Baldor motor wiring for 115 AC for home use.

[Walther Shiner]

I have a Powermatic model 141 bandsaw I bought from a school. I assumed it was wired for 115AC. It ran fine at the school. In my home woodshop it does nothing - not even hums, as might indicate a bad capacitor. The plate on this motor identifies it as a L3507, 3/4 HP, 1725 RPM single phase, 115/208-230V, frame 56. The wiring diagram for this motor on Baldor's website shows 6 wires numbered 1 thru 8, there being NO NUMBER 6 or 7 wires, and (2) BRN (un-numbered) wires which connect to an optional thermostat. Having said all of that, the author of a previous thread on this website wanted to know how to wire this motor so that it would run on what I would assume is his house current, i.e., 115VAC, and his house wires would be a black "hot" wire, a white "neutral" wire, and a green "ground wire. The answer to this person's question was: "Tie 1, 3, and 8 wires together for Line A. Number 4 wire is Line B. Tie the J, the 2, and the 5 together for low voltage run." My issues/questions: There are (2) BRN wires each identified only with a letter "J" on the diagram. Connecting only one of the "J" wires will not do much, assuming there is a thermostat installed on his motor. Second question: Does the Line A and Line B comment correspond to the "hot" and "neutral" wires? He does not mention the green or "ground wire", and the L3507 wiring diagram does not show it, but I assume it would connect to a separate grounding lug on the motor and the other end connecting to the ground pin on the plug. I've tested the wiring on my motor as it sits and the green wire shows 115VAC, which I do not believe is correct. There are other issues also but if someone could give me some advice, I would be grateful. This motor is in the base in a cabinet under the saw and very difficult to remove to take to a Baldor repair center if all I have is a wiring issue. Thank you in advance.

[Ken Combs]

The brn wires are probably for a thermal overload switch, not a thermostat. Normally, such a switch is in series with the 'hot', black wire from the source.

First of all, does your motor have a thermal overload installed? Or two brn wires? If not you can ignore that portion.

Line A and B do refer to the white and black from the power source. And you're correct, green is never a current carrying wire in normal use. It's only used to provide a path to trip the breaker in case of an internal short to ground. Where are you measuring the voltage, inside the motor's wiring box?

It should be attached to the motor frame in some way.

If you could get a pic of the motor wiring with the cover removed it would be a great help.

[Walther Shiner]

Mr. Combs: Thank you for your reply. I dropped the saw on my right foot while unloading it from my truck to get it down into my basement several weeks ago. Foot is better but really prevents me from much manual labor right now so I have been trying to do some simple electrical troubleshooting until I can bend over far enough to ar least be able to loosen the motor mount to be able to turn the motor to get at the plate. There are (3) switches that operate the motor, all in series from the plug end; a magnetic switch req'd by OSHA, a push/pull large switch normally seen on machines of this type, and a simple light switch thing that I've seen on old Powermatic machines, which might be an original installation, the other two being required by some highschool or OSHA regulation. When running the saw at the school, the seller could not initially get it to run because the magnetic switch was humming. He finally got the machine to run so when I finally got it set up, the first thing I did was cut that magnetic switch off. That got power to the large push/pull switch. Machine still wouldn't run so I used a Fluke AC detector to see if there was a potential in the wires to the motor. I actually did not get beyond that light switch looking thing because inside the box where that switch was located I found a green insulated wire screwed to the switch grounding lug and the Fluke AC detector glowed brightly. I immediately unplugged the machine because if that ground wire is carrying the 115 VAC, and if I am sitting on a metal stool and touch the steel cabinet, I will get zapped. Tomorrow I will try to get the plate cover off the motor to see the wires inside. Very likely I will end up simply replacing what is on the machine now. It is likely the person who wired this machine was electrically challenged! Thank you, and I will post pics and my findings in the near future.

[Carroll Courtney]

Pics are a big help when it comes to electrical issues.Since it work at the school,maybe it was wired for 230v.Maybe you are applying 115v,lots of time people just stick on a cord cap but its not the correct cord cap.A cord cap that is made for 115v someone may have wired it for 230v but the cord cap at a glance looks like"Oh its 115v" but someone has it wired for 230v.Only way to tell is see how the motor is wired then go from there.Since the contactor done nothing which would indicate that the coil may be 230volts,so applying 115 volts did not pull it in.Get to feeling better then tackle the problem.Post some pics of your saw,I have couple but love seeing others PM

[John K Jordan]

Fluke AC detector

I like to use those little detectors as a final safety check before working on something but I want a good meter for debugging. I don't trust the detectors for tracing a circuit or debugging since they can miss things and they can get false readings.

With a meter you can know the exact electrical voltage on any any terminal RELATIVE to any other terminal or ground. For example, if concerned that you have 110v power on the equipment ground, first check between the chassis and some ground in your shop. Then check between the shop ground and the terminal the green wire is connected. Then between ground and other terminals. With the cord unplugged you can use the resistance/continuity mode to check for broken wires, shorts, switch function, etc., and trace the wiring all the way from the plug to the motor windings. Hint: I write down everything and draw a diagram. Usually by then any problem is obvious.

JKJ

[lowell holmes]

I agree with John. Meters from the borg are not expensive.