Taken from old silo unloader to use as second parallel from alternate
location DC in shop...
240V coil relay, 240V 2hp-rated contacts of the mechanical spring
type--load contacts a common and one open/one closed pair. Relay
operates by momentary make/break--when cycled, the spring-loaded
contacts switch positions rather than by being held by continuous load.
Switch is manual pushbotton, START is NO, STOP is NC and one side of
each are common.
The wiring on the unloader was so decrepit I didn't try to trace it out
when salvaging pieces/parts but I'll be darned if I can figure out how
Dad had this wired to work (but I know it did, I was around for years
while still were using it and it was sitting there as was removed and
parked).
I can see how to get the START to work, what I haven't got my head
around is the STOP function since it breaks a contact instead of makes
one to cause the relay coil to momentarily energize/release to flip the
spring-loaded contacts...
I'll see if I can manage an ASCII pictogram here...
X C X Contacts (C common)
/
/
|
Coil
L1-\/\-L2
x____x START
/
|
\x x STOP
____
Anybody draw a schematic to start/stop a load across an X-C pair?
There's a jumper from L2 to C for starters for supply...
--
On Tue, 19 Jun 2012 13:59:00 -0500, dpb <[email protected]> wrote:
>Taken from old silo unloader to use as second parallel from alternate
>location DC in shop...
>
>240V coil relay, 240V 2hp-rated contacts of the mechanical spring
>type--load contacts a common and one open/one closed pair. Relay
>operates by momentary make/break--when cycled, the spring-loaded
>contacts switch positions rather than by being held by continuous load.
>
>Switch is manual pushbotton, START is NO, STOP is NC and one side of
>each are common.
>
>The wiring on the unloader was so decrepit I didn't try to trace it out
>when salvaging pieces/parts but I'll be darned if I can figure out how
>Dad had this wired to work (but I know it did, I was around for years
>while still were using it and it was sitting there as was removed and
>parked).
>
>I can see how to get the START to work, what I haven't got my head
>around is the STOP function since it breaks a contact instead of makes
>one to cause the relay coil to momentarily energize/release to flip the
>spring-loaded contacts...
>
>I'll see if I can manage an ASCII pictogram here...
>
> X C X Contacts (C common)
> /
> /
> |
>
> Coil
> L1-\/\-L2
>
>
> x____x START
> /
> |
> \x x STOP
> ____
>
>
>Anybody draw a schematic to start/stop a load across an X-C pair?
>There's a jumper from L2 to C for starters for supply...
https://www.google.com/search?hl=en&safe=off&client=firefox-a&hs=PIQ&rls=org.mozilla:en-US:official&channel=np&q=start+stop&bav=on.2,or.r_gc.r_pw.r_cp.r_qf.,cf.osb&biw=1016&bih=593&um=1&ie=UTF-8&tbm=isch&source=og&sa=N&tab=wi&ei=6dfgT46KEY6c8QS36uT5DA#um=1&hl=en&safe=off&client=firefox-a&hs=Byk&rls=org.mozilla:en-US%3Aofficial&channel=np&tbm=isch&sa=1&q=start+stop+diagram&oq=start+stop+diagram&aq=f&aqi=g1g-mS2&aql=&gs_l=img.3..0j0i5i24l2.9766.11941.0.12357.8.8.0.0.0.1.888.1427.7j6-1.8.0...0.0.wbuTYf1s24c&pbx=1&bav=on.2,or.r_gc.r_pw.r_cp.r_qf.,cf.osb&fp=f8eb300daecb8750&biw=1016&bih=593
On Jun 19, 2:59=A0pm, dpb <[email protected]> wrote:
> Taken from old silo unloader to use as second parallel from alternate
> location DC in shop...
>
> 240V coil relay, 240V 2hp-rated contacts of the mechanical spring
> type--load contacts a common and one open/one closed pair. =A0Relay
> operates by momentary make/break--when cycled, the spring-loaded
> contacts switch positions rather than by being held by continuous load.
>
> Switch is manual pushbotton, START is NO, STOP is NC and one side of
> each are common.
>
> The wiring on the unloader was so decrepit I didn't try to trace it out
> when salvaging pieces/parts but I'll be darned if I can figure out how
> Dad had this wired to work (but I know it did, I was around for years
> while still were using it and it was sitting there as was removed and
> parked).
>
> I can see how to get the START to work, what I haven't got my head
> around is the STOP function since it breaks a contact instead of makes
> one to cause the relay coil to momentarily energize/release to flip the
> spring-loaded contacts...
>
> I'll see if I can manage an ASCII pictogram here...
>
> =A0 =A0 =A0 =A0 =A0X =A0 C =A0 X =A0Contacts (C common)
> =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0/
> =A0 =A0 =A0 =A0 =A0 =A0 =A0 /
> =A0 =A0 =A0 =A0 =A0 =A0 =A0|
>
> =A0 =A0 =A0 =A0 =A0 =A0Coil
> =A0 =A0 =A0 =A0 =A0L1-\/\-L2
>
> =A0 =A0 =A0 =A0 =A0x____x =A0START
> =A0 =A0 =A0 =A0 /
> =A0 =A0 =A0 =A0|
> =A0 =A0 =A0 =A0 \x =A0 =A0x =A0STOP
> =A0 =A0 =A0 =A0 =A0 ____
>
> Anybody draw a schematic to start/stop a load across an X-C pair?
> There's a jumper from L2 to C for starters for supply...
>
> --
I can see why you have a mental block. I have one
too just from trying to read this.....
On Tue, 19 Jun 2012 12:19:44 -0700 (PDT), "[email protected]"
<[email protected]> wrote:
>On Jun 19, 2:59 pm, dpb <[email protected]> wrote:
>> Taken from old silo unloader to use as second parallel from alternate
>> location DC in shop...
>>
>> 240V coil relay, 240V 2hp-rated contacts of the mechanical spring
>> type--load contacts a common and one open/one closed pair. Relay
>> operates by momentary make/break--when cycled, the spring-loaded
>> contacts switch positions rather than by being held by continuous load.
>>
>> Switch is manual pushbotton, START is NO, STOP is NC and one side of
>> each are common.
>>
>> The wiring on the unloader was so decrepit I didn't try to trace it out
>> when salvaging pieces/parts but I'll be darned if I can figure out how
>> Dad had this wired to work (but I know it did, I was around for years
>> while still were using it and it was sitting there as was removed and
>> parked).
>>
>> I can see how to get the START to work, what I haven't got my head
>> around is the STOP function since it breaks a contact instead of makes
>> one to cause the relay coil to momentarily energize/release to flip the
>> spring-loaded contacts...
>>
>> I'll see if I can manage an ASCII pictogram here...
>>
>> X C X Contacts (C common)
>> /
>> /
>> |
>>
>> Coil
>> L1-\/\-L2
>>
>> x____x START
>> /
>> |
>> \x x STOP
>> ____
>>
>> Anybody draw a schematic to start/stop a load across an X-C pair?
>> There's a jumper from L2 to C for starters for supply...
>>
>> --
>
>I can see why you have a mental block. I have one
>too just from trying to read this.....
Help us out. Just take pictures.
On Jun 19, 10:34=A0pm, dpb <[email protected]> wrote:
> On 6/19/2012 9:16 PM, [email protected] wrote:
> ...
>
> > =A0 =A0So you are saying the relay coil is NOT energized when the motor=
is
> > running????? AND it uses a NO and an NC switch???
>
> Those are the pieces parts that were in use, yes...
>
> > Sounds fishy to me. A "galopping ghost" relay starts with one pulse
> > and stops with a second pulse - a modification of that circuit uses 2
> > separate NO switches and a spdt pilot switch to select which switch
> > sends the pulse.
>
> Well, until I started wiring I had presumed the switch was to NO to do
> precisely that--a start and a stop pulse and was in process when
> realized wasn't so...
>
>
>
> > GENERALLY a NO/NC pushbutton starter uses an electrical "latching
> > relay" circuit, the ON button momentarily closes the relay, and the
> > pilot contacts of the relay close the circuit to the relay by
> > bypassing the ON switch, with current flowing through the NC OFF
> > switch. By pressing the OFF switch the circuit to the coil is broken,
> > the relay opens, and the pilot contacts also open. To restart, control
> > voltage is applied to the coil through the normally closed off switch
> > and the pressed normally open ON switch, which pulls in the contacts
> > of the relay to start the motor as well as the pilot contacts, which
> > hold the coil in when the ON switch is released.
>
> And now you see why I am left puzzled how Dad had this working on the
> old unloader from which I took the pieces... :) =A0I'm virtually positive
> it hadn't been touched since last time it was pulled out of the silo and
> set in the corner for the auction (but it didn't sell; by then nobody
> else was filling upright silos anymore, either). =A0So, I figured might a=
s
> well use the parts for something...
>
> If I can't dream up what he did tomorrow, guess I'll rummage around for
> something else and figure out another workaround -- it just bugs me that
> somehow this seemed to have been working before. =A0I wish now I had trie=
d
> to trace out the old wiring more carefully, but that ship has sailed at
> this point...
>
> --
If you don't have an installation manual or circuit diagram
to work from you should have taken a picture at the very
least before pulling everything apart...
It is sounding more and more like you should go and
buy a new motor controller which works in the more
conventional way...
What are you trying to control anyway ?
"dpb" <[email protected]> wrote in message news:[email protected]...
> Taken from old silo unloader to use as second parallel from alternate
> location DC in shop...
>
> 240V coil relay, 240V 2hp-rated contacts of the mechanical spring
> type--load contacts a common and one open/one closed pair. Relay operates
> by momentary make/break--when cycled, the spring-loaded contacts switch
> positions rather than by being held by continuous load.
>
> Switch is manual pushbotton, START is NO, STOP is NC and one side of each
> are common.
>
> The wiring on the unloader was so decrepit I didn't try to trace it out
> when salvaging pieces/parts but I'll be darned if I can figure out how Dad
> had this wired to work (but I know it did, I was around for years while
> still were using it and it was sitting there as was removed and parked).
>
> I can see how to get the START to work, what I haven't got my head around
> is the STOP function since it breaks a contact instead of makes one to
> cause the relay coil to momentarily energize/release to flip the
> spring-loaded contacts...
>
> I'll see if I can manage an ASCII pictogram here...
>
> X C X Contacts (C common)
> /
> /
> |
>
> Coil
> L1-\/\-L2
>
>
> x____x START
> /
> |
> \x x STOP
> ____
>
>
> Anybody draw a schematic to start/stop a load across an X-C pair? There's
> a jumper from L2 to C for starters for supply...
>
Look up a 3 wire stop start circuit. The stop button contacts are normally
closed. The start button will be normally open. A set of normally open
contacts from the coil are in parallel with the start button. When you push
the start button the coil pulls in and the contacts parallel the start
button to simulate keeping it pressed. When you press the stop button, the
coil looses power and drops out the contacts in parallel with the start
button.
On Tue, 19 Jun 2012 19:56:43 -0500, dpb wrote:
> On 6/19/2012 3:58 PM, dpb wrote:
>> On 6/19/2012 3:23 PM, Ralph Mowery wrote: ....
>>
> ...
>
>> Excepting for the kicker on this relay that the contacts only actually
>> switch on a pulse instead of on/off--they're spring loaded and it's the
>> spring action when the coil de-energizes that causes them to actually
>> change position--they don't on power-on only.
> ...
>
> And, I just wired up a test cord to make certain I wasn't seeing
> something I wasn't--that is precisely how it operates...
>
> Head scratchin' time a little longer here...
The contactor has an auxiliary contact for control voltage
that is NO and makes up with the pulling in of the main contacts.
control power hot goes into one side of the stop switch (nc)
and is jumped to one side of the start switch (no), the other side of the
stop switch goes to the auxiliary contact, the other side of the start
switch goes to the other side of the auxiliary contacts and is jumped
from the auxiliary to the coil of the contactor.
the other side of the coil is connected to the overload contact relay,
withe the neutral hooked to the other connection of the overload relay.
The start switch temporarily supplies power to the coil until the power
can come through the auxiliary switch, the stop switch breaks the circuit
and allows the contactor to drop out.
If I remember correctly the auxiliary contacts on a furnas are built
along side the main contacts. There will be two small connections at the
bottom behind the motor leads that are the overload contact relay.
basilisk
--
A wink is as good as a nod to a blind horse
On Tue, 19 Jun 2012 15:58:59 -0500, dpb <[email protected]> wrote:
>On 6/19/2012 3:23 PM, Ralph Mowery wrote:
>...
>
>> Look up a 3 wire stop start circuit. The stop button contacts are normally
>> closed. The start button will be normally open. A set of normally open
>> contacts from the coil are in parallel with the start button. When you push
>> the start button the coil pulls in and the contacts parallel the start
>> button to simulate keeping it pressed. When you press the stop button, the
>> coil looses power and drops out the contacts in parallel with the start
>> button.
>
>Excepting for the kicker on this relay that the contacts only actually
>switch on a pulse instead of on/off--they're spring loaded and it's the
>spring action when the coil de-energizes that causes them to actually
>change position--they don't on power-on only.
>
>So, I can start it w/ the momentary but can't figure out how to generate
>the pulse w/ the NC Stop contacts.
>
>I initially thought both were NO until I went to wire it up this morning
>and discovered that isn't so and what I thought it was doesn't work...
So you are saying the relay coil is NOT energized when the motor is
running????? AND it uses a NO and an NC switch???
Sounds fishy to me. A "galopping ghost" relay starts with one pulse
and stops with a second pulse - a modification of that circuit uses 2
separate NO switches and a spdt pilot switch to select which switch
sends the pulse.
GENERALLY a NO/NC pushbutton starter uses an electrical "latching
relay" circuit, the ON button momentarily closes the relay, and the
pilot contacts of the relay close the circuit to the relay by
bypassing the ON switch, with current flowing through the NC OFF
switch. By pressing the OFF switch the circuit to the coil is broken,
the relay opens, and the pilot contacts also open. To restart, control
voltage is applied to the coil through the normally closed off switch
and the pressed normally open ON switch, which pulls in the contacts
of the relay to start the motor as well as the pilot contacts, which
hold the coil in when the ON switch is released.
On 6/19/2012 2:49 PM, Metspitzer wrote:
...
> Help us out. Just take pictures.
Of what, specifically do want a picture?
All I can take a picture of would be the face of the relay in the box
and it'll show 3 relay contact screws at the top and the two coil
connections (plus the jumper from one of them to the common terminal of
the output contacts).
It's an old Furnas contactor and Furnas is, of course, long gone.
AFAICT there's no part number to try to find old stock or reference
diagrams from...
--
On 6/19/2012 2:52 PM, Metspitzer wrote:
...
>> Anybody draw a schematic to start/stop a load across an X-C pair?
>> There's a jumper from L2 to C for starters for supply...
>
> https://www.google.com/search?hl=en&...
Thanks, that shows a bunch of schematics indeed--I'll try to work
through and see if anything seems to fit.
The diagram at <http://sub.allaboutcircuits.com/images/04176.png> is
good when the relay is powered to hold the relay contacts closed but the
kicker in this case that has me puzzled is that the contacts change
position only when the coil is energized/de-energized because they're
spring-loaded and it's the spring action when the coil de-energizes that
causes them to switch position, not the coil magnetic field causing an
actuator to move...
The switch is similar to
<http://www.automationdirect.com/adc/Overview/Catalog/Pushbuttons_-
z-_Switches_-z-_Indicators/Eaton_Cutler-Hammer_22mm_%28E22_Series%29
/Start_-z-_Stop_Combos_-a-_Stations>
just a normal manual switch as shown in the above schematic as well w/
the one side of Start/Stop connected as shown there to be in series.
It's clear to get a coil pulse thru the coil to press "Start"; what's
got me is then if the coil stays energized the contacts don't switch
position to actually start the motor.
'Tis a puzzle (to me, at least at the moment still)...
I'm sure at some point the light will dawn and I'll be realizing how
silly I've been in not seeing the obvious... :)
--
On 6/19/2012 3:23 PM, Ralph Mowery wrote:
...
> Look up a 3 wire stop start circuit. The stop button contacts are normally
> closed. The start button will be normally open. A set of normally open
> contacts from the coil are in parallel with the start button. When you push
> the start button the coil pulls in and the contacts parallel the start
> button to simulate keeping it pressed. When you press the stop button, the
> coil looses power and drops out the contacts in parallel with the start
> button.
Excepting for the kicker on this relay that the contacts only actually
switch on a pulse instead of on/off--they're spring loaded and it's the
spring action when the coil de-energizes that causes them to actually
change position--they don't on power-on only.
So, I can start it w/ the momentary but can't figure out how to generate
the pulse w/ the NC Stop contacts.
I initially thought both were NO until I went to wire it up this morning
and discovered that isn't so and what I thought it was doesn't work...
--
On 6/19/2012 3:58 PM, dpb wrote:
> On 6/19/2012 3:23 PM, Ralph Mowery wrote:
> ....
>
...
> Excepting for the kicker on this relay that the contacts only actually
> switch on a pulse instead of on/off--they're spring loaded and it's the
> spring action when the coil de-energizes that causes them to actually
> change position--they don't on power-on only.
...
And, I just wired up a test cord to make certain I wasn't seeing
something I wasn't--that is precisely how it operates...
Head scratchin' time a little longer here...
--
On 6/19/2012 3:54 PM, dpb wrote:
...
> kicker in this case that has me puzzled is that the contacts change
> position only when the coil is energized/de-energized because they're
> spring-loaded and it's the spring action when the coil de-energizes that
> causes them to switch position, not the coil magnetic field causing an
> actuator to move...
...
Well, of course the magnetic field does cause the actuator to move, the
thing is when it moves in the contacts don't move; they only change
position on power removal when the spring action causes the contact
changeover.
As noted in reponse earlier to follow up to Ralph I just went and
confirmed the mode of operation w/ a test cord...
--
On 6/19/2012 9:16 PM, [email protected] wrote:
...
> So you are saying the relay coil is NOT energized when the motor is
> running????? AND it uses a NO and an NC switch???
Those are the pieces parts that were in use, yes...
> Sounds fishy to me. A "galopping ghost" relay starts with one pulse
> and stops with a second pulse - a modification of that circuit uses 2
> separate NO switches and a spdt pilot switch to select which switch
> sends the pulse.
Well, until I started wiring I had presumed the switch was to NO to do
precisely that--a start and a stop pulse and was in process when
realized wasn't so...
>
> GENERALLY a NO/NC pushbutton starter uses an electrical "latching
> relay" circuit, the ON button momentarily closes the relay, and the
> pilot contacts of the relay close the circuit to the relay by
> bypassing the ON switch, with current flowing through the NC OFF
> switch. By pressing the OFF switch the circuit to the coil is broken,
> the relay opens, and the pilot contacts also open. To restart, control
> voltage is applied to the coil through the normally closed off switch
> and the pressed normally open ON switch, which pulls in the contacts
> of the relay to start the motor as well as the pilot contacts, which
> hold the coil in when the ON switch is released.
And now you see why I am left puzzled how Dad had this working on the
old unloader from which I took the pieces... :) I'm virtually positive
it hadn't been touched since last time it was pulled out of the silo and
set in the corner for the auction (but it didn't sell; by then nobody
else was filling upright silos anymore, either). So, I figured might as
well use the parts for something...
If I can't dream up what he did tomorrow, guess I'll rummage around for
something else and figure out another workaround -- it just bugs me that
somehow this seemed to have been working before. I wish now I had tried
to trace out the old wiring more carefully, but that ship has sailed at
this point...
--
On 6/19/2012 10:34 PM, Dan Coby wrote:
...
> Have you tried connecting the relay the same as a normal holding
> relay?
>
> I think that it will work. The Start button energizes the coil.
> When the Start button is released the coil is de-energized.
> Then the relay toggles and power is sent to the load. That also
> allows current to be sent back to the coil via the normally closed
> contact of the Stop button. However the relay stays in its same
> position (i.e. still sending power to the load) until the current
> to the coil is interrupted. This happens when the Stop button
> is pressed.
>
> Even though this relay does not need to have it coil energized
> during normal run operation, it would be in this case. Hopefully
> this does not cause the coil to over heat. Since you said that
> your father used this arrangement for years, I am guessing that
> this is not a problem.
>
> A loss of input power while running would also toggle off the relay.
> That is a nice safety feature.
...
That may be (probably was?) the way it was; it's too long ago that I
have no way of knowing. I can give it a try; I did notice it's pretty
noisy when actuated altho in the silo 50 ft in the air w/ the unloader
fan running who would have noticed? :) It won't take long to see how
much heat it dissipates altho I've only cycled it in playing around so far.
It's a 240V coil; I tried it w/ 120V and it doesn't have enough oomph to
move it so it's both hot legs instead of a neutral/hot, but that's a
detail; the path is the same if your supposition is right (that that's
the way it had been used and I've been trying to make it more
complicated than it was, not that it won't work). I just had a mindset
when I started that it was only momentary and kept trying to work around
that idea that just doesn't seem that can be (or ever was so)...
Appreciate the input from all; anybody gets any more really
clever/strange ideas... :)
--
On 6/21/2012 12:15 AM, Evan wrote:
...
> If you don't have an installation manual or circuit diagram
> to work from you should have taken a picture at the very
> least before pulling everything apart...
Easy enough to say now... :)
Having set out for 20+ yrs since last used, it was already well gone as
far as the wiring between boxes so...besides who'dda thunk there was
anything unique going on, anyway?
> It is sounding more and more like you should go and
> buy a new motor controller which works in the more
> conventional way...
Not agonna' happen... :) (Altho if there isn't something in the pile of
other pieces-parts in the barn that makes it more convenient (haven't
had time to dig through yet) I did locate a P&B relay at Newark for <$15
that would serve the purpose precisely and I might just go that way.
See follow-up later in this subthread that it turned out to not be so
unconventional after all although won't all go in the small relay box...
>
> What are you trying to control anyway ?
Rigging up a remote tethered Start/Stop for the dust collector to carry
around...
--
"dpb" wrote in message news:[email protected]...
Taken from old silo unloader to use as second parallel from alternate
location DC in shop...
240V coil relay, 240V 2hp-rated contacts of the mechanical spring
type--load contacts a common and one open/one closed pair. Relay
operates by momentary make/break--when cycled, the spring-loaded
contacts switch positions rather than by being held by continuous load.
Switch is manual pushbotton, START is NO, STOP is NC and one side of
each are common.
The wiring on the unloader was so decrepit I didn't try to trace it out
when salvaging pieces/parts but I'll be darned if I can figure out how
Dad had this wired to work (but I know it did, I was around for years
while still were using it and it was sitting there as was removed and
parked).
I can see how to get the START to work, what I haven't got my head
around is the STOP function since it breaks a contact instead of makes
one to cause the relay coil to momentarily energize/release to flip the
spring-loaded contacts...
I'll see if I can manage an ASCII pictogram here...
************************
When you turn the thing on, part of the current goes through the stop switch
circuit and that current holds the contacts together with the electromagnet
coil. You press stop and the circuit holding the magnet is broken, so the
contacts come apart and no power goes to the machine or the holding coil.
-- Jim in NC
On 6/21/2012 8:48 PM, Morgans wrote:
...
> When you turn the thing on, part of the current goes through the stop
> switch circuit and that current holds the contacts together with the
> electromagnet coil. You press stop and the circuit holding the magnet is
> broken, so the contacts come apart and no power goes to the machine or
> the holding coil.
Not if the it is a pulsing relay...
The mystery has been resolved elsewhere in the thread...
--
On 6/19/2012 1:59 PM, dpb wrote:
> Taken from old silo unloader to use as second parallel from alternate
> location DC in shop...
>
...
> The wiring on the unloader was so decrepit I didn't try to trace it out
> when salvaging pieces/parts but I'll be darned if I can figure out how
> Dad had this wired to work (but I know it did, I was around for years
> while still were using it and it was sitting there as was removed and
> parked).
....
OK, I now know how it was done...as concluded earlier, I was
overlooking/forgetting a key part and now it has come to me what that is...
This switch and relay were mounted on the unloader up _in_ the silo;
normally, however, the whole point of the unloader was to avoid having
to climb the silo every (cold winter, particularly :) ) morning and
throw feed down manually. But, on occasion it would malfunction by
digging in or somesuch and it was necessary.
The controls I've salvaged were therefore in parallel to the "real"
motor starter on the ground and connected via the umbilical cord that
went from the unloader down the silo chute to the ground. The rest of
the control logic and power feed for the motors was there...
Mea culpa, sorry... :(
For my present purpose I've ordered a rated DPDT Form C from Mr Newark
that'll work as desired as couldn't find anything suitable w/o being way
overkill in the various salvaged pieces-parts in the barn...
Anyway, thanks for the input even though it was a snipe hunt owing to me
thinking only of the part of the puzzle was holding in hand when posted...
--
On 6/19/2012 5:56 PM, dpb wrote:
> On 6/19/2012 3:58 PM, dpb wrote:
>> On 6/19/2012 3:23 PM, Ralph Mowery wrote:
>> ....
>>
> ...
>
>> Excepting for the kicker on this relay that the contacts only actually
>> switch on a pulse instead of on/off--they're spring loaded and it's the
>> spring action when the coil de-energizes that causes them to actually
>> change position--they don't on power-on only.
> ...
>
> And, I just wired up a test cord to make certain I wasn't seeing something I wasn't--that is precisely how it operates...
>
> Head scratchin' time a little longer here...
>
Have you tried connecting the relay the same as a normal holding
relay?
I think that it will work. The Start button energizes the coil.
When the Start button is released the coil is de-energized.
Then the relay toggles and power is sent to the load. That also
allows current to be sent back to the coil via the normally closed
contact of the Stop button. However the relay stays in its same
position (i.e. still sending power to the load) until the current
to the coil is interrupted. This happens when the Stop button
is pressed.
Even though this relay does not need to have it coil energized
during normal run operation, it would be in this case. Hopefully
this does not cause the coil to over heat. Since you said that
your father used this arrangement for years, I am guessing that
this is not a problem.
A loss of input power while running would also toggle off the relay.
That is a nice safety feature.
/
/
Line C / NO LOAD
------+-------O/ O-------+----------------
| |
| |
+--* | +--*|
| Start | Stop
+--* | +--*|
| |
| |
+---------+------------+
|
* L1
|
Coil
|
* L2
Neutral |
----------------+-----------------------------
Dan