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120 VAC coils — Parallax Forums

120 VAC coils

ArchiverArchiver Posts: 46,084
edited 2002-05-08 20:27 in General Discussion
So I guess this means you are NOT interested in any kind of bet that
say's a 24 VAC coil WILL NOT function longer that 24 hours on 24 VDC and
that in fact it will burn up from over current and over load.. Is that
correct, Mr. Higgins? Any other opinions on this matter? I know that
AC coils are not meant to work on DC, but that is not the question.
Question is will they or not?? Come on be brave let's hear about your
technical expertise. Any real opinions or just a bunch of wimps?

Leroy

I might be willing to make a small wager on whether an AC valve,
solenoid, or other type of coil could be run on an equivalent value of
DC, if there are any takers, I could use some extra money. :-))))

Leroy, I've seen 120 VAC coils burned up by 24 VDC. It all depends on
the DC resistance of the coil. I'm sure you can find a solenoid that
works fine if you search hard enough, but in general, without knowing
the
specifications of the solenoid beforehand, recommending use of DC to
power an AC solenoid, voltage remaining the same, is a very bad idea.
As to any bet, Leroy, just give it a few hours to a day and maybe some
of the other guys who have been there will straighten you out - and it
won't cost you a dime.

Comments

  • ArchiverArchiver Posts: 46,084
    edited 2002-05-07 02:31
    At 08:54 PM 5/6/02 -0400, Leroy Hall wrote:
    >So I guess this means you are NOT interested in any kind of bet that
    >say's a 24 VAC coil WILL NOT function longer that 24 hours on 24 VDC and
    >that in fact it will burn up from over current and over load.. Is that
    >correct, Mr. Higgins? Any other opinions on this matter? I know that
    >AC coils are not meant to work on DC, but that is not the question.
    >Question is will they or not?? Come on be brave let's hear about your
    >technical expertise. Any real opinions or just a bunch of wimps?

    If I may jump in here: the 24 Vac solenoids I usually use here at Trinity
    Electronics will, without question, eventually disappear in a cloud of
    smoke if left powered continuously at 24 Vdc.

    For example, one solenoid I use in my desoldering stations has 2 ratings on
    the coil: 120 Vac 60 Hz *and* 32 Vdc. I run them at 32 Vdc.

    We control a lot of Asco solenoids with our oven control systems and I
    spent many hours abusing the solenoids to see how they react to various
    over voltage and under voltage conditions. They don't smell nice if you
    hit them with 24 Vdc and leave them for a while.

    I'm sure there must be solenoids out there that will work with the same AC
    or DC voltage but not the ones I use.

    dwayne


    Dwayne Reid <dwayner@p...>
    Trinity Electronics Systems Ltd Edmonton, AB, CANADA
    (780) 489-3199 voice (780) 487-6397 fax

    Celebrating 18 years of Engineering Innovation (1984 - 2002)
    .-. .-. .-. .-. .-. .-. .-. .-. .-. .-
    `-' `-' `-' `-' `-' `-' `-' `-' `-'
    Do NOT send unsolicited commercial email to this email address.
    This message neither grants consent to receive unsolicited
    commercial email nor is intended to solicit commercial email.
  • ArchiverArchiver Posts: 46,084
    edited 2002-05-07 03:08
    Dear Dwayne,

    The physic of this means that 24VDC DOES NOT EQUAL 24 volts RMS. All
    the text books I have read seem to make this analogy. Maybe they are
    wrong. Thanks for your input..

    Leroy


    Reid wrote:
    >
    > At 08:54 PM 5/6/02 -0400, Leroy Hall wrote:
    > >So I guess this means you are NOT interested in any kind of bet that
    > >say's a 24 VAC coil WILL NOT function longer that 24 hours on 24 VDC and
    > >that in fact it will burn up from over current and over load.. Is that
    > >correct, Mr. Higgins? Any other opinions on this matter? I know that
    > >AC coils are not meant to work on DC, but that is not the question.
    > >Question is will they or not?? Come on be brave let's hear about your
    > >technical expertise. Any real opinions or just a bunch of wimps?
    >
    > If I may jump in here: the 24 Vac solenoids I usually use here at Trinity
    > Electronics will, without question, eventually disappear in a cloud of
    > smoke if left powered continuously at 24 Vdc.
    >
    > For example, one solenoid I use in my desoldering stations has 2 ratings on
    > the coil: 120 Vac 60 Hz *and* 32 Vdc. I run them at 32 Vdc.
    >
    > We control a lot of Asco solenoids with our oven control systems and I
    > spent many hours abusing the solenoids to see how they react to various
    > over voltage and under voltage conditions. They don't smell nice if you
    > hit them with 24 Vdc and leave them for a while.
    >
    > I'm sure there must be solenoids out there that will work with the same AC
    > or DC voltage but not the ones I use.
    >
    > dwayne
    >
    > Dwayne Reid <dwayner@p...>
    > Trinity Electronics Systems Ltd Edmonton, AB, CANADA
    > (780) 489-3199 voice (780) 487-6397 fax
    >
    > Celebrating 18 years of Engineering Innovation (1984 - 2002)
    > .-. .-. .-. .-. .-. .-. .-. .-. .-. .-
    > `-' `-' `-' `-' `-' `-' `-' `-' `-'
    > Do NOT send unsolicited commercial email to this email address.
    > This message neither grants consent to receive unsolicited
    > commercial email nor is intended to solicit commercial email.
    >
    > To UNSUBSCRIBE, just send mail to:
    > basicstamps-unsubscribe@yahoogroups.com
    > from the same email address that you subscribed. Text in the Subject and Body
    of the message will be ignored.
    >
    >
    > Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
  • ArchiverArchiver Posts: 46,084
    edited 2002-05-07 03:24
    At 20:54 05/06/02, Leroy Hall wrote:

    >>>I might be willing to make a small wager on whether an AC valve,
    >>>solenoid, or other type of coil could be run on an equivalent value of
    >>>DC, if there are any takers, I could use some extra money. :-))))

    >>Leroy, I've seen 120 VAC coils burned up by 24 VDC. It all depends on
    >>the DC resistance of the coil. I'm sure you can find a solenoid that
    >>works fine if you search hard enough, but in general, without knowing
    >>the
    >>specifications of the solenoid beforehand, recommending use of DC to
    >>power an AC solenoid, voltage remaining the same, is a very bad idea.
    >>As to any bet, Leroy, just give it a few hours to a day and maybe some
    >>of the other guys who have been there will straighten you out - and it
    >>won't cost you a dime.

    >So I guess this means you are NOT interested in any kind of bet that
    >say's a 24 VAC coil WILL NOT function longer that 24 hours on 24 VDC and
    >that in fact it will burn up from over current and over load.. Is that
    >correct, Mr. Higgins? Any other opinions on this matter? I know that
    >AC coils are not meant to work on DC, but that is not the question.
    >Question is will they or not?? Come on be brave let's hear about your
    >technical expertise. Any real opinions or just a bunch of wimps?

    Leroy, I imagine my industrial experience in this area will only be
    apocryphal evidence as far as you are concerned so I'll not waste my time
    citing real world incidents of exactly this problem, as well as burning out
    the coils of AC solenoids simply because they were removed from their
    armatures and left off for a period of time on the order of only a few
    hours while activated. But I'm just sick enough of your nonsense to bet
    you $5 on the following terms.

    1. Wording of the bet to be "that it is, IN GENERAL, a bad idea to operate
    a solenoid actuator coil designed for 24 VAC continuous service on 24 VDC
    continuously because it is likely to overheat and burn up as a result." No
    added conditions, modifications or reservations to the quoted words allowed.

    2. We run no tests on any real relays because I can find one to support my
    assertion and I will stipulate that you can find one to support your
    assertion and that we'd have to test or perform calculations on too many
    different relays to demonstrate the truth (or lack thereof) of the GENERAL
    assertion in #1 above.

    3. Therefore, if you agree to the bet, it will be turned over to any one
    of Al Williams, Tracy Allen, Beau Schwabe, Ben Trueblood, Ken Gracey, or
    Peter Anderson, for final decision, assuming for a second any of these
    gentlemen care to get into the middle of this pissing contest. (I have
    deliberately left out Dwayne Reid because he has already weighed in with
    the opinion that you are wrong. Any other omissions are not meant to
    slight anyone.)

    4. If none of these "judges" volunteers for the task within a time frame
    that indicates they ever will, say 48 hours from the date of this posting,
    the bet is off and we both shut the hell up about it. (There's incentive
    not to volunteer if ever there was any, but I'm counting on a desire to
    support the best advice to prevail. After all, there's areal guy out there
    who may go either way on it.)

    5. Payment to be made by mail in the form of a $5 bill, US currency, and
    admission of defeat is to be made to the mailing list by the one losing the
    bet in the form of:

    "Dear (winner's name here),

    You da MAN!

    Love, (loser's name here)"

    What say, Leroy? (Al, Tracy, Beau, Ben, Ken or Peter?)


    Jim H
  • ArchiverArchiver Posts: 46,084
    edited 2002-05-07 06:09
    The heating of a coil depends on the coil current. Operating a coil above
    rated current may well overheat it. How much current will flow in a coil?
    I = V/Z where Z is the coil impedance. Operating from AC, the impedance, Z,
    is sqrt[noparse][[/noparse]R^2+(2*Pi*f*L)^2]. sqrt is square root. R is coil resistance; Pi
    is 2.14159; f is frequency, like 60 Hz. L is coil inductance. In plain
    english, the AC impedance is determined by resistance and inductance. When
    operating the same coil on DC, total impedance is simply R, so more current
    will flow in the DC case. The relay or coil will certainly operate on DC
    because of the higher current, since magnetic force is determined by
    ampere-turns of the coil, but heating will also increase. I have
    successfully operated AC relays on DC by applying reduced DC voltage. If
    you can determine the rated coil current, all you have to do is measure the
    coil resistance and apply a DC voltage that will yield that current.

    Long-winded, but hopefully useful,
    Ray McArthur
  • ArchiverArchiver Posts: 46,084
    edited 2002-05-07 14:33
    Pi = 3.14159

    Original Message
    From: "Ray McArthur" <rjmca@u...>
    To: <basicstamps@yahoogroups.com>
    Sent: Monday, May 06, 2002 10:09 PM
    Subject: Re: [noparse][[/noparse]basicstamps] 120 VAC coils


    > The heating of a coil depends on the coil current. Operating a coil above
    > rated current may well overheat it. How much current will flow in a coil?
    > I = V/Z where Z is the coil impedance. Operating from AC, the impedance,
    Z,
    > is sqrt[noparse][[/noparse]R^2+(2*Pi*f*L)^2]. sqrt is square root. R is coil resistance;
    Pi
    > is 2.14159; f is frequency, like 60 Hz. L is coil inductance. In plain
    > english, the AC impedance is determined by resistance and inductance.
    When
    > operating the same coil on DC, total impedance is simply R, so more
    current
    > will flow in the DC case. The relay or coil will certainly operate on DC
    > because of the higher current, since magnetic force is determined by
    > ampere-turns of the coil, but heating will also increase. I have
    > successfully operated AC relays on DC by applying reduced DC voltage. If
    > you can determine the rated coil current, all you have to do is measure
    the
    > coil resistance and apply a DC voltage that will yield that current.
    >
    > Long-winded, but hopefully useful,
    > Ray McArthur
    >
    >
    > To UNSUBSCRIBE, just send mail to:
    > basicstamps-unsubscribe@yahoogroups.com
    > from the same email address that you subscribed. Text in the Subject and
    Body of the message will be ignored.
    >
    >
    > Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
    >
    >
    >
    >
  • ArchiverArchiver Posts: 46,084
    edited 2002-05-07 16:25
    I started the this mess by incorrectly stating power dissipation. I already
    explained I made a stupid mistake. However, I have learned a lot from the
    discussion. I have seen other arguments on this and other boards get down
    right nasty. I congratulate all that responded for keeping every thing on a
    fairly high level. Things were limited to pointing out typos, others
    opinions and basic A.C theory. Though I have significant industry experience
    I am always interested in someone else's actual experience.

    Sorry I got this started - but I did benefit from the discussion.

    Richard


    Original Message
    From: "Leroy Hall" <leroy@f...>
    To: <basicstamps@yahoogroups.com>; <dwayner@p...>
    Sent: Monday, May 06, 2002 9:08 PM
    Subject: Re: [noparse][[/noparse]basicstamps] 120 VAC coils


    > Dear Dwayne,
    >
    > The physic of this means that 24VDC DOES NOT EQUAL 24 volts RMS. All
    > the text books I have read seem to make this analogy. Maybe they are
    > wrong. Thanks for your input..
    >
    > Leroy
    >
    >
    > Reid wrote:
    > >
    > > At 08:54 PM 5/6/02 -0400, Leroy Hall wrote:
    > > >So I guess this means you are NOT interested in any kind of bet that
    > > >say's a 24 VAC coil WILL NOT function longer that 24 hours on 24 VDC
    and
    > > >that in fact it will burn up from over current and over load.. Is that
    > > >correct, Mr. Higgins? Any other opinions on this matter? I know that
    > > >AC coils are not meant to work on DC, but that is not the question.
    > > >Question is will they or not?? Come on be brave let's hear about your
    > > >technical expertise. Any real opinions or just a bunch of wimps?
    > >
    > > If I may jump in here: the 24 Vac solenoids I usually use here at
    Trinity
    > > Electronics will, without question, eventually disappear in a cloud of
    > > smoke if left powered continuously at 24 Vdc.
    > >
    > > For example, one solenoid I use in my desoldering stations has 2 ratings
    on
    > > the coil: 120 Vac 60 Hz *and* 32 Vdc. I run them at 32 Vdc.
    > >
    > > We control a lot of Asco solenoids with our oven control systems and I
    > > spent many hours abusing the solenoids to see how they react to various
    > > over voltage and under voltage conditions. They don't smell nice if you
    > > hit them with 24 Vdc and leave them for a while.
    > >
    > > I'm sure there must be solenoids out there that will work with the same
    AC
    > > or DC voltage but not the ones I use.
    > >
    > > dwayne
    > >
    > > Dwayne Reid <dwayner@p...>
    > > Trinity Electronics Systems Ltd Edmonton, AB, CANADA
    > > (780) 489-3199 voice (780) 487-6397 fax
    > >
    > > Celebrating 18 years of Engineering Innovation (1984 - 2002)
    > > .-. .-. .-. .-. .-. .-. .-. .-. .-. .-
    > > `-' `-' `-' `-' `-' `-' `-' `-' `-'
    > > Do NOT send unsolicited commercial email to this email address.
    > > This message neither grants consent to receive unsolicited
    > > commercial email nor is intended to solicit commercial email.
    > >
    > > To UNSUBSCRIBE, just send mail to:
    > > basicstamps-unsubscribe@yahoogroups.com
    > > from the same email address that you subscribed. Text in the Subject
    and Body of the message will be ignored.
    > >
    > >
    > > Your use of Yahoo! Groups is subject to
    http://docs.yahoo.com/info/terms/
    >
    >
    > To UNSUBSCRIBE, just send mail to:
    > basicstamps-unsubscribe@yahoogroups.com
    > from the same email address that you subscribed. Text in the Subject and
    Body of the message will be ignored.
    >
    >
    > Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
    >
    >
  • ArchiverArchiver Posts: 46,084
    edited 2002-05-07 16:42
    Dear Richard,

    From my teaching experience I would say that the most learning occurs in
    this type of situation. Ever coin has two sides and every question has
    more than one answer. If you don't seek out all the answers, you have
    just a dim light of reality. My reason for being on this board is to
    learn a little and maybe teach a little. I am glad you raised the
    question, it's really good for the group. Some may get a little
    nervous, but they usually can't understand that they may not know the
    whole truth.
    I certainly don't know everything and I would be the first to admit
    that, Just because I have taught Electro-mechanical engineering for 15+
    years doesn't mean that I taught everything.


    Thanks again for your question.

    HTH,

    Leroy
    > I started the this mess by incorrectly stating power dissipation. I already
    > explained I made a stupid mistake. However, I have learned a lot from the
    > discussion. I have seen other arguments on this and other boards get down
    > right nasty. I congratulate all that responded for keeping every thing on a
    > fairly high level. Things were limited to pointing out typos, others
    > opinions and basic A.C theory. Though I have significant industry experience
    > I am always interested in someone else's actual experience.
    >
    > Sorry I got this started - but I did benefit from the discussion.
    >
    > Richard
    >
    >
    Original Message
    > From: "Leroy Hall" <leroy@f...>
    > To: <basicstamps@yahoogroups.com>; <dwayner@p...>
    > Sent: Monday, May 06, 2002 9:08 PM
    > Subject: Re: [noparse][[/noparse]basicstamps] 120 VAC coils
    >
    > > Dear Dwayne,
    > >
    > > The physic of this means that 24VDC DOES NOT EQUAL 24 volts RMS. All
    > > the text books I have read seem to make this analogy. Maybe they are
    > > wrong. Thanks for your input..
    > >
    > > Leroy
    > >
    > >
    > > Reid wrote:
    > > >
    > > > At 08:54 PM 5/6/02 -0400, Leroy Hall wrote:
    > > > >So I guess this means you are NOT interested in any kind of bet that
    > > > >say's a 24 VAC coil WILL NOT function longer that 24 hours on 24 VDC
    > and
    > > > >that in fact it will burn up from over current and over load.. Is that
    > > > >correct, Mr. Higgins? Any other opinions on this matter? I know that
    > > > >AC coils are not meant to work on DC, but that is not the question.
    > > > >Question is will they or not?? Come on be brave let's hear about your
    > > > >technical expertise. Any real opinions or just a bunch of wimps?
    > > >
    > > > If I may jump in here: the 24 Vac solenoids I usually use here at
    > Trinity
    > > > Electronics will, without question, eventually disappear in a cloud of
    > > > smoke if left powered continuously at 24 Vdc.
    > > >
    > > > For example, one solenoid I use in my desoldering stations has 2 ratings
    > on
    > > > the coil: 120 Vac 60 Hz *and* 32 Vdc. I run them at 32 Vdc.
    > > >
    > > > We control a lot of Asco solenoids with our oven control systems and I
    > > > spent many hours abusing the solenoids to see how they react to various
    > > > over voltage and under voltage conditions. They don't smell nice if you
    > > > hit them with 24 Vdc and leave them for a while.
    > > >
    > > > I'm sure there must be solenoids out there that will work with the same
    > AC
    > > > or DC voltage but not the ones I use.
    > > >
    > > > dwayne
    > > >
    > > > Dwayne Reid <dwayner@p...>
    > > > Trinity Electronics Systems Ltd Edmonton, AB, CANADA
    > > > (780) 489-3199 voice (780) 487-6397 fax
    > > >
    > > > Celebrating 18 years of Engineering Innovation (1984 - 2002)
    > > > .-. .-. .-. .-. .-. .-. .-. .-. .-. .-
    > > > `-' `-' `-' `-' `-' `-' `-' `-' `-'
    > > > Do NOT send unsolicited commercial email to this email address.
    > > > This message neither grants consent to receive unsolicited
    > > > commercial email nor is intended to solicit commercial email.
    > > >
    > > > To UNSUBSCRIBE, just send mail to:
    > > > basicstamps-unsubscribe@yahoogroups.com
    > > > from the same email address that you subscribed. Text in the Subject
    > and Body of the message will be ignored.
    > > >
    > > >
    > > > Your use of Yahoo! Groups is subject to
    > http://docs.yahoo.com/info/terms/
    > >
    > >
    > > To UNSUBSCRIBE, just send mail to:
    > > basicstamps-unsubscribe@yahoogroups.com
    > > from the same email address that you subscribed. Text in the Subject and
    > Body of the message will be ignored.
    > >
    > >
    > > Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
    > >
    > >
    >
    > To UNSUBSCRIBE, just send mail to:
    > basicstamps-unsubscribe@yahoogroups.com
    > from the same email address that you subscribed. Text in the Subject and Body
    of the message will be ignored.
    >
    >
    > Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
  • ArchiverArchiver Posts: 46,084
    edited 2002-05-07 23:44
    Whoops, you're right. They put my "2" and "3" keys too close together [noparse]:)[/noparse]

    Thanks,
    Ray McArthur

    Original Message
    From: Stephen H Chapman <chapman@t...>
    To: <basicstamps@yahoogroups.com>
    Sent: Tuesday, May 07, 2002 9:33 AM
    Subject: Re: [noparse][[/noparse]basicstamps] 120 VAC coils


    > Pi = 3.14159
    >
    >
    Original Message
    > From: "Ray McArthur" <rjmca@u...>
  • ArchiverArchiver Posts: 46,084
    edited 2002-05-08 19:19
    Jim,

    I was wrong here send me your address:

    leroy

    5. Payment to be made by mail in the form of a $5 bill, US currency,
    and
    admission of defeat is to be made to the mailing list by the one losing
    the bet in the form of:

    "Dear (Jim H),

    You da MAN!

    Love, (Leroy)"

    What say, Leroy? (Al, Tracy, Beau, Ben, Ken or Peter?)


    Jim H
  • ArchiverArchiver Posts: 46,084
    edited 2002-05-08 19:23
    Leroy, the HEAT from the "DC coils" is making you delirious. HA!

    >Jim,
    >
    >I was wrong here send me your address:
    >
    >leroy
    >
    >5. Payment to be made by mail in the form of a $5 bill, US currency,
    >and
    >admission of defeat is to be made to the mailing list by the one losing
    >the bet in the form of:
    >
    >"Dear (Jim H),
    >
    > You da MAN!
    >
    >Love, (Leroy)"
    >
    >What say, Leroy? (Al, Tracy, Beau, Ben, Ken or Peter?)
    >

    Beau Schwabe Mask Designer IV - ATL
    National Semiconductor Enterprise Networking Business Unit
    500 Pinnacle Court, Suite 525 Wired Communications Division
    Mail Stop GA1 Norcross, GA 30071
  • ArchiverArchiver Posts: 46,084
    edited 2002-05-08 20:27
    At 14:19 05/08/02, Leroy Hall wrote:

    >Jim,
    >
    >I was wrong here send me your address:

    Leroy,

    If you don't mind just forgetting about it, I am glad to just forget it also.

    In the alternative, I've sent my address privately.


    Jim H
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