Why 277 volt lighting

[mikeames]

I can see 277 volt lamps being more durable, long life and more efficient at 277 volts

Are you referring to incandescent? Your pictures show bulbs (unless halogen) but you wrote lamps? Can you explain your thinking? I am referring to the efficiency in the bulb not the circuit.

 

[ActionDave]

The Fact that you are raising questions about convention is good. I suggest looking into anything by Eric Dollard you can find.
There is gold in there.
What I will tell you that that besides the constant degradation in Engineered Systems due to everything being rooted in a debt based monetary system being bad, the Attempt to Engineer around common sense and proper education FOR PROFIT is a colossal mistake and can only end badly.
There is a major lot of time being wasted which people seem to think is normal, and we are getting more and more things that either work very badly or not at all. Its a form of collective insanity that is playing out with all kinds of people who should know better turning a blind eye to the entire affair.....


Star

Well there's got to be not just millions, but hundreds of millions of 277V lights wired up to shared nuetral branch circuits and there is not much to report other than they are all working fine, so I'm not worried about the 277V lighting apocalypse in my lifetime, or my children's lifetime, or my grandchildren's lifetime.

 

[kwired]

Well there's got to be not just millions, but hundreds of millions of 277V lights wired up to shared nuetral branch circuits and there is not much to report other than they are all working fine, so I'm not worried about the 277V lighting apocalypse in my lifetime, or my children's lifetime, or my grandchildren's lifetime.

And same for 120 volt also.

 

[mbrooke]

Are you referring to incandescent? Your pictures show bulbs (unless halogen) but you wrote lamps? Can you explain your thinking? I am referring to the efficiency in the bulb not the circuit.

Incandescent lamps or rather bulbs.

A 277 volt bulb has a thicker filament than a hypothetical 480 volt bulb at the same wattage.

 

[mbrooke]

The Fact that you are raising questions about convention is good. I suggest looking into anything by Eric Dollard you can find.
There is gold in there.
What I will tell you that that besides the constant degradation in Engineered Systems due to everything being rooted in a debt based monetary system being bad, the Attempt to Engineer around common sense and proper education FOR PROFIT is a colossal mistake and can only end badly.
There is a major lot of time being wasted which people seem to think is normal, and we are getting more and more things that either work very badly or not at all. Its a form of collective insanity that is playing out with all kinds of people who should know better turning a blind eye to the entire affair.....


Star

Links to Eric Dollard?

I do agree though with what you said, using the electrical center point of a transformer for load is just blind insanity.

 

[winnie]

All installations are a trade-off between cost and performance.

Apparently during the WW II period, in some areas it was common to wire circuits using a single wire and the conduit as the grounded conductor. This is simply using a shared grounded conductor and EGC and taking it to an extreme.

When you ask 'why 277 volt lighting' the big objection seems to be the shared neutral. If you used 277V lighting but without the shared neutral this objection goes away, at the cost of more copper usage.

You could take this further, and use only 120V lighting with no shared neutrals. Such would be minutely safer, but would be much more expensive to install.

IMHO shared neutral circuits are perfectly acceptable if properly/carefully installed, and 480/277V for lighting is perfectly acceptable in commercial situations where qualified individuals are expected to work on them. I would not want 277V lighting in my home

-Jon

 

[mbrooke]

Well there's got to be not just millions, but hundreds of millions of 277V lights wired up to shared nuetral branch circuits and there is not much to report other than they are all working fine, so I'm not worried about the 277V lighting apocalypse in my lifetime, or my children's lifetime, or my grandchildren's lifetime.

You do know people have been directly and indirectly electrocuted, thousands of fires resulting, money thrown away, while we bask in 100% avoidable magnetic fields. Its dumb, hack and DIY level thought process.

 

[mbrooke]

All installations are a trade-off between cost and performance.

Apparently during the WW II period, in some areas it was common to wire circuits using a single wire and the conduit as the grounded conductor. This is simply using a shared grounded conductor and EGC and taking it to an extreme.

When you ask 'why 277 volt lighting' the big objection seems to be the shared neutral. If you used 277V lighting but without the shared neutral this objection goes away, at the cost of more copper usage.

You could take this further, and use only 120V lighting with no shared neutrals. Such would be minutely safer, but would be much more expensive to install.

IMHO shared neutral circuits are perfectly acceptable if properly/carefully installed, and 480/277V for lighting is perfectly acceptable in commercial situations where qualified individuals are expected to work on them. I would not want 277V lighting in my home

-Jon

A 480 volt lighting circuit (with 480 volt luminaries) uses less copper than a 277/480 volt MWBC lighting circuit.

 

[winnie]

A 480 volt lighting circuit (with 480 volt luminaries) uses less copper than a 277/480 volt MWBC lighting circuit.

Debatable.

Absolutely true that if you have a perfectly balanced loading that a pure 480V system delivers the same power with 3 wires as a 480/277V system does with 4 wires. So in this case 480V uses less copper.

But once you include switch loops, separate power for different rooms, local control, requirements for 2 pole rather than single pole switches, etc. I suspect that the copper savings will vanish.

I wonder if there are differences in dangers from arcing when you have 2 or 3 legs of a 480/277V system rather than just a single 277V leg.

-Jon

 

[mbrooke]

Debatable.

Absolutely true that if you have a perfectly balanced loading that a pure 480V system delivers the same power with 3 wires as a 480/277V system does with 4 wires. So in this case 480V uses less copper.

But once you include switch loops, separate power for different rooms, local control, requirements for 2 pole rather than single pole switches, etc. I suspect that the copper savings will vanish.


-Jon

Why would you need 2 pole switching? Its better to just design a single pole switch to break 480.

I wonder if there are differences in dangers from arcing when you have 2 or 3 legs of a 480/277V system rather than just a single 277V leg.

The risk of bad connection causing fire is there even with 120. No one cares about joule heating.

 

[petersonra]

There are a bazillion 277V lighting circuits out there working every day perfectly safe.

 

[mbrooke]

There are a bazillion 277V lighting circuits out there working every day perfectly safe.

For the most part. But my question is- what stopped Magnetek, Advance, Universal, Sylvania, GE, ect from offer 480 volt ballasts?

 

[petersonra]

For the most part. But my question is- what stopped Magnetek, Advance, Universal, Sylvania, GE, ect from offer 480 volt ballasts?

If i had to guess it is that the listing standards for a 480V device make the product cost more than for a 277V product.

For a properly installed system there is no real difference in safety between 277V and 480V lamps.

There are people who have an aversion to MWBC. I am not a huge fan of them but for lighting circuits they make a lot of sense.

OTOH, a 480V system is just as safe and gets rid of the extra wire.

 

[mbrooke]

If i had to guess it is that the listing standards for a 480V device make the product cost more than for a 277V product.

For a properly installed system there is no real difference in safety between 277V and 480V lamps.

There are people who have an aversion to MWBC. I am not a huge fan of them but for lighting circuits they make a lot of sense.

OTOH, a 480V system is just as safe and gets rid of the extra wire.

Could be.

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

 

[mbrooke]

Could this be it?

(D) 600 Volts Between Conductors. Circuits exceeding
277 volts, nominal, to ground and not exceeding 600 volts,
nominal, between conductors shall be permitted to supply the
following:

(1) The auxiliary equipment of electric-discharge lamps
mounted in permanently installed luminaires where the
luminaires are mounted in accordance with one of the
following:

a. Not less than a height of 6.7 m (22 ft) on poles or
similar structures for the illumination of outdoor
areas such as highways, roads, bridges, athletic fields,
or parking lots

b. Not less than a height of 5.5 m (18 ft) on other structures
such as tunnels
Informational Note: See 410.137 for auxiliary equipment
limitations.

(2) Cord-and-plug-connected or permanently connected
utilization equipment other than luminaires

(3) Luminaires powered from direct-current systems where
either of the following apply:
a. The luminaire contains a listed, dc-rated ballast that
provides isolation between the dc power source and
the lamp circuit and protection from electric shock
when changing lamps.

b. The luminaire contains a listed, dc-rated ballast and
has no provision for changing lamps.

Exception No. 1 to (B), (C), and (D): For lampholders of infrared
industrial heating appliances as provided in 425.14 .
Exception No. 2 to (B), (C), and (D): For railway properties as described
in 110.19.

How can such a document be so devoid of logic, reason and physics? Its like they want fires, electrocutions, conflicts, and skyrocketing capitol costs.

https://imgur.com/Zkjc0Z3

https://imgur.com/QhBXgAF

 

[mikeames]

How can such a document be so devoid of logic, reason and physics? Its like they want fires, electrocutions, conflicts, and skyrocketing capitol costs.

While we all agree the NEC is not perfect, be cautions not to go to the other extreme and pass judgement solely on academic paper based logic, and dismiss reality. Seldom is the world perfect enough where physics books become a manual.

 

[mbrooke]

While we all agree the NEC is not perfect, be cautions not to go to the other extreme and pass judgement solely on academic paper based logic, and dismiss reality. Seldom is the world perfect enough where physics books become a manual.

The NEC isn't based on physics, thats the thing. Let alone reflecting the real world.

 

[n1ist]

For mag ballasts, it was just more copper on the transformer. Going solid-state changed things. Until recently, there were very few small high-voltage FETs and and driver chips for 480V for use in LED drivers and ballasts. For 347, I could go with 900V FETs (and there are drivers with them built-in) but for 480 I would have needed 1200V external transistors.

480V also requires larger spacing on the PCBs and more insulation. In my last job I had done a number of designs; up to 347V was a lot easier to do than 480.

I used to use lots of the 277V incandescents as test loads (as well as 3 120V in series for 347V). Every time I tried to buy them, some sales guy tried to convince me to go LED to reduce the power; that's the reason I chose them...

/mike

 

[mbrooke]

How much more copper? I'd think the turns would be more, but at the same time, the magnet wire would be thinner I'd assume. I'll agree with expensive isolation on the circuit boards.

 

[ActionDave]

You do know people have been directly and indirectly electrocuted, thousands of fires resulting, money thrown away, while we bask in 100% avoidable magnetic fields. Its dumb, hack and DIY level thought process.

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.