Why 277 volt lighting

[mbrooke]

I'm intrigued by the thought process that what we don't have or don't do is better than what we do have and use. I don't live my life that way though, it's not practical or productive.

We we don't do is way better and history has shown that time and time again. Humans have to start living this way if we want our problems to go away. Highly practicable and productive. To say otherwise is purely fanatical dogma.

 

[ActionDave]

For what it's worth, I am in-lawed to a couple of highly skilled linemen and out of every voltage level they deal with they hate 480V. Based on talking w them and other research I have done it's because 480V sustains an arc better than anything above it or below it.

 

[mbrooke]

For what it's worth, I am in-lawed to a couple of highly skilled linemen and out of every voltage level they deal with they hate 480V. Based on talking w them and other research I have done it's because 480V sustains an arc better than anything above it or below it.

Under what conditions? Short circuits? They don't have EPR blankets?

The bulk of fires come from joule heating, yet no one protests it.

 

[kwired]

For what it's worth, I am in-lawed to a couple of highly skilled linemen and out of every voltage level they deal with they hate 480V. Based on talking w them and other research I have done it's because 480V sustains an arc better than anything above it or below it.

Above 480 probably sustains well, is just likely they have protective devices that respond well to it.

 

[Electricmo]

https://www.utilityproducts.com/safety/article/16003440/defending-against-480-volt-arc-flash Maybe this is why.

 

[mbrooke]

https://www.utilityproducts.com/safety/article/16003440/defending-against-480-volt-arc-flash Maybe this is why.

Fuse the secondaries or feed via smaller transformers. Or don't work live.

Typically 208 volts is restricted to law amp services, while 480 volt takes on more than it should with spot networks or 2,500kva trafos.

 

[Hv&Lv]

Under what conditions? Short circuits? They don't have EPR blankets?

The bulk of fires come from joule heating, yet no one protests it.

If you have never worked on it, you won’t understand...

 

[mbrooke]

If you have never worked on it, you won’t understand...

Really? Most electricians find burned up devices and splices on a daily basis yet few stop to think why nothing is in place to stop or prevent them. Whether you understand what I just wrote...

 

[mbrooke]

If you have never worked on it, you won’t understand...

We're talking about lighting circuits btw...

 

[mbrooke]

If you have never worked on it, you won’t understand...

Paint a scenario for me of what you think ActionDave had in mind.

 

[kwired]

Really? Most electricians find burned up devices and splices on a daily basis yet few stop to think why nothing is in place to stop or prevent them. Whether you understand what I just wrote...

Well they maybe might have had better success with AFCI theories on 277/480 than they have had on 120 volts. At least 277 is able to sustain arcing for more than a few cycles. Still wouldn't work so well for "joule heating" though

 

[mbrooke]

Well they maybe might have had better success with AFCI theories on 277/480 than they have had on 120 volts. At least 277 is able to sustain arcing for more than a few cycles. Still wouldn't work so well for "joule heating" though

Arcing is the end stage of joule heating. Assuming combustion has not already initiated.

 

[kwired]

Arcing is the end stage of joule heating. Assuming combustion has not already initiated.

And will probably arc longer at 277 volts and up than at 120 volts - but as mentioned if combustion has already started doesn't really matter anymore.

 

[mbrooke]

And will probably arc longer at 277 volts and up than at 120 volts - but as mentioned if combustion has already started doesn't really matter anymore.

AFCIs basically wait to trip after the fire starts. The NEC is wrong about literally everything. Getting others do "get" this is the hard part... lets just say it doesn't make anyone take you seriously or garner respect from individuals who you otherwise looked up to.

 

[Hv&Lv]

The NEC is wrong about literally everything. Getting others do "get" this is the hard part

??
Really?
it’s kind of hard to take you seriously with these self-opinionated comments..

 

[kwired]

AFCIs basically wait to trip after the fire starts. The NEC is wrong about literally everything. Getting others do "get" this is the hard part... lets just say it doesn't make anyone take you seriously or garner respect from individuals who you otherwise looked up to.

The CMP's were convinced by manufacturers that this is a necessary thing, the rest of us that know better don't have deep enough pockets to campaign against them. They have lots of $$ to gain by having them required and is worth the efforts needed to sell the idea to the CMP's.

 

[mbrooke]

??
Really?
it’s kind of hard to take you seriously with these self-opinionated comments..

Thanks for proving me right.

Anyways, can you give me a scenario regarding 480 volt arc flash and linemen?

 

[kwired]

??
Really?
it’s kind of hard to take you seriously with these self-opinionated comments..

I only took it as they are wrong on the AFCI concepts. Though there are other areas of concern, but they are not wrong on "everything" IMO.

 

[mbrooke]

The CMP's were convinced by manufacturers that this is a necessary thing, the rest of us that know better don't have deep enough pockets to campaign against them. They have lots of $$ to gain by having them required and is worth the efforts needed to sell the idea to the CMP's.

Which leaves every single person outside the code making process powerless, over a law that is enforced upon on us.

 

[Besoeker3]

Could be.

Anyone know why 277 volt lighting came about when 480 already existed?

Good point. UK is 230V/400V.