problem with new (used) band saw

I recently bought a used Rockwell bandsaw, which had been refitted with a Baldor 1 hp motor, that was set up to run on 220V. I was told that I could rewire it to run on 110V, which is all I have in my garage. The saw ran on 220v when I tested it just fine.

So, I dutifully tried to make the change, but now it does not run. I=92m hoping someone can tell me my mistake.

Here=92s what I did: The motor had 2 schematics on it, for =93low voltage= =94 and one for =93high voltage.=94 The high voltage schematic showed this: wires #2/3/5 together; wire #1 alone (which I found to be connected to the cord=92s brown wire also); wire #4 to =93line=94 (I found #4 to be connected to the cord=92s black wire); wires #J/8 together. This is, in fact, how it was wired when I opened it up.

The second schematic showed this: wires #1/3/5 together (which I left also connected to the cord=92s brown wire); wire #4 to =93line=94 (which I left connected to the cord=92s black wire); wires #2/J/8 together. I reconnected things following this schematic (in other words, I moved #2 from 2/3/5 to J/8 and connected 1/brown to 3/5; I left 4/black alone).

[As a sidenote, the motor also indicated that =93to reverse rotation interchange #5 and #8=94=97since #s 5 and 8 had been switched in the existing wiring I found, and therefore rotation had already been reversed, I also treated #5 as #8=85including all of the descriptions above, where I=92ve already substituted 5 for 8]

Then, I switched the male plug. The 220V plug had green, black, and brown wires going to it; green connected to =93G=94, black connected to =93Y=94, and brown connected to =93X=94. I put on a new 110V plug and connected the green to the green screw, the black to the brass screw, and the brown to the silver screw.

It does not turn on now. Please help! I really appreciate it. I don=92t have much money and really need to get this working=85

Reply to
bob
Loading thread data ...

Sounds very complicated to me. I know it's a bandsaw and therefore woodworking related - sort of - but maybe you should direct you question to

alt.engineering.electrical

However, do beware there are some foul mouthed idiots there who love to hurl abuse at people and each other. They don't know anything either. Best put a killfile on domain @webtv.net, which is where some of them post from, before you start.

Reply to
Stuart

So, I dutifully tried to make the change, but now it does not run. I?m hoping someone can tell me my mistake.

Here?s what I did: The motor had 2 schematics on it, for ?low voltage? and one for ?high voltage.? The high voltage schematic showed this: wires #2/3/5 together; wire #1 alone (which I found to be connected to the cord?s brown wire also); wire #4 to ?line? (I found #4 to be connected to the cord?s black wire); wires #J/8 together. This is, in fact, how it was wired when I opened it up.

The second schematic showed this: wires #1/3/5 together (which I left also connected to the cord?s brown wire); wire #4 to ?line? (which I left connected to the cord?s black wire); wires #2/J/8 together. I reconnected things following this schematic (in other words, I moved #2 from 2/3/5 to J/8 and connected 1/brown to 3/5; I left 4/black alone).

[As a sidenote, the motor also indicated that ?to reverse rotation interchange #5 and #8??since #s 5 and 8 had been switched in the existing wiring I found, and therefore rotation had already been reversed, I also treated #5 as #8?including all of the descriptions above, where I?ve already substituted 5 for 8]

Then, I switched the male plug. The 220V plug had green, black, and brown wires going to it; green connected to ?G?, black connected to ?Y?, and brown connected to ?X?. I put on a new 110V plug and connected the green to the green screw, the black to the brass screw, and the brown to the silver screw.

It does not turn on now. Please help! I really appreciate it. I don?t have much money and really need to get this working?

------------------------------------------------------ I would take it to an electric motor shop. They could surely correct your wiring while you wait.

My take on your message is:

"low voltage" means 110v. The usual 110v cord has a black (hot) wire, a white (ground) wire, and a green (neutral) wire. "high voltage" means 220v. The usual 220v cord has a black (hot) wire, a red (hot) wire, and a green (neutral) wire. Sometimes other hot wire is white instead of red.

Unless you have a multimeter to test continuity, you may not be able to solve the problem by yourself.

What the schematics show is how to change the wiring of field coils from being in parallel to being in series. Jim

Reply to
Jim

That 110V will require several more amps than the 220V did. Make sure your circuit can accommodate them.

Reply to
Mule Skinner

Yes, true. The saw claims 12.4 amps and it's on a 20 amp circuit so if I don't use anything else there I should be ok.

Reply to
bob

Warning Warning.

Jim has his colours mixed up. GREEN is GROUND and NOT Neutral In the US White is neutral not Red. In fact red is not used in most places in line cords today. Red was GROUND in Germany many years ago. Blue is generally neutral in 230volt countries and brown or black for Line or active.. Be careful. If you are not sure get some professional help.

John G.

Reply to
John G.

I was describing cords for two different voltages. The black wire is always hot. The green wire is always neutral (or ground more or less). In 110 cords, the neutral wire is white. In 110 cords, the other hot wire can be red or white or (I suppose in the OP's case) brown. Some people say that if you are using three wire romex (which has black and white wires with a bare ground wire), you are supposed to paint the end of the white wires black to indicate that it is hot. I have only seen a green wire in 220v circuits (it is neutral which is not necessarily ground).

I believe that the OP is in over his head and should take the motor to an electrical motor shop.

Reply to
Jim

The green wire is NEVER neutral, it is ALWAYS earth ground, period end of report.

Lew

Reply to
Lew Hodgett

In the US (Europe is quite different):

Not always hot, though it is always *a* hot (it may be switched).

No! Green is ground. Ground and neutral are different animals.

Yes. If there is a neutral in 240V cords it is also white.

In *240V* (split-phase - US style) cords the second hot it is usually red, but I believe it can be anything other than green or white. (Blue is commonly used for the third phase in 3-phase).

In a 240V circuit you may "paint" the white wire black (or red) to indicate that it is a hot. It's done for the "traveling" wires in

120V 3-way circuits, as well.

Absolutely not! It most certainly is *NOT* neutral. The green wire

*MUST* be ground. Ground and neutral are different. 220V circuits may or may not have a neutral.

He sure as hell shouldn't listen to you. If you don't know what you're doing, please don't give advice. You could get someone killed!

Reply to
krw

2+ground is fine for a 240 volt circuit. 240v circuits do not use a neutral wire unless it's a multiwire circuit (like for a range, dryer, etc) that has to supply 120v as well as 240. Straight 240v only uses 2 hots and a ground.

Tom Veatch Wichita, KS USA

Reply to
Tom Veatch

I think that is probably the most sensible course though he may get better advice across in alt.engineering.electrical.

However, it is important to remember that whatever codes or regulations may say regarding new installations, these have changed over the years at different times in different counties and different states.

It is also important to realise that the internal wiring within a motor or appliance is not usually governed by such codes and a manufacturer can use whatever he fancies.

As far as the UK (240V) was concerned, the three live phase colours were always red yellow and blue, neutral was black and green was earth.

However, in order to save paying pensions to electricians, they changed the colours a couple of years ago, swapping over the functions of the blue and black wires, and, at the same time, turning red into brown. The fixed wiring within a domestic premises was Red and black with a bare earth but they changed that at the same time as the above, to Brown and blue.

Flexible cordage used to be a nice obvious red and black (Red for danger, "hot", nice and easy) with green for earth but they changed that around

20/30 years ago to blue, brown and green with a yellow tracer. Having said that, I've come across some very interesting colour combinations in the cordage for early Singer electric sewing machines! - presumably these were american imports.
Reply to
Stuart

I believe that most US codes call for four wire outlets with separate neutral and ground on all new domestic 220v installations that have outlets. If the equipment is to be permanently wired then it's a different story.

If US code is not an issue where you are then do what you feel appropriate.

Reply to
J. Clarke

I believe that is true now, however up until recently 3-wire 240V (H-G-H) were permitted as long as there wasn't a "significant" imbalance in the 120V legs. Driers and ranges usually did not have a neutral. As you point out, they do now but there are a lot of houses already wired with 3-wire circuits and they are still permitted.

Change "you feel appropriate" to "what the local code requires".

Reply to
krw

Local Jurisdiction rules? I know the codes here certainly don't require an unnecessary, unusable wire in a straight 240v circuit equipped with NEMA 6-XX receptacles. Circuits for ranges, dryers and other such loads that use 240v and 120v simultaneously are 4-wire circuits (2 hot, neutral and ground) with NEMA14-XX wiring devices, but that's because of the need for the circuit to supply 120v as well as 240v.

In those jurisdictions that require a neutral for a straight 240v circuit, what is done with the neutral wire? NEMA 6-XX devices don't have a provision for a third conductor so there's nowhere to connect it unless it's tied to the boxes and used as a duplicate grounding conductor. Or do all 240v plug-in loads have to be fitted with a NEMA

14 plug with the neutral connection left vacant?

Tom Veatch Wichita, KS USA

Reply to
Tom Veatch

Well, it's impossible for a straight 240v load to have any imbalance between the 120v legs unless there's a ground fault, and using the equipment grounding conductor as the neutral for the 120v supply in a dual voltage appliance is a big NO-NO in the NEC. Just for my education, do you know when the NEC last allowed that?

Tom Veatch Wichita, KS USA

Reply to
Tom Veatch

Driers and ranges used ground as the neutral. they only used 120V for the timers, so the *ground* current was deemed safe, saving a lot of copper.

It wasn't until recently. Like most code, this has been grand fathered. There is no requirement to change existing homes.

Don't remember the dates, but it's been in the last 20 years. My last house (built in '86) had a three wire connection to the dryer, but four to the range. Both were aluminum. :-(

Reply to
krw

But those are not "straight" 240v loads since there is a requirement to supply 120v to driers and ranges. It's not necessary to supply 120v to a 240v table saw. Supplying 120v in a 4-wire circuit certainly introduces an imbalance anytime the 120v is used. But for "straight"

240v, there's no possibility of an imbalance between the legs.

I think we're talking "apples and oranges" here.

If I understand you correctly, you're saying that, according to current codes (perhaps local interpretations), ALL 240v circuits, even the branch circuits feeding the 240v tools in my shop, have to be wired with 4-wire circuits and NEMA 14 outlets. NEMA 14 because if NEMA 6 receptacles are used, there's no way to pass a neutral connection to the load. That implies that my tablesaw (3HP/240v) would have to have a NEMA 14 plug even though there's no neutral wire in the power cord to connect to the (unused) neutral prong.

My shop was wired within the last 7 years by licensed electricians and passed by local code enforcement officers. Straight 240v branch circuits were not required to be 4-wire circuits nor did they require NEMA 14 outlets. In fact, except for the connection of the white wires to one pole of a double pole breaker instead of the neutral bus, and the presence of NEMA 6 instead of NEMA 5 outlets, they are identical to a 120v circuit. The neutral conductor is simply not used or needed for a circuit that supplies ONLY 240v.

Tom Veatch Wichita, KS USA

Reply to
Tom Veatch

Yes, I KNOW that, which is why I noted the small imbalance (I am an EE

- but this is not an EE group).

I never said it was. I was talking about loads where there *is* a

120V component. I didn't use 12-3 to my table saw either.

I guess so!

No, I'm saying that 4-wires (H-N-G-H) are _now_ required for all loads with a 120V component, but that this has only been the case for a short while. Up until perhaps ten or fifteen years ago loads with a small 120V component (dryers and ranges) could get away with a shared neutral-ground. These applications are grandfathered in existing homes, so they are still prevalent. Any application that has no 120V component (table saws and air conditioners, etc.) still do not require a neutral. There would be nothing to connect one to[*]. ;-) For the most part, the NEC makes perfect sense.

[*] At my PPoE the safety "experts" demanded a three-wire plug on a plastic clock, so my tech connected the green wire to a lug screwed to the plastic case. They were happy. :-/

Yes, this is fine, other than there should *NOT* be a white wire on the breaker, nor in the outlet box. This wire should have been "painted" red or black (I used red Sharpie when I installed my table saw recently). The only drawback I see to this is that the Romex isn't marked as 240V (it runs next to a 120V circuit). If someone taps into this thinking it's a 120V circuit he's going to get a surprise. I don't see a reasonable alternative, though.

I hope I cleared up any miscommunication.

Reply to
krw

HomeOwnersHub website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.