Allen Bradley 709 runs when manually engaged only

I'm wanting to remove the coil but can't figure out ho to actually do it! Not sure if I have to remove the entire starter from the box?
 
bradpj53 said:
Both connections to the contactor show 120v even when the start switch is not engaged; can that be right?
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Yes this is correct that you have voltage to the contactor, as there needs to be power for the latching circuit. Phase to phase should be 230VAC as I do not see a separate step down transformer. I have not worked on these older style contactors, as I usually replace everything with newer style versions with an overload thermal relay. The wiring to the contactor seems like it has been modified. I would most likely rewire it with newer contactor/overload relay, but would need to determine the wiring of the start/stop circuit. I think it may be difficult to get a replacement contactor of that vintage, I seem to also recall that the heater elements are only in two legs of the power.

It is possible to buy a new motor starter contactor with overload relay in a new enclosure and then wire it in with latch circuit.
 
Your overload heater is burned up on the right hand side of the contactor.
No power will flow through it .
You momentarily could test this by removing and jumping the overload heater terminals.
If it runs after the test, you know the OL is problem
 
The 709 is common and although old, they are very durable. Heaters are very cheap on ebay, I have a whole box I bought for a few bucks years ago. As said earlier, jump the bad heater with a wire and see if the machine starts up. You can remove the coil but it is rarely the problem. You do want to look at the contacts and see how pitted they are. A little scotchbrite will shine them up.

In the old starter world, the starter is cheap to find. The enclosure is difficult and often more expensive than the electricals. For those of us wanting to keep vintage stuff as original, The AB 709 is easy to source. I don't disagree that new is much more compact and reasonably priced but I've replaced more newer Euro contactors than the old NEMA large ones by far. The newer 709 will have three overloads but you won't fit it in the enclosure you have now. Dave
 
Ulma Doctor said:
Your overload heater is burned up on the right hand side of the contactor.
No power will flow through it .
You momentarily could test this by removing and jumping the overload heater terminals.
If it runs after the test, you know the OL is problem
Click to expand...
Both heaters are fine so the problem lies elsewhere.

Brad
 
Eddyde said:
It sounds like the problem might be with the "power lever" does that contact a switch?
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It's wired through the rotary switch; I'm trying to puzzle out the wiring diagram.
 
mksj said:
Have you checked the voltage to the coil? If the it has voltage then the contactor is bad, if not then it is a switch issue and and complicated to repair. Phase perfect gives symmetrical output, but it does pass through the L1 and L2 phases which I would connect to the circuit that goes to the coil.
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The wiring diagram for the motor and starter show a Wye figure; might I need a delta-Wye transformer for that?IMG_4243.JPG
 
This thread from the Practical Machinist forum may hold some clues; any insights here? Messages #19 and #20 especially.

my new old Clausing Colchester 13 Master Mk. 1 lathe

This past weekend, I purchased an older Clausing Colchester lathe at a local estate sale. The sale went from Friday to Sunday, and I left work early enough to get there on Friday afternoon. I bought a few things, but wasn't intending to purchase a lathe. But this model seemed so interesting...
www.practicalmachinist.com
 
Here is your starter. The problem will be with it or the start stop buttons, wye is irrelevent. Check that the reset isn't stuck and then start with the coil. There should be 120v on one side of it when the power is on but not the machine. When you press the start button, there should be 240 across the two leads. That is what energizes the coil. If you have 120v on one side only whether you press the start button or not, the stop normally closed chain is open and you need to examine those buttons. If you have 240 when depressing start, you have a coil problem. Those are more rare than button problems but I've replaced a few so it is not unheard of. Coils are fairly cheap on ebay but your starter doesn't look to be in the best of shape so I'd probably not attempt to just replace parts. A new one will be cheaper and fit into the existing enclosure.

I'm hoarding a few NOS old starters for machines I want to keep original and they do last forever if not abused.

N29 relates to 8.35 amps as that chart is hard to focus in. Dave
DSCN4271.JPGDSCN4274.JPG
 
I have yet to see good pictures but I can pretty much guarantee that there is nothing wrong with that AB contactor..
With the power off you should be able to ring your way through the control circuit..
You were able to make the motor run by manually actuation the starter correctable?
If not then you need to investigate the thermal overload section of the starter .
Break this problem into 2 sections.
1 control
2motor
 
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