I have a contactor with 120v coil , need a manual reset in case of power out...

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Voltage Monitoring

Voltage Monitoring

I am using some ICM-408 phase protectors for basic protection on a number of HVACR systems subject to browns and generally dirty power.
They work pretty good for this purpose, for line side monitoring only.

http://www.supplyhouse.com/ICM-Controls-ICM408-ICM408-Phase-Loss-and-Removal-Protection-190-480-VAC

They will give you DOB and DOM time outs.

There are some machines I have that have some proprietary units built in that will stop the unit if under or over voltage is sensed.
I have one of those on a Hoshizaki Ice Machine and One on a Trane RTU. The elctronics guys could likely tell you how that control logic works or how to emulate it possibly.
 
 
Besoeker said:
It just astonishes me that someone in the electrical field wouldn't know about the logic of very basic control circuits.
But I seem to have touched a raw nerve and, for that, I apologise.
Click to expand...
The issue is that knowledge of motor control circuits, in fact control circuits of any kind, no matter how "basic" it might appear to you or I, is not a prerequisite to attaining a license as an electrician, at least not in this country. People go through their entire careers without ever having hooked up an industrial motor starter. Even if taught, they may never use the information and forget it. This is partly because there is a lot of other very challenging and rewarding work to be done in the electrical field without having to include industrial controls.

Conversely there are plenty of people in the field, like myself, who do not (or should not) take on residential electrical work either. I did it as an apprentice 30+ years ago and I was fine doing my own house, but I would never be so bold as to assume I could just go back to it now professionally. Too much to remember and too many changes to keep up with to be effective. When I did my own house 17 years ago, I had to stop and study so many code changes that I would have (should have) fired myself for taking so long. A seasoned pro who does resi work all of the time would have done my entire house in a couple of days, rather than the 6 weeks it took me. I have some more work coming up on my house that I suppose I could do myself, but I have told the wife I consider it a "pay the man" job now, having learned my lesson.
 
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Besoeker said:
I thought this place was for those in the trade. You'd think that something like a no volt release/reset would be quite well understood.
Perhaps no but it seemed to me like a bit of a DIY question. I didn't mean to judge unjustifiably harshly.
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You might think so but over the years I have run across a lot of electricians that do not understand things that I would have expected them to. Like being able to read simple schematics. I cannot tell you how many electricians I have run into over the years that just do not understand even very simple schematics.

It astounds me that any electrician could work an entire career and not be able to read simple electrical drawings, but people tend to get focused in certain areas of the trade and that is what they do and things not needed for that niche are either not learned or forgotten.
 
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Jraef said:
The issue is that knowledge of motor control circuits, in fact control circuits of any kind, no matter how "basic" it might appear to you or I, is not a prerequisite to attaining a license as an electrician, at least not in this country. People go through their entire careers without ever having hooked up an industrial motor starter. Even if taught, they may never use the information and forget it. This is partly because there is a lot of other very challenging and rewarding work to be done in the electrical field without having to include industrial controls.

Conversely there are plenty of people in the field, like myself, who do not (or should not) take on residential electrical work either. I did it as an apprentice 30+ years ago and I was fine doing my own house, but I would never be so bold as to assume I could just go back to it now professionally. Too much to remember and too many changes to keep up with to be effective. When I did my own house 17 years ago, I had to stop and study so many code changes that I would have (should have) fired myself for taking so long. A seasoned pro who does resi work all of the time would have done my entire house in a couple of days, rather than the 6 weeks it took me. I have some more work coming up on my house that I suppose I could do myself, but I have told the wife I consider it a "pay the man" job now, having learned my lesson.
Click to expand...

All fair and valid comments. I still do my own domestic stuff and, at a push, for relatives. My late BIL was an expert at finding cables - with nails when hanging pictures. And, being a practical sort of chap, I do a bit of plumbing and carpentry too.
 
petersonra said:
You might think so but over the years I have run across a lot of electricians that do not understand things that I would have expected them to. Like being able to read simple schematics. I cannot tell you how many electricians I have run into over the years that just do not understand even very simple schematics.

It astounds me that any electrician could work an entire career and not be able to read simple electrical drawings, but people tend to get focused in certain areas of the trade and that is what they do and things not needed for that niche are either not learned or forgotten.
Click to expand...

Yes, it surprises me in my own organisation what people know - and sometimes don't.
 
Besoeker said:
Yes, it surprises me in my own organisation what people know - and sometimes don't.
Click to expand...

Bes - I'm not particularly picking on you*.

When one says "electrician" there are several skill sets. One set of divisions could be, Pipe and Wire, Termination, Troubleshooter.

When one says "engineer", again, there are several skill sets - say, Designer, Project, Field (troubleshooter).

For a project of any size, one needs all six. It is rare to find an electrician that can do the three really well. Even rarer to the find an engineer that can do their three.

The skill sets are not mutually exclusive but it seems the required termperment is.

I would never expect an electrician troubleshooter to do any good at day after day pipe and wire - any more than I would expect a power system/generator/field guy to do any good siting in an office day after day designing power systems.

*however, you could put the shovel down:roll:

ice
 
fmtjfw said:
google "three wire pushbutton motor control"

You will find (among other descriptions) the following tutorial:

https://www.youtube.com/watch?v=Ndv8zpxvb_A/URL]

This circuit allows you to start and stop the device manually.
Other links may be better but this one shows step-by-step how to wire it and what parts you need.

Besoeker's circuit is exactly what you requested, it allow you to start the load manually, trips on a power outage, and will not start the load until you press the start button after the outage.

If the load is other than a single hot and a neutral, you would need to break each hot by passing it through L1-T1, L2-T2, or L3-T3.

The control contact, wired across the start pushbutton is usually marked A1 A2
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I'm not looking for a manual restart, just manual reset.

I'll be using contactors for the motor loads, along with undervoltage drop out contactors that are N O, These will be in a J boxes
so that students will not have access.
The instructor will shut down disconnect and start buttons, then access the resets in the drop out coils inside jboxes once all equipment is safed off.

There is an RC kill switch in the design that shuts down all stationary equipment in the shop, should the instructor observe a
dangerous situation, or need emmediate attention of his students, Fire Drills etc....
 
StarCat said:
I am using some ICM-408 phase protectors for basic protection on a number of HVACR systems subject to browns and generally dirty power.
They work pretty good for this purpose, for line side monitoring only.

http://www.supplyhouse.com/ICM-Controls-ICM408-ICM408-Phase-Loss-and-Removal-Protection-190-480-VAC

They will give you DOB and DOM time outs.

There are some machines I have that have some proprietary units built in that will stop the unit if under or over voltage is sensed.
I have one of those on a Hoshizaki Ice Machine and One on a Trane RTU. The elctronics guys could likely tell you how that control logic works or how to emulate it possibly.
Click to expand...

Nice,

I did something similar with an ac unit years ago, so that when I went out of town to work I would have no worries of the ac kicking
off the breaker with knee jerk restarts.... We had frequent power outs.

I think I was able to set it for around 7 minutes or so.

This would be perfect for my current application if not for the timer, unless it has a manual reset option.
 
Stratovarious said:
I'm not looking for a manual restart, just manual reset.

I'll be using contactors for the motor loads, along with undervoltage drop out contactors that are N O, These will be in a J boxes so that students will not have access.
The instructor will shut down disconnect and start buttons, then access the resets in the drop out coils inside jboxes once all equipment is safed off.

There is an RC kill switch in the design that shuts down all stationary equipment in the shop, should the instructor observe a dangerous situation, or need emmediate attention of his students, Fire Drills etc....
Click to expand...

You lost me completely. Here is what I am hearing: You got several methods to do exactly what you asked for in post 1. But that is not what you want.
Sometimes I'm a bit slow - help clarify:

What is an "RC kill switch"? Is that an "emergency stop" wired into the rotating equipment motor starters control circuits? I've not heard the term "RC" applied to an emergency stop.

What exactly is the difference between a "manual restart" and a "manual reset"?

Most all motor starters/contactors are low voltage dropout.* Requires the 3Wire Stop/Start circuit as mention above. What is it you are looking for different than that?

Are you looking for a control relay that interupts the control power to the "undervoltage drop out contactors"? When the manual reset is activated, the UV drop out contactors won't pull in until other controls are activated?

maybe a one-line would help us - it definitely would help me.

ice

*No, I am not discussing mechanically held contactors
 
Stratovarious said:
I'm not looking for a manual restart, just manual reset.
Click to expand...

Start with the standard 3-wire control scheme (I assume this is what you are calling manual restart)
Now, remove the "stop" button from the circuit (wire the line directly to the Start button and 'holding circuit' contact).
Finally rename, the Start button to be "Reset".


Or, are you looking for a factory made unit that you simply have to wire to?
 
jim dungar said:
Start with the standard 3-wire control scheme (I assume this is what you are calling manual restart)
Now, remove the "stop" button from the circuit (wire the line directly to the Start button and 'holding circuit' contact).
Finally rename, the Start button to be "Reset".
Click to expand...
And you get what I offered in post #20........:)
 
Besoeker said:
So, I fail to see why you think I'm wielding one. (a shovel - ice)
I'm done with this.
Click to expand...

I suspect we have a failure to communicate* caused by an American idiomatic expression. "Put down the shovel" in this context means you have appolozied enough. More is not going to help. The comment was not meant to be demeaning.

ice

*Possibly another American idomatic expression. From the movie Cool Hand Luke - maybe thirty years ago.
"What we've got here is failure to communicate."
 
I think the distinction between restart and reset is purely that the textbook circuit directly controls the motor, and whenever you push the start button the motor starts.
If instead you put the same circuit on the line side of the existing motor controls you now have a reset circuit. Pushing the button just enables the normal controls rather than directly starting the motor.
The reset circuit could be incorporated into the existing controls so that the contactor only switches control lines and does not have to carry full motor power.
All of this seems obvious to a person with controls background, but may be a conceptual leap to someone coming in cold. :)
 
GoldDigger said:
I think the distinction between restart and reset is purely that the textbook circuit directly controls the motor, and whenever you push the start button the motor starts.
If instead you put the same circuit on the line side of the existing motor controls you now have a reset circuit. Pushing the button just enables the normal controls rather than directly starting the motor.
The reset circuit could be incorporated into the existing controls so that the contactor only switches control lines and does not have to carry full motor power.
All of this seems obvious to a person with controls background, but may be a conceptual leap to someone coming in cold. :)
Click to expand...

Yes. I am hearing three levels of controls. This is where I work with the client to write up a control document detailing exactly what each level does. This one is pretty simple. But if there is ambiguity, then the client won't be satified.

ice
 
iceworm said:
I suspect we have a failure to communicate* caused by an American idiomatic expression. "Put down the shovel" in this context means you have appolozied enough. More is not going to help. The comment was not meant to be demeaning.
Click to expand...
Here we'd see it as digging, or continuing to dig yourself into a hole. That would not be taken as a compliment. .
I have seen it used that way there too - my wife is a southern belle - very both I might add - so I have some knowledge of idiomatic expressions from both sides of the pond.
I'm also aware that the USA is a very large and diverse country and the diversity in the use of idioms across the states.

I'd give the usual guff - two nations divided by a common language. Except that such diversity occurs within both nations.

Enough. I offered a simple, workable solution to the original problem.
 
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