# Lathe revverse only



## j4872 (Feb 27, 2022)

Hello, 
Have read  most of  past threads relating  to this problem but unable to solve my problem  I am new to machining and very green to electrical. Will try to keep short
and on point. 
Lathe Model Smithy BZ239. 110v similar to ENCO 110-2034
Acquired lathe recently. Forward and Reversed worked, but Forward not working since  delivered and set up  in  garage
Forward hums  but very little movement and will trip circuit breaker.
Replaced both capacitors on motor
Tightened all wire screws
Emergency button  and other buttons work as expected
Switched power leads on micro switches and both appear to work fine.
 Assume wiring at motor is correct as it worked before. However the  wire leads out of motor are 5 blue
 and 2 red. The red is larger gauge than blues. So no idea which is what when attempting to wire motor direct to a pig tail.
Energizing contactors, cause set buttons  to recess.

* QUESTION *On testsing OHMs on wires from beginging of power source to contactors., I assume that the hot and common,( Black and White) wires should not have 
  an ohm reading when testing Black to White. However they do show a connection. This leads me to believe there is a short somewhere.  Is this a bad assumption?
Any advice would be appreciated. Thank you


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## cathead (Feb 27, 2022)

Motor windings have quite a low resistance so it is not surprising that that the winding would show continuity.  Depending
on the ohm meter and the ohms scale set, it is possible to measure the resistance of the winding.  Usually the ohm reading
would be an ohm or or so or even somewhat less than one ohm.  If one has an ohm meter that has a X1 scale, you may
be able to differentiate between a dead short()ohms) and the resistance of the motor winding.  Of course a winding may only
be partially shorted too so something to think about as well.  Also if the motor has a starter winding, the reading may appear
to be abnormally low.

Welcome to HM!


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## j4872 (Feb 27, 2022)

Thanks for reponse, but these readings are with motor removed and wire terminals on V1,V2,Z1,Z2 are not touching,  so should I still get a reading?


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## benmychree (Feb 27, 2022)

If the motor runs in one direction but not the other, I'd look elsewhere for the problem.


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## j4872 (Feb 27, 2022)

Ok that makes sense. So does it appear there is a short in the system with the ohms reading across the hot and common ?
If I disconnect the bridging of hot wire and common to each respective terminal on contactor, then readings before that bridge have no ohms reading when cross checked. Does that make since? Hope that explanation is clear .


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## cathead (Feb 27, 2022)

j4872 said:


> Thanks for reponse, but these readings are with motor removed and wire terminals on V1,V2,Z1,Z2 are not touching,  so should I still get a reading?



If you are reading the motor winding only, then yes you should read a low resistance.  On the other hand if a capacitor is
in series with the winding, it would show an open circuit.  

Benmychree is probably right so the problem could be elsewhere.


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## cathead (Feb 27, 2022)

Maybe with the power plug unplugged and the motor disconnected and the on-off set to forward, you could do
a test and see if the wiring is shorted on the way to the motor.

The process of elimination can be very helpful in determining where the problem lies.


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## j4872 (Feb 27, 2022)

OK will give that try and report back.
Thank you


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## silence dogood (Feb 27, 2022)

I had a problem similar to yours. Except when I put the motor on reverse, it would blow a circuit breaker. After taking the motor apart, I found the neutral white wire from start winding was pinched between the motor cover and the motor housing. Reinsulating the wire and carefully putting motor back together solved the problem. What had happened was at first the motor worked fine in both directions. But as time went on the copper on the wire became exposed and shorted to ground. On forward it was not a problem. But on reverse the neutral became hot and shorted to ground. I know your problem is not quite the same, but it is something to look at. Another thing to look at, do you have chattering when you first turn on the motor especially on reverse? The contacts on the drum switch and maybe the on/off switch could be burnt.  I had to replace mine (probably because of the short) and now everything works just fine. Hope this helps, good luck.


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## matthewsx (Feb 27, 2022)

I have a similar lathe branded Samson. Problem is likely one of the contactors, mine did the same thing when I got it home but I already knew I wanted to change it over to three phase with a VFD.

Highly recommend this option if you can afford it.

John


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## markba633csi (Feb 27, 2022)

Low ohm reading at power plug is probably the transformer primary- it's normal
Either the forward contactor isn't pulling or it is but there is a loose wire or the contactor is damaged/worn. The problem is an open, not a short.
Can you determine if the forward contactor is pulling?  Should make a loud clack like the other one.  Is there a carriage switch that selects forward and reverse? They sometimes give trouble.  Bad capacitors don't cause this type of problem; both directions would be affected.
Do you have the Smithy manual with schematic diagram?  The contactors look different as if one has been replaced already
Testing a system like this under power is a bit dangerous unless you know what you are doing- do you know anyone with some electrical experience you can pay/bribe/extort?
-M


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## j4872 (Feb 27, 2022)

Thanks all, for the suggestions and input.. all very  helpful. 

Switched the hot wires on motor and now have forward , and little to no reverse. So seems motor is fine.
Have ordered contactor replacements.

The contactor that is energized when depressing  the green activation button seems to be the culprit. Do you see anything wrong with switching  wires so the other contactor  is energized by  the green contol button and see if that works? Then, for sure would know it is the contactor causing the problem.
Thanks


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## j4872 (Feb 27, 2022)

markba633csi said:


> Low ohm reading at power plug is probably the transformer primary- it's normal
> Either the forward contactor isn't pulling or it is but there is a loose wire or the contactor is damaged/worn. The problem is an open, not a short.
> Can you determine if the forward contactor is pulling?  Should make a loud clack like the other one.  Is there a carriage switch that selects forward and reverse? They sometimes give trouble.  Bad capacitors don't cause this type of problem; both directions would be affected.
> Do you have the Smithy manual with schematic diagram?  The contactors look different as if one has been replaced already
> ...


Yes, both contactors clack, but the one on the left in picture hums even after contactor is pulling.
There is a  carriage lever switch that offers forward and reverse. Today I disconnected the wires on both micro switches. When open there was no ohms reading . When closed the each had ohm reading so from that result, assumed they were OK.
I have a schematic, for 220v set up, ( mine is 110,) but most all of wires seem to match location except for transformer terminals.The 110v diagram that I do have is almost impossible to decipher.


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## markba633csi (Feb 27, 2022)

I have the Enco manual that might be very close to yours electrically.  Have you asked Smithy about replacement contactors?
I was a bit suspect of the left one also- I think I see what looks like a crack in the plastic- I wager that replacing that one will fix you up.
Unless I'm mistaken the green button is for momentary forward jog only- at least it seem like it must operate that way from studying the schematic


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## j4872 (Feb 28, 2022)

Thanks Mark, these will be helpful


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## markba633csi (Feb 28, 2022)

When you go to replace one (or both) make sure to take copious notes about the wire numbers/positions
And of course, shut off all power
-M
PS If you can eventually convert the system to run 220/240 volts the contactor lifetime would be considerably extended- the current is halved so the arcing and pitting of the contacts is much reduced


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## j4872 (Feb 28, 2022)

Ok, Mark thanks for diagrams. I was able to determine which wire  to exchange on contactor so the  the momentary (jog) switch activated it.
It confirmed the one on left isbad.
 I have ordered 2 contactors,
relieved to know the exact problem.
 Not looking forward to rewire,as you say wire numbers and position is critical.
 Also thanks to everyone who offered input.
Judge


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## markba633csi (Feb 28, 2022)

BTW, where did you buy the contactors from?  Smithy?


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## j4872 (Feb 28, 2022)

I had left message for Smithy early today, but they have not returned call yet. Called around locally with no luck, so ordered them from AliExpress $26 for  2 shipped .
Ebay had  them for $37 each ,but  the seller was shipping  from China (2 weeks) so opted for ALi. Should arrive 10-14 days. 

FYI, if ordering from Ali only buy from merchants that ship with ALiExpress. If shipping with Caniro, you may never get package or 
can take 60 days or  more


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## markba633csi (Mar 1, 2022)

Cool. I've had good luck with Aliexpress,  although it usually took about a month for anything I ordered
-M


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## Illinoyance (Mar 6, 2022)

If the motor just humms you have power to the run windings but the capacitor is not connected.  Look for a loose or disconnected wire on th forward relay.  Also a bad relay is a possibility.


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## whitmore (Mar 7, 2022)

j4872 said:


> Ok, Mark thanks for diagrams. I was able to determine which wire  to exchange on contactor so the  the momentary (jog) switch activated it.
> It confirmed the one on left isbad.
> I have ordered 2 contactors,


Contactors are worth doing an occasional bit of preventive maintenance; have you tried cleaning
and burnishing the contacts?   Sometimes just dragging a dollar bill between the buttons
fixes it right up.   On fancy relays, use a twenty...


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## j4872 (Mar 7, 2022)

Illinoyance said:


> If the motor just humms you have power to the run windings but the capacitor is not connected.  Look for a loose or disconnected wire on th forward relay.  Also a bad relay is a possibility.


Thanks.. good input


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## j4872 (Mar 7, 2022)

whitmore said:


> Contactors are worth doing an occasional bit of preventive maintenance; have you tried cleaning
> and burnishing the contacts?   Sometimes just dragging a dollar bill between the buttons
> fixes it right up.   On fancy relays, use a twenty...


Thanks, good idea, but unable to locate where that is possible. Seems to be sealed within the contactor


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## j4872 (Mar 12, 2022)

It appears the contactors needed are not available for my lathe (4pole 110 coil ) and  will need to buy different contacators and transformer . My question, does converting to VFD eliminate contactors and transformer?
Thanks


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## mksj (Mar 12, 2022)

You can get contactors in about any configuration and coil voltage, there are lots of 110V contactors that could be used, as well as auxiliary switch blocks. You just need to match up the switch configuration, you can always go to a higher Hp rated contactor. Motor is single phase, so there is no reasonable VFD option w/o replacing the motor. VFD's do eliminate the contactors and require a direct motor connection, but then there are control issues with proper wiring the low voltage inputs for safety reasons.


			contactor 110v | eBay


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## j4872 (Mar 13, 2022)

Any good sources for  contactors?? cjx1 12/22 110 v 4 pole
Received  contactors for replacement, but unfortunately they are 3 pole 110v and I need 4 pole . They look exactly the same except,
4th pole has plastic insert. The vendor ( China) says it must be custom  and unable to help.
Smithy, the original seller of the Lathe BZ239, has none. Patrick their parts person ( super helpful ) has searched the wharehouse  and the internet with no luck.  If I am unable to find replacement, then Smithy has  different out-put contactors and  will need to replace both plus the transformer,
which will need to do if unable to replace the current contactors.Thanks


mksj said:


> You can get contactors in about any configuration and coil voltage, there are lots of 110V contactors that could be used, as well as auxiliary switch blocks. You just need to match up the switch configuration, you can always go to a higher Hp rated contactor. Motor is single phase, so there is no reasonable VFD option w/o replacing the motor. VFD's do eliminate the contactors and require a direct motor connection, but then there are control issues with proper wiring the low voltage inputs for safety reasons.
> 
> 
> contactor 110v | eBay


Thanks for clarification. The current contactor is 110 v, 110 coil, 4 pole and 4 auxillary with 2nc and 2 no and 110v to transformer. Do you think the teco cua-422








						CUA-422 Teco Auxiliary Contact 2A2B 2 Normally Open & 2 Normally Close  | eBay
					

Find many great new & used options and get the best deals for CUA-422 Teco Auxiliary Contact 2A2B 2 Normally Open & 2 Normally Close at the best online prices at eBay! Free shipping for many products!



					www.ebay.com
				



is the right match
Thanks
just noticed you are in Fallbrook. I am just east  in Pauma Valley


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## j4872 (Mar 13, 2022)

After checking more, I don't think this will work, because it does not have the 4 pole in and out that become active on energizing , plus the auxillary
that are  2 nc and 2no


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## mksj (Mar 13, 2022)

Maybe you should just contact the eBay seller with what you have and what you need. The contactor is available in either either 2NC and 2NO or 4NO, the same for the auxiliary contact block that can be added onto the contactor. You can also call Automation Direct, Wolf Automation, Eisen, etc. to as to the specifications and they can guide you. When you replace the contactor, mark all the wires with labels. I would replace both contactors.
The configuration that I can read on the 2nd one is 3TB41, I cannot read the first.








						3TB41 for sale | eBay
					

Get the best deals for 3TB41 at eBay.com. We have a great online selection at the lowest prices with Fast & Free shipping on many items!



					www.ebay.com
				




3TB41 Contactor,NEW Direct Replacement Siemens Contactor 3TB4122 110/120V 2NO2NC








						3TB41 Contactor 120V coil AC replace Siemens Contactor 3TB4122-0AK6 12A 2NO2NC  | eBay
					

Find many great new & used options and get the best deals for 3TB41 Contactor 120V coil AC replace Siemens Contactor 3TB4122-0AK6 12A 2NO2NC at the best online prices at eBay! Free shipping for many products!



					www.ebay.com


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## j4872 (Mar 13, 2022)

Have emailed ebay seller and will call the other. Thanks. The Siemens replacement you pointed out is the one I initailly oredered. Problem is it is a 
 3pole not 4. Same housing but 4 pole position is a plastic insert ( inert).  Will see what is recommended on Monday.


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## mksj (Mar 13, 2022)

If you are looking for 2NC/2NO for both the main contactor and the auxiliary contact then use the combination below or choose a different contactor configuration. The options below WEG are rated for 2 Hp @ 240VAC, they are mini-contactors, I use them frequently for smaller applications and they have worked well. Above 22A the contactor configuration is typically 3 P.  Alternative would be searching AliExpress. 

CWC016-00-22V18 - Contactor, 4-P 2NO/2NC, 120VAC, 16A, Mini, AC1=22A 








						CWC016-00-22V18
					

Contactor, 4-P 2NO/2NC, 120VAC, 16A,




					www.galco.com
				




BFC0-22 Auxiliary Contact 2NO 2NC 3-P








						BFC0-22
					

Auxiliary Contact 2NO 2NC 3-P




					www.galco.com


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## j4872 (Mar 13, 2022)

mksj said:


> If you are looking for 2NC/2NO for both the main contactor and the auxiliary contact then use the combination below or choose a different contactor configuration. The options below WEG are rated for 2 Hp @ 240VAC, they are mini-contactors, I use them frequently for smaller applications and they have worked well. Above 22A the contactor configuration is typically 3 P.  Alternative would be searching AliExpress.
> 
> CWC016-00-22V18 - Contactor, 4-P 2NO/2NC, 120VAC, 16A, Mini, AC1=22A
> 
> ...


Thanks, learning a lot with your input. The two, I am returning were from Aliexpress. Visually they were exact with one's I currently have, but the main contactor was 3 pole not 4 pole. Had 4 ports but 4th port was blocked with platic insert They said that is a custom configuration, so return item for refund.

Will also call WEG  Monday. However not sure WEG  will have, as  their catalogue does not list 4 pole configuration as needed
For clarity each contactor configuration:

 main contactor =  110v 4 pole, all 4 NO
 auxiliary contact =2NC, 2NO,  however only need 1 terminal with NC


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## mksj (Mar 13, 2022)

CWC016-00-40V18 Contactor, 4-P N/O, 120VAC, 16A, Mini, AC1=22A 





						Galco
					






					www.galco.com


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## whitmore (Mar 13, 2022)

j4872 said:


> Thanks, learning a lot with your input. The two, I am returning were from Aliexpress. Visually they were exact with one's I currently have, but the main contactor was 3 pole not 4 pole. ...



It's confusing, but a modern-ish Siemens listing shows lots of three-pole contactors, and
also an add-on option to make a fourth or fifth pole.   The original part number is not necessarily
still in production...  Siemens contactor document


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## tq60 (Mar 13, 2022)

Many industrial units are stackable. 

Allen Bradley and others, they can stack modules from single coil to increase size.

Also try calling grainger, have your old one in hand and see what they can come up with.

Brand no matter, just coil voltage, numbe of contacts and current.

Worst case, just use 2 for each...

Sent from my SM-G781V using Tapatalk


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## j4872 (Mar 14, 2022)

Ok Thanks MKSJ and TQ60. I think I had tunnel vision that 4 poles were needed on first row to match current contactor, when that thought was wrong

So if I understand the add auxiliary 
 continues the configuration as long as input and coil v match with add-ons  For example :  contactor  110v input, 110v coil 3pole NO plus auxiliary add-on 110v, 110v coil  2 pole NC,NO 
=  110v input 110v coil 5 pole 4NO and 1 NC.
is that correct?


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## mksj (Mar 14, 2022)

When adding auxiliary contact, it attaches to the contactor and operates the same. The difference is auxiliary contacts do not have the same current capacity as the contactor contacts, they are usually used to control other functions such as locking out the coil of the opposite direction contactor. Also note that some contactors the 4th pole is meant to be used as an auxiliary contact and not rated as the same current as the first 3 power poles. The 40 series WEG is 4 power poles L1-L4/T1-T4. The Auxiliary block needs to be matched to specific contactor frame and poles (at least on the WEG series).

This combination will give the same configuration as your current contactors, looking at the auxiliary block the 4 pole contactor's needs the BC4 series auxiliary contact block. Issue will be finding stock, but you get how these are configured and connected. 
CWC016-00-40V18 Contactor, 4-P N/O, 120VAC, 16A, Mini, AC1=22A





						Galco
					






					www.galco.com
				



BFC4-22 Auxiliary Contact, 2NO & 2NC








						BFC4-22
					

Auxiliary Contact, 2NO & 2NC




					www.galco.com


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## j4872 (Mar 14, 2022)

mksj said:


> When adding auxiliary contact, it attaches to the contactor and operates the same. The difference is auxiliary contacts do not have the same current capacity as the contactor contacts, they are usually used to control other functions such as locking out the coil of the opposite direction contactor. Also note that some contactors the 4th pole is meant to be used as an auxiliary contact and not rated as the same current as the first 3 power poles. The 40 series WEG is 4 power poles L1-L4/T1-T4. The Auxiliary block needs to be matched to specific contactor frame and poles (at least on the WEG series).
> 
> This combination will give the same configuration as your current contactors, looking at the auxiliary block the 4 pole contactor's needs the BC4 series auxiliary contact block. Issue will be finding stock, but you get how these are configured and connected.
> CWC016-00-40V18 Contactor, 4-P N/O, 120VAC, 16A, Mini, AC1=22A
> ...


OK spoke with Galco  and ordered . Should be 12 days or so. Thanks so much for the help, very educational and informative. Good knowledge
to have in the future
Judge


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