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Relay Switch, something else???

jwnc | Posted in Energy, Heating & Insulation on July 16, 2007 05:07am

What I want seems to make sense and is in principle simple, but after asking at 2 different electrical supply houses I am starting to wonder.

I have a dedicated circuit for outdoor lights that is controlled by an old fashioned mechanical clock switch. As such, even when it is off there is a trickle charge running through it. I would like to replace it with a relay switch so the line is truly dead when it is in the off position. Does anyone know of such an animal?

If you have gotten this far you may ask why?…As it is currently configured, I cannot run any motion detectors or compact fluorescent bulbs. There are something like 14 sockets out there. If I ran everyone with a 100w or 150w bulb I’d be burning up the grid. I’d like to be a bit more intelligent about this….

Thanks for your suggestions….

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Replies

  1. User avater
    MarkH | Jul 16, 2007 05:12am | #1

    huh?  I don't understand the question.

  2. User avater
    BillHartmann | Jul 16, 2007 05:27am | #2

    "As such, even when it is off there is a trickle charge running through it"

    How do you know what? What kind of test/measurement have you made?

    "If you have gotten this far you may ask why?...As it is currently configured, I cannot run any motion detectors or compact fluorescent bulbs."

    Why not? What happens?

    The mechanical clocks that I am familar with the out put is via a mechancial toggle switch and work just like a wall switch Either On or OFF and no trickle current through the LOADS.

    On one the line side it is still drawing a very small amount of current to run the clock. But none of that is through the load.

    .
    .
    A-holes. Hey every group has to have one. And I have been elected to be the one. I should make that my tagline.
    1. jwnc | Jul 16, 2007 05:36am | #3

      >"As such, even when it is off there is a trickle charge running >through it">How do you know what? What kind of test/measurement have you made?Voltmeter and ampmeter, can't remember the current off-hand....>"If you have gotten this far you may ask why?...As it is currently >configured, I cannot run any motion detectors or compact fluorescent >bulbs.">Why not? What happens?There are some other recent posts on this that I just saw...I get similar results. The clock does not keep time and some of the fixtures flicker. I have not tried the motion detector, but have been told it will not work by people that get paid to be electricians (unlike myself)...>The mechanical clocks that I am familar with the out put is via a >mechancial toggle switch and work just like a wall switch Either On >or OFF and no trickle current through the LOADS.>On one the line side it is still drawing a very small amount of >current to run the clock. But none of that is through the load.Hmm, maybe mine is not wired right. There is definitely current there though

      1. DanH | Jul 16, 2007 06:04am | #5

        How many wires are connected to the clock switch? There should be at least three -- a neutral, a hot, and the wire running to the load.
        So convenient a thing it is to be a reasonable Creature, since it enables one to find or make a Reason for everything one has a mind to do. --Benjamin Franklin

  3. DanH | Jul 16, 2007 06:02am | #4

    If the mechanical clock was properly connected then there would be no juice on the output terminals when the switch was off.

    So convenient a thing it is to be a reasonable Creature, since it enables one to find or make a Reason for everything one has a mind to do. --Benjamin Franklin
  4. caseyr | Jul 16, 2007 06:50am | #6

    The clock mechanism of a mechanical timer usually has a cam or arm that just trips a switch on or off at the set times, although it could have contact points that are actuated by a cam instead. The switch acts just like the normal light switch on your wall. With either the switch or the contact points, there should be no current flow through when in the open (or off) position.

  5. rasconc | Jul 16, 2007 07:01am | #7

    Where are you trying to put the motion detectors?  If a time clock has turned the lights off all is/should be off.  If properly wired a motion detector should work on a fixture controlled by clock if it is in the "on" time period.  You will see voltage and minimal amperage on the "line" side which is driving the clock as others have said.  Should not see any on "load" or output terminals in "off" mode.  Could have bad contacts in switch if you do.

    Fill out your profile and you might get some local or nearby help from here.

  6. DanH | Jul 16, 2007 12:48pm | #8

    Of course, this could be "phantom voltage" you're reading.

    http://en.wikipedia.org/wiki/Phantom_voltage

    So convenient a thing it is to be a reasonable Creature, since it enables one to find or make a Reason for everything one has a mind to do. --Benjamin Franklin
    1. jwnc | Jul 16, 2007 05:19pm | #9

      While I can not recall the current, the voltage on the line was 120v. 

      I will check the timer and see if I can determine how it is wired in.  There are some good suggestions in the string.

      Jeff

      1. User avater
        BillHartmann | Jul 16, 2007 08:08pm | #10

        Get the brand and model number of the timer. We can probably find the wiring schematic on the web..
        .
        A-holes. Hey every group has to have one. And I have been elected to be the one. I should make that my tagline.

  7. JohnD1 | Jul 16, 2007 08:58pm | #11

    http://www.intermatic.com/Default.asp?action=prod&pid=193&did=3&cid=43&sid=112

    This is Intermatic's Heavy-Duty Digital 7-Day Wall Switch Timer SS7C.  The timer is run by a AA cell, and the unit uses a microswitch to open and close the power.  NO line power is drawn by the timer itself.

    And, because it is a true switch, you can use it on any fluorescent fixture.

    1. jwnc | Jul 16, 2007 10:15pm | #12

      Ahhah! This is exactly what I had in mind.  I guess I did not have the words to describe it....

      -jw-

      1. DanH | Jul 16, 2007 11:10pm | #13

        But you don't need that unless the timer is downsteam of a wall switch or whatever, so it isn't constantly powered (and hence doesn't keep corect time). Any standard timer (even a lamp timer) is a three-terminal device, and should not cause power to be on the load wire when the timer switch is off.In fact, the electronic timer, if it uses an electronic switch internally, is more likely to leave a slight leakage voltage on the load wire than is a standard mechanical switch,=.
        So convenient a thing it is to be a reasonable Creature, since it enables one to find or make a Reason for everything one has a mind to do. --Benjamin Franklin

        1. JohnD1 | Jul 17, 2007 09:21pm | #14

          Uhh...the particular timer in question is battery operated.  It does not need any line power to run.

          And, the switch is a mechanical one (a microswitch, operated by a miniature motor driving a cam).  I took a dead one apart to see how it is made.  Really ingenious in its minimilism; quite cheap to make and yet quite reliable.

          1. DanH | Jul 17, 2007 10:33pm | #15

            OK, if it's got a mechanical switch then there should be no leakage. But I still don't see the need for the battery-powered timer, unless the timer iself is on a switched circuit. AC powered would be more robust in most conditions.
            So convenient a thing it is to be a reasonable Creature, since it enables one to find or make a Reason for everything one has a mind to do. --Benjamin Franklin

          2. JohnD1 | Jul 18, 2007 12:28am | #16

            When I first started installing the units, I wondered about that very thing.  But the more I thought about it, I think I have the answer.

            This is an integrated circuit with memory.  To run it off of 110v, it would have to have a power supply which is bulky.  I really doubt if it could be fitted into the space of a single gang fixture, as it is really tight now.

            The price would probably be more.

            Also, it would be sensitive to power glitches.

            Since price point is important to the retail consumers, who I strongly suspect are the chief purchasers of this item, I am guessing that they chose to use the battery as the solution to the problem.  And, the battery lasts a couple of years in most cases.

          3. DanH | Jul 18, 2007 12:32am | #17

            I can understand it for this kind of device, which is a 2-terminal device intended to replace a wall switch.
            So convenient a thing it is to be a reasonable Creature, since it enables one to find or make a Reason for everything one has a mind to do. --Benjamin Franklin

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