Contactor Overload Relay not working - need help

[jteneyck]

I got Ken Vick's mega jointer running today with the upgraded static phase converter he bought for it.  It comes up to speed in 3 seconds now and seems to run very smoothly.  I wired it so we could use the machine's normal on/off switches.  This SPC replaces a lower rated unit.  When I installed that one I couldn't get power to the motor and traced it to a thermal overload on the contactor.  I bypassed the contactor, temporarily, and the contactor closed when I pushed the start button and the motor started.  I didn't fool with the overload today when I installed the new SPC, but I'd like to resolve the issue for peace of mind. 

The contactor is a Telemecanique, made in USA which I didn't expect with that name:



Attached at the bottom of the contactor is this overload relay:



What's confusing to me is that the relay is rated for a normal range of 5.5 to 8 amps (now set at 8 amps, as I found it), but the motor has a FLA rating of 11.2 amps and draws around 10 amps when running with no load except turning the cutterhead.   There is a reset button on the relay, the red button at the right in the photo, but it won't reset when I push it.  The wires now connected to T1, T2, and T3 on the contactor were connected to the 3 lugs on the overload relay until I bypassed it.  

The former owner ran it on 230 V 3 phase power.  We're running it on 220V single phase power through a static phase converter.  He claims it ran fine.  If so, the relay must have been the appropriate size, though it seems undersized to me.  This is a new motor, but of the same 5 HP rating and amp. draw (actually, marginally lower) as the one it replaced. 

Anyone have any ideas of what's going on here?  Any input is appreciated.  Thanks in advance. 

John

[daddo]

Can't see the pics.

[jteneyck]

OK, let's try this:

[BloomingtonMike]

telemecanique is an Italian company and a divison of Schneider

I cannot see your pictures either.


Is it wired back through the coli and start circuit too? It needs more than just L1,L2L3 so it can disconnect the coil when it trips and open the contactor. But 95 and 96 between the coil A1 and the stop uttons NC contact

so:
overload 95 to A1 on contactor
and overload 96 to the NC on the momentary contact for stop.

[jteneyck]

OK, maybe now:





And this is what is on the side of the overload relay:

[jteneyck]

Thanks very much Mike.  Hopefully you can see the photos now.  Google Photos has some interesting "features"; seems I can't copy a photo that directly uploads from my phone to my account, it has to go through my PC first in order for it to be visible to anyone else.  Anyway, I think I have it figured out. 

I'll have to go study the wiring again to confirm, but I think it's wired as your schematic indicates.  If so, how can an 8 amp overload handle a motor drawing 11 amps?  The prior motor drew fractionally more amps.  Could the static phase converter being playing a role in this?  The fact that the overload relay won't reset has my scratching my head.

John

[BloomingtonMike]

Un hook motor at overload and see if it latches with contactor and overload wired only. It should.

[BloomingtonMike]

Any luck? Any more testing?

[jteneyck]

Any luck? Any more testing?

I haven't been up to Ken's this week, but I plan to go tomorrow.  Stay tuned, and thanks again for your help.

John

[BloomingtonMike]

Ok great. Looking forward to hearing more. You are a great guy too for helping him.