Contactor Question

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That's a question? Yes, the start button is wired in parallel with the aux contact and the stop button is wired in series with the aux contact.

wiringdiagram3.jpg
 
Contactor

Contactor

Marc, Thank you, The AUX is a NO contact. The start/stop switch is a NO contact for the start button and a NC contact for the stop button. The common terminal of the start/stop switch is wired to the lower terminal of the Aux. The NO start button is wired two both the NO Aux and one of the coil leads. Marc would you agree with this wiring?
Thanks again
Fran
 
Marc -
I've not ever seen one wired like that. The attachment would be the norm that I have seen.

Francis -
I think this is what you are refering to.

Hot wire (1) out to the STOP
S/S common back to the AUX contact (2)
START (3) back to the coil
 
coulter said:
Marc -
I've not ever seen one wired like that. The attachment would be the norm that I have seen.
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What the heck are you talking about? My written description is an exact description of what's in the attached schematic. The only difference between my drawing and yours is where the O/L contact is stuck in at. Big deal. Yours is a NEMA style drawing and mine's an IEC style drawing.
 
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mdshunk said:
... The only difference between my drawing and yours is where the O/L contact is stuck in at. ...
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I thought yours showed the START/AUX ahead of the STOP

mdshunk said:
... Yours is a NEMA style drawing and mine's an IEC style drawing.
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Ahh -- I wondered where the numbers came from. I don't do much with IEC

mdshunk said:
What the heck are you talking about? ...
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Uhhhh - possibly the US industry standard of putting the Stop ahead of the Start in 3/4 wire S/S circuits - or then again - possibly I have no clue:roll:

carl
 
Note to post 4 attachment:

For those who might consider me one of the "anti-grounding" fanatics:

Please add a ground symbol to the X1 terminal. Most all buckets I have seen ground the X1 side of the xfmr.:)

carl
 
FrancisDoody said:
The start/stop switch is a NO contact for the start button and a NC contact for the stop button.
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Greetings all. Don Quixote de la Mancha here, on his never ending and ?guaranteed-to-be-unsuccessful? quest to rid the world of all windmills, and to eliminate forever the use of the phrases ?Normally Open? and ?Normally Closed.? Perhaps, and this may be all that there is to be hoped, I will make one convert.

Consider a main line contactor for a fan motor. When a particular contact closes, the fan runs. Suppose that fan is turned on once, and is never, never turned off. The ?Normal? condition of that fan is ?running.? Is, therefore, the ?Normal? state of that contact ?closed?? Does that contact change its identity from NO to NC by virtue of the intended use of the fan that it serves? It is the word ?normal? that bothers me.

I much prefer the notation of ?a contact? and ?b contact? and ?c contact.? If the device is still in its box, with no wires attached and certainly no power to its relay, then any contact that is open is an ?a contact,? and any contact that is closed is a ?b contact.? A contact that has a center pole that connects one way with the relay turned off and that connects the other way with the relay energized would be a ?c contact.?

OK. No more jousting for today. Feel free to ignore the ravings of an old and tired knight.
 
Start/Stop/Jog control wiring can be accomplished in many ways. There is no specific correct method. MD's diagram is a standard common connect. It can be done with a relay if you wanted. You could even use a manual starter if you are challenged in control wiring.
Once again we take a simple procedure and make it a nuclear test.

Note: MD. The holding contact should be labeled M1R or something like that.
What drawing program are you using. looks real nice. Or did you scan it?
 
All the buckets I've ever seen have the ground on the X2 side of the transformer. Also most buckets are wired so a pilot light is in parralel with the motor relay. The nice thing about this is that if your over loads are tripped the light will come on as long as the start button is held down but will go off when start button is released because the relay will not pull in with tripped OL's. Nice quick dirty trouble shooting aid.
 
charlie b said:
...and to eliminate forever the use of the phrases “Normally Open” and “Normally Closed.”
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The "normal" state has always been the lowest mechanical energy state of any contact or device.
 
Marc,
The "normal" state has always been the lowest mechanical energy state of any contact or device.
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While that is what I was taught..I have worked with drawings where "normal" was normal operating conditions and not the de-energized state.
Don
 
don_resqcapt19 said:
I have worked with drawings where "normal" was normal operating conditions and not the de-energized state.
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So have I. That is the reason I have, on occasion, jousted with the windmills of the "normal" terminology.

Kidding aside, I believe that there are terms that we use from time to time, and that we should use with care. We should not expect that our listener will understand the terms in the same way we intended. The notion of "normally open" versus "normally closed" (as these phrases apply to mechanical valves as well as to electrical contacts) is one of these cases. The notion of "low voltage" versus "high voltage" is another.
 
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