Allen-Bradley 709 TOD

G

geshka

Aluminum

Joined

Sep 9, 2016

• Sep 18, 2021

• #1

Hello folks.

Restoring K.O.Lee surface grinder and having issues with electric wiring. For some reason cannot make spindle motor working. I was applying three phase and manually moved AB starter armature - motor is starting. Something is wrong with control circuitry. SO I am looking for any info about those AD 709 starters/contactor What are those two additional modules on a sides ? What are those push levers for ? what are these round knobs ? Any help will be greatly appreciated.

 

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JST

Diamond

Joined

Jun 16, 2001

Location

St Louis

• Sep 18, 2021

• #2

They look like overloads, and would act to open the contactor, normally by opening the control power to the contactor.. That could have something to do with your problem.

That bluish stuff, is it corrosion? That won't help.

 

rons

Diamond

Joined

Mar 5, 2009

Location

California, USA

• Sep 18, 2021

• #3

Who ever is using that bare copper bundle as a tie wrap deserves a merit badge. The strands are hanging above a high voltage component.

Remove every connection and clean all the corrosion with vinegar or phosphoric acid.
Do this one wire at a time and you won't have a chance to screw anything up.
Then push in those white overload reset buttons.

I suspect electrical discontinuity.

 

G

geshka

Aluminum

Joined

Sep 9, 2016

• Sep 19, 2021

• #4

Yes, indeed, this is corrosion - machine spent some time on a junk yard.

 

G

geshka

Aluminum

Joined

Sep 9, 2016

• Sep 19, 2021

• #5

rons said:

Then push in those white overload reset buttons.

Click to expand...

Thanks for the answer - Rons
So those half-round buttons are overload protection and do you know what are these rounded for ? They are not rotating or moving up or down.

 

Just a Sparky

Hot Rolled

Joined

May 2, 2020

Location

Minnesota

• Sep 19, 2021

• #6

Left to right:

Overload heater, auxiliary contact jumpered to coil, three power contacts and then another overload heater.

Old style three phase starter with only two heaters before that became illegal.

Judging by the visible corrosion, your contacts are probably filthy. Strip it down and clean the contacts by rubbing a dollar bill between them - especially those overloads.

 

rons

Diamond

Joined

Mar 5, 2009

Location

California, USA

• Sep 20, 2021

• #7

geshka said:

Thanks for the answer - Rons
So those half-round buttons are overload protection and do you know what are these rounded for ? They are not rotating or moving up or down.

Click to expand...

The half-round while buttons are manual reset buttons.

I suggest that if you are not sure then just remove the control while properly labeling every wire. Maybe your picture above is good enough.
Then clean the heck out of it. Take a close-up picture of the thing for a better evaluation. The eval is free.

 

Last edited: Sep 21, 2021

TDegenhart

Diamond

Joined

Mar 26, 2011

Location

Geneva Illinois USA

• Sep 20, 2021

• #8

The round white objects are heaters for the overload relay. Current pass through them which then heats a stem that is called a "solder pot". There is a spring loaded rod inside the sleeve that held in place with solder. When the heater gets too hot because of an overload, the solder melts, the rod rotates and opens a set of electrical contacts thus shutting off the motor. Once the overload cools the solder solidifies allowing the ol to be reset by pushing the half round white buttons.

Tom

 

rons

Diamond

Joined

Mar 5, 2009

Location

California, USA

• Sep 21, 2021

• #9

I removed my guess about the round pieces being a knob.
I know the heaters are directly below secured by two screws. Are the two round cylinders on top of the heaters just handles?

 

G

geshka

Aluminum

Joined

Sep 9, 2016

• Sep 21, 2021

• #10

Looks like heaters - I unscrewed two screws and detached it for cleaning. Body is ceramic, not plastic and it seems to be a resistance (need to measure with better ohmmeter) It is sitting on the brass stem (loosely)and heating it - as TDegenhart suggested.

I am in process of cleaning all the contacts and wires. Hopefully it will work.

 

TDegenhart

Diamond

Joined

Mar 26, 2011

Location

Geneva Illinois USA

• Sep 21, 2021

• #11

geshka said:

Looks like heaters - I unscrewed two screws and detached it for cleaning. Body is ceramic, not plastic and it seems to be a resistance (need to measure with better ohmmeter) It is sitting on the brass stem (loosely)and heating it - as TDegenhart suggested.

I am in process of cleaning all the contacts and wires. Hopefully it will work.

Click to expand...

The heaters are sized for the motor they are used with. A resistance check will do no good other than saying the heater is good or open. The correct heater is selected from a chart from A-B with motor full load amps (FLA) and the correct heater to be used. There probably is a heater table pasted inside the enclosure.

Tom

 

G

geshka

Aluminum

Joined

Sep 9, 2016

• Sep 22, 2021

• #12

Thanks Tom. No paper was found inside the electric box -hopefully it was properly picked by manufacturer, Anyway - I am isolating issue right now.

 

G

geshka

Aluminum

Joined

Sep 9, 2016

• Sep 30, 2021

• #13

Thanks folks. I found and issue. It was rewired by somebody later - I don't believe manufacturer did that - and this added wire was broken in the middle...