Grainfather s40 to 3 prong dryer outlet.

[z-bob]

The neutral wire on a NEMA 10-30 or 10-50 (10-50 is used for an electric range) is not a normal neutral. It has to originate in the service entrance panel, not a subpanel. So it makes a perfectly good and acceptable ground. The neutral wire from a subpanel is not safe to use as a ground. (unless it's a subpanel in an outbuilding that bonds the neutral again) Grainfather not knowing if a NEMA 10 is wired correctly is a little different than knowing if a NEMA 5 or 6 is correct; those can originate from a subpanel with no problems.

 

[InspectorJon]

so it just dumps all the used electrons that 'cooled' off to the dirt? which is why it doesn't work with a GFCI?

Regarding GFCI:
It provides no over current protection. That’s what a circuit breaker is for. The circuit breaker protects the wire from over heating. GFCI protection protects people. It will trip with a very small amount of current going to the wrong place. Far less than will cause electrocution.

Now both kinds of protection can be found in one circuit breaker device so that kind of confuses some people. But GFCI protection and over current protection are different things, sometimes provided by separate devices and sometimes it’s all in one device.

 

[bracconiere]

Regarding GFCI:
It provides no over current protection. That’s what a circuit breaker is for. The circuit breaker protects the wire from over heating. GFCI protection protects people. It will trip with a very small amount of current going to the wrong place. Far less than will cause electrocution.

Now both kinds of protection can be found in one circuit breaker device so that kind of confuses some people. But GFCI protection and over current protection are different things, sometimes provided by separate devices and sometimes it’s all in one device.

i'm loosley familar with the difference between them, one protects the house, and is slow. the other protects you, and is really fast. GFCI is like a accountant that makes sure, every electron that goes out charged comes back uncharged....

i'm not sure why i couldn't find a 250v 20a GFCI plug though? the one with both hot & neutral sideways...just 120v 20a plugs with the single sideways pin?

as island lizard said, is it because 220v is ALWAYS shared neutral-ground at the box?

 

[InspectorJon]

240 volts can originate in a main panel or sub panel, if it is wired that way. Most sub panels have 240 volt capacity. Neutral and equipment grounding wires are handled differently in a sub panel than a main panel.

240 volt circuits do no use a neutral conductor but should always include an equipment ground. The old scenario where a dryer or range used the third wire in a 240 volt circuit to function as a neutral conductor was confusing and potentially dangerous, thus it is no longer allowed.

The equipment grounding system is one of the most confusing parts of the electrical code. In general practice it simply connects all the bare and green wires together and bonds them to the utility neutral in the main panel and the earth. It gets confusing when sub panels and separate structures are introduced. I’ve seen a lot of electricians and jurisdictional inspectors get it wrong in obscure situations. All the experts can’t even agree on some best practices.

I’m pretty sure we have gone a lot deeper than that OP though when he asked if a dryer plug could be used for the Grainfather. I think the answer is it could be used but it is clearly debatable whether it should be. One would have to investigate the wiring at the origination point to be sure the equipment grounding is correct. Then one must decide if they want to live by the letter or spirit of the law.

 

[bracconiere]

I’m pretty sure we have gone a lot deeper than that OP though when he asked if a dryer plug could be used for the Grainfather.

probably right. (but i've learned a thing or two, and still kind confused...why do they sell 4 prong->3prong with the added ground wire to use...and not the 20a 250v plug to 3 prong with a similar ground wire to use?)

 

[z-bob]

probably right. (but i've learned a thing or two, and still kind confused...why do they sell 4 prong->3prong with the added ground wire to use...and not the 20a 250v plug to 3 prong with a similar ground wire to use?)

Perhaps because the overcurrent protection is wrong? (30A vs 20A) I don't know, but that is a plausible reason.

 

[bracconiere]

Perhaps because the overcurrent protection is wrong? (30A vs 20A) I don't know, but that is a plausible reason.

good point! but that would only effect the cord to the device right? so if I was rigging up an electric kettle, to plug into my dryer socket, just make sure to use wire rated for 30A?

edit: but then why would they sell them without the ground wire?

 

[z-bob]

good point! but that would only effect the cord to the device right? so if I was rigging up an electric kettle, to plug into my dryer socket, just make sure to use wire rated for 30A?

The cord to the device, and the device itself. (btw, the electrical code does not concern itself with cord-attached devices) I assume the GF will not be left running unattended for hours on end, so I would not worry about the breaker rating being 50% too high. If it starts to overheat, unplug it I would use 12 gauge high temperature cable. In smaller sizes it's called HPN. In #12 it'll be some kind of SJ-something but I don't remember what.

Edit: I have a 105°C cord on my heat stick. The markings on the jacket are hard to read, but it says SJEOW.

 

[bracconiere]

so if just the cord going to the device isn't rated for 30A and the breaker at the box is...then something like this for the OP's question?

https://www.amazon.com/AC-WORKS-3-P...t=&hvlocphy=1013509&hvtargid=pla-888414843968

it's got a built in 20a breaker, i think, for the plug conversion? (but still no ground?)

 

[z-bob]

12 gauge high-temperature cable is rated for 30A, but not continuous 30A. (at least it used to be, and that's not the sort of thing that changes) But you're not drawing 30A, only at the most 20. Does the GF have a detachable cord? Or a wiring box for hard-wiring it? Make your own cord with #12 cable and a replacement NEMA 10-30P plug (they are cheap), then you won't need any adapters. Even better, buy a replacement dryer cord with a molded plug, but those cables are pretty big so make sure it will fit through the strain relief clamp.

 

[bracconiere]

12 gauge high-temperature cable is rated for 30A, but not continuous 30A. (at least it used to be, and that's not the sort of thing that changes) But you're not drawing 30A, only at the most 20. Does the GF have a detachable cord? Or a wiring box for hard-wiring it? Make your own cord with #12 cable and a replacement NEMA 10-30P plug (they are cheap), then you won't need any adapters. Even better, buy a replacement dryer cord with a molded plug, but those cables are pretty big so make sure it will fit through the strain relief clamp.

LOL, man...that's what i was thinking..but thought it would be too complicated, and was trying to simplify.....still i'm just left more confused. that i'd have to convert the 20a 220v plug to four prong, then back to 3 prong to get the ground wire......

 

[RufusBrewer]

No I do not.
He may do what ever he want's to do. I just know that I wouldn't want a 30 A breaker "protecting" my $500 investment, a 15 A. rated appliance.
Cheers,
Joel B.

You plug your 100 watt lamp into your 15 amp circuit breaker.

I think the failure that circuit breakers protect equipment against is a short circuit. If my grainfather starts drawing 23 amps, I do not count on my 30 amp breaker to protect it. I am sure there are sections of the grainfather that would be damaged with 10 amps flowing through it.

 

[kartracer2]

@RufusBrewer You can do what ever feels OK & safe to you. Also read post #20, & 21 where I try to clarify my point. As I have said, I wouldn't.
Cheers,
Joel B.

 

[InspectorJon]

probably right. (but i've learned a thing or two, and still kind confused...why do they sell 4 prong->3prong with the added ground wire to use...and not the 20a 250v plug to 3 prong with a similar ground wire to use?)

The first adapter you speak of is a listed device made for a specific purpose, to plug a new dryer into an old receptacle. In theory there are an unlimited number of adapters they could sell. What they do sell is limited by demand. They only make ones that there is a significant demand for. You could maybe make your own but it would not be a listed device. Listed means it was tested in a lab environment and they know how it will perform when used according to instructions. Unlisted does not specifically mean unsafe, it just means untested. An unlisted, homemade device may or may not be safe.

Some of the listed products are a bit disingenuous. The dryer adapter you speak of assumes you will connect the ground wire to an approved equipment grounding source, which is a properly sized wire that goes back to the equipment grounding system in the panel. That is part of its listing. Pretty much nobody is going to do that. If one did go to that trouble then they might as well just install a four prong receptacle and skip the adapter.

 

[bracconiere]

If one did go to that trouble then they might as well just install a four prong receptacle and skip the adapter.

but then the dryer wouldn't work anymore!

 

[z-bob]

but then the dryer wouldn't work anymore!

Not sure if this is a joke or not. The dryer will work with a 3-wire or 4-wire cords; it doesn't care, and replacement cords are cheap. If you install a 4-wire cord on a dryer that use to be 3-wire, there should be a bonding screw or jumper wire or something that you have to remove in the wiring box. (it connects the neutral connection to the frame) HTH

 

[bracconiere]

Not sure if this is a joke or not. The dryer will work with a 3-wire or 4-wire cords; it doesn't care, and replacement cords are cheap. If you install a 4-wire cord on a dryer that use to be 3-wire, there should be a bonding screw or jumper wire or something that you have to remove in the wiring box. (it connects the neutral connection to the frame) HTH

but the dryer cord i learned, in my dryer epic. carries both 120v & 220v.....so the 3 prong GrainFather plug with the two sideways prongs, just carries 220v, with a ground also? i'm thinking, so if someone converted their dryer plug to the 6-20?..for the GF to plug into with proper ground...even if you swaped the plug on the dryer to match, it wouldn't work, would it?

 

[z-bob]

The dryer needs a 10-30 (3-wire) or a 14-30 (4-wire) outlet to plug into. It could be adapted to plug into a 6-30, but that would be wrong, and why would you do that because 6-30 receptacles are more expensive than 10-30s. Its 120V requirement is just one side of the 240V to neutral. In a 3-wire dryer, it pretends the neutral wire is a ground and ties it to the frame. The 10-30 circuit anticipates this and has extra restrictions on its neutral wire (it has to originate at the service entrance panel, not just a subpanel unless that subpanel is also a service entrance (that would be weird but it can be done))

The Grainfather I assume wants a 6-20 receptacle, (2 hot wires and a ground, no neutral) so you need to derive one or replace the cord and plug. I don't know how many watts the GF draws, but probably less than 3840 because it has a 20 amp plug and being a resistive load you have to derate the plugs and cords 20%. (240V x 20A x 0.8)

Can you just run a new 240V 20A circuit with a NEMA 6-20 outlet? That would be the cleanest solution, and if you can do it yourself it might be cheaper than buying adapters. Use 12 gauge cable (or wire and conduit) and a 20A 2-pole breaker.

 

[bracconiere]

Can you just run a new 240V 20A circuit with a NEMA 6-20 outlet? That would be the cleanest solution, and if you can do it yourself it might be cheaper than buying adapters. Use 12 gauge cable (or wire and conduit) and a 20A 2-pole breaker.

either way if the 3 prong with sideways prongs and round one.....install a second plug with a box next to the dryer plug....good idea....and now i'm kinda making a joke but, why is it all the sudden people aren't recycling their electrons, and sending them back to the power company? and just dumping them in the ground? did california start this separate grounding stuff like CRV?

i mean i've apparently learned from this thread....i can run my 120-220v stuff with one wire, and just another stuck in the dirt?

 

[z-bob]

A single wire ground return system is possible. I don't know why anyone would ever do that; I doubt that it's legal.

 

[bracconiere]

A single wire ground return system is possible. I don't know why anyone would ever do that; I doubt that it's legal.

LOL, maybe it would put a hop in people's step! and only the unfit for recycling electrons get dumped to ground normally?

edit: and i hope this thread has helped someone else get interested in the flow of stuff, like it has me.....

 

[doug293cz]

A single wire ground return system is possible. I don't know why anyone would ever do that; I doubt that it's legal.

What do you mean by "single wire ground return system?"

Brew on

 

[z-bob]

What do you mean by "single wire ground return system?"

Brew on

Just a hot wire. No neutral. You drive a grounding electrode into the earth and use that to complete the circuit. I'm not sure "single wire ground return" is the right terminology; it's a bastard wiring system and I doubt that it's safe. But it would work, at least for low-current circuits.

 

[doug293cz]

Just a hot wire. No neutral. You drive a grounding electrode into the earth and use that to complete the circuit. I'm not sure "single wire ground return" is the right terminology; it's a bastard wiring system and I doubt that it's safe. But it would work, at least for low-current circuits.

The ground return would probably have an unacceptably high voltage drop, thus degrading system performance.

My understanding is that the grounding stake in a normal system doesn't carry significant current. It just provides a level reference for the system. Is this correct?

Brew on

 

[z-bob]

The ground return would probably have an unacceptably high voltage drop, thus degrading system performance.

My understanding is that the grounding stake in a normal system doesn't carry significant current. It just provides a level reference for the system. Is this correct?

Brew on

It should never carry any current. It *can* carry some current if there's a failure. That's about the extent of my knowledge. I'm not sure if it's primary purpose is a reference voltage (0V) or for safety; it provides both.

 

[kartracer2]

@bracconiere The dryer cord and plug and the GF cord and plug carry the same voltage. They differ in that the dryer is designed to carry more "current" (or amps or watts or what ever you want to call it) than the GF. That is the reason for the different cord/plug configuration.

220v "only" devices require two separate 120v legs in residential service and can operate without any more wires, just the two legs, although not considered safe. (no grounding) A "neutral" is not needed or used in such a circuit.

In the dryer seniaro, it needs a "neutral" (or a "ground/neutral") for the 120v circuit in the dryer. In a lot of dryers, that includes the drum motor, timer motor, lights etc.

In a 120v circuit there is just one "power" leg and a neutral. Again a ground is not "needed" for operation but employed for safety.

All that said, I am not bringing up any "best practices or code requirements". Those are many and they can vary per situation and local.

Cheers to all, it's time to start having Birthday libations and my focus will be of Blue Moon clone nirvana.
Joel B.

 

[bracconiere]

220v "only" devices require two separate 120v legs in residential service and can operate without any more wires, just the two legs, although not considered safe. (no grounding) A "neutral" is not needed or used in such a circuit.

so 220v is 100% effecient, and there's no 'used' electrons to dispose of to keep the 'wheels turning'?

and here ya go for your clone!

 

[SaltNeck]

so 220v is 100% effecient, and there's no 'used' electrons to dispose of to keep the 'wheels turning'?

and here ya go for your clone!

short answer: it's because the two, 180 degrees out of phase, feed wires essentially take turns being the return wire every time the phase switches. 240V is the difference between them, and so when leg 1 is at +120V the other leg is at -120V and power is flowing from leg 1 to leg 2, but half a cycle later they are swapped and the power is flowing in the opposite direction, with leg1 acting as the return.

https://diy.stackexchange.com/questions/33602/why-do-240v-circuits-not-require-neutral

 

[bracconiere]

short answer: it's because the two, 180 degrees out of phase, feed wires essentially take turns being the return wire every time the phase switches. 240V is the difference between them, and so when leg 1 is at +120V the other leg is at -120V and power is flowing from leg 1 to leg 2, but half a cycle later they are swapped and the power is flowing in the opposite direction, with leg1 acting as the return.

https://diy.stackexchange.com/questions/33602/why-do-240v-circuits-not-require-neutral

i'll revisit and read the link, but now i'm thinking, i'm thinking in DC not AC terms? so this is AC so alternating for better distance, not DC for better efficiency?

and once again have to apolagize for making this MY education....in case i ever get the urge to use a 220v dryer plug instead of my NG stove.....