| Return to index
(a) General. The requirements of section 4208.1 shall apply to all part revolution mechanical power presses used in the PSDI mode of operation.
(1) The applicable requirements of sections 4192 through 4211 shall apply to all presses used in the PSDI mode of operation, whether or not crossed referenced in this section. Such cross-referencing of specific requirements from sections 4192 through 4211 is intended only to enhance convenience and understanding in relating the new provisions to the existing standard, and is not to be construed as limiting the applicability of other provisions in sections 4192 through 4211.
(2) Full revolution mechanical power presses shall not be used in the PSDI mode of operation.
(3) Mechanical power presses with a configuration which would allow a person to enter, pass through, and become clear of the sensing field into the hazardous portion of the press shall not be used in the PSDI mode of operation.
(4) The PSDI mode of operation shall be used only for normal production operations. Die-setting and maintenance procedures shall comply with sections 4192 through 4211, and shall not be done in the PSDI mode.
(b) Brake and Clutch Requirements.
(1) Presses with flexible steel band brakes or with mechanical linkage actuated brakes or clutches shall not be used in the PSDI mode.
(2) Brake systems on presses used in the PSDI mode shall have sufficient torque so that each average value of stopping times (Ts) for stops initiated at approximately 45 degrees, 60 degrees, and 90 degrees, respectively, of crankshaft angular position, shall not be more than 125 percent of the average value of the stopping time at the top crankshaft position. Compliance with this requirement shall be determined by using the heaviest upper die to be used on the press, and operating at the fastest press speed if there is speed selection.
(3) Where brake engagement and clutch release is effected by spring action, such spring(s) shall operate in compression on a rod or within a hole or tube, and shall be of non-interleaving design.
(c) Pneumatic Systems.
(1) Air Valve and Air Pressure Supply/Control.
(A) The requirements of sections 4193j, 4193k, 4195, 4201, and 4193(i) apply to the pneumatic systems of machines used in the PSDI mode.
(B) The air supply for pneumatic clutch/brake control valves shall incorporate a filter, an air regulator, and, when necessary for proper operation, a lubricator.
(C) The air pressure supply for clutch/break valves on machines used in the PSDI mode shall be regulated to pressures less than or equal to the air pressure used when making the stop time measurements required by section 4208.1(b)(2).
(2) Air Counterbalance Systems.
(A) Where presses that have slide counterbalance systems are used in the PSDI mode, the counterbalance system shall also meet the requirements of section 4194.
(B) Counterbalances shall be adjusted in accordance with the press manufacturer's recommendations to assure correct counterbalancing of the slide attachment (upper die) weight for all operations performed on presses used in the PSDI mode. The adjustments shall be made before performing the stopping time measurements required by paragraphs (b)(2), (e)(3), and (i)(6) of this section.
(d) Flywheels and Bearings.
(1) Presses whose design incorporates flywheels running on journals on the crankshaft or back shaft, or bull gears running on journals mounted on the crankshaft, shall be inspected, lubricated, and maintained as provided in paragraph (j) of this section to reduce the possibility of unintended and uncontrolled press strokes caused bearing seizure.
(e) Brake Monitoring.
(1) Presses operated in the PSDI mode shall be equipped with a brake monitor that meets the requirements of sections 4193(o) and 4200(b). In addition, the brake monitor shall be adjusted during installation certification to prevent successive stroking of the press, if increases in stopping time cause an increase in the safety distance above that required by paragraph (i)(6) of this section.
(2) Once the PSDI safety system has been certified/validated, adjustment of the brake monitor shall not be done without prior approval of the validation organization for both the brake monitor adjustment and the corresponding adjustment in the safety distance. The validation organization shall in its installation validation, state that in what circumstances, if any, the employer has advance approval for adjustment, when prior oral approval is appropriate, and when prior approval must be in writing. The adjustment shall be done under the supervision of an authorized person whose qualifications include knowledge of safety distance requirements and experience with the brake system and its adjustment. When brake wear or other factors extend press stopping time beyond the limit permitted by the brake monitor; adjustment, repair or maintenance shall be performed on the brake or other press system element that extends the stopping time.
(3) The brake monitor setting shall allow an increase of no more than 10 percent of the longest stopping time for the press or 10 milliseconds, whichever is longer, measured at the top of the stroke.
(f) Cycle Control and Control Systems.
(1) The control system on presses used in the PSDI mode shall meet the applicable requirements of sections 4193, 4204, 4193(o), and 4193(m).
(2) The control system shall incorporate a means of dynamically monitoring for decoupling of the rotary position indicating mechanism drive from the crankshaft. This monitor shall stop slide motion and prevent successive press strokes if decoupling occurs, or if the monitor itself fails.
(3) The mode selection means of section 4193(c) shall have at least one position for selection of the PSDI mode. Where more than one interruption of the light sensing field is used in the initiation of the stoke, either the mode selection means must have one position for each function or a separate selection means shall be provided which becomes operable when the PSDI mode is selected. Selection of PSDI mode and the number of interruptions/withdrawals of the light sensing field required to initiate a press cycle shall be by means capable of supervision by the employer.
(4) A PSDI set-up/reset means shall be provided which requires an overt action by the operator, in addition to PSDI mode selection, before operation of the press by means of PSDI can be started.
(5) An indicator visible to the operator and readily seen by the employer shall be provided which shall clearly indicate that the system is set-up for cycling in the PSDI mode.
(6) The control system shall incorporate a timer to deactivate PSDI when the press does not stroke within the period of time set by the timer. The timer shall be manually adjustable, to a maximum time of 30 seconds. For any timer setting greater than 15 seconds, the adjustment shall be made by the use of a special tool available only to authorized persons. Following a deactivation of PSDI by the timer, the system shall make it necessary to reset the set-up/reset means in order to reactivate the PSDI mode.
(7) Reactivation of PSDI operation following deactivation of the PSDI mode from any other cause, such as activation of the red color stop control required by section 4193(b), interruption of the presence sensing field, opening of an interlock, or reselection of the number of sensing field interruptions/withdrawals required to cycle the press, shall require resetting of the set-up/reset means.
(8) The control system shall incorporate an automatic means to prevent initiation or continue operation in the PSDI mode, unless the press drive motor is energized in the forward direction of crankshaft rotation.
(9) The control design shall preclude any movement of the slide caused by operation of power on, power off, selector switches, or from checks for proper operations as required by section 4208.1(f)(13).
(10) All components and subsystems of the control system shall be designed to operate together to provide total control system compliance with the requirements of this section.
(11) Where there is more than one operator of a press used for PSDI, each operator shall be protected by a separate, independently functioning, presence sensing device. The control system shall require that each sensing field be interrupted, the selected number of times prior to initiating a stroke. Further, each operator shall be provided with a set-up/reset means that meets the requirements of section 4208.1(f), and which must be actuated to initiate operation of the press in the PSDI mode.
(12) The control system shall incorporate interlocks for supplemental guards, if used, which will prevent stroke initiation or will stop a stroke in progress if any supplemental guard fails or is deactivated.
(13) The control system shall perform checks for proper operation of all cycle control logic element switches and contacts at least once each cycle. Control elements shall be checked for correct status after power "on" and before the initial PSDI stroke.
(14) The control system shall have provisions for an "inch" operating means meeting the requirements of section 4193(d). Die-setting shall not be done in the PSDI mode. Production shall not be done in the "inch" mode.
(15) The control system shall permit only a single stroke per initiation command.
(16) Controls with internally stored programs (e.g., mechanical, electro-mechanical, or electronic) shall meet the requirements of section 4193(o), and shall default to a predetermined safe condition in the event of any single failure within the system. Programmable controllers which meet the requirements for controls with internally stored programs stated above, shall be permitted only if all logic elements affecting the safety system and point of operation safety are internally stored and protected in such a manner that they cannot be altered or manipulated by the user to an unsafe condition.
(g) Environmental Requirements. Control components shall be selected, constructed, and connected together in such a way as to withstand expected operational and environmental stresses, at least including those outlined in Appendix A. Such stresses shall not so affect the control system as to cause unsafe operation.
(h) Safety System.
(1) Mechanical power presses used in the PSDI mode shall be operated under the control of a safety system which, in addition to meeting the applicable requirements of sections 4193(o) and 4193(m) and other applicable provisions of this section, shall function such that a single failure or single operating error shall not cause injury to personnel from point of operation hazards.
(2) The safety system shall be designed, constructed, and arranged as an integral total system including all elements of the press; the controls; the safeguarding, any required supplemental safeguarding, and their interfaces with the operator; and that part of the environment which has effect on the protection against point of operation hazards.
(i) Safeguarding the Point of Operation.
(l) The point of operation of presses operated in the PSDI mode shall be safeguarded in accordance with the requirements of section 4206, except that the safety distance requirement of section 4208.1(i)(6) shall be used for PSDI operation.
(2) PSDI shall be implemented only by use of light curtain (photoelectric) presence sensing devices which meet the requirements of paragraph 4208(c)(3), unless the requirements of the following paragraph have been met.
(3) Alternatives to photo-electric light curtains may be used for PSDI when the employer can demonstrate, through tests and analysis by the employer or the manufacturer, that the alternative is as safe as the photo-electric light curtain, that the alternative meets the conditions of this section, and that the alternative has the same long term reliability as light curtains and can be integrated into the entire safety system as provided for in this section. Prior to use, both the employer and manufacturer must certify that these requirements and all the other applicable requirements of this section are met, and these certifications must be validated by a Division-recognized third-party validation organization to meet these additional requirements and all the other applicable requirements of sections 4192 through 4211 and Appendix A of this section. Three months prior to the operation of any alternative system, the employer must notify the Division of the name of the system to be installed, the manufacturer, and the Division-recognized third-party validation organization. Upon request, the employer must make available to the Division all tests and analyses for Division review.
(4) Individual sensing fields of presence sensing devices used to initiate strokes in the PSDI mode shall cover only one side of the press.
(5) Light curtains used for PSDI operation shall have minimum object sensitivity not to exceed one and one-fourth inches. Where light curtain object sensitivity is user-adjustable, either discretely or continuously, design features shall limit the minimum object sensitivity adjustment not exceed one and one-fourth inches. Blanking of the sensing field is not permitted.
(6) The safety distance (Ds) from the sensing field of the presence sensing device to the point of operation shall be greater than or equal to the distance determined by the formula:
Ds = Hs (Ts + Tp + Tr + 2Tm) + Dp
Ds = Minimum safety distance.
Hs = Hand speed constant of 63 inches per second.
Ts = Longest press stopping time, in seconds, computed by taking averages of multiple measurements at each of three positions (45 degrees, 60 degrees, and 90 degrees) of crankshaft angular position; the longest of the three averages is the stopping time to use. (Ts is defined as the sum of the kinetic energy dissipation time plus the pneumatic/magnetic/hydraulic reaction time of the clutch/brake operating mechanism(s).)
Tp = Longest presence sensing device response time, in seconds.
Tr = Longest response time, in seconds, of all interposing control elements between the presence sensing device and the clutch/brake operating mechanism(s).
Tm = Increase in the press stopping time at the top of the stroke, in seconds, allowed by the brake monitor for brake wear. The time increase allowed shall be limited to no more than 10 percent of the longest press stopping time measured at the top of the stroke, or 10 milliseconds, whichever is longer.
Dp = Penetration depth factor, required to provide for possible penetration through the presence sensing field by fingers or hand before detection occurs. The penetration depth factor shall be determined from Figure G-9 using the minimum object sensitivity size.
Figure G-9 - Penetration Depth Factor Calculation
(7) The presence sensing device location shall either be set at each tool change and set-up to provide at least the minimum safety distance, or fixed in location to provide a safety distance greater than or equal to the minimum safety distance for all tooling set-ups which are to be used on that press.
(8) Where presence sensing device location is adjustable, adjustment shall require the use of a special tool available only to authorized persons.
(9) Supplemental safeguarding shall be used to protect all areas of access to the point of operation which are unprotected by the PSDI presence sensing device. Such supplemental safeguarding shall consist of either additional light curtain (photo-electric) presence sensing devices or other types of guards which meet the requirements of sections 4207 and 4208.1.
(A) Presence sensing devices used as supplemental safeguarding shall not initiate a press stroke, and shall conform to the requirements of section 4208(c) and other applicable provisions of this section, except that the safety distance shall comply with section 4208.1(i)(6).
(B) Guards used as supplemental safeguarding shall conform to the design, construction and application requirements of section 4207, and shall be interlocked with the press control to prevent press PSDI operation if the guard fails, is removed, or is out of position.
(10) Barriers shall be fixed to the press frame or bolster to prevent personnel from passing completely through the sensing field, where safety distance or press configuration is such that personnel could pass through the PSDI presence sensing field and assume a position where the point of operation could be accessed without detection by the PSDI presence sensing device. As an alternative, supplemental presence sensing devices used only in the safeguard mode may be provided. If used, these devices shall be located so as to detect all operator locations and positions not detected by the PSDI sensing field, and shall prevent stroking or stop a stroke in process when any supplemental sensing field(s) are interrupted.
(11) Hand tools. Where tools are used for feeding, removal of scrap, lubrication of parts, or removal of parts that stick on the die in PSDI operations:
(A) The minimum diameter of the tool handle extension shall be greater than the minimum object sensitivity of the presence sensing device(s) used to initiate press strokes; or
(B) The length of the hand tool shall be such as to ensure that the operator's hand will be detected for any safety distance required by the press set-ups.
(j) Inspection and Maintenance.
(l) Any press equipped with presence sensing devices for use in PSDI, or for supplemental safeguarding on presses used in the PSDI mode, shall be equipped with a test rod of diameter specified by the presence sensing device manufacturer to represent the minimum object sensitivity of the sensing field. Instructions for use of the test rod shall be noted on a label affixed to the presence sensing device.
(2) The following checks shall be made at the beginning of each shift and whenever a die change is made:
(A) A check shall be performed using the test rod, according to the presence sensing device manufacturer's instructions, to determine that the presence sensing device, used for PSDI is operational.
(B) The safety distance shall be checked for compliance with section 4208.1(i)(6).
(C) A check shall be made to determine that all supplemental safeguarding is in place. Where presence sensing devices are used for supplemental safeguarding, a check for proper operation shall be performed using the test rod according to the presence sensing device manufacturer's instructions.
(D) A check shall be made to assure that the barriers and/or supplemental presence sensing devices, required by section 4208.1(i)(10), are operating properly.
(E) A system or visual check shall be made to verify correct counterbalance adjustment for die weight according to the press manufacturer's instructions, when a press is equipped with a slide counterbalance system.
(3) When presses used in the PSDI mode have flywheel or bullgear running on crankshaft mounted journals and bearings, or a flywheel mounted on back shaft journals and bearings, periodic inspections following the press manufacturer's recommendations shall be made to ascertain that bearings are in good working order, and that automatic lubrication systems for these bearings (if automatic lubrication is provided) are supplying proper lubrication. On presses with provision for manual lubrication of flywheel or bullgear bearings, lubrication shall be provided according to the press manufacturer's recommendations.
(4) Frequent inspections of clutch and brake mechanisms shall be performed to assure they are in proper operating condition. The press manufacturer's recommendations shall be followed.
(5) When any check of the press, including those performed in accordance with the requirements of section 4208.1(j)(2), (3), or (4) reveals a condition of noncompliance, improper adjustment, or failure, the press shall not be operated until the condition has been corrected by adjustment, replacement, or repair.
(6) It shall be the responsibility of the employer to ensure the competence of personnel caring for, inspecting, and maintaining power presses equipped for PSDI operation through initial and frequent training.
(k) Safety System Certification/Validation.
(l) Prior to the initial use of any mechanical press in the PSDI mode, two sets of certification and validation are required:
(A) The design of the safety system required for the use of a press in the PSDI mode shall be certified and validated prior to installation. The manufacturer's certification shall be validated by a Division-recognized third-party validation organization to meet all applicable requirements of sections 4192 through 4211 and Appendix A of section 4208.1.
(B) After a press has been equipped with a safety system whose design has been certified and validated in accordance with section 4208.1(k)(l), the safety system installation shall be certified by the employer and then shall be validated by a Division-recognized third-party validation organization to meet all applicable requirements of sections 4192 through 4211 and Appendix A of section 4208.1.
(2) At least annually thereafter, the safety system on a mechanical power press used in the PSDI mode shall be recertified by the employer and revalidated by a Division-recognized third-party validation organization to meet all applicable requirements of sections 4192 through 4211 and Appendix A of section4208.1. Any press whose safety system has not been recertified and revalidated within the preceding 12 months, shall be removed from service in the PSDI mode until the safety system is recertified and revalidated.
(3) A label shall be affixed to the press as part of each installation certification/validation and the most recent recertification/revalidation. The label shall indicate the press serial number, the minimum safety distance (Ds) required by section 4208.1(i)(6), the fulfillment of design certification/validation, the employer's signed certification, the identification of the Division-recognized third-party validation organization, its signed validation, and the date the certificate/validation and recertification/revalidation are issued.
(4) Records of the installation certification and validation and the most recent recertification and revalidation shall be maintained for each safety system equipped press by the employer, as long as the press is in use. The records shall include the manufacture and model number of each component and subsystem, the calculations of the safety distance as required by section 4208.1(i)(6), and the stopping time measurements required by section 4208.1(b)(2). The most recent records shall be made available to the Division upon request.
(5) The employer shall notify the Division-recognized third-party validation organization within five days whenever a component or a subsystem of the safety system fails or modifications are made which may affect the safety of the system. The failure of a critical component shall necessitate the removal of the safety system from service until it is recertified and revalidated, except recertification by the employer without revalidation is permitted when a non-critical component or subsystem is replaced by one of the same manufacture and design as the original, or determined by the third-party validation organization to be equivalent by similarity analysis, as set forth in Appendix A.
(6) The employer shall notify the Division-recognized third-party validation organization within five days of the occurrence of any point of operation injury while a press is used in the PSDI mode. This is in addition to the report of injury required by section 342; however, a copy of that report may be used for this purpose.
(l) Die Setting and Work setup.
(1) Die Setting on presses used in the PSDI mode shall be performed in accordance with sections 4197 and 4208.1.
(2) The PSDI mode shall not be used for die setting or set-up. An alternative manual cycle initiation and control means shall be supplied for use in die setting which meets the requirements of section 4193.
(3) Following a die change, the safety distance, the proper application of supplemental safeguarding, and the slide counterbalance adjustment (if the press is equipped with a counterbalance) shall be checked and maintained by authorized persons whose qualifications include knowledge of the safety distance, supplemental safeguarding requirements, and the manufacturer's specifications for counterbalance adjustment. Adjustment of the location of the PSDI presence sensing device shall require use of a special tool available only to the authorized persons.
(m) Operator Training.
(1) The operator training required by section 4203 shall be provided to the employee before the employee initially operates the press and as needed to maintain competence, but not less than annually thereafter. It shall include instructions relative to the following items for presses used in the PSDI:
(A) The manufacturer's recommended test procedures for checking operation of the presence sensing device. This shall include the use of the test rod required by section 4208.1(j)(l).
(B) The safety distance required.
(C) The operation, function and performance of the PSDI mode.
(D) The requirements for hand tools that may be used in the PSDI mode.
(E) The severe consequences that can result if he/she attempts to circumvent or by-pass any of the safeguard or operating functions of the PSDI system.
(2) The employer shall certify that employees have been trained by preparing a certification record which includes the identity of the person trained, the signature of the employer or the person who conducted the training, and the date the training was completed. The certification record shall be prepared at the completion of training and shall be maintained on file for the duration of the employee's employment. The certification record shall be made available upon request to the Division.
NOTE: Authority cited: Section 142.3, Labor Code. Reference: Section 142.3, Labor Code.
1. New section filed 4-20-90; operative 5-20-90 (Register 90, No. 20).
Go Back to Article 55 Table of Contents