rewired TS from 120-> 240 Updated

[Jeff Fritzson]

I have been running my delta 36-675 since I acquired the saw in March on 240v. I rewired the motor, I have a link belt with machined pulleys, upgraded the wings to CI and the saw has been great. Today, after cutting some dados for some drawers, I turned the saw back on and it was moving at 1/4 speed or less. I immediately turned it off.

The motor was hot. I let it rest and rechecked all my wiring and tried again. The same thing. I removed the extension cord out of the equation and tried again. The same thing. I changed 240 outlets and tried again, the same thing.

Is it possible for my original wiring to be incorrect? It seems correct. Black to black, red to gray, yellow to white based on the wiring diagram on the inside of the motor. It would make more sense if it happened right away but after 8 weeks of use, I find it hard to believe that the wiring could be wrong but I have done worse.

I was under the impression that 240 should allow the motor to run cooler. Yet the motor seems quite warm. There is a good amount of dust but not even close to too much. I have been cutting poplar and soft maple for drawer construction with 1/4" dados using Freud dado blades at a 1/4" depth.

Any thoughts? I left Delta a message and thought I would get better results here.

TIA,
Jeff

[Tim Morton]

what happens if you rewire it back to its original 110v and plug it into a 110v outlet? Generally speaking there is no need to wire a 1.5HP motor at 220v. It IS possible that your 220v rewirte was done incorrectly, but i am not an electrical expert by any means. 220v is wired P1 wird to one leg of the 220v and T4 and T5 wired to the other leg. P2 is capped by itself and T8, T3, and T2 are capped together.

[James Biddle]

Also, did you check to make sure you have 240 at the receptacle instead of 120?

[Robert E Lee]

Check your breaker in the breaker box. I had one leg of a breaker go bad and it acted the same way. Never did find out why.
Bob

[Jeff Fritzson]

Thanks for the replies. I have not tried to rewire back to its original 110. I have checked the breakers (I have more than one 240 outlet) and the voltage and it all seems to work fine. I verified the 240 in each receptacle by hooking up the E16 bandsaw and it worked fine.

I have decided to bring it back to the service outlet tomorrow. It is well within its warranty period and opening up the motor is out of my comfort zone. I may try and set it back to it's original wiring and see the results.

I will keep you informed of the results and their response.

Thanks,
Jeff

[Tim Morton]

Thanks for the replies. I have not tried to rewire back to its original 110. I have checked the breakers (I have more than one 240 outlet) and the voltage and it all seems to work fine. I verified the 240 in each receptacle by hooking up the E16 bandsaw and it worked fine.

I have decided to bring it back to the service outlet tomorrow. It is well within its warranty period and opening up the motor is out of my comfort zone. I may try and set it back to it's original wiring and see the results.

I will keep you informed of the results and their response.

Thanks,
Jeff
I think that it should go back to the original wiring before bring it in for service...FWIW

[CPeter James]

As a guess, the starter relay is not releasing, or if no relay, then you have a capacitor problem. If the starter circuit stays engages, you get exactly the symptoms you have described. Is there a set of contacts inside the motor that are controlled by a governor assembly?

CPeter

[Dev Emch]

Hi Jeff...

When you said that you "re-wired" your motor, exactly what did you do? Your brief description of the wire job posted in your intial posting is only for the pig tail or connection cord. I got no mention of redoing any internal leads to the motor. This concerns me.

I am a three phase guy so I will not venture to be an expert in single phase motors. I hate them! But I did stay at a holiday inn a while back:rolleyes:

Dual voltage motors often have two sets of internal stator windings per winding group. Do not confuse these with the run windings versus the start windings. Single phase motors have an extra winding group called the start winding.

The two windings in each group are connected at one end. Depending on what voltage will be applied, the two windings can now be in series or folded back on each other to make them in parallel. So if your winding is rated at say 110 volts, then two of them will make up the group. By running them in series across 220 volts, you will see a 110 volt drop at the end of the first winding as it enters the second winding which in turn will drop to zero at the neutral. If the motor is running on 110 volts only, then by placing the two in parallel, each winding in the group sees 110 volts.

On the inside of the motor box cover or on the motor data plate, etc., there should be a diagram showing the connections. The various winding leads from the various stator winding groups exit the motor and are numbered in accordance with the data plate diagram or schematic. On a dual voltage motor, there should be two pictures. One is for high voltage and the other is for low voltage.

The various leads will be connected in accordance to one of these diagrams and the desired voltage on which the motor is to be run. You need to open up the motor junction box and verify that the run configuration is correct for the voltage your running. On a single phase motor, all these leads distill down to two power leads and a ground. On 110 volts, one will be hot and the other will be neutral. On a 220 or 240 volt setup, one will be left hot and the other will be right hot. Red versus black. Because 240 volt is differential and not single ended, you dont have a dedicated neutral. In either case, make sure your green lead or chasis ground is hooked up. DO NOT USE A GROUND LEAD AS A NEUTRAL!

As I said before, I have done this a million times in three phase systems. In a three phase system, you have three run winding groups in the stator and no start winding group. In a single phase system, you have one run group and one start group. I have done this once before on a lathe with a single phase motor and all the three phase concepts remain the same only adapted appropriately to single phase. Because newer motors are made in chiwan, I cannot vouch for how things are currently being done. They may be doing things a bit different these days. The three phase stuff is all the same. Also, on newer single phase motors, I have noticed the lack of clearly printed data plates. So you may need to contact the motor builder or machine supplier to obtain this information.

My concern over what you did or did not do is excess heat. It is possible that you have slowly cooked some of your windings. Bear in mind that the start winding group is designed to start the motor and not run it. When the motor comes up to speed, a centrifical cutout switch disconnects the start winding group from the stator. So one possible explanation of what your seeing is that your running the motor on the start winding and your run windings are toast. Heat is the arch enemy of electrical motors because it breaks down the varnish insulation on the stator windings themselves thus shorting everything together.

So your first task is to stop running the motor until you know what is or is not going on in there! Second, crack the motor junction box and verify your winding lead configuration. Third, reconfigure the motor to run on 110 volts before you did any changes. Give it a quick try. Does it start? Does it run? Any excess heat or smoke smell? If your motor does not wish to start, disconnect immediatly and dont push it. Remove your start capacitor and get it checked out. These are electrolytics and overvoltage and cook out chemicals and reduce the life span. Without this capacitor, you cannot generate the virtual rotating magnetic field needed to start the motor and you run the risk of frying your start windings.

Not being there and not seeing or *SMELLING* what is going on makes it difficult for me to acess where this motor actually is. Its possible that you have fried something. Its equally possible that you have a motor that is completely intact except for one or two incorrect connections. Or the motor may be somewhere inbetween these extremes. So reread this post and go out into the shop and find out what you know and what you have.

Good Luck...

[Jim Becker]

Did part of your rewire on the motor housing come loose? Did you check for it??

[Jeff Fritzson]

Jim,I did recheck the wiring that I changed and the wires that are outside the motor in the motor box cover where the wires come from both the switch and the internal motor.


Tim,
Thanks for the suggestion but I will keep the wiring as is and if there is a mistake I will learn but I am confident that based on Delta's instructions it is correctly wired. I know I do not have to wire a 1-1/2 HP for 240 but I like the idea of running 7 and 8 amps over two legs rather than 14-16 amps over 1.

CPeter,
Since there is a warranty in place, I feel more comfortable letting the service people check "under the casing" in the motor.

Dev,
The rewiring for the Delta from 100 to 220 has to do with the wiring in the motor box cover where the switch wires and the wires from within the motor are joined. The rewiring took place inside the motor box cover. I followed the diagram and had my questions answered by Delta. So I am confident about the wiring. However, you never know who you are talking to sometimes at the Delta help desk. The heat is my biggest concern as well, since I know the green wire is attached as ground throughout.

I have decided not to rewire to 120 for a couple of reasons. 1. I would prefer to run it at 240. 2. To rewire it would mean removing and resplicing a 120 connector on to the switch. I would just as soon let the "experts" look and let me know. 3. If it is my mistake I would rather learn what I did wrong and pay the piper now.

The worst they can say is that I messed up and they will not honor the warranty. I highly doubt that but you never know. At least they will have to explain why and give me a nice motor lesson. Delta has a reasonable reputation and I will see how I am treated.

I appreciate all the help. It appears there is no quick fix unless I want to open the motor housing and I am not ready to do that yet.

Thank you all for your input.

Regards,
Jeff

[Jerry Clark]

<TABLE class=tborder id=post186583 cellSpacing=1 cellPadding=6 width="100%" align=center border=0><TBODY><TR><TD class=alt2 style="PADDING-RIGHT: 0px; PADDING-LEFT: 0px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px"><TABLE cellSpacing=6 cellPadding=0 width="100%" border=0><TBODY><TR><TD noWrap>CPeter James (http://www.sawmillcreek.org/member.php?u=1605) http://www.sawmillcreek.org/images/statusicon/user_offline.gif<SCRIPT type=text/javascript> vbmenu_register("postmenu_186583", true); </SCRIPT>
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</TD></TR></TBODY></TABLE><!-- / user info --></TD></TR><TR><TD class=alt1><!-- message, attachments, sig --><!-- message -->As a guess, the starter relay is not releasing, or if no relay, then you have a capacitor problem. If the starter circuit stays engages, you get exactly the symptoms you have described. Is there a set of contacts inside the motor that are controlled by a governor assembly?

CPeter
</TD></TR></TBODY></TABLE>



It appears that it is in the starter circuit as CPeters suggested- My RS does this at times. Caused by the starter contacts not releasing- because of sawdust.:mad:

[Jeff Fritzson]

If this is all because of saw dust it will be very ironic as I am building a table saw workstation to gain better DC. An open contractor saw like this 36-675 makes it almost impossible, without some serious modifications to perform good dust collection. The workstation I am building will put the saw on the workstation without legs and an opening within a a set of drawers and shelves. This box will allow me to collect underneath the saw using my DC, with my new shark guard I will gain DC at the blade itself and then I only need to attach a cardboard/masonite mock up to cover the back where the motor sticks out (when I get this back up and running.)

Perhaps when I post pics it will all make sense.

[Jim Dunn]

You said you checked for 240v across the two hots, correct? But did you check for 110v from nuetral to both hots? Seems that maybe your shorting your self on voltage possibly. Remember 110v + 110v does not necessarily mean that you get 240v across both hots. It has happened to me.

[Jeff Fritzson]

Monday - Brought the motor in and after a brief exchange regarding replacement of their cast pulley with a machined pulley voiding the warranty, they saw things differently and responded very well. They first were going to replace the motor with a brand new motor. However, they are backordered until June 30. They then checked out the motor and could not get the motor to release from the start windings either. They thought they could give me an older version but that model is slightly longer and would not work for 45 degree cuts as the end of the motor would stick out above the table height. They felt bad about the delay and ordered a brand new motor. I offered to upgrade to a Delta X5 left or right tilt Unisaw at no charge if they felt really bad, but alas they did not bo for it.:D I guess I will focus on restoring that small lathe for the next 4-6 weeks.

Thank you for all the help and suggestions.