# Help with Allen Bradley 709 Magnetic Switch



## jbaccell (Jan 13, 2021)

Hi,

This is my first post but I am a long time lurker.  I am hoping through the colletive wisdom of the members I might get some guidance on the Allen Bradley 709 that is mounted to my Gemco Shaper.  The shaper has a 3 phase 3 HP Baldor Motor that was originally wired for 480 volts.  I rewired the motor to 240 and changed the "N" type heater coils to the proper size for the higher amps the motor will run at on 240 volt.

The intermittent problem I now experience is sometimes when I hit the start button, the motor jumps and the switch will smoke (not good I know).  I have to jog the switch and then the motor will start and run properly.  It almost seems like the coil is not strong enough to activate the switch.  Sometimes, it works fine with no issue whatsoever.  After initially experiencing the problem today, I kept turning the motor on and off throughout the day and it worked perfectly.  Nothing is getting hot and the motor runs fine.  Aside from any advice and guidance my question is am I suppose to change to coil in addition to the heaters I already changed?

I attached a photo of the switch including the coil.  Making things even more challenging is the decal on the inside cover is oil soaked and almost impossible to read.

Thank you in advance for any and all comments, suggestions, guidance etc... I sure appreciate it as I am at a loss how to fix it.

Thank you.

Joe


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## benmychree (Jan 13, 2021)

Yes, you need to change the coil as well as the heaters when changing operating voltage, some coils are dual voltage, some are not, that one is not. Some starters may use a reduced voltage transformer kicking down to 24 volt, obviously, that one is not.  I had some equipment with starters from that era, could be as old as the 1930s or 40s.


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## jbaccell (Jan 13, 2021)

Thanks so much for your help, I truly appreciate it.  Would you know of any reference that I can use to figure out which coil I need?

Thanks again.

Joe


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## benmychree (Jan 13, 2021)

No, I do not, sorry!


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## jbaccell (Jan 13, 2021)

Thank again...


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## benmychree (Jan 13, 2021)

In a pinch, you could install a transformer to boost the voltage to the coil, but as old as the starter is, finding a suitable coil could be a problem, you may just want to replace the starter.


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## jbaccell (Jan 13, 2021)

benmychree said:


> In a pinch, you could install a transformer to boost the voltage to the coil, but as old as the starter is, finding a suitable coil could be a problem, you may just want to replace the starter.


Thank you so much for taking the time to help, I do appreciate it.


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## jbaccell (Jan 13, 2021)

benmychree said:


> In a pinch, you could install a transformer to boost the voltage to the coil, but as old as the starter is, finding a suitable coil could be a problem, you may just want to replace the starter.


John, would this work for me?In addition to the 3 Hp 3 phase motor, there is also a 240 volt 1/3 Hp motor for the rapid traverse that this would feed.






						SQUARE D MAGNETIC MOTOR STARTER CONTROL 5HP 20AMP 208-230VOLT 3-PHASE FOR AIR COMPRESSOR MOTORS - - Amazon.com
					

SQUARE D MAGNETIC MOTOR STARTER CONTROL 5HP 20AMP 208-230VOLT 3-PHASE FOR AIR COMPRESSOR MOTORS - - Amazon.com



					www.amazon.com
				




Again, my sincerest thanks for your help.

Joe


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## projectnut (Jan 14, 2021)

You should be able to find just the coil for a fraction of the price they're asking for the complete starter.  I had to do the same thing when I bought a Racine power hacksaw.  It has a 3 phase motor and was wired for 480 volts.  I found the proper heaters and coil new on eBay for less than $50.00.

Here's a bulletin from Allen Bradley listing all the replacement parts for the 709 series starters.  The coils are the first item on the first page.  About the only thing you'll need to know is the size (00 thru 5).  Then you can search using the part number provided.


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## jbaccell (Jan 14, 2021)

projectnut said:


> You should be able to find just the coil for a fraction of the price they're asking for the complete starter.  I had to do the same thing when I bought a Racine power hacksaw.  It has a 3 phase motor and was wired for 480 volts.  I found the proper heaters and coil new on eBay for less than $50.00.
> 
> Here's a bulletin from Allen Bradley listing all the replacement parts for the 709 series starters.  The coils are the first item on the first page.  About the only thing you'll need to know is the size (00 thru 5).  Then you can search using the part number provided.


Thanks very much for your help, I do appreciate it.  I wil give it a try.

Thanks again,

Joe


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## jbaccell (Jan 14, 2021)

Duplicate post, sorry...


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## jbaccell (Jan 14, 2021)

jbaccell said:


> Thanks very much for your help, I do appreciate it.  I will give it a try.
> 
> Thanks again,
> 
> Joe


Using the link you provided as a starting point, I did some searching.  Apparently, as Frank stated previously, this is a very old control.  I just ordered what I believe is a coil that will work.  I am grateful for the help that the both of you have provided.

Thank you so very much,

Joe


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## FOMOGO (Jan 14, 2021)

If you are replacing just the coil, make sure to clean all of the contacts in the starter. Mike


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## markba633csi (Jan 14, 2021)

Yes I going to suggest you might have some oil in the contacts causing the smoke, clean well
-Mark


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## jbaccell (Jan 14, 2021)

FOMOGO said:


> If you are replacing just the coil, make sure to clean all of the contacts in the starter. Mike


Thank you.


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## jbaccell (Jan 14, 2021)

markba633csi said:


> Yes I going to suggest you might have some oil in the contacts causing the smoke, clean well
> -Mark


Thanks, will do..  May I ask your technique to clean them?

Thanks again.

Joe


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## markba633csi (Jan 14, 2021)

Lighter fluid or alcohol should be ok
I wouldn't use anything strong like brake cleaner or acetone- it might soften plastic pieces nearby
You just want a gentle degreaser


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## Jim F (Jan 14, 2021)

markba633csi said:


> Lighter fluid or alcohol should be ok
> I wouldn't use anything strong like brake cleaner or acetone- it might soften plastic pieces nearby
> You just want a gentle degreaser


Ordered Tuesday, arrived today.









						ISOPROPYL ALCOHOL 99% - QUARTS
					

Isopropyl Alcohol 99% - 1 Quart to 16 Quart Packs in stock and ready to ship! Free, same day shipping Mon-Fri if order is placed before 2pm Eastern Standard Time (EST).




					isopropyl-alcohol.com


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## Bi11Hudson (Jan 16, 2021)

Allen-Bradley is a well known "C_adillac_" of industrial controls. It will be necessary to change the coil on the starter to 240 volts. With AB, no big deal. The starter is designed for such modifications. Even though it's an older version, the cost of a coil will be insignificant compared to replacing the entire assembly. Continued use of the starter, as is, will eventually damage the contacts. It would be wise to replace the coil ASAP.

There are starters available that cost little more than the coil will cost. From WWGrainger down to Grizzly. But, in my own opinion, the AB starter is worth repairing. It's that good. . . Stay with AB if you can. I can only offer 50+ years dealing with them as a perspective.

.


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## jbaccell (Jan 17, 2021)

Bi11Hudson said:


> Allen-Bradley is a well known "C_adillac_" of industrial controls. It will be necessary to change the coil on the starter to 240 volts. With AB, no big deal. The starter is designed for such modifications. Even though it's an older version, the cost of a coil will be insignificant compared to replacing the entire assembly. Continued use of the starter, as is, will eventually damage the contacts. It would be wise to replace the coil ASAP.
> 
> There are starters available that cost little more than the coil will cost. From WWGrainger down to Grizzly. But, in my own opinion, the AB starter is worth repairing. It's that good. . . Stay with AB if you can. I can only offer 50+ years dealing with them as a perspective.
> 
> .


Bill,

Thank you for taking the time to share your insight and many years of experience.  I have stopped using the starter in it's current condition and have ordered a new coil from a vendor on Ebay.  I should receive it next week and hopefully get this working properly.

Thank you again, I appreciate your help.

Joe


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## jbaccell (Jan 19, 2021)

Thanks to Jim, Mark, Bill, Mike, Frank and others, I was able to locate a coil on Ebay for $25.00 delivered.  I just installed it and made sure to clean the contacts thoroughly using alcohol.  SUCCESS!!!!!  She fired right up and works perfectly, I cannot convey how grateful I truly am.

Thanks again to all.

Joe


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