An Urgent Bulletin from CSA Group

Transcription

1 Ref No: I Elevator Equipment No. 20 (Supersedes Elevator Equipment Certification Notice No. 1A, and Informs Elevator Equipment No 1B) Date: January 21, 2015 An Urgent Bulletin from CSA Group Existing Certification not affected Apply any time to have your products evaluated Announcing: Extension of the Certification Program For Escalator Braking Systems to Include Variable Torque Brakes and Update to the Requirements of ASME A /CSA B44-13, Safety Code for Elevators and Escalators See Attachment 1 for affected Class Numbers. Who is affected? Manufacturers of Escalator Braking Systems. What do you do? 1. This publication outlines certification revisions that do not affect your currently certified product designs. 2. Please contact CSA technical staff if you have questions or need information concerning this publication and how it applies to you. 3. If you would like to arrange for an evaluation of new products to the revisions, initiate a certification project by contacting our Client Services Centre at Please supply appropriate supporting documentation*. If testing is needed, we will inform you of the samples required. *which includes technical information, company name, address, factory locations and CSA file number or master contract number (if assigned), and any other relevant documentation. Approvals: Products may be submitted any time for CSA Certification to the requirements as specified in Attachments 2 and 3. Background and Rationale: The certification program for escalator braking systems was announced in Elevator Equipment Certification Notice No 1, dated March 1987, at the request of industry and with the advice of elevator regulatory authorities to demonstrate compliance of escalator brakes with CSA Standard B44-M85. The program was amended by Elevator Equipment Certification Notice No 1A, dated March 2, The program was extended in Certification Informs Elevator Equipment No 1B to include compliance with Canadian and US requirements in the harmonized standard ASME A / CSA B44-00, Safety Code for Elevators and Escalators. This Informs updates the program with the requirements of standard ASME A /B44-13 Safety Code for Elevators and Escalators and adds test requirements for variable torque brakes. Attachment 2 of this Informs specifies Clause numbers of the applicable requirements of ASME A /CSA B44-13 and Marking requirements. Attachment 3 details the information required for certification, construction and updated test procedures of Certification Program for fixed torque brakes, and adds the test procedures for variable torque brakes. For questions specific to your file or products contact your CSA Group technical staff associate. Go to and enter your Master Contract # and the class numbers associated with this Informs to view your certified products. For technical questions on this Informs Contact Anna Zemanek by phone , fax or anna.zemanek@csagroup.org Visit us at Click on "Contact Us" for the online phone listing of our Offices and Partners The Canadian Standards Association. All rights reserved. Page 1 of 12

2 ATTACHMENT 1 Affected Class Numbers Class No: , ELEVATOR EQUIPMENT - Escalator Braking Systems , ELEVATOR EQUIPMENT-Escalator Braking Systems - Certified to US Standards Circulated for information: , ELEVATOR EQUIPMENT - Enclosed Elevator and Escalator Electrical Equipment , ELEVATOR EQUIPMENT - Enclosed Elevator Electrical Equipment-Certified to US Standards ATTACHMENT 2 Certification Program For Escalator Braking Systems Certification of an escalator braking system shall be based on the following: 1. Applicable Requirements: Clauses , , , 8.3.1and of ASME A /CSA B44-13, Safety Code for Elevators and Escalators 2. Markings: The markings shall appear on a data plate readily visible on the machine brake and, when necessary, a duplicate date plate with the CSA Mark shall be placed adjacent to the machine brake. The markings shall consist of the following: Brake identification (Model, catalogue number, etc); Type of brake (Fixed torque, or Variable torque, as applicable); Range of brake torque that complies with clauses and in ASME A /CSA B44-13 (for Fixed torque brake); Minimum brake torque for a loaded escalator (for Variable torque brake); Minimum stopping distance for the unloaded escalator which complies with clauses and in ASME A /CSA B44-13 (for Variable torque brake); Method of measuring the torque, designated BREAKAWAY or DYNAMIC based on the method used when measuring the torque; Location where torque is to be measured, such as MOTOR SHAFT, MACHINE INPUT SHAFT, or MAIN DRIVE SHAFT ; Maximum stopping distance with rated load in the down direction, corresponding to the minimum distance between the comb and the step as required by Clause d(5) (a) and (b); CSA Mark with indicators ASME A /CSA B44-13 Clause 8.3.6, and US, or C and US, as applicable. Page 2 of 12

3 ATTACHMENT 3 This Attachment is provided to expedite the evaluation of the escalator braking system and to help ensure that our testing covers your product for the range of its intended use. I. REQUIRED INFORMATION: - Factory address(es) of escalator manufacturer; - Escalator speed(s) (e.g. 0.5m/s); - Design distance between the skirt switch and comb-plate (lower and upper landing) for each escalator type; -Maximum design load per step; -Minimum and maximum rise of escalator series; -Width(s) of escalator series; -Minimum and maximum slope of escalator series (30 deg is Standard); -The name of brake manufacturer (if different from escalator manufacturer), catalogue numbers or model designations, factory address, certification/listing details; -Brake Type(s) (i.e. mechanical operation): Disc, drum, band [spring(s)], permanent magnet., etc.; Recommended minimum time between consecutive brake applications (i.e. cooling time); II. REQUIRED CONSTRUCTION DETAILS : A set of drawings and descriptive data (specifications) shall be submitted detailing the following: A. The Escalator Drive Machine (i.e. Primary) Brake: 1. Type: Fixed torque brake or variable torque brake; 2. Assembly Drawing, Blow-up drawing plus black and white picture of the disassembled brake (or enlarged isometric view) containing bill of materials, parts description (material specifications) with emphasis on the critical elements; spring description, including: Number of turns, coil diameter, spring material diameter, material specification, heat treatment, spring rate, size, spring force versus coil force, etc.; 2. Full description (specification/composition) of the brake including all critical elements such as: brake friction materials and surfaces; Methods of fastening of the friction materials; Size of the braking material surface; drawing of the friction material with the brake arms; Notes: (a) Please detail alternate materials intended to be used (b) Results of in house endurance tests (if available). Endurance test results must include: dates, location, name and office address of independent third party witness, description of the instrumentation used and the set-up, number of cycles of operation, time between operations (cooling), type of brake used, loads, type of failure, amount of wear, type of adjustments, etc. 3. Brake maintenance manual indicating clearances, acceptable lining wear, inspection intervals, etc. Page 3 of 12

4 4. Detailed description of brake torque adjustment and measurement procedures (mechanical/electrical) [e.g., (a) location, (b) break away type or dynamic type, (c) adaptor piece (if any) required for torque wrench application] (d) Clockwise/counter-clockwise. Notes: (a) The location where the torque is to be measured shall be clearly stated. E.g. End of Motor Shaft, Machine Input Shaft etc; (b) It is important that the test set up be such that the brake torque can be accurately measured. (i.e. That sufficient clearance is provided for the adaptor and torque wrench to be applied square to the adjustment) (c) Indicate the back-up parameter (e.g. brake spring length). 5. Relationships between escalator rise and width, motor size, flywheel size, coil size, brake size for each escalator type including: Formulas covering sliding, rotating masses versus brake size (in English); Calculations covering all round rises (e.g. 2m, 3m, etc.) and widths to be Certified. Note: Please provide flywheel drawings and sizing table as necessary. 6. Sketch of Proposed Nameplate (including Safety Warnings); 7. Dimensions for each critical mechanical part (i.e.parts directly involved in braking, and operation or release of the brake, springs etc). (e.g. Brake pads, disc, flywheel); 8. Outline of the Principle of Operation - (Sketch or schematic); 9. Wiring schematic of brake with the safety circuits/control panel diagram related to brake.; 10. List of Electrical Components: e.g. electromagnetic release coil, controls, switches, hydraulic oil pump motor and power supply are provided on the brakes; Notes: Electrical components shall comply with the requirements of CSA Standard CSA B44.1/ASME-A17.5 Elevator and Escalator Electrical Equipment as applicable.. The list shall include the following details: Reference file numbers for Certified components, UL listing sheets and copies of UL reports for UL Recognized components will help to expedite the evaluation of the brake system, if available. Otherwise please provide the following: Drawing with Bill of Material (and Material Specifications). Description of the Insulation System, Insulation Class, Ratings, Markings, Electrical Spacing(s) 11. Brake coils shall comply with the temperature, under and over-voltage operation tests required by item 10 above for the maximum brake loads required by the application of the braking system. B. The Main Drive (i.e. Secondary)_Brake: Outline of the sequence of operation of the main drive shaft brake. Page 4 of 12

5 Documentation to confirm compliance with ASME A /B44-13, Clause Note: This is to confirm the construction requirement only. Provide adjustment and maintenance instructions. Table with brake sizes versus escalator type, rise and width. Note: CSA-International offers Letter of Attestation service to allow manufacturers to document compliance of these devices with the requirements. C. Drive Train: Description of the entire drive train including the brake system. D. Lower Landing Area: Description E. Skirt Switch And Emergency Stop Assembly: (Certification /Listing Details) F. The Escalator Controller: (Certification /Listing Details), G. Variable Torque Brake Control Card ( for variable torque brakes) H. Electric Motor: (Certification /Listing Details) I. Brake Coil: (Certification /Listing Details) III. TESTING: 1. Facility: It will be necessary for the submittor to have access to a testing facility (e.g., Test Tower) with equipment to conduct the tests required by Clauses & of B44/ASME A17.1. Alternatively, the tests could be conducted in the manufacturer s factory or on an escalator of the type and size required installed in a building, subway station, railway station, as per Clause In order to accept the manufacturer s test data, the test facility will have to be assessed in accordance with ISO and the appropriate laboratory qualification program as outlined in DQD 309, Qualification Programs Playbook To ensure compliance with the submitted construction data, examination of the brake may be conducted at the testing site. 2. Required Test Equipment: (1) Calibration of testing instruments and equipment is up to date, documented, and traceable to a national standard. In connection with the testing, the following information will be required: (For the client provided instrumentation). (1.1) A list of the measurement and test equipment to be including the following information: type, manufacturer, model, serial number, measurement tolerances (accuracies) calibration status (See item 2). (1.2) A description of how the acquired data is processed (e.g. filtering levels) Page 5 of 12

6 Note: Provide copies of instrumentation instruction manuals. (1.3) A sketch illustrating the testing instruments set-up. Note: The stopping distance shall be measured with an automated system. (e.g.., cam, proximity switch and ferrous scale) in order to reduce errors due to human reaction time. (2) Calibration Record of Each Measuring and Test Device: Note: Check calibration status of all instruments in advance of the test week. (2.1) Describe the system used to maintain calibration schedules (computerized recall). (2.2) How is the correct calibration status of measuring and test equipment identified? (Calibration sticker with date, number and recall date). (2.3) Are permanent calibration records maintained for each measuring and test device? (Provide a copy of all the calibration records). Check if the calibration date is valid at the time of the test. (2.4) What standard instruments and devices are used for calibration? (2.5) Measuring and testing equipment must be calibrated to applicable reference Standards, which, in turn, are certified as being traceable to internationally or nationally recognized standards. Describe how the standard instruments and devices are traced to national or international Standards (i.e., name of the company that performed the calibration). (3) Test instruments shall comply with Clause of ASME A /B (4) The instruments used for speed and acceleration measuring shall comply with the following: (a) (b) They shall be of the recording type. They shall provide data for the plotting of the brake performance curves showing time intervals, stopping distance, speed and (negative) acceleration of step during the escalator stopping The accuracy of the instruments shall be within the following tolerances: i. The devices shall record time in increments of not more than 1/100 ths second during the entire stop. ii. Time increments and total time shall be recorded with an error of less than +/- 1 percent. iii. The position of the step at each time interval shall be recorded with an error of less than +/- 1 percent. (c) (d) Time, travel, speed (negative) acceleration shall be determined by means of a device which will provide the accuracy specified above. They shall indicate the power off moment (start of braking). (Second channel on the speed chart recorder). The instrumentation set-up shall have as a data collector a digital tachometer (tacho generator) or a transducer with approx 10 pulses/mm step travel installed Page 6 of 12

7 on either the main shaft or the flat step at the lower landing. (An electronic counter shall also be considered acceptable). Note: Due to slippage, measurements on the hand-rail are not acceptable. (5) The torque wrench shall be of +/- 1 percent accuracy, i.e., Snap-On-Tools, dial type precision series with peak indicator or equal. Two directions dial. WARNING: DO NOT OVER TORQUE! (6) Weights: shall be identified by manufacturer, size; owner and owners identification mark (if applicable) and calibration status (See item 2.). 3. Samples: Usually, a given brake/motor/gear/flywheel/(chain)/sprocket/etc. combination is used by the manufacturer for a range of heights. The type test program is designed to simulate the braking system response on the maximum and minimum height and width of escalator for which the braking system is intended to be used and to verify that this response complies with the criteria indicated in the Safety Code for Elevators. The most economic method is to test as many representative escalators from a model line as possible during a single investigation. e.g. The Certification of an entire model line of escalators from 1.5m rise to 12m rise may consist of a typical model selection as follows: (a) One, approx 2m rise (the smaller the better), 600mm width (escalator). (Simulate between 1.5m to 3m rises). (b) One, approx 4.6m rise, 1000mm width (escalator). (Simulate between 3m to 5m rises). (c) One, approx 8m rise, 1000mm width (escalator). (Simulate between 5m to 8m rises). (d) One, approx 12m rise, 1000mm width double drive, double brake. (Simulate between 8m and 12m rises). The objective is to determine the range of brake adjustments (alternate brake settings), that comply with the load/no load stopping distance limits (i.e. braking envelope), the maximum deceleration and the maximum time duration of horizontal peak decelaration set by the ASME A /B44-13 Safety Code for Elevators and Escalators Clauses & for a specific series of escalators. This provides the field inspection and maintenance personnel with a basis for safe adjustment of the brakes for that series of escalators. 4. Supporting Documentation: For many designs there is a mathematical relationship between the stopping distance and the load, torque, voltage and gap and spring length or visible spindle length, or visible thread length, etc. Where such a relationships are documented (e.g. by formula, tables, graphs etc), the test will attempt to validate the relationship. (i.e. compare the theoretical brake envelope curve with the tests generated one). Supporting design test data can help to expedite the task of selecting the appropriate models for the required witnessed testing. Please provide test results of previously conducted tests, if available. Page 7 of 12

8 (E.g.: Prototype testing conducted by the manufacturer during the brake development process or at the request of inspection authorities and witnessed by CSA or other Recognized testing laboratories). A. Typical Test Procedure ( For Fixed Torque Brake) In order to save time, it is suggested that the manufacturer conduct preliminary automatic trigger instrumented tests by himself (i.e. cold runs) to resolve logistical problems before the actual test is witnessed by the CSA staff. Since the instrumentation is installed towards the upper landing the weights should be loaded from the lower landing. The motor shall be capable carrying the 100 percent running load in the up direction. Pulling the hand rail shall be permitted to supplement the starting torque of the motor. Verify escalator nominal speed with hand-held tachometer on step or side skirt. For safety, the maximum step load value shall not be exceeded during testing. A rubber mat or cardboard is recommended to be used between weight and step. Please provide sketch of the load distribution per each step for each test condition (e.g. running, static) of the load tests. (Suggestion: Use the upper 2/3 of the escalator steps or less to save time when loading and counting weights and to ensure that design load per step is not exceeded). See Attachment 8. In the steps below h 1 represents the highest of the simulated rises, h 2 the next highest rise etc. Test 1 (h 1 Rise,): - Adjust the brake torque to the maximum specified value with the escalator stopped and no load on the steps. Verify with the calibrated torque wrench. (Take at least three independent readings). - Measure the following stopping distances (i.e. Test 1 to Test 5) by operating the escalator in the downward direction, with the load indicated and initiating the emergency stop at a predetermined points. - Measure the stopping distances with a Running load (b 1 ): down running at 25 percent, 50 percent, 75 percent and 100 percent of running load. 1. Measure the average deceleration over total retardation time (shall be 0.91m/s 2 ). - Measure the time duration of peak horizontal deceleration over 0.91 m/s 2 (shall be to 0.125s). Test 2 (h 2 Rise): - Same brake torque as above. - Measure stopping distance: Unloaded - down running. - Measure the stopping distances: Running load (b 2 ) - down running at 25 percent, 50 percent, 75 percent and 100 percent of running load. 2. Measure the average deceleration over total retardation time (shall be less 0.91m/s 2 ). - Measure the time duration of peak horizontal deceleration over 0.91 m/s 2 (shall be 0.125s). Page 8 of 12

9 Test 3 (h 3 Rise): - Same brake torque as above. - Measure the stopping distance: Unloaded - down running. - Measure the stopping distances: Running load (b 2 ) - down running at 25 percent, 50 percent, 75 percent and 100 percent of running load. - In actual testing, 2, 3, 4 are combined. Points on the brake envelope curves for h 1, h 2 and h 3 are obtained by increasing the number of weights in a progressive series (e.g., 25 percent h 3, 25 percent h 2, etc). Covers the curve between Point A and Point B. - Measure the average deceleration over total retardation time (shall be 0.91m/s 2 ). - Measure the time duration of peak horizontal deceleration over 0.91 m/s 2 (shall be 0.125s). Test 4 (h 1 Rise): - Adjust the brake torque to the minimum specified value. - Verify with the torque wrench at the end of the test only when the escalator is unloaded. (step 8). - Measure the stopping distance with 100 percent running load. - If the results are acceptable per clauses b, a (2) and of ASME A /B , then proceed with Test 5 (step 6), otherwise readjust to obtain Point (C) and repeat the above tests. - Measure the average deceleration over total retardation time (shall be 0.91m/s 2 ). - Measure the time duration of peak horizontal deceleration over 0.91 m/s 2 (shall be 0.125s). Test 5 (h 1 Rise): - Immediately after Test 4 (step 5) load the escalator steps with the maximum static rated load and hold for 5 minutes, to verify the brake s ability to hold the stopped escalator at rest with the maximum static load as per Clause a (1). Notes: 1. The calibrated weights shall be located on the incline. 2. The weights shall be equally distributed on each step. 3. The weight on each step shall not exceed the maximum load rating for the step. 4. It is the submittor s responsibility to ensure that the weights are loaded onto the escalator in a safe method, anticipating the safety of all personnel should the brake fail to hold while the test is being set up. CSA-International staff shall be permitted to terminate the testing before completion should he/she consider that the method does not provide adequate personnel safety. 5. It is the submittor s responsibility to confirm that load testing is acceptable to the building s structural engineer. (Especially for testing at installation sites!). 6. Repeat the above Tests 1 to 4 with minimum brake torque settings (100 percent, 75 percent, 50 percent, 25 percent and unloaded). Page 9 of 12

10 Note: Covers the curve between Point C and Point D. (7.) Verify the maximum torque with the calibrated torque wrench. (Note: Three independent readings are required). (8.) Reset the brake to set up for operation Point E (optional). Note: Must be done for escalators in service after testing to ensure safe operation! (9.) Each point on the curve shall be tested twice in the down direction (two runs for 25 percent load, two 50 percent, etc.). The average value of the stopping distance shall be used for to determine the braking envelope curve (10.) (Optional but recommended) Tests shall be performed in the up direction with 0, 50 percent and 100 percent loading at minimum torque values. The roll back distance shall be determined. A typical roll back distance is 3 to 5 mm. Roll back distances of greater than 10 mm may be an indication of time delay within the brake operating circuits that should be investigated. (Preferred sequence of testing: Up, down, down). Comment: The above steps allow the manufacturer to eliminate the need for 100 percent running load tests with subsequent brake adjustments for each escalator installation. The points A and D set curves that determine the limits of adjustment for the admissible stopping distances for the defined escalator without exceeding the maximum deceleration value. Determination Of Braking Envelope ( Fixed Torque Brake) (i.e. curve limits) Figure A is provided as an example of how the brake envelope is determined: Step 1 Determine the no load, maximum torque stopping distance (i.e. Point A of the Group III values on the maximum torque-load curve) Note The lower limit is set by Fig 11 of Appendix I in ASME A /B44-1. (Criteria: Maximum Deceleration 0.91m/s 2 ) with the escalator unloaded and running down (See Figure B in this document). Examples: Speed = 0.5m/s mm Step 2 Determine the maximum load, minimum torque stopping distance (i.e. Point C of the Group I values on the minimum torque-load curve) Note: The upper limit 100 percent full running load down running is given by skirt switch to comb plate distance. B. Typical Test Procedure ( For Variable Torque Brake) 1. Select a test escalator for the brake test in accordance with Clauses and of ASME A /CSA B Record a minimum break-away torque value. 3. With the torque adjusted to the minimum break-away torque value: (a) Verify that the brake stops down running escalator with any load up to the brake rated load while maintaining the average deceleration rate not greater than 0.91 m/s 2 over the total retardation time. (b) Verify that the peak deceleration greater than 0.91 m/s 2 during stops does not occur for a period longer than 0.125s for an escalator running down with no-load to the brake rated load. Page 10 of 12

11 4. Verify that the stopping distance for an unloaded down-running escalator complies with the minimum stopping distance required in clauses , in ASME A /CSA B Measure the maximum stopping distance for an escalator with respect to full brake rated load in accordance with ASME A /CSA B44-13, Clause (d) (5). FIGURE A We are aiming to prepare (generate) such Curves (A) to (B) and (C) to (D) For each of the excalator samples tested Page 11 of 12

12 FIGURE B Fig. I-11 Stopping Distances Corresponding to a deceleration Rate of 0.91 m/s 2 [ (c)] Page 12 of 12