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Discussion Starter · #1 ·
I'm planning to wire a 240v 1000w metal halide bulb. It will be plugged into a digital timer via a NEMA 6-15 plug. The NEMA plug has hot, neutral, and ground. The ballast has one hot tap. This is probably a stupid question, but:

is it OK to run 240v across one hot lead (black only) from the NEMA plug to the ballast tap? I'm going to use 12 AWG wire, rated for 600v. Common sense tells me since it's rated for 600v, then this would be fine.

Everything I'm reading online mentions running 2x 120v wires, one with red and one with black. This is confusing. It seems weird for my application considering the NEMA plug's single hot terminal can handle "up to 10 AWG." 2x 12AWG wires wouldn't fit. Same goes for the ballast tap.

I just want to confirm because I want to do this properly. Thanks
 

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There in no neutral used in 240v set ups.
Instead you use 2 x 120v hots ( 2 x 120 =240)
So the neutral pin in the plug is actually the second hot.

So instead of the usually set up used for 120v -
hot neutral @ earth.

it becomes for 240 -
hot 1, hot 2, & earth.

:vs_bulb:
 

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I'm planning to wire a 240v 1000w metal halide bulb. It will be plugged into a digital timer via a NEMA 6-15 plug. The NEMA plug has hot, neutral, and ground. The ballast has one hot tap. This is probably a stupid question, but:

is it OK to run 240v across one hot lead (black only) from the NEMA plug to the ballast tap? I'm going to use 12 AWG wire, rated for 600v. Common sense tells me since it's rated for 600v, then this would be fine.

Everything I'm reading online mentions running 2x 120v wires, one with red and one with black. This is confusing. It seems weird for my application considering the NEMA plug's single hot terminal can handle "up to 10 AWG." 2x 12AWG wires wouldn't fit. Same goes for the ballast tap.

I just want to confirm because I want to do this properly. Thanks
Where do you think you are going to get 240V from one leg?

Everything you are reading online is partially wrong, and I doubt it's everything.

OK, your NEMA 6-15 is NOT a hot and neutral. It is two hots and a ground. NEMA 6-15 is 15A/250V, and used for straight 240V circuits that do NOT use a neutral.

For a straight 240V circuit you can use a cable with black and red and just cap off the white. You can also, and this is more common, use a cable with just black and white for a circuit like this. You just need to mark the white as a hot with a perm mark or similar means.
 
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Discussion Starter · #4 ·
If it helps any, this is a european manufactured ballast (Tridonic). I'm told that the neutral (comm) of the supply is to connect to the outside of the lamp socket, as well as the neutral tap on the ignitor. The capacitor is supposed to be wired parallel, 240v on one tap and neutral on the other. Here is more info:

I have a 240v digital timer hooked up to my electrical panel.* The digital timer has 240v receptacles built in.* I have the corresponding NEMA 6-15 plugs to fit these receptacles.* The plugs have 3 taps, the manufacturer website says they are for hot neutral and ground.* Common sense tells me that one wire runs from the single 'hot' tap on the NEMA plug, to the single 'hot' tap on the ballast.* But now I'm told the plug's neutral tap is actually for a second hot wire, and that each hot wire carries 120v.* If that's correct, then I'd connect both hot leads up to the single tap on the ballast? But then where does the neutral wire come from? Do I run a separate neutral wire directly from the electrical box to the lamp socket and ignitor? Or does the ground serve as neutral in this scenario? Please help me to understand this better. Thanks
 

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The light should have three incoming wires ?
If it is definatily a 240v light ? then there is NO neutral !
Instead there will be 2 x hots and an earth.
If it is 240v then, what you assume is a neutral ?
actually is one of the incoming hot lines.
And the other is hot goes to the hot input.

BUT

lets be sure,
what brand and model light is it ?
Is it still factory condition ?
If not what ballast is in it ?
 

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Discussion Starter · #6 ·
see diagram. here are the provided instructions from the manufacturer. the ballast has the following taps (since its not shown in the diagram): 220 , 230 , 240 , DRM .

the black unit is the ballast.

Ø**L. the hot wire has to be connected to the correct tap (if 240V should be connected to the 240V tap of the ballast.)

Ø**All other taps stay free

Ø**The (ZRM(D) connection of the ballast goes to the D contact of the igniter

Ø**LA of Igniter goes to “center” of the lamp (or to one side if it is a linear lamp)

Ø**The N of the igniter goes to the neutral (Comm) of the supply

Ø**Capacitor is in parallel to the whole



Please help me to understand this better
 

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see diagram. here are the provided instructions from the manufacturer. the ballast has the following taps (since its not shown in the diagram): 220 , 230 , 240 , DRM .

the black unit is the ballast.

Ø**L. the hot wire has to be connected to the correct tap (if 240V should be connected to the 240V tap of the ballast.)

Ø**All other taps stay free

Ø**The (ZRM(D) connection of the ballast goes to the D contact of the igniter

Ø**LA of Igniter goes to “center” of the lamp (or to one side if it is a linear lamp)

Ø**The N of the igniter goes to the neutral (Comm) of the supply

Ø**Capacitor is in parallel to the whole



Please help me to understand this better
See on the left the incoming wires are marked L & N.
In your case L goes to one of the incoming hots of the 240 line,
And the N goes to the second hot of the incoming hot lines.

THERE IS NO NEUTRAL WITH 240V !

I can see how you are confused !

Have you enquired with the light manufacturer re 240v set up ?
most reputable manufacturers will provide such information.


Are you really sure this light is for 240v ?
 

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Discussion Starter · #8 ·
I'm 1,000,000% sure this is a 1000w 60 hz 220-240v ballast. Tridonic OGLIS 140. It will power a german Radium metal halide bulb.

As previously mentioned there are 4 taps on the ballast, 220 , 230 , 240 , ZRM. ZRM goes to ignitor. The manufacturer said "the hot lead goes to whichever one of those three (220, 230, 240) taps is closest to your hot lead's voltage. The others stay free.

What you're saying wouldn't make sense. The ballast needs 240v. If neutral became a second hot lead, 120v would feed the ballast, and 120v would directly feed the outside of the lamp and the ignitor (separate from the ballast). The capacitor being in parallel wouldn't make sense either. 120v entering each side of the capacitor, with nowhere to go? That can't be right?

Common sense tells me electricity enters the ballast, then to the ignitor, then the bulb, and then needs to go somewhere. It should return via the neutral (common) wire. The ground being a precautionary measure.

Let's start at the beginning. From the main electrical panel in the house, there is a 60A breaker. Affixed to that breaker is the 2 hot leads of a length of 6 AWG cable (with black, red, white, and bare copper inside). White is attached to the neutral bar and bare copper to the ground bar. At the other end, the black and red feed the 2 hot terminals of a 60A subpanel. The white attaches to the neutral bar. The bare copper to the ground bar.

The neutral and ground bar are not bonded in the subpanel. The ground bar doesn't require connection to earth via a grounding rod. It's only bonded to the metal subpanel chassis itself.

Inside the subpanel is a 30A breaker. Affixed to that breaker is the digital timer. The digital timer came with 4 wires coming out of it (black, red, white, green). Black and red go to both poles of the breaker. White goes to the neutral bar. Green to the ground bar. There are built in NEMA 6-15 receptacles on the timer. I have a NEMA 6-15P hospital grade plug to fit one of the receptacles. The manufacturer of this NEMA plug says it has 3 taps, HOT NEUTRAL and GROUND. From said plug, I hope to attach a length of 12 AWG wire that will feed the ballast, which feeds the ignitor, which feeds the lamp. The schematic I attached above was the correct one, direct from the manufacturer, for this ballast and configuration.

If I did what you suggest, not using a neutral wire, then the return path of the electricity would be through the ground wire.? To the subpanel's ground bar. Through the bare copper on the 6GA wire. To the main panels ground bar. To earth. That doesn't seem right, or safe, to me. Am I missing something here? I have a hard time believing that both the ballast's manufacturer, and the NEMA plug manufacturer are wrong about there being a neutral. Someone please help and explain this to me. Thank you!
 

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Discussion Starter · #9 ·
Do I just not understand the flow of electricity? I've been told about the water analogy. The electricity flows out the faucet (hot leads) into the tub (the service), but it needs a way to drain (the neutral). The ground being like the little hole at the top of the tub in case the waters on and the drain isn't functioning, so it doesn't spill over (burn your house down). I always thought of the ground as a safety net. I would never have thought it to be appropriate to use the little hole (ground) to constantly drain the entire tub. How is this any different? Purposefully using the ground to constantly return all that energy doesn't seem right. Especially when there's a perfectly good, thicker white wire affixed to a neutral bar inside the panel box? Is it possible that what you're trying to say is that there is no GROUND on the NEMA plug, because GROUND in this case, is the neutral (white wire)? That would make a hell of a lot more sense. Let me know if I'm retarded or not. :p Thanks everybody
 

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I'm planning to wire a 240v 1000w metal halide bulb. It will be plugged into a digital timer via a NEMA 6-15 plug. The NEMA plug has hot, neutral, and ground. The ballast has one hot tap. This is probably a stupid question, but:

is it OK to run 240v across one hot lead (black only) from the NEMA plug to the ballast tap? I'm going to use 12 AWG wire, rated for 600v. Common sense tells me since it's rated for 600v, then this would be fine.

Everything I'm reading online mentions running 2x 120v wires, one with red and one with black. This is confusing. It seems weird for my application considering the NEMA plug's single hot terminal can handle "up to 10 AWG." 2x 12AWG wires wouldn't fit. Same goes for the ballast tap.

I just want to confirm because I want to do this properly. Thanks
If it helps any, this is a european manufactured ballast (Tridonic). I'm told that the neutral (comm) of the supply is to connect to the outside of the lamp socket, as well as the neutral tap on the ignitor. The capacitor is supposed to be wired parallel, 240v on one tap and neutral on the other.
Do I just not understand the flow of electricity?

Is it possible that what you're trying to say is that there is no GROUND on the NEMA plug, because GROUND in this case, is the neutral (white wire)? That would make a hell of a lot more sense.
Much advice has been given to you since you posted the above.
However, it appears that you do not understand the distribution of AC energy to North American premises and how it differs from the distribution of AC energy in Europe, and most of the remainder of the world.

You stated "The NEMA (6-15) plug has hot, neutral, and ground."
NO. It does NOT.
It has two (flat - horizontal) Line terminals (L1 and L2) and a (round) Earth terminal.

You also asked "Is it possible that what you're trying to say is that there is no GROUND on the NEMA plug, because GROUND in this case, is the neutral (white wire)?
NO. What is trying to be said is that there is no "NEUTRAL" on the (three pin) NEMA 6-15 plug (because it is unnecessary), but there is an Earth" connection - because it will be necessary (unless the equipment concerned is "Double Insulated")

You also stated "Everything I'm reading online mentions running 2x 120v wires, one with red and one with black." to which I would add, "plus an Earth."

It seems to come as a surprise to you that (just like Europe, and most of the remainder of the world) North America has a 240 V (230 V) single phase distribution system to domestic premises.
The significant difference is that (in Europe etc.) one side of the 240 V AC single phase transformer supplying the premises is connected to Earth (as a Neutral) BUT, in North America a "centre tap" of the transformer supplying the premises is connected to Earth (as a Neutral.)

The result of this is that European (etc.) premises are "fed" via only TWO wires (Line and Neutral). with 240/230 V AC available between Line and Neutral.
However, in North America, premises are fed with THREE wires Line 1, Line 2 and Neutral. Because the transformer is "centre tapped", each of these two "Lines" is at 120 V AC with respected to the "Earthed" Neutral.
(Because these 2 120 V AC supplies are 180 degrees "out-of-phase", 240 V AC is "available" between them.)

Most (low wattage/low current) devices in North America can operate quite happily on 120 V. However, at 120 V, a 15 A circuit cannot supply more than 1800 W and a 20 A circuit cannot supply more than 2400 W.
To obtain up to double this "Wattage" via conductors of similar size it is necessary to double the voltage, by connecting across Line 1 and Line 2, where a potential difference of 240 V AC is available.

Note that the "outside" of your "Edison Screw" lamp socket will be connected to one of the 120 V AC (with respect to Earth) "Line" supplies. While it should be externally insulated, it represents a possible 120 V AC "danger".

----------------------------------------------------------------------------------
As a bit of "History", (largely because of the "War of the Currents" [which should be called the "War of the Voltages] between Edison and Westinghouse) the "powers that be" in North America (read USA) became convinced that 240 V AC (of which the "peak" voltage is 340 V) was more "dangerous" than 120 V AC (of which the "peak" voltage is 170 V). So the dual 120 V AC (with respect to Earth) supplies became the "norm" in North America.

(Edison would have preferred the use of his nice "safe" 110 V DC.)

Perhaps you should read https://en.wikipedia.org/wiki/War_of_Currents
 

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Discussion Starter · #11 · (Edited)
although i have a hard time believing that a 240v ballast would only get 120v to it, i'll take your and everyone elses word for it. :plain: i guess everything i thought i knew about electricity is plain wrong.

so then according to this information and the wiring diagram, it's correct to run black from the NEMA plug's line 1 to the ballast tap, and red from the plugs line 2 directly to the "outside" of the lamp socket, thereby bypassing the ballast? and green just goes from the plugs ground, to the grounding screw on the ballast housing?

capacitor gets black on one side, red on the other? has no ground or neutral?

thanks
-----------------------------------------------------
p.s. here is the manufacturer website for the NEMA plug, so you can see where i got the idea about there being a neutral.

Terminal ID: Brass-Hot, Green-Ground, White-Neutral

http://www.leviton.com/OA_HTML/ProductDetail.jsp?partnumber=8656-V&section=41808&minisite=10251
 

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Discussion Starter · #12 ·
The ballast manufacturer just said not to hook it up that way, either. He said I will have a "high" Line (120V) instead of a neutral. He recommended that I get a step up transformer rated for 1.5kv so I have 240v 1 phase and 1 neutral.

this whole thing is just getting more and more confusing.
 

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The ballast manufacturer just said not to hook it up that way, either. He said I will have a "high" Line (120V) instead of a neutral. He recommended that I get a step up transformer rated for 1.5kv so I have 240v 1 phase and 1 neutral.

this whole thing is just getting more and more confusing.
If the ballast manufacturer told you that he is playing CYA.
Dump it and buy a fixture made for US voltages.
 
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Discussion Starter · #14 · (Edited)
i've put so much time and money into this. i have to figure it out.

he said i don't have 240v., i have 208. i have no idea where that figure comes from or if it's accurate. i don't know what's what anymore.

i know that i have 2 other 240v HPS ballasts that work perfectly fine attached to this timer.

there has got to be an easier way to go about this.

out of curiosity, what would happen if i ran black from line 1 of the NEMA plug to the ballast tap, AND red from line 2 of the plug to the same ballast tap together.? doesn't 120v black + 120v red = 240v when combined?

does the ground of the nema plug really only serve to attach to the ballast chassis' exterior ground screw? it doesn't seem right to me that the plugs ground would serve almost no purpose. how is all the electricity flowing back into the subpanel? it has to go somewhere.? doesn't it?

for neutral, couldn't i just run a separate wire from the neutral bar on the subpanel, to the outside of the lamp socket and the ignitor, the way the schematic suggests?
-----------------------
to simplify:

can we just ditch the words neutral and ground for a second? let's just call it the return path. so on the nema connector, there are 2 hot leads and a return path. (see attached photo). can't i combine the two 120v hot leads (L1 + L2) to make 240v, and feed that to the single ballast tap?

could i hook up the return path on the plug, to the outside of the lamp socket, and to the ignitor (exactly the way the schematic shows it, marked on the schematic as N)?

then just hook a ground wire from the grounding screw on the ballast chassis, up to the ground bar on the subpanel?

why wouldn't that work, exactly?.

and how would his recommendation work? if i used a step up transformer to change one of the plugs hot leads (L1) from 120v to 240v, then in doing so, how does that create a neutral? isn't the other leg (L2) of the nema connector still feeding 120v?
 

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If you connect line 1&2 to the same ballast tap you have a dead short and will trip the breaker. The ground pin is not a return path. Connect line 1 to the hot terminal, line 2 to the neutral. Ground only goes to the lamp chassis.
 
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although i have a hard time believing that a 240v ballast would only get 120v to it, i'll take your and everyone elses word for it. :plain: i guess everything i thought i knew about electricity is plain wrong.

so then according to this information and the wiring diagram, it's correct to run black from the NEMA plug's line 1 to the ballast tap, and red from the plugs line 2 directly to the "outside" of the lamp socket, thereby bypassing the ballast? and green just goes from the plugs ground, to the grounding screw on the ballast housing?

capacitor gets black on one side, red on the other? has no ground or neutral?

thanks
-----------------------------------------------------
p.s. here is the manufacturer website for the NEMA plug, so you can see where i got the idea about there being a neutral.

Terminal ID: Brass-Hot, Green-Ground, White-Neutral

http://www.leviton.com/OA_HTML/ProductDetail.jsp?partnumber=8656-V&section=41808&minisite=10251
Why would you think that anyone here has suggested that the ballast would only have 120 V applied to it. No, There would be 240 V AC applied across the whole "set-up", which includes the ballast.

Just forget the reference which you supplied. I would argue that the wording is incorrect. I appeal to all North American electrical 'experts' to correct the statement in this URL that "Terminal ID: Brass-Hot, Green-Ground, White-Neutral"

Why Oh why is it that you appear to not understand that of which you are being advised?

In none of the advice to you has it ever been suggested to "bypass" the ballast.

Simply connect the "Line" and "Neutral" connections of the European 240 V AC device to the "Line 1" and "Line 2" connections of the North American 240 V AC supply - however it is obtained.

I have checked and this discussion is not taking place on April 1.
However, I am still suspicious that this cannot be a rational discussion.

"The ballast manufacturer .... recommended that I get a step up transformer rated for 1.5kv so I have 240v 1 phase and 1 neutral."

OK. Go ahead and spend the extra money to derive 240 V AC from a 120 V AC supply, when a 240 V AC supply is already available to you.

If you cannot understand the situation that has been explained to you (over and over), I am afraid that this is now your problem!

Dump it and buy a fixture made for US voltages.
You could take the advice of rjniles and "Dump it and buy a fixture made for US voltages"

(I have just checked up with some more recent previous posts and can assure you that [in the North American 240 V context] one does not need a Neutral, unless there is also a need of some associated 120 V AC "control" equipment.
In such cases, a four pin NEMA 14 type plug/socket outlet would be required.)

Also, in this case "Return Path" means "Earth Return".
 

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Frodo you come across as a total prick and shouldn't be on a DIY electrical forum if you're going to belittle people trying to learn to do things the right way. Thank you rjniles for helping to explain things while biting your tongue and not being rude. everyone has to start somewhere and this whole thing is clearly confusing as ****, unnecessarily so. aside from dumping the ballast which i'm not going to do, i will probably just go with the damn step up transformer, unless somebody can actually help me and explain to me how to hook it up *properly.* because the manufacturer is telling me that you're wrong. there *is* a neutral in this application. the manufacturer of the ballast isn't wrong. and i'm not going to run the ballast and bulb any other way than the way the manufacturers of both recommend i do so. i'll get in touch with the guys at radium and verify that they agree with tridonic. as for this post, forget i asked anything. i see this was a bad idea
I am sorry that you see my poor attempts to explain things in any such way.

I can assure you that I was not attempting to belittle you (or anyone)
Suggesting that you may not understand something (and then attempting to explain it) should not be construed as belittling.

(There is, or should be, no shame in "ignorance" - although the word is often used pejoratively. I have no shame in telling you, and everyone else, that I am completely "ignorant" of any or all aspects of Brain Surgery.)


Did you perceive that, at one point, you wrote "Let me know if I'm retarded or not". and I deliberately removed those words from that which I quoted?
 

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Discussion Starter · #20 · (Edited)
i'm getting different, contradictory information from multiple different sources. "do this." "no don't do that, do this." "no don't do that!" repeatedly.

i wired the subpanel myself. i wired the timer myself. i installed wall outlets myself. i wired my car stereo and subwoofer myself. i wired my oven myself. i wired my fluorescent fixtures myself. i wired new construction microsoft buildings myself. etc. all of it made logical sense. this doesn't.

after the way you guys have explained it, i still just don't understand how the ballast, ignitor, nor the lamp could be without a return path of any kind. wiring L1 to the ballast tap and L2 in place of N on the schematic, with ground simply attaching to the little green screw on the external ballast chassis, leaves nothing whatsoever to carry the current back to the electrical box.

the black and decker home wiring book says, when describing the water analogy, "water finally leaves the home through a drain system, which is not pressurized. similarly, electrical current flows back through neutral wires." however it doesn't say, "except for 240v. don't worry about 240v."

forgive me for not knowing that 240v doesn't need the current to go back to the box. but that still feels wrong to me.

you guys have basically been telling me that the manufacturers of the ballast, the bulb, and the nema connectors are all wrong. forgive me for being hesitant to blindly believe this. forgive me for asking questions to clarify things. forgive me for visiting this godawful excuse for a DIY forum

...and it doesn't speak highly of your credibility when you say, "then just get rid of it and get one for the US." that sounds to me like you don't even have a viable answer.
 
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