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Thread: UL relays

  1. #1
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    UL relays

    I'm involved with a project with a number of relays mounted inside a steel box in a residence, and switching 240VAC (1 or 3∅)
    Do the relays need to be UL approved?

  2. #2
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    "Approval" of equipment is up to the AHJ.
    The AHJ may well take into account any listing by a NRTL such as UL in determining his approval.
    At my age, I'm accustomed to restaurants asking me to pay in advance, but now my bank has started sending me their calendar one month at a time.

  3. #3
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    170817-1711 EDT

    What are the relays for?

    I suggest you look at GE RR relays that are two coil pulsed mechanically latching relays with substantial current capability and low voltage drop.

    .

  4. #4
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    Quote Originally Posted by Open Neutral View Post
    I'm involved with a project with a number of relays mounted inside a steel box in a residence, and switching 240VAC (1 or 3∅)
    Do the relays need to be UL approved?
    3 phase in a residence?
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  5. #5
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    170817-2402 EDT

    Jraef:

    There are at least two residences in my neighborhood with 3 phase (wild leg). I could have it if I wanted it.

    But, I just go to the shop when I want to play with three phase where we have 240 with a wild leg, two transformers. DTE will only add a third transformer if the loading gets too high.

    We have a lot of wild leg service around here.

    .

  6. #6
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    Quote Originally Posted by Jraef View Post
    3 phase in a residence?
    Well, one of the single phase mansions err houses has 800 A service.....
    Wouldn't 3 have made better sense?

    And to respond to another aspect, the relays drop out on power failure; latching is the last thing we want.....
    We're using Struthers-Dunn 450 series.

    BTW, rural Califunny seems to have lots of open-Delta 3∅ for deep well pumps.

  7. #7
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    170819-1328 EDT

    Open Neutral:

    Why do you want your relays to drop out on power loss?

    An ordinary SPST wall switch does not drop to off on power loss, it just stays in the last state it was set to.

    ..

  8. #8
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    Quote Originally Posted by gar View Post
    170819-1328 EDT

    Open Neutral:

    Why do you want your relays to drop out on power loss?

    An ordinary SPST wall switch does not drop to off on power loss, it just stays in the last state it was set to.

    ..
    Because we stage the restart sequence. That's the whole point of the project.

  9. #9
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    UL approved

    Time to gingerly talk to your inspector.

    Where I live UL 508 is a common occurrence. It is ul parts AND a ul assembly which might be the got ja on your installation.
    The recommendations for the GE RR's is right on. They are rated for 20 amps and when properly sized pretty bullet proof.
    You can even get them with a set of wires that you can use for status. I did a lightning panel where each room had 3 RR-9's and the return was daisy chained together to use as the status light. No light time to go trouble shoot.

  10. #10
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    Quote Originally Posted by Belevolk View Post
    Time to gingerly talk to your inspector.

    Where I live UL 508 is a common occurrence. It is ul parts AND a ul assembly which might be the got ja on your installation.
    The recommendations for the GE RR's is right on. They are rated for 20 amps and when properly sized pretty bullet proof.
    You can even get them with a set of wires that you can use for status. I did a lightning panel where each room had 3 RR-9's and the return was daisy chained together to use as the status light. No light time to go trouble shoot.
    The relays are mounted and wired by the EC; we just provide 24vac to their coils.

    I looked up "GE 99" and they appear to be SPST latching relays. We need DPDT form B or C, not latching.
    We also need DIN Rail mounting.

    I'm spec'ing Struthers Dunn 450XBX50L-24VAC units for up to 50A, and we seek a 80-100A DPDT 24VAC contactor for those circuits. Thus far, no standouts.

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