Page 2 of 3 FirstFirst 123 LastLast
Results 11 to 20 of 22

Thread: Binding Head Screw Terminals

  1. #11
    Join Date
    Sep 2008
    Location
    UK
    Posts
    10,213
    Compression lugs anyone?
    Si hoc legere scis nimium eruditionis habes.

  2. #12
    Join Date
    Jun 2003
    Location
    Hawthorne, New York NEC: 2014
    Posts
    3,164
    Let me ask you this- you mention 1-5 ton range. I would think that 1-2 ton would be wired with 12-10ga conductors. But if you are saying that the requirements for the larger units require a wire size larger than the #10 the clamp plate can accommodate, then yes I agree that the manufacturer needs to make some changes.

    -Hal

  3. #13
    Join Date
    Jun 2017
    Location
    San Clemente
    Posts
    12
    MCA for a Lennox 5 ton unit is 29.6 amps with a MOC of 50 amps. Following NEC Article 440 this unit could operate on #10 wire with a 50 amp breaker however, proper wire sizing guidelines for distance and temperature could more than likely dictate a larger wire size. We typically find #8 wire for 4 & 5 ton condenser unit installations.

    A 4 ton unit is 24.2 & 40 respectively.

    At a minimum I think installation instructions need to address this with verbiage.

    Interesting thread on our HVAC Talk site. Time Builder introduced this site within this thread. He speaks highly of this organization.

    http://hvac-talk.com/vbb/showthread....c-units/page14

  4. #14
    Join Date
    Feb 2003
    Location
    Bremerton, Washington
    Posts
    7,637
    Since you posted this in the Proposal topic, we need to see some suggested language and what code section it would be in. Then we can comment.
    While this is more of a UL issue, perhaps a well worded proposal would get more attention from UL, et al
    Moderator-Washington State
    Ancora Imparo

  5. #15
    Join Date
    Jun 2017
    Location
    San Clemente
    Posts
    12
    Quote Originally Posted by tom baker View Post
    Since you posted this in the Proposal topic, we need to see some suggested language and what code section it would be in. Then we can comment.
    While this is more of a UL issue, perhaps a well worded proposal would get more attention from UL, et al
    Thanks for your clarity, yes this could be a UL issue. I think they [UL] could require that the part have verbiage of this limitation on the label. This still does not address how the installer handles connecting a larger size conductor than what's specified by the component manufacturer.

    If the code book were to address this, it could read "Binding Head Screw Terminals - The manufacturer shall state the maximum size conductor allowed with this connector. If connecting a larger size conductor, it shall be required to utilize a mechanical connector approved for this size conductor".

    This being such a common occurrence, it needs to be stated by code that it is ok to hook up a larger conductor than the "max" specified by the component manufacturer.

    john

  6. #16
    Join Date
    Feb 2003
    Location
    Bremerton, Washington
    Posts
    7,637
    Please provide a proposal so we can comment. You have until September to get it submitted to the NFPA as a first draft.
    Moderator-Washington State
    Ancora Imparo

  7. #17
    Join Date
    Dec 2007
    Location
    NE Nebraska
    Posts
    33,489
    Most terminals with the pressure plate like you showed that I have seen are usually rated to accept 8 AWG.

    I can't recall ever seeing a 5 ton unit that needed larger then 8 AWG, unless it had electric heating in it, but then you typically are not landing directly on a contactor either in those instances.

    You usually need a disconnecting means near the unit, if voltage drop is an issue run the larger conductor to the disconnecting means and a smaller conductor the short distance of the disconnect to the unit.

  8. #18
    Join Date
    Jun 2017
    Location
    San Clemente
    Posts
    12
    Quote Originally Posted by kwired View Post
    Most terminals with the pressure plate like you showed that I have seen are usually rated to accept 8 AWG.

    I can't recall ever seeing a 5 ton unit that needed larger then 8 AWG, unless it had electric heating in it, but then you typically are not landing directly on a contactor either in those instances.

    You usually need a disconnecting means near the unit, if voltage drop is an issue run the larger conductor to the disconnecting means and a smaller conductor the short distance of the disconnect to the unit.
    Thanks for your input. How did you know most are approved for #8? I looked up this component manufacturer product catalog surprised to read that #10 was max. No mention of stranded or solid so you have to assume they approved for both. Other than this one location for this data it is non existent.

  9. #19
    Join Date
    Dec 2007
    Location
    NE Nebraska
    Posts
    33,489
    Quote Originally Posted by Jgkopp View Post
    Thanks for your input. How did you know most are approved for #8? I looked up this component manufacturer product catalog surprised to read that #10 was max. No mention of stranded or solid so you have to assume they approved for both. Other than this one location for this data it is non existent.
    I don't know, but seems like most that I can recall would accept #8.

  10. #20
    Join Date
    Jun 2017
    Location
    San Clemente
    Posts
    12
    Your where I was at till I looked into this further and was surprised to learn about this #10 limitation. Number 8 fits too, but that makes this a connection that is not UL listed. This exposes a contractor to unintended additional liability. Then one has to wonder and question why the component manufacturer published this wire size as the limitation? They must have their reasons. Then I add a UL listed connector approved for the size wire I am connecting but technically this limitation is still in play.

    i could see this being addressed by UL. But if they don't, there has to be an approved way of connecting larger wire sizes to Binding Head Screw terminals.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •