Confused on 220V plug & socket

[scott vroom]

I have a very basic misunderstanding of the 220V requirement for my new TS. My understanding was that I needed a 20A double breaker in the load panel from which I would run red, black, white, ground to a 220V recepticle. Grizzly is recommending a NEMA 6-20 which has connections for 3 wires not 4. And, the TS wiring is only white, black, ground...no red. Can someone explain to me what I am missing? What type of breaker do I need? Single pole? If so, then I don't understand the distinction between a 110V 20A and a 220V 20A if both have only black and white conductors and are run off a single pole breaker.

Thanks-
Scott

[Dan Friedrichs]

In your breaker box, you have access to 4 conductors (hot1, hot2, neutral, and ground). Connecting between hot1 and neutral gives you 120V. Connecting between hot2 and neutral gives you 120V. Connecting between hot1 and hot2 gives you 240V.

All circuits (either 120V or 240V) require a safety ground wire, as well.

Your TS uses 240V. You need 3 wires to run it (hot1, hot2, and safety ground).

Regular 120V appliances need 3 wires, as well. However, those are hot1 (or hot2 - one or the other, not both), neutral, and ground. Roughly half your household 120V circuits are connected to hot1, and the other half are connected to hot2 (to balance them).

You do need a double-pole breaker - it will connect to both hot1 and hot2. Then you need a safety ground wire. 3 wires, total.

For a 120V circuit, you only need a single pole breaker because there is only one "hot" wire - the neutral wire is at (or close to) ground. For a 240V circuit, you need a double pole breaker, because both hot1 and hot2 are "hot" relative to ground. Thus, you need a way to shut both of them off (hence, a double-pole breaker).

Wiring 120/240 circuits seems like it should be easy, but in reality, there are some small, but very important, details that many DIY'ers don't notice. If your screwdriver slips and lands in the wrong place, it could EASILY kill you (and it's not a matter of there being a "small probability" - touching a live 120V circuit is like driving your car into a tree. You might walk away...you might not...). If you aren't TOTALLY sure what you're doing, do the right thing and hire an electrician.

[scott vroom]

OK, I've done some research on the web and it appears that I need a double pole 20A breaker with 2 HOT leads and NO NEUTRAL to the socket. Does this sound right? It's counter-intuitive to me to omit a neutral, I guess I need to bone up on fundamentals of electricity.

Am I on the right track with a 20A double breaker and 2 hot leads + ground and no neutral to run my table saw?

Thanks!!

[Bruce Volden]

Scott,

It sounds to me, from your description, that your saw came pre-wired for 110VAC and requires a 20A breaker-hence the black/white/ground which you mention. For 220VAC you will need to "re-wire" the motor and there should be a wiring diagram on the motor plate. Once this is done then you can wire the supply (outlet) with the 3 wires needed-black/red/white. I "think" the ground is not needed as that is tied to the neutral "bus" in the load center~ AKA breaker box. If the saw was recommended a dedicated 20A breaker @ 110VAC you will be OK with a 15A 220VAC double throw breaker @ the box. I don't know the codes in your area but this kind of stuff is pretty straight forward. Anybody else???

Bruce

[scott vroom]

Dan, that was a very clear explanstion....thanks. I indeed purchased 20A double breakers for my load center. You mentioned a "balancing" between hot 1 and hot 2. Are load center lugs constructed in such a way that alternating lugs are connected to Hot 1, Hot 2, Hot 1, Hot 2, etc? If so, then I guess that guarantees distributed load no matter what placement of the double breaker. Is this corrrect?

Again, thanks very much. I have extensive experience with 120V and have completely wired my house including installing a new main panel and doing all wiring. I just have had little experience with 240V and have never encountered a 240V w/no neutral.

BTW, I've installed a new load center in my shop area. I installed a 60A 240V breaker in the main panel, pulled #6 THW through 1" conduit to the new load center (2 hot, 1 neutral, 1 ground).

[Dennis Ford]

You do need a double pole breaker for the 220v. The wire color is confusing you. The four wire circuit you described has two hot wires, a neutral and a ground. The three wire circuit has two hot wires and a ground (no neutral). Three conductor wire often comes with black, white & green, the white wire should be wrapped with black tape near the ends to identify it as a hot wire.

[scott vroom]

Dennis, thanks. As Dan explained, I should be using a 3 wire 220V connection for my Grizzly TS: 2 hot, 1 ground and no neutral off a double pole 20A breaker. I believe this is what you are saying as well, correct?

[Don Jarvie]

A few things to chine in here...

1st is to make sure the motor is wired for 220. There should be a wiring diagram on the motor or in the manual. It will entail rearranging the wires to match the diagram. Example- 1,2 5 to the black wire of the cord and 3,4 6 to the white. The ground (green) to the green of the cord. It should be marked on the saw which way it was wired at the factory.

2nd- wire the outlet from the box to the black screw, white (on my outlet one of these was indicated, can't remomber which one) to the other and the ground to the ground screw.

3rd - At the box the black and white go into the breaker and the groundd to the side bar with the rest of the grounds.

for 220, Both the white and black are considered hot where in 110 the black is hot (into the breaker) and the white is neutral.

It's pretty easy to do.

[scott vroom]

Thanks, Don. I'll try to view the motor wiring tonight, If I have questions or doubts I'll call Grizzly tomorrow. They spec the saw at 220V so one would hope they ship the motor already set up for 220V.

I installed 20A double breakers in the panel and ran RED (Hot 1) and BLACK (Hot 2) + ground to the gang boxes. I'm running THHN through surface conduit so decided to use red rather than white to designate hot 1. Seems this would be the safer route in the event someone else ever serviced the gang boxes.

Thanks-

[John Coloccia]

I just have had little experience with 240V and have never encountered a 240V w/no neutral.

You would run a neutral if your appliance or tool required 120 service as well. For example, my cyclone needs 240 for the motor (so 2 hots and a ground), but I also need 120V for the remote control and relay. I could plug the remote into a separate 120 outlet, but instead I wired up a box that used the 4th wire (i.e. the neutral) to generate 120 and drive the remote. Many appliances do this internally. My washing machine, for example, requires a neutral. Since the remote was designed for 20A service (not the 30A that is protecting the motor), I used combo fuse/switch to protect the wiring in the remote and the relay.

Since we're on the subject of shop wiring, the other thing I did was wire EVERYTHING with 10 gauge. This came in handy since I just finished changing the configuration of the shop and I was able to convert a bunch of 20A/120V outlets into 30A/240V outlets simply by installing a new plug and switching a couple of terminals around at the box. You just have to watch your conduit and box fill (box fill can be the killer sometimes).

[Rick Moyer]

Sounds like you got it right. The saw is wired 220, two hots--blk and wht w/blk taped end (to designate hot), and grn for ground. I just wired up my 0691 the other day. I added an extension cord as the original wiring was only six feet, I needed about 8-9 ft.

Thanks, Don. I'll try to view the motor wiring tonight, If I have questions or doubts I'll call Grizzly tomorrow. They spec the saw at 220V so one would hope they ship the motor already set up for 220V.

I installed 20A double breakers in the panel and ran RED (Hot 1) and BLACK (Hot 2) + ground to the gang boxes. I'm running THHN through surface conduit so decided to use red rather than white to designate hot 1. Seems this would be the safer route in the event someone else ever serviced the gang boxes.

Thanks-

[Jim O'Dell]

The 3 hp Leeson motor on the G0690/691 is 220/240 volt only. Can't be wired 120. The color wires you quote for the 3 prong Nema 6-20 is confusing to the normal color scheme, but it is 2 hots and 1 ground, no neutral as has already been posted. Re-mark the hot wires black and red, and use the bare as ground and all will be fine. Enjoy your saw!! Jim.

[Jason Strauss]

The E.S.P. on this site is often freaky! I'm just getting ready to pull the trigger on a new Griz 0690. I was at Menards today to try and figure out what I needed to get 220v to my garage. This thread has explained everything! Thanks, guys!

[Dan Friedrichs]

You mentioned a "balancing" between hot 1 and hot 2. Are load center lugs constructed in such a way that alternating lugs are connected to Hot 1, Hot 2, Hot 1, Hot 2, etc? If so, then I guess that guarantees distributed load no matter what placement of the double breaker. Is this corrrect?

That's correct. If you look how the bus bars are arranged, the hot1 and hot2 leads from the power company come in the top, then the bus bars usually alternate left and right - that way, when you plug a double-pole breaker into 2 adjacent slots, you get hot1 and hot2.

VERY smart idea on using the red wire. That certainly insures that no one will mistake it for a neutral in the future.

[Wayne Cannon]

Sounds good. Running a red wire instead of the white is great, but unnecessary.

While it is required that the hot wires be either black or red, and definitely not white; when converting from 120 V (black + white) to 240 V, you don't have to run a new wire. You can simply color the white wire with a black or red magic marker, or tape both ends of it with black or red electrical tape.

It's ok to have two black wires for 240 V -- having black and red simply makes it easier to distinguish one from the other should you ever have a need.