UL 2021-2006 pdf free download.Opening of All Ungrounded Conductors.
Carl Radcliffe gave a PowerPoint presentation to update the STP on the task group’s research. At the time of this presentation research was not complete. However, approximately 1/3 of the test data was available for review. Several research takeaways were discussed and are provided below. It was emphasized that these items are preliminary in nature and may be modified as additional data becomes available.
• There appears to be significant variance from one manufacturer to another within a given sample set
• Mandrel crushing appears to more severe than rod crushing – Results lower by approximately 25 percent
• SPT-2 appears to provide greater abrasion resistance than HPN
This PowerPoint presentation will be attached as Supporting Documentation to the CSDS Meeting Area.
Subsequent to the PowerPoint presentation a lengthy discussion on flex testing developed. Several STP members requested the addition of flex testing to the current research project. In response to this request, a flex test proposal will be developed, discussed, and finalized with working group membership. Due to the research timeline and additional sample requirements it is not anticipated that this testing will be added to the current research project. However, the possibility for a project addendum or part b will be discussed and considered.
In addition to the ongoing research testing, Carl Radcliffe also discussed the following recommendations made by the Joint Task Group:
Electrical Connections in Heaters: As noted in Table 2 of the task group report, heater power supply cords are de-rated unless the connection between the conductor and plug-blade is additionally secured by welding, brazing or soldering. Since its adoption, this requirement has been effective in reducing overheating in plugs that could lead to fire. The Joint Task Group recommends that the same requirement (mechanically secured and welded, brazed or soldered) be applied to the point of connection of the power supply cord to internal wiring/connectors in heaters. Draft proposed revisions to Table 16.2 of UL 1278 were discussed. Based on the discussion, it was determined that Carl Radcliffe and Mike Phy will work on revising the draft proposal, before it is made available to the STP for preliminary review and comment.
Instructions Supplied WIth Heaters: It was noted that the cord or plug damage instructions in UL 1278 differ in wording with respect to that in UL 1042 and UL 2021. The Joint Task Group recommends that common instructions be developed based on the current “Important Instructions” of UL 1278. Draft proposed revisions to the important Instructions” in UL 1042 and UL 2021 were discussed. Based on the discussion, the draft proposal will be modified before it is made available to the STP for preliminary review and comment.
Extension Cord or Relocatable Power Tap: The Joint Task Group recommends that UL 1278. UL 2021, and UL 1042 be revised to state that heaters shall never be used with an extension cord or relocatable power tap. This would strengthen the current marking and instruction requirements of the standards that advise the user to avoid the use of and extension cord.UL 2021 pdf download.