# Allen Bradley coil #



## MDShunk (Jan 7, 2007)

"100-fl11b"


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## MDShunk (Jan 7, 2007)

it keeps changing my upper case letters to lower case.


```
100-FL11B
```


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## erics37 (May 7, 2009)

Kind of curious why the coil is being changed out. Eliminating the control circuit?


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## John Valdes (May 17, 2007)

erics37 said:


> Kind of curious why the coil is being changed out. Eliminating the control circuit?


Lots of combination starters use line voltage for the control circuit. At least they did when I was using them.
Some had transformers, but most just used what was available.

Has that practice been revised? I always disliked using 480 for push buttons and pilot lights.


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## MDShunk (Jan 7, 2007)

John Valdes said:


> Lots of combination starters use line voltage for the control circuit. At least they did when I was using them.
> Some had transformers, but most just used what was available.
> 
> Has that practice been revised? I always disliked using 480 for push buttons and pilot lights.


I'm not sure what standard (nfpa 79? Maybe something Euro?) required this ,but it's been maybe 10 years or better that panel mounted controls were 24 volts. Definitely no line voltage on panel switches, pushbuttons, and indicator lamps anymore. For that matter, none of the field I/O is line voltage without some really good reason.


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## don_resqcapt19 (Jul 18, 2010)

MDShunk said:


> I'm not sure what standard (nfpa 79? Maybe something Euro?) required this ,but it's been maybe 10 years or better that panel mounted controls were 24 volts. Definitely no line voltage on panel switches, pushbuttons, and indicator lamps anymore. For that matter, none of the field I/O is line voltage without some really good reason.


I don't think it is 79...all of the listed control panels that I have installed in the past 10 years have 120 volt devices on the doors. Also all of our field I/O, with the exception of the analog, is 120 volts.


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## te12co2w (Jun 3, 2007)

erics37 said:


> Kind of curious why the coil is being changed out. Eliminating the control circuit?


 The owners are revamping some of their equipment. The operator told me that the 120 volt control voltage was going to be removed. Don't know the reason. From the other posts, it sounds like this may be a violation of some standard? This is for a hot tar loading station.


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## erics37 (May 7, 2009)

te12co2w said:


> The owners are revamping some of their equipment. The operator told me that the 120 volt control voltage was going to be removed. Don't know the reason. From the other posts, it sounds like this may be a violation of some standard? This is for a hot tar loading station.


Well it's just kind of weird to me to see a 480 volt coil being utilized in a contactor. The control circuitry and components would have to all be 480 too and that is abnormal as far as I know.


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## tates1882 (Sep 3, 2010)

I see it quite often, mostly ag stuff but two years ago I had a two compressor system that was all 480 controls, brand new, ul listed, from Texas. It went into a car wash


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## JRaef (Mar 23, 2009)

NFPA79 does require control voltages to not exceed 120VAC (9.1.2.1), unless the coil circuit consumes 20A or more, in which case you can use line voltage through an interposing relay that breaks BOTH sides of the coil.

However, machines that have ANOTHER NRTL listing that is acceptable to the AHJ do NOT need to conform to NFPA 79. 


> 1.3.2
> This standard shall not apply to the following:
> (1) Fixed or portable tools judged under the requirements of
> a testing laboratory acceptable to the authority having jurisdiction
> (2) Machines used in dwelling units


Air compressors and their controls have their own separate UL listing category, so _*FACTORY BUILT*_ and listed air compressor systems fall into that category. It's still common to see line voltage controls on a lot of these air compressors, especially because a lot of them don't have any control devices on the door, they just have a pressure switch, an unloader valve and a starter. Some that do have control devices for the starter use the type that leave the contact blocks on the back panel and just have the operators on the door. 

But... if you MODIFY an air compressor system from it's ORIGINAL listed design, then you revert to NFPA 79 applying. 


> 1.3.1.1
> When changes other than repairs are made to machines
> that do not comply with the provisions of this standard,
> the changes shall conform with the provisions of this standard


So te12co2w, if your compressor was built with 120V control, you CANNOT change to using 480V control now without violating NFPA 79 specs for industrial machinery. Now mind you, there are no NFPA 79 police, but where that comes into play is that if, at some later date, someone gets hurt or killed by a 480V control circuit accident, OSHA will be all over the fact that the machinery was modified against code. And by the way, OSHA can now CRIMINALLY prosecute managers and supervisors who demand these kinds of safety violations. If you are not in that capacity you are OK from a criminal standpoint, but if you are, I'd refuse to do it or make someone above you insist on it in writing.


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## Southeast Power (Jan 18, 2009)

Oh man,
trouble shooting line to line voltage controls is way too much of a PITA.
The back feeds take quite a bit to work out when trying to find a problem.
And, 480 sucks the worst. Its just plain scary.


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## tates1882 (Sep 3, 2010)

jrannis said:


> Oh man, trouble shooting line to line voltage controls is way too much of a PITA. The back feeds take quite a bit to work out when trying to find a problem. And, 480 sucks the worst. Its just plain scary.


 man you nailed it. I chased a back feed for 8 hours right after I turned as a jman. There was a mix of 240 and 120 controls, was getting 120 back feed on a 120 ice cube neutral terminal, maintenance smoked 5 relays before they called, I finally called the boss. He comes out asks a few questions, grabs a 240v relay of the truck, calls it a day. Made me feel stupid but also was super irritating because he didn't fix the backfeed


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