specified conditions
Note: See Figure 4.
3.16
working travel
distance travelled by an object, moving in a direction perpendicular to the reference axis (3.11), from where this object touches the effective sensing surface (3.9), under specified conditions, to where a stated limit force is exerted on the object
Note: See Figure 4.
3.17
overtravel
difference between the working travel (3.16) and the pre-travel (3.15) when both are measured with the same object applied under the same conditions
Note: See Figure 4.
3.18
force-travel relationship
relationship between force applied perpendicular to the reference axis (3.11) and the distance travelled by a specified object perpendicular to the reference axis under specified conditions
Note: See Figure 4.
3.19
reset
function which permits an ON state (3.6) in an output signal switching device (3.5) provided that certain conditions are met
3.20
total travel
movement or deformation of the effective sensing surface (3.9) of a pressure-sensitive edge (3.1) or pressure-sensitive bar (3.2) which is measured in the direction of the actuating force (3.8) from the point of contact to the point at which no further significant deformation of the effective sensing surface occurs (e.g. at a force of 600 N)
3.21
start interlock
means which prevents the start of an automatic machine when power (e.g. the electrical supply) is switched on to the pressure-sensitive edge (3.1) or pressure-sensitive bar (3.2), or is interrupted and restored
3.22
operating speed
any speed at which an object is pressed against the sensor (3.3) and which causes the output signal switching device (3.5) to go to the OFF state (3.7)
4 Requirements for design and testing
4.1 Effective sensing surface
Note: For the purposes of this part, “normal operation” means compliance with the requirements of Clause 4, verified according to Clause 7.
The manufacturer of the pressure-sensitive protective device shall state the effective sensing surface by giving the dimensions X, Y, Z, the angles α and β and the effective sensing length L in accordance with Figures 2 and 3.
The effective sensing angle of pressure-sensitive protective devices with heights (see Figure 2) X + Z ≥ 40 mm shall be ≥ 90°.
The effective sensing angle of pressure-sensitive protective devices with heights X + Z < 40 mm shall be at least 40°.
If the effective sensing angle is less than 90°, a clear warning shall be given in the information for use (see Clause 6).
Foreword i
Introduction iv
1 Scope
2 Normative references
3 Terms and definitions
4 Requirements for design and testing
4.1 Effective sensing surface
4.2 Actuating force for testing
4.3 Pre-travel
4.4 Working travel
4.5 Overtravel
4.6 Force–travel relationships
4.7 Minimum operating speed
4.8 Number of operations
4.9 Sensor output
4.10 Response of output signal switching device to actuating force
4.11 Reset function
4.12 Environmental conditions
4.13 Power supply variations
4.14 Electrical equipment
4.15 Hydraulic equipment
4.16 Pneumatic equipment
4.17 Enclosure
4.18 Additional coverings for sensors
4.19 Access
4.20 Performance levels and categories for SRP/CS in accordance with GB/T 168
4.21 Adjustments
4.22 Sensor fixing and mechanical strength
4.23 Recovery after deformation
4.24 Connections
4.25 Sharp corners, sharp edges and rough surfaces
4.26 Mechanical features
4.27 Inhibition and blocking
5 Marking
6 Information for selection and use
6.1 General
6.2 Essential data for the selection of suitable pressure-sensitive edge or pressure-sensitive bar
6.3 Information for use
7 Verification of requirements
7.1 General
7.2 Test samples
7.3 Test pieces
7.4 Test No. 1 — Safety-related data for selection, installation, commissioning, operation and maintenance of suitable pressure-sensitive edges or pressure-sensitive bars
7.5 Test No. 2 — Mounting orientations of sensors
7.6 Test No. 3 — Actuating force
7.7 Test No. 4 — Force–travel relationship(s)
7.8 Test No. 5 — Number of operations
7.9 Test No. 6 — Output state of sensor and output signal switching device
7.10 Test No. 7 — Response of output signal switching device to actuating force, reset and state of power supply
7.11 Test No. 8 — Environmental conditions
7.12 Test No. 9 — Power supply variation
7.13 Test No. 10 — Electrical, hydraulic and pneumatic equipment
7.14 Test No. 11 — Enclosure
7.15 Test No. 12 — Additional coverings for sensors
7.16 Test No. 13 — Access
7.17 Test No. 14 — Performance Level (PL) according to GB/T 168
7.18 Test No. 15 — Adjustments
7.19 Test No. 16 — Sensor fixing and mechanical strength
7.20 Test No. 17 — Recovery after deformation
7.21 Test No. 18 — Connections
7.22 Test No. 19 — Sharp corners, sharp edges and rough surfaces
7.23 Test No. 20 — Mechanical features
7.24 Test No. 21 — Inhibition and blocking
7.25 Test No. 22 — Marking
7.26 Test No. 23 — Information for selection and use
Annex A (Normative) Timing diagrams for pressure-sensitive edges/bars with/without reset
Annex B (Informative) Operating speed, force and travel — Explanatory remarks and recommendations
Annex C (Informative) Device selection guidance for machinery manufacturer/user
Annex D (Informative) Design guidance
Annex E (Informative) Application guidance
Annex F (Informative) Guidance on commissioning and testing after installation
Annex G (Informative) General considerations for systems meeting GB/T 16855.1, category
Bibliography
