Troubleshooting assistance needed for Delta Unisaw 34-806

[Jacob Pagliocca]

Hello, I recently upgraded to a Delta Unisaw Model 34-806, and am having some difficulties with getting it set up. Any and all suggestions are welcome. The problem is that I cannot get the saw to start with the start switch. I don't believe the motor is bad, because if I manually bridge the magnetic contactor, then it turns, and stays on (as long as I keep the contacts in place with my insulated screw driver). This has been the case before and after I have replaced the Magnetic Contactor Motor Starter #583-00-001-0066. In both cases I the mag coil hasn't seemed to turned on and engaged the contacts. I am fairly new to wood working, and even newer to electrical stuff, so if I have left out any pertinent information, or have ended up over looking anything obvious, then I greatly appreciate your patience and understanding. Below are any and all details I can think to list. Finally thank you to all who spend the time looking over this and offering their assistance. The Starter Diagram is attached, as well as the Phase a Matic Converter information.

I have found the instruction manual at: https://www.manualslib.com/manual/725906/Delta-Unisaw-34-801.html#product-UNISAW%2034-806
The Phase a Matic Instruction manual can be found here: https://phaseconverters.phase-a-matic.com/Asset/SIS.pdf

Saw: Delta Unisaw #34-806
Motor: 3 Phase, 5hp, 230v Motor #87-369
Phase Converter: Phase a Matic #PAM-900
Mag Contactor: #583-00-001-0066

[Paul F Franklin]

So when you push the start switch, the contactor doesn't pull in? Do you have the "connect as per line voltage wire connected to the 230V tap of the control transformer? Is the fuse blown?

[Paul F Franklin]

Also, do you have the correct overload relay and heater for the size motor you have? You could try *temporarily* jumping the OL contacts if you don't have a meter to check the overload relay.

Finally, I don't see it on the schematic, but the parts list includes an interlock switch, which might prevent the unit from operating if the cover is off.

[Bill Dufour]

Sounds like the stop switch circuit is open. If it stops when you remove the stick holding the contacts closed the stop circuit is bad. Maybe a loose wire or likely the stop switch has dust in it and is not closing
The stop circuit should be no resistance from end to end. Then when you pres the stop switch it is open with infinite high Resistance. You can jumper the stop wiring and see if it will hold in.
Bil lD

[Bill Bukovec]

What exactly are you jumpering with the insulated screwdriver? Terminals 2 & 3?

[Bill Dufour]

What exactly are you jumpering with the insulated screwdriver? Terminals 2 & 3?

I do not think he is jumping anything with the screwdriver. I think he is using that, instead of a piece of dry wood, to physically close the contacts. This should start the motor, and if held closed for a second or so, it should latch closed and keep running until the stop switch is pushed.
Bill D.

BTW: do not use a pencil, the graphite is a conductor! I have no idea if ink in a ball point pen is conductive or not.

[Bill Bukovec]

Thanks Bill, that makes sense. My next step would be to wire a light switch across terminals 2 & 3. Put this switch in the open position. Name this one Start.

Next, wire a switch across terminals 1&2. Put this switch in the closed position. Name this one Stop.

Then close the switch named Start and see if the magnetic coil kicks in.

[Charles Lent]

It's either an open stop circuit, the transformer, or the fuse. If you have power at the output end of the fuse, then it's most likely a wire connection problem or saw dust in the stop switch keeping the contacts from closing when you release the button. When my stop switch had saw dust in it, I could start the motor with the start button, but it would only run while I was holding in the start button. Cleaning the saw dust out of the switch and using emery cloth to clean the switch contacts was all that was needed to fix the problem. There is one auxiliary contact set on the contactor that is part of this circuit too. It also needs to be clean. It serves to latch the contactor in the on position and will produce similar results if it fails. Again, emery cloth cleaning of the contacts will fix it.

Charley