Appendix
A:
Mandatory
requirements for certification / validation of safety systems for presence
sensing device initiation of mechanical power presses
Purpose
The purpose of the certification/validation of safety systems for
presence sensing device initiation (PSDI) of mechanical power presses
is to ensure that the safety systems are designed, installed, and
maintained in accordance with all applicable requirements of 29 CFR
1910.217 (a) through (h) and this Appendix A.
General
The certification/validation process shall utilize an independent
third-party validation organization recognized by OSHA in accordance
with the requirements specified in Appendix
C of this section.
While the employer is responsible for assuring that the certification/validation
requirements In 1910.217(h)(11) are fulfilled, the design certification
of PSDI safety systems may be initiated by manufacturers, employers,
and/or their representatives. The term “manufacturers”
refers to the manufacturer of any of the components of the safety
system. An employer who assembles a PSDI safety system would be a
manufacturer as well as employer for purposes of this standard and
Appendix.
The certification/validation process includes two stages. For design
certification, in the first stage, the manufacturer (which can be
an employer) certifies that the PSDI safety system meets the requirements
of 29 CFR 1910.217 (a) through (h) and this Appendix A, based on appropriate
design criteria and tests. In the second stage. the OSHA-recognized
third-party validation organization validates that the PSDI safety
system meets the requirements of 29 CFR 1910.217 (a) through (h) and
this Appendix A and the manufacturer’s certification by reviewing
the manufacturer’s design and test data and performing any additional
reviews required by this standard or which it believes appropriate.
For installation certification/validation and annual recertification/revalidation,
in the first stage the employer certifies or recertifies that the
employer is installing or utilizing a PSDI safety system validated
as meeting the design requirements of 29 CFR 1910.217 (a) through
(h) and this Appendix A by an OSHA-recognized third-party validation
organization and that the installation, operation and maintenance
meet the requirements of 29 CFR 1910.217 (a) through (h) and this
Appendix A. In the second stage. the OSHA-recognized third-party validation
organization validates or revalidates that the PSDI safety system
installation meets the requirements of 29 CFR 1910.217 (a) through
(h) and this Appendix A and the employer’s certification, by
reviewing that the PSDI safety system has been certified; the employer’s
certification, designs and tests, if any; the installation, operation,
maintenance and training; and by performing any additional tests and
reviews which the validation organization believes is necessary.
Summary
The certification/validation of safety systems for PSDI shall consider
the press, controls, safeguards, operator, and environment as an integrated
system which shall comply with all of the requirements in 29 CFR 1910.217
(a) through (h) and this Appendix A. The certification/validation
process shall verify that the safety system complies with the OSHA
safety requirements as follows:
A. Design Certification/Validation
1. The major parts, components and subsystems used shall be defined
by part number or serial number, as appropriate, and by manufacturer
to establish the configuration of the system.
2. The identified parts, components and subsystems shall be certified
by the manufacturer to be able to withstand the functional and operational
environments of the PSDI safety system.
3. The total system design shall be certified by the manufacturer
as complying with all requirements in 29 CFR 1910.217 (a) through
(h) and this Appendix A.
4. The third-party validation organization shall validate the manufacturer’s
certification under paragraphs 2 and 3.
B. Installation Certification/Validation
1. The employer shall certify that the PSDI safety system has been
design certified and validated, that the installation meets the
operational and environmental requirements specified by the manufacturer,
that the installation drawings are accurate, and that the installation
meets the requirements of 29 CFR 1910.217 (a) through (h) and this
Appendix A. (The operational and installation requirements of the
PSDI safety system may vary for different applications.)
2. The third-party validation organization shall validate the employer’s
certifications that the PSDI safety system is design certified and
validated, that the installation meets the installation and environmental
requirements specified by the manufacturer, and that the installation
meets the requirements of 29 CFR 1910.217 (a) through (h) and this
Appendix A.
C. Recertification/Revalidation
1. The PSDI safety system shall remain under certification/validation
for the shorter of one year or until the system hardware is changed,
modified or refurbished, or operating conditions are changed (including
environmental, application or facility changes), or a failure of
a critical component has occurred.
2. Annually, or after a change specified in paragraph 1., the employer
shall inspect and recertify the installation as meeting the requirements
set forth under B., Installation Certification/Validation.
3. The third-party validation organization, annually or after a
change specified in paragraph 1., shall validate the employer’s
certification that the requirements of paragraph B., Installation
Certification/Validation have been met.
(NOTE: Such changes in operational conditions as die changes or
press relocations not involving disassembly or revision to the safety
system would not require recertification/revalidation.)
Certification/Validation
Requirements
A. General Design Certification/Validation Requirements
1. Certification/Validation Program Requirements. The manufacturer
shall certify and the OSHA-recognized third-party validation organization
shall validate that:
(a) The design of components, subsystems, software and assemblies
meets OSHA performance requirements and are ready for the intended
use; and
(b) The performance of combined subsystems meets OSHA’s
operational requirements.
2. Certification/Validation Program Level of Risk Evaluation Requirements.
The manufacturer shall evaluate and certify, and the OSHA-recognized
third-party validation organization shall validate, the design and
operation of the safety system by determining conformance with the
following:
a. The safety system shall have the ability to sustain a single
failure or a single operating error and not cause injury to personnel
from point of operation hazards. Acceptable design features shall
demonstrate, in the following order or precedence, that:
(1) No single failure points may cause injury; or
(2) Redundancy, and comparison and/or diagnostic checking, exist
for the critical items that may cause injury, and the electrical,
electronic, electromechanical and mechanical parts and components
are selected so that they can withstand operational and external
environments. The safety factor and/or derated percentage shall
be specifically noted and complied with.
b. The manufacturer shall design, evaluate, test and certify,
and the third-party validation organization shall evaluate and
validate, that the PSDI safety system meets appropriate requirements
in the following areas.
(1) Environmental Limits:
(a) Temperature
(b) Relative humidity
(c) Vibration
(d) Fluid compatibility with other materials
(2) Design Limits
(a) Power requirements
(b) Power transient tolerances
(c) Compatibility of materials used
(d) Material stress tolerances and limits
(e) Stability to long term power fluctuations
(f) Sensitivity to signal acquisition
(g) Repeatability of measured parameter without inadvertent
initiation of a press stroke
(h) Operational life of components in cycles, hours, or both
(i) Electromagnetic tolerance to:
(1) Specific operational wave lengths; and
(2) Externally generated wave lengths
(3) New Design Certification/Validation. Design certification/validation
for a new safety system, i.e., a new design or new integration
of specifically identified components and subsystems, would
entail a single certification/validation which would be
applicable to all identical safety systems. It would not
be necessary to repeat the tests on individual safety systems
of the same manufacture or design. Nor would it be necessary
to repeat these tests in the case of modifications where
determined by the manufacturer and validated by the third-party
validation organization to be equivalent by similarity analysis.
Minor modifications not affecting the safety of the system
may be made by the manufacturer without revalidation.
Substantial modifications would require testing as a new
safety system, as deemed necessary by the validation organization.
B. Additional Detailed Design Certification/Validation
Requirements
1. General. The manufacturer or the manufacturer’s representative
shall certify to and submit to an OSHA-recognized third-party validation
organization the documentation necessary to demonstrate that the
PSDI safety system design is in full compliance with the requirements
of 29 CFR 1910.217(a)-(h) and this Appendix A, as applicable, by
means of analysis, tests, or combination of both, establishing that
the following additional certification/validation requirements are
fulfilled.
2. Reaction Times. For the purpose of demonstrating compliance with
the reaction time required by 1910.217(h), the tests shall use the
following definitions and requirements:
a. “Reaction time” means the time, in seconds, it
takes the signal, required to activate/deactivate the system,
to travel through the system, measured from the time of signal
initiation to the time the function being measured is completed.
b. “Full stop” or “No movement of the slide
or ram” means when the crankshaft rotation has slowed to
two or less revolutions per minute, just before stopping completely.
c. “Function completion” means for, electrical, electromechanical
and electronic devices, when the circuit produces a change of
state in the output element of the device.
d. When the change of state is motion, the measurement shall be
made at the completion of the motion.
e. The generation of the test signal introduced into the system
for measuring reaction time shall be such that the Initiation
time can be established with an error of less than 0.5 percent
of the reaction time measured.
f. The instrument used to measure reaction time shall be calibrated
to be accurate to within 0.001 second.
3. Compliance with 1910.21 7(h)(2)(ii). For compliance with these
requirements, the average value of the stopping time, Ts, shall
be the arithmetic mean of at least 25 stops for each stop angle
initiation measured with the brake and/or clutch unused, 50 percent
worn, and 90 percent worn. The recommendations of the brake system
manufacturer shall be used to simulate or estimate the brake wear.
The manufacturer’s recommended minimum lining depth shall
be identified and documented, and an evaluation made that the minimum
depth will not be exceeded before the next (annual) recertification/revalidation.
A correlation of the brake and/or clutch degradation based on the
above tests and/or estimates shall be made and documented. The results
shall document the conditions under which the brake and/or clutch
will and will not comply with the requirement. Based upon this determination,
a scale shall be developed to indicate the allowable 10 percent
of the stopping time at the top of the stroke for slide or ram overtravel
due to brake wear. The scale shall be marked to indicate that brake
adjustment and/or replacement is required. The explanation and use
of the scale shall be documented.
The test specification and procedure shall be submitted to the validation
organization for review and validation prior to the test. The validation
organization representative shall witness at least one set of tests.
4. Compliance with 1910.217(h)(5)(iii) and (h)(9)(v). Each reaction
time required to calculate the Safety Distance, including the brake
monitor setting, shall be documented in separate reaction time tests.
These tests shall specify the acceptable tolerance band sufficient
to assure that tolerance build-up will not render the safety distances
unsafe.
a. Integrated test of the press fully equipped to operate in the
PSDI mode shall be conducted to establish the total system reaction
time.
b. Brakes which are the adjustable type shall be adjusted properly
before the test.
5. Compliance with 1910.21 7(h)(2)(iii).
a. Prior to conducting the brake system test required by paragraph
(h)(2)(ii), a visual check shall be made of the springs. The visual
check shall include a determination that the spring housing or
rod does not show damage sufficient to degrade the structural
integrity of the unit, and the spring does not show any tendency
to interleave.
b. Any detected broken or unserviceable springs shall be replaced
before the test is conducted. The test shall be considered successful
If the stopping time remains within that which is determined by
paragraph (h)(9)(v) for the safety distance setting. If the increase
in press stopping time exceeds the brake monitor setting limit
defined in paragraph (h)(5)(iii), the test shall be considered
unsuccessful, and the cause of the excessive stopping time shall
be investigated. It shall be ascertained that the springs have
not been broken and that they are functioning properly.
6. Compliance with 1910.21 7(h)(7).
a. Tests which are conducted by the manufacturers of electrical
components to establish stress, life, temperature and loading
limits must be tests which are in compliance with the provisions
of the National Electrical Code.
b. Electrical and/or electronic cards or boards assembled with
discreet components shall be considered a subsystem and shall
require separate testing that the subsystems do not degrade in
any of the following conditions:
(1) Ambient temperature variation from -20 deg. C to +50 deg.
C.
(2) Ambient relative humidity of 99 percent.
(3) Vibration of 45G for one millisecond per stroke when the
item is to be mounted on the press frame.
(4) Electromagnetic interference at the same wavelengths used
for the radiation sensing field, at the power line frequency
fundamental and harmonics, and also from outogenous radiation
due to system switching.
(5)
Electrical power supply variations of + or - 15 percent.
c. The manufacturer shall specify the test requirements and procedures
from existing consensus tests in compliance with the provisions
of the National Electrical Code.
d. Tests designed by the manufacturer shall be made available
upon request to the validation organization. The validation organization
representative shall witness at least one set of each of these
tests.
7. Compliance with 1910.21 7(h)(9)(iv).
a. The manufacturer shall design a test to demonstrate that the
prescribed minimum object sensitivity of the presence sensing
device is met.
b. The test specifications and procedures shall be made available
upon request to the validation organization.
8. Compliance with 1910.217(h)(9)(x).
a. The manufacturer shall design a test(s) to establish the hand
tool extension diameters allowed for variations in minimum object
sensitivity response.
b. The test(s) shall document the range of object diameter sizes
which will produce both single and double break conditions.
c. The test(s) specifications and procedures shall be made available
upon request to the validation organization.
9. Integrated Tests Certification/Validation
a. The manufacturer shall design a set of integrated tests to
demonstrate compliance with the following requirements:
Sections 1910.217(h)(6) (ii); (iii); (iv); (v); (vi); (vii); (viii);
(ix); (xi); (xii); (xiii); (xiv); (xv); and (xvii).
b. The integrated test specifications and procedures shall be
made available to the validation organization.
10. Analysis.
a. The manufacturer shall submit to the validation organization
the technical analysis such as Hazard Analysis, Failure Mode and
Effect Analysis, Stress Analysis, Component and Material Selection
Analysis, Fluid Compatibility, and/or other analyses which may
be necessary to demonstrate, compliance with the following requirements:
Sections 1910.217(h)(8) (i) and (ii); (h)(2)(ii) and (iii); (h)(3)(i)
(A) and (C), and (ii); (h)(5) (i), (ii) and (iii); (h)(6) (i),
(iii), (iv), (vi), (vii), (viii), (ix), (x), (xi), (xiii), (xiv),
(xv), (xvi), and (xvii); (h)(7) (i) and (ii); (h)(9) (iv), (v),
(viii), (ix) and (x); (h)(10) (i) and (ii).
11. Types of Tests Acceptable for Certification/Validation.
a. Test results obtained from development testing may be used
to certify/validate the design.
b. The test results shall provide the engineering data necessary
to establish confidence that the hardware and software will meet
specifications, the manufacturing process has adequate quality
control and the data acquired was used to establish processes,
procedures, and test levels supporting subsequent hardware design,
production, installation and maintenance.
12. Validation for Design Certification/Validation. If, after review
of all documentation, tests, analyses, manufacturer’s certifications,
and any additional tests which the third-party validation organization
believes are necessary, the third-party validation organization
determines that the PSDI safety system is in full compliance with
the applicable requirements of 29 CFR 1910.217(a) through (h) and
this Appendix A, it shall validate the manufacturer’s certification
that it so meets the stated requirements.
C. Installation Certification/Validation Requirements
1. The employer shall evaluate and test the PSDI system installation,
shall submit to the OSHA-recognized third-party validation organization
the necessary supporting documentation, and shall certify that the
requirements of 1910.217(a) through (h) and this Appendix A have
been met and that the installation is proper.
2. The OSHA-recognized third-party validation organization shall
conduct tests, and/or review and evaluate the employer’s installation
tests, documentation and representations. If it so determines, it
shall validate the employer’s certification that the PSDI
safety system is in full conformance with all requirements of 29
CFR 1910.217(a) through (h) and this Appendix A.
D. Recertification/Revalidation Requirements
1. A PSDI safety system which has received installation certification/validation
shall undergo recertification/revalidation the earlier of:
a. Each time the systems hardware is significantly changed, modified,
or refurbished;
b. Each time the operational conditions are significantly changed
(including environmental, application or facility changes, but
excluding such changes as die changes or press relocations not
involving revision to the safety system);
c. When a failure of a significant component has occurred or a
change has been made which may affect safety; or
d. When one year has elapsed since the installation certification/validation
or the last recertification/revalidation.
2. Conduct or recertification/revalidation. The employer shall evaluate
and test the PSDI safety system installation, shall submit to the
OSHA-recognized third-party validation organization the necessary
supporting documentation, and shall recertify that the requirements
of 1910.217(a) through (h) and this Appendix are being met. The
documentation shall include, but not be limited to, the following
items:
a. Demonstration of a thorough inspection of the entire press
and PSDI safety system to ascertain that the installation, components
and safeguarding have not been changed, modified or tampered with
since the installation certification/validation or last recertification/revalidation
was made.
b. Demonstrations that such adjustments as may be needed (such
as to the brake monitor setting) have been accomplished with proper
changes made in the records and on such notices as are located
on the press and safety system.
c. Demonstration that review has been made of the reports covering
the design certification/validation, the installation certification/validation,
and all recertification/revalidations, in order to detect any
degradation to an unsafe condition, and that necessary changes
have been made to restore the safety system to previous certification/validation
levels.
3. The OSHA-recognized third-party validation organization shall
conduct tests, and/or review and evaluate the employer’s installation,
tests, documentation and representations. If It so determines, It
shall revalidate the employer’s recertification that the PSDI
system is in full conformance with all requirements of 29 CFR 1910.217(a)
through (h) and this Appendix A.
[53 FR 8358, Mar. 14, 1988]
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