# is it possible to get shocked by 480v without touching all 3 busses?



## william1978

You only need to touch 2 of them to get 480. To ground on the second question.


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## william1978

From the sounds of it you don't need to be messing with anything that is hot.


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## gold

william1978 said:


> You only need to touch 2 of them to get 480. To ground on the second question.


120v to ground from 1 leg of 480? 

lulwut


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## Widestance_Politics

Maybe I missed it over the years, but I am pretty certain it will be 277v to ground.......


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## william1978

gold said:


> 120v to ground from 1 leg of 480?
> 
> lulwut


 I thought it was coming out of a different panel. My bad.


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## RIVETER

Widestance_Politics said:


> Maybe I missed it over the years, but I am pretty certain it will be 277v to ground.......


It was just a guess.


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## TOOL_5150

This must be a union apprentice...

~Matt


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## TheRick

btr said:


> How many volts are running through each phase in a 3 phase 480v panel? I hear of stories of people getting "hit" by 480v. how is this possible?... And how do you get 120v from the same panel if it has no neutral? Please explain!
> 
> Thanks


Each phase should have 277 volts to ground, and 480 volts between any 2 phases. 

Without a transformer involved you cannot get 120 volts from a 480 volt system.


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## miller_elex

He must be talking about a control transformer for a contactor coil. (120V)


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## nitro71

It's a Y transformer. 277 per leg to ground. 480 phase to phase. You have your neutral at the center tap. You don't get 120 volts out of a 277/480 transformer. You have to step down the voltage with another transformer. Most guys who think they have been hit off 480 really got hit with 277.


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## MaintenanceGeek

gold said:


> 120v to ground from 1 leg of 480?
> 
> lulwut


 
When last I check with my meter from phase to ground it measured 277V.


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## jwjrw

Why would you not get shocked? 3 phase is sorta like 3 single phase circuits.


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## Southeast Power

I always wondered how many lives would have been spared if our systems were not grounded?


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## Introyble

jrannis said:


> I always wondered how many lives would have been spared if our systems were not grounded?


Nevermind, just nevermind ~ I was just going to butcher the original question in the post , but I deleted it all, just not worth it.

Let me know when your ready to hire an electrician is all I can advise you.


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## Introyble

william1978 said:


> You only need to touch 2 of them to get 480. To ground on the second question.


3 phase delta , 1 leg to ground gives you 120???????

Thought 1 phase to ground gave me 277


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## McClary’s Electrical

jwjrw said:


> Why would you not get shocked? 3 phase is sorta like 3 single phase circuits.


 

I don't think anybody said you wouldn't get shocked, they mean you won't get shocked with (480) without grabbing at least two busses. You will be getting shocked by 277 from only one lead.


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## Toronto Sparky

480 delta can give you all sorts of strange readings to ground.. In theory it would be 0 volts to ground on a delta feed , but we all know thats not so. 

Here in Canada we deal with 600 volt delta and personally I have never had a 347 v reading to ground on a delta.


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## Toronto Sparky

btr said:


> How many volts are running through each phase in a 3 phase 480v panel? I hear of stories of people getting "hit" by 480v. how is this possible?... And how do you get 120v from the same panel if it has no neutral? Please explain!
> 
> Thanks



Keep in mind one phase of a delta could be grounded (shorted wire or shorted motor winding fed from that panel) without blowing fuses or even being noticed.

Then the other two phases would be 480 to ground

Also keep in mind that a motor winding may be shorted anywhere within the length of the winding there by producing different voltages to ground from each phase.


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## Old Spark

*3 phase 480 volt*



btr said:


> How many volts are running through each phase in a 3 phase 480v panel? I hear of stories of people getting "hit" by 480v. how is this possible?... And how do you get 120v from the same panel if it has no neutral? Please explain!
> 
> Thanks


 You must touch at least two phases at the same time to get 480 volts, but if you manage to touch all three at the same time you will probably start to spin at about 1500 rpm and screw yourself 6 feet into the ground where as they can place a stone marker over the hole with a warning not to do what you did.
Old Spark


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## william1978

Old Spark said:


> You must touch at least two phases at the same time to get 480 volts, but if you manage to touch all three at the same time you will probably start to spin at about 1500 rpm and screw yourself 6 feet into the ground where as they can place a stone marker over the hole with a warning not to do what you did.
> Old Spark


 I just got one question would he spin clock ways or counter clock ways?:jester:


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## McClary’s Electrical

william1978 said:


> I just got one question would he spin clock ways or counter clock ways?:jester:


 

That depends on if you're in the southern hemisphere, or northern


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## Widestance_Politics

william1978 said:


> I just got one question would he spin clock ways or counter clock ways?:jester:


If it is counter-clockwise he could just swap hands between phases B and C......just be sure to keep your tounge on A......


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## william1978

Widestance_Politics said:


> If it is counter-clockwise he could just swap hands between phases B and C......just be sure to keep your tounge on A......


 Could you make a video on how to do this?


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## micromind

The answer to the original question depends on the system. All 480 systems are 480 between any two phases.

Wye connection (most common) 277 from any phase to ground. 

3 wire delta (also known as grounded B or corner grounded) one phase is 0 volts to ground because it is intentionally grounded. The other two phases are 480 to ground. 

4 wire delta. Two phases are 240 to ground, the high leg is 416 to ground. 

Rob


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## Big John

micromind said:


> ...4 wire delta. Two phases are 240 to ground, the high leg is 416 to ground....


 A 480V 4-wire delta? Is that something more common in other countries...? What would the application be all the single phase 240?

-John


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## micromind

Big John said:


> A 480V 4-wire delta? Is that something more common in other countries...? What would the application be all the single phase 240?
> 
> -John


The few that I've seen didn't have any 240 loads, the only reason I can think of is they were connected to avoid having a grounded B. 

The POCO around here won't connect a grounded B anymore, but they will connect a 4 wire delta of either 240 or 480. 

Rob


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## iaov

Old Spark said:


> You must touch at least two phases at the same time to get 480 volts, but if you manage to touch all three at the same time you will probably start to spin at about 1500 rpm and screw yourself 6 feet into the ground where as they can place a stone marker over the hole with a warning not to do what you did.
> Old Spark


 The casket will be closed as the charred remains will not be pretty!!


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## iaov

A couple of quick points. First voltage doesn't go through any thing. It is developed across resistences. Second 480 is phase to phase. 277 or so to ground. The square root of 3 times 279 is appx 480. If you are asking these questions you should definately NOT be f...ing with this stuff!!


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## LARMGUY

Old Spark said:


> You must touch at least two phases at the same time to get 480 volts, but if you manage to touch all three at the same time you will probably start to spin at about 1500 rpm and screw yourself 6 feet into the ground where as they can place a stone marker over the hole with a warning not to do what you did.
> Old Spark


 
ROFL! :laughing: :laughing: :laughing:


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## eric7379

About 12 years ago, I got hit by 480, and yes, I do mean 480. I was reaching into a control panel for the electrical prints that "looked" like they were leaning up against the back wall with nothing else behind them. I reached in and WHAM! The tip of my middle finger on my left hand hit exactly between 2 poles of a 3 pole contactor that had 480 3 phase going to it. My forearm on my left arm was touching the cabinet door. 

It knocked me off of my feet. I knew immediately what had happened and at first I was scared to look down at my left hand because I thought for sure that at least the tip of my middle finger was going to be gone. Nope, all fingers accounted for. There was a big black, charred mark on either side of my finger that took about a full 3 months to completely heal and I had no sensation in my middle finger for about a month. Full recovery though.

I consider myself extremely fortunate and extremely lucky. That was my one get-out-of-jail free card. Obviously, I was not wearing any PPE. I have been extremely vigilant since then and have worn PPE ever since then. 

I NEVER take anything for granted anymore.


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## btr

Introyble said:


> Nevermind, just nevermind ~ I was just going to butcher the original question in the post , but I deleted it all, just not worth it.
> 
> Let me know when your ready to hire an electrician is all I can advise you.


MIGHT WANT TO DELETE THE BEER MONEY QUOTE FROM YOUR ADVERTISEMENT IF YOU ARE LOOKING FOR CLIENTS/ELECTRICIANS. 

ddddd duh!

..idiot :001_huh:


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## JRaef

william1978 said:


> I just got one question would he spin clock ways or counter clock ways?:jester:


This reminds me of a funny story, you guys will appreciate it.

While working on commissioning the overhead cranes at Boeing's new 777 production facility in 1993, my partner, and old salt, and I had worked out a very specific routine of powering off the bus rails when working on a bridge crane near people on JLGs so that any mistakes could not make us run into them. So he knew that the minute we passed onto the buss section we needed to work on, I would LOTO the disconnect for it before climbing down into the bridge.

While up there, two of the electricians we had hired out of the hall who had no industrial experience were watching us connecting to the bus rail fingers and one asked my partner "How can you tell the direction of rotation on a 3 phase bus like that?" He looked at me and winked, then licked his fingers and touched 2 rails. He immediately jerked his had back with a twisting motion to the right. He then said "See, that's clockwise. If my hand had twisted to the left, it would have been counter-clockwise!" These two noobs stood there slack jawed for what seemed like 10 minutes...

I made him tell them that he knew the bus was locked out, I would have hated having them try it themselves because they would have believed him.:no:


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## JRaef

Old Spark said:


> You must touch at least two phases at the same time to get 480 volts, but if you manage to touch all three at the same time you will probably start to spin at about 1500 rpm and screw yourself 6 feet into the ground where as they can place a stone marker over the hole with a warning not to do what you did.
> Old Spark


1500RPM? is it 50Hz? I would think that at 60Hz he would screw into the ground at 1800RPM (nominal).

And along those lines, if he were "bipolar", would that make them screw into the ground at 3600RPM?

:whistling2:


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## Wirenuting

He might have be shocked by 120 off of one leg. 
If his right leg is lifted off the ground & he used his left pinky finger in an upwards swipe.


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## Nildogg

TOOL_5150 said:


> This must be a union apprentice...
> 
> ~Matt


LOL
I can hook you up if you're serious.

-IBEW Bro.


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## Toronto Sparky

So.... how many times have you been "Electrocuted" ? I love it when they ask me that..


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## BuzzKill

I've hit two buses of a 277/480 system years ago doing some of my first work inside a hot control panel...knocked me on my ass literally; my neck was sore for days; experiences like that make you a a more respectful and safer electrician afterward.


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## McClary’s Electrical

iaov said:


> A couple of quick points. First voltage doesn't go through any thing. It is developed across resistences. Second 480 is phase to phase. 277 or so to ground. The square root of 3 times 279 is appx 480. If you are asking these questions you should definately NOT be f...ing with this stuff!!


 

Read post #25. You might wanna edit yours:no:


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## Lsparky

It has been my experence (retired now) that 277v has a really good kick and many think it was 480v...but usually it is just 277v. I will never forget the night I was on the roof using a sawsall to cut through a 3" AL conduit with 3 500MCM inside which were suppost to be locked off down below (it was 2am and a light rain) it happend that one of the 480/277 phases was still hot and.....yes I sawed right into it.....that was the end of the sawsall and part of the conduit......lesson learned...never trust anyone else. Still here with all my fingers, etc.


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## erics37

Toronto Sparky said:


> So.... how many times have you been "Electrocuted" ? I love it when they ask me that..


I just ask if they like zombie movies.


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