1、AMERICAN NATIONAL STANDARDS ACCREDITED STANDARDS COMMITTEE ASC A92 AERIAL WORK PLATFORMS INTERPRETATIONS 1986 - 2013 400 Admiral Boulevard Kansas City, MO 64106 Phone: 816-595-4860, Fax: 816-472-7765 www.saiaonline.org 2013 Scaffold (2) the dielectric characteristics of oil and insulating hose; (3)
2、the ability to control the various functions to position the platform; (4) the resistance to bursting of critical components under pressure; and (5) the provision for the lower controls to override the upper controls. Question 1. It is my understanding that the meaning of the work line is hose, tubi
3、ng, or any other conduit for hydraulic fluid. In other words, this requirement for appropriate devices to be present within the hydraulic system to prevent unrestricted motion of the aerial device is intended to address the possible failure of specific hydraulic system components. An alternative int
4、erpretation, which I believe is incorrect, has been offered that suggests that the word line is intended to have a more comprehensive meaning, namely, that it means the entire hydraulic system. This interpretation would require that appropriate devices be installed to guard against the failure of an
5、y and all components that comprise the entire hydraulic system(4.8 System Protection. Where the operation of the aerial device is accomplished by hydraulic means, the system shall be equipped with appropriate devices to prevent motion of the platform(s) or material lifting device, or both in the eve
6、nt of hydraulic line failure.) 2013 Scaffold the outriggers extended but not used to level the lift? Does the second paragraph simply provide detailed instructions to be used in order to properly conduct the test? 3. Are the first and second paragraphs under 4.5.2 indicating two separate tests, i.e.
7、 one test on a 5 degree slope where the outriggers cannot be used and a second test on a 5 degree slope where the outriggers can be used? 4. Does paragraph 4.5.2, stability, require the vehicle to rotate 360 degrees at all angles of elevation, if capable, while on a 5 degree side slope? Specifically
8、 does the standard require the vehicle to be capable of lifting the test load towards the downward slope in the direction most likely to cause overturning? 5. If we restrict lifting to the high side of the vehicle, can we consider that to be within the definition of the specific configuration? 6. Ca
9、n we restrict the use of the vehicle to level ground only and would that be considered within the definition of the specific configuration? 7. Does this require the load to be lifted in the direction of the downward slope, the direction that is most likely to cause overturning? (4.5.2 Stability on S
10、lopes. Each aerial device, when mounted on a vehicle meeting the manufacturers minimum vehicle specifications without readily removable tools and material and used in a specific configuration, shall comprise a mobile unit capable of sustaining a static load one and on-third times its rated load capa
11、city in every position in which the load can be placed within the definition of the specific configuration when the vehicle is on a slope of 5 degrees downward in the direction most likely to cause overturning.The load shall be applied at one and one-third times the platform(s) rated load at the cen
12、ter of the platform, simultaneously with one and one-third times the lifting device rated load at the point of load application in its position of maximum overturning moment when so equipped. If having the outriggers extended to a firm footing is part of the 2013 Scaffold we quote aerial devices wit
13、h (emphasis added) a chassis insulating system We note that the drawing attached to the email communication was a facsimile of Figure 3A in the A92.2-1990 standard (and similarly in A92.2-2001) that is an optional test configuration for Category C aerial devices. We assume this illustration was for
14、purposed of explanation of what the questioner was calling the Up and Down boom. It should be noted that Figure 3 and Figure 3A either can be used for testing of the upper boom of the aerial device and Figure 4 is illustrative of the test positions for testing of units with the chassis insulating sy
15、stems that are in most cases a part of the lower boom. Question 1. I am concerned with the visual and/or audible safety warning devices which would tell an operator/user that one of the outriggers had been taken up and would preclude the hydraulic/electrical system from allowing the boom to be lifte
16、d into the air. I believe this type of system can either be accomplished through a hydraulic bypass, flashing lights or an audible sounding system device that would either preclude movement or warn of unstable condition. (6.3.1.2 Frequent Inspection and Test. Items such as, but not limited to, the f
17、ollowing shall be inspected for defects at intervals as defined in 6.3.1.1(2)(a) or as specifically indicated, including observation during operation, for any defects which might appear between regular inspections. These tests and inspections may be performed by the operator; any suspected items sha
18、ll be carefully examined and determination made by a qualified person as to whether they constitute a safety hazard. All unsafe items shall be corrected before further use. (3) Visual and audible safety devices for malfunction.) Response 1. Paragraph 6.3.1.2(3) which you referenced in a part of the
19、maintenance section. Its purpose is to remind maintenance forces that audible alarms and shutdown devices can and do fail, and as such, must be checked on an ongoing, scheduled basis. 2013 Scaffold will this satisfy the ANSI A92.2 requirements stated above? In other words, can the operator for the n
20、ext day begin to use the aerial device based on the prior days end of day inspection, assuming the aerial device was not used between those two times? Response 1. Section 8.2.3 of the ANSI A92.2-2001 concerning frequent inspection and test of aerial devices does not address the time of day an inspec
21、tion prior to use is made. The Standard is not interested in the time when the inspection is made, only in the intervals between inspections. The following is excerpted for that section: “once daily prior to use.” Since “prior” is not prefaced with the word “just”, no time constraint seems intended.
22、 Question 1. Section 4.8 of the ANSI/SIA A92.2 Standard covers System Protection. In this section there are requirements for system protection relating to hydraulic failure for hydraulic actuating systems and electrical failure for electrical actuating systems but I cannot locate any mention of the
23、requirements for system protection relating to mechanical actuating systems. Does the standard address this issue? If yes, where? Response 1. A92.2 does not contain equivalent requirements for mechanical actuating systems as it calls for in Section 4.8 for hydraulic or electrical actuating systems.
24、Section 4.8 was crafted out of concern for uncontrolled motion in the event of damage or failure of control lines, supply lines or circuits. Question 1. Upon inspection of a newly purchased boom truck at maximum basket capacity with the lower boom vertical and the upper boom at 90 degrees, we notice
25、d that the upper boom would drift down several inches over a period of an hour. 2013 Scaffold it is not a comprehensive design guide for the designers and manufacturers of such aerial devices. In reply to the specific questions we advise: As to Section 4.2 For ductile material, the calculated design
26、 stress shall not be more than 50% of yield or 20% of ultimate for brittle material and fiber reinforced plastic based on the following: -The rated load capacity of the platform and material carrying attachments (if applicable) 2013 Scaffold the interpretation committee of the A92.2 Subcommittee has
27、 crafted the following response: Response 1. “Section 8, Responsibilities of Owners in 8.2.2 (2) delineates that there are to be periodic inspections and tests that take place at one to twelve month intervals. In Section 8.2.4 (16) there are outlined requirements for dielectric testing of components
28、 of aerial devices that are 2013 Scaffold & Access Industry Association A92.2-24 used as insulating aerial devices, in particular that section says, “the electrical components and systems shall be tested in accordance with one emphasis added of the applicable methods and procedures outlined in Secti
29、on 5.4.3.”. Further in Section 5 .4.3 a test according to Table Two is outlined as a possibility. Table Two then allows a test using either AC or DC current. Accordingly we conclude that the use of either AC or DC tests outlined in Table Two meet the requirements of 8.2.4 (16) and that both tests ar
30、e not required.” A92.2-2009 Question 1. The lower controls of the insulating aerial devices shall be designed in such a manner that an operator is not placed in the electrical path between the aerial device and the ground. Does this mean that the controls cant be physically touched or operated from
31、the ground and thus can not be an umbilical cord lower controls? Can you give us an example? Response 1. The Standard Section 4.3.3 does not prohibit umbilical cord lower controls. However when provided they “shall be designed in such a manner that an operator is not placed in the electrical path be
32、tween the aerial device and the ground Question I am an Equipment Engineer with the California Department of Transportation. I am looking for an official interpretation of a section of ANSI A92.2 for aerial devices. My questions are regarding section 4.3.5 - Outrigger Controls, which states “The con
33、trols shall be located so that the operator can see the outrigger being operated.“ 1. Is looking beneath the vehicle to the outrigger on the opposite side of the unit considered a sufficient view? 2. Can mirrors be installed and used to indirectly “see the outrigger being operated“? 3. Can the requi
34、rement be satisfied by the use of a signalperson who can “see the outrigger being operated“ and signal to the operator at the controls? Response 1. A92.2 2009 States: (italics added for emphasis) 2013 Scaffold & Access Industry Association A92.2-25 4.3.5 Outrigger Controls. When the aerial device is
35、 equipped with outrigger controls, these controls shall be guarded to protect against unintentional operation, and shall return to neutral when released by the operator. The controls shall be located so that the operator can see the outrigger being operated. The language in this section requires tha
36、t the operator can see the outrigger being operated from the controls. Mounting the outrigger controls in a location that then requires an operator to look beneath a typical motor vehicle to the outrigger on the opposite side would not meet the intent of the standard. 1. Depending on how the vehicle
37、 and unit are designed, permanently installed mirrors or other remote vision devices may be aids through which the operator can see the outrigger being deployed. If the design uses such devices to meet the requirement, they would be subject to 6.6 Mechanical Tests and Inspection. 6.6.1 Operational T
38、ests. during Manufacture and 8.2.3 Frequent Inspection and Test. during Use. 2. As 4.3.5 requires the operator see the outrigger being deployed, and the Section is within 4. Design Requirements, 4.3 Controls., a signal person would not meet the intent of the standard. Question 1. Accept this as our
39、official request for interpretation on ANSI/SIA A92.2 2009 Section 4.3, sub-section 4.3.3 as it relates to the lower controls of an insulated aerial device and the placement of ground accessible controls. Our concern is that by providing ground accessible controls, there is still a possibility that
40、an operator could access them without standing on an isolation platform. Under that scenario, do the ground accessible controls need to be placed so that they cannot be accessed from the ground? In other words, placed high enough that an average height person could not reach-up and utilize the contr
41、ols. Response 1. With reference to your question regarding A92.2 2009 section 4.3.3 Lower Controls “as it relates to the lower controls of an insulated aerial device and the placement of ground accessible controls.” 2013 Scaffold & Access Industry Association A92.2-26 You asked do such controls “nee
42、d to be placed so that they cannot be accessed from the ground? In other words, placed high enough that an average height person could not reach-up and utilize the controls?” The Standard Section 4.3.3 does not require ground accessible controls. Readily accessible lower controls are required, and o
43、n insulated aerial devices they “shall be designed in such a manner that an operator is not placed in the electrical path between the aerial device and the ground”. The standard does not require that such controls be designed so that they are inaccessible from the ground. 2013 Scaffold & Access Industry Association A92.2-27
