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When can us Americans stop using neutral wires?

Strostkovy

Titanium
Joined
Oct 29, 2017
Granted this situation is my fault, since I assumed a three wire oven used two hots and a ground, not two hots and a neutral (which is also now illegal, so I get to buy a new cord and receptacle). But at what point can we stop running neutral wires? They aren't very useful these days.

It's long been my opinion (and I think the opinion of many) that machine tools running on 208 or 240 volts and requiring a neutral connection for the controls is lazy. It's cheaper to add in a transformer for the half amp or so you need (or just use 240V based controls on capacitive dropped timers and such) than to run a 6 gauge or larger neutral everywhere. It just doesn't justify the copper or the conduit. Residential appliance makers seem to disagree, but I haven't yet met a single person happy with their modern appliances anyway.

But now that I get to shove an extra 6 gauge wire in conduit already at 36% fill, I started wondering what I have that needs neutral. The answer is a space heater, old oscilloscope, toaster, microwave, and heat gun totaling maybe $300 in value. Everything else I have runs fine on 240 with nothing other than a different cord.

So given the advantages of double the power for the same amount of wire, and running fewer wires, and being able to use true 240 delta for all 3 phase stuff, why not just ditch the neutral in general? I honestly like having double pole breakers because it lets you have only 120VAC to ground instead of 240 directly as well.

So, as I would like to at some point grow my business to being able to get a new tilt up shop built, would it be a bad idea just to get 240 delta (Probably wye for ground)? Is there any reason other than strictly 120V appliances to run a neutral connection to anything?

Also, is it to code to install European sockets for 240, since it's readily available?
 
I agree it is dumb for an end use device to require a neutral on 240V single phase. No machine tool would be made like that (or very few), they would have a control transformer, or directly use 240V controls, etc.

As for the european connector.....

If it is listed for the application, by a US lab, then NEC cannot be used as a basis to complain about it. All the NEC says is just that, "listed for the application", meaning UL, ETL, etc. Any US "NRTL", (Nationally Recognized Testing Lab). They all generally test to UL standards.

But, if not listed, or you cannot prove it, the inspector can order the connectors removed, and shut you down until that is done.
 
I owned a machine tool that required neutral on 240 - it was an Omax Protomax. When I asked them about this awkward arrangement (for a shop full of 208 3-phase plugs with no neutral) I was told that it was required to get UL listing. (A transformer would surely have done as well, but that might have cost more money?) It was intended for labs/offices rather than shops, which may explain part of it.

Some of things noted above will have dual voltage, and so it's either hot-hot-netural-ground, OR a whole separate circuit (customer pays) OR a transformer with related costs and hassles (customer pays.) Did you really want two whole circuits for your oven, stovetop, or clothes washer? Do you really want the failure point of a transformer inside your oven?

So, we're going to have it for the forseeable future. Have to plan ahead better.
 
Or you design the electronics to run on 240V or 120-277V. Chances are there's some EU-sourced hobs in a store near you with 240V-only supply, no 120V required, no transformers either.
 
......

Some of things noted above will have dual voltage, and so it's either hot-hot-netural-ground, OR a whole separate circuit (customer pays) OR a transformer with related costs and hassles (customer pays.) Did you really want two whole circuits for your oven, stovetop, or clothes washer? Do you really want the failure point of a transformer inside your oven?

So, we're going to have it for the forseeable future. Have to plan ahead better.

None of that has any need to be an issue. The timers and processors etc, etc are already in the stoves and dryers (and are maybe even wifi enabled), so adding a little bit of well-proven electronics is not going to either break the bank nor cause added unreliability. Small SMPS are extremely well proven and reliable.

The "needed for UL" is also puzzling. I do not know why that would be, and I was involved with putting many dozens of products through UL/CSA/CE/C-Tick, etc, etc.

It may be due to some specific issue with the product. But no UL requirement exists to run a neutral to a motor, all you need is the Mains and the PE/equipment grounding conductor. Most industrial equipment needs only the power and PE/egc.
 
Granted this situation is my fault, since I assumed a three wire oven used two hots and a ground, not two hots and a neutral (which is also now illegal, so I get to buy a new cord and receptacle). But at what point can we stop running neutral wires? They aren't very useful these days.

It's long been my opinion (and I think the opinion of many) that machine tools running on 208 or 240 volts and requiring a neutral connection for the controls is lazy. It's cheaper to add in a transformer for the half amp or so you need (or just use 240V based controls on capacitive dropped timers and such) than to run a 6 gauge or larger neutral everywhere. It just doesn't justify the copper or the conduit. Residential appliance makers seem to disagree, but I haven't yet met a single person happy with their modern appliances anyway.

But now that I get to shove an extra 6 gauge wire in conduit already at 36% fill, I started wondering what I have that needs neutral. The answer is a space heater, old oscilloscope, toaster, microwave, and heat gun totaling maybe $300 in value. Everything else I have runs fine on 240 with nothing other than a different cord.

So given the advantages of double the power for the same amount of wire, and running fewer wires, and being able to use true 240 delta for all 3 phase stuff, why not just ditch the neutral in general? I honestly like having double pole breakers because it lets you have only 120VAC to ground instead of 240 directly as well.

So, as I would like to at some point grow my business to being able to get a new tilt up shop built, would it be a bad idea just to get 240 delta (Probably wye for ground)? Is there any reason other than strictly 120V appliances to run a neutral connection to anything?

Also, is it to code to install European sockets for 240, since it's readily available?

"WE" Americans, "US" Ingeonears.

Also Japanese, "etc".

I submit you've taken leave of your "lazy" senses.

Life is cheaper than Copper in Europe, Africa, Asia, Middle-East. Always HAS been.
Austere economics drove their dangerous distribution system, not Engineering. Japan alone got it right.

US & Canada had more Copper, prehistoric times, onward. Celestial body impact-area thing.

Modern times no different. Why make a system safer if their population cannot SUE as we do in the twelve-plus TIMES more litigeous USA? Second most litigeous? About a full order of magnitude LESS, but ta da.. Japan!

Roll back to the years I was in the Manufacturing Jewlery trade '74-'84. One gets to know a lot of people who wanted a retirement home in Israel. And got it!

For ten years, it seemed "the community" lost a person every year or two to electrocution. Year after year.

Homes usually had tile on concrete floors. Climate as it is, they needed frequent cleaning. With soap and water.

It was easier to manage an electric floor buffer in the water and suds ..... in bare feet.

But THEIR 2XX Volts AC had no Neutral, tied to the centre-tap to Earth ... at a mere 120 Volt potential .. above the bare feet on the floor. As they had grown up with. In the USA.

Cynical New Yorkers .. of the Jewish persuasion .. began referring to any floor buffer in sight - anywhere - as "Jew killers"? You knew there was a problem.

And you want to remove the Neutral?

Whilst I'm running FIVE WIRE 3-Phase outlets..... because I re-derived a 'local' Neutral, (Delta-Wye transformer..) for the output side of Phase Perfect XOR RPC (transfer switched, not both at once). Gen set is already split-phase ELSE 3-P WYE NATO has had electrocution deaths as well.

And I'm only a lapsed Presbyterian!

Go figure it isn't ABOUT the cost or convenience of the devices.

It is about the safety of the PEOPLE!
 
None of that has any need to be an issue. The timers and processors etc, etc are already in the stoves and dryers (and are maybe even wifi enabled), so adding a little bit of well-proven electronics is not going to either break the bank nor cause added unreliability. Small SMPS are extremely well proven and reliable.

The "needed for UL" is also puzzling. I do not know why that would be, and I was involved with putting many dozens of products through UL/CSA/CE/C-Tick, etc, etc.

It may be due to some specific issue with the product. But no UL requirement exists to run a neutral to a motor, all you need is the Mains and the PE/equipment grounding conductor. Most industrial equipment needs only the power and PE/egc.

In the case of kitchen ranges, ovens, and stoves, I think there was a tendency for the old appliances to use dual voltages for the lower heat settings.

The current 240VAC with two hots, a neutral, and a ground are a carry forward from making everything backwards compatible.

Yes maintaining the status quo with backwards standards is rather wasteful until you start spending the money to make adaptions to support the old standards you wanted to abandon.

It is very likely that the 240VAC 3 wire with a ground arrangement is going to be around for a long time or at least until the 240VAC wall outlet becomes accepted. I do not see this happening in the US as there is a huge market inertia to continue with 120VAC as the appliance standard.
 
In the case of kitchen ranges, ovens, and stoves, I think there was a tendency for the old appliances to use dual voltages for the lower heat settings.

The current 240VAC with two hots, a neutral, and a ground are a carry forward from making everything backwards compatible.

Yes maintaining the status quo with backwards standards is rather wasteful until you start spending the money to make adaptions to support the old standards you wanted to abandon.

It is very likely that the 240VAC 3 wire with a ground arrangement is going to be around for a long time or at least until the 240VAC wall outlet becomes accepted. I do not see this happening in the US as there is a huge market inertia to continue with 120VAC as the appliance standard.

Not only.."inertia". Even in life-is-cheap Asia..

Hong Kong first, YEARS AGO PRC later.. mud-boot construction jobsites NOW want a local power transformer, center-tapped to Earth- so they may operate US/Japan market 120 VAC corded AC power tools... with fewer electrocution deaths each year.

UK & europe have begun to follow suit.

First move, a 1:1 Isolation transformer.

Next step, 2XX to 1XX step-down, center tappable to protective Earth.

Works well, it can be made safer yet. So ... a transformer even splits the 110 VAC to 55-0-55 for safer use of portable power tools:

110V Centre Tap Earth (55V-0V-55V) - Electrical Transformers | GS Transformers

Bottom line?

Folks are getting MORE aware of safety. Not LESS!

If we make a change? It is more likely to be from split-phase to 3-Phase.
But it will be WYE 3-phase! With a Neutral ... as well as PE/Ground.

Ask your local Powerco about the future of Delta at the smallholder consumption end.

Well. "History of" would be more accurate than "future".

Many jurisdictions have been Wye for "a while".
 
Hong Kong first, YEARS AGO PRC later.. mud-boot construction jobsites NOW want a local power transformer, center-tapped to Earth- so they may operate US/Japan market 120 VAC corded AC power tools... with fewer electrocution deaths each year.
Where do you get this stuff ? Hong Kong and China jobsites have no interest whatever in Japanese or US 120v tools. They cut off the ground prong then plug into the local 220 and saw/grind/hammer away. When they can buy local for $12 why they hell would they pay for Makita or Bosch ?

They don't. And they have no interest in. Where they swing guys on ropes off the roof of a thirty story building to wash windows, this claim about safety concerns is ludicrous.
 
It is about the safety of the PEOPLE!

I only caught about half of that but I'm proposing two out of phase 120V lines. The buffer in this case would be connected to a protective ground, which would protect the operator.

The transformer secondaries would still be wound wye, but the center tap would connect to protective ground and need not be propagated further.



If we make a change? It is more likely to be from split-phase to 3-Phase.
But it will be WYE 3-phase! With a Neutral ... as well as PE/Ground.

Ask your local Powerco about the future of Delta at the smallholder consumption end.

Well. "History of" would be more accurate than "future".

Many jurisdictions have been Wye for "a while".

I would absolutely love to see more three phase, but that's a lot of wire to run.

The reason I don't see a huge future for three phase wye service where the neutral is actually in use is because of the strange (to Americans) voltages. You either deal with 277 single phase or 416V 3 phase, neither of which is particularly well supported domestically. If you need transformers to connect up all of your machines then it doesn't solve the extra cost and inconvenience issues.

The advantage of "balanced 240" (split phase with the neutral ditched) is that hardly any rewiring is required, and all that's needed for the transition in the future is for manufacturers to abandon frivelous use of neutral connections.
 
In the case of kitchen ranges, ovens, and stoves, I think there was a tendency for the old appliances to use dual voltages for the lower heat settings.

The current 240VAC with two hots, a neutral, and a ground are a carry forward from making everything backwards compatible.

Yes maintaining the status quo with backwards standards is rather wasteful until you start spending the money to make adaptions to support the old standards you wanted to abandon.

It is very likely that the 240VAC 3 wire with a ground arrangement is going to be around for a long time or at least until the 240VAC wall outlet becomes accepted. I do not see this happening in the US as there is a huge market inertia to continue with 120VAC as the appliance standard.

It's backwards compatible to provide a neutral, but not to use the neutral. If the transition was made to sensible control circuitry in appliances, neutral connections in future construction could be abandoned because there are plenty of options of appliances that don't need one.


I don't think there needs to be a huge market change, as plenty of 240V rated appliances are widely available, and most other stuff is 100-277 so it doesn't matter much anyway (other than getting double the power in a circuit).

As someone who has done years of cooking on a hot plate, I would like more than 1500 watts.
 
Where do you get this stuff ? Hong Kong and China jobsites have no interest whatsoever in Japanese or US 120v tools. They plug into the local 220 and saw/grind/hammer away. When they can buy local for $12 why they hell would they pay for Makita or Bosch ?

They don't. And they have no interest in. And where they swing guys on ropes off the roof of a thirty story building to wash windows, this claim about safety concerns is ludicrous.

Guess you have never even been on a Hong Kong jobsite, then "Ludicrous-San"?

HKG Gov top gun for enforcement of that was a bud of mine. As was the "Slopes Stabilization" head - 80 THOUSAND numbered locations under active monitoring and management as-at the 1997 handover, already. So were two Senior Partners in a row of the Jerde Partnership. We had begun with adjacent offices, Lippo Centre. And several more Architects, two of them a niece and nephew/Godson.

The frustration was that when they first got them to do the Voltage step-downs?
The transformers being used were home-made out of scrap, and had big protruding terminals - primary as well as secondary - hanging out as calf-snaggers, and sitting right in the middle of a mud hole as the main deterrent to walking into it!

Hollywood Road, mid-levels, you could see several such rigs most weeks in but a few short blocks! More than twenty years ago, already!

They "got" the regulation.

They didn't really grok the SPIRIT ...or much care about the "why" of it.

You've probably never seen the high-tech gear used for washing the glass of Hong Kong's skyscrapers, either. Nor even the low-rise 30-stories of our home - Kornhill, Quarry Bay, the lifting gear and platform built-in to each building from the outset over 30 years ago.

"Pay for <US/Japanese/Euro brand> power tools?
Not as if they had to IMPORT them, is it? Made in China to begin with!

It's your MIND and your menu of lies that is out of step with realities in Asia, fool.

https://youtu.be/ixgEpXUG6pI

Clever f**kers even have electric LIGHTS on the buildings... networked, even, light shows both sides of the harbour in sync.. and that too, for loong years, already!

https://youtu.be/0VAJa8Gv66s

You can't afford the good stuff in Asia? Economically exiled in some muddy-legs backwater? Worse YET the desolate mudslides and ashes of the Kalifornickyah SSR?

Why are we not surprised you are as ignorant of all that as you are of human nature?

Self-reliance JF works. Communism JF sucks.

JF work to suck at that.

You can do it!

Unfair advantage to start with hard-vacuum between your ears, "Red Guard" retread..but wotever..

Ruin what you got!
 
If the US wants to even start talking to Europe or Australasia about electrical safety, three things need to happen:

  • Shrouded pins or recessed sockets to stop people grabbing the exposed pins while plugging/unplugging, and things getting dropped behind outlets. After all, this is more-or-less why AFCIs were first required in bedrooms. You're 20+ years late to the party, likewise with the fancy 'new' tamper-resistant sockets. They're called shutters and they've been around since the 40s.
  • Insulation and shrouding inside panels - why can you hit live parts with your elbow when pretty much everything 250A or below is rated to IP20 in the EU and has been since the 90s? Add uninsulated ground wires held clear by nothing more than being bent into the right shape and you've got a recipe for busbars going bang.
  • Require your sparkies to actually test things. If an electrician or inspector showed up with one of those dinky little three-light things, they'd be laughed off site then there'd be a call to the registration board. UK, Aus/NZ, and I believe Europe all require earthing conductors, correct polarity, and insulation integrity to be proven with actual test equipment during any installation, addition, or maintenance/repair. There's usually also a requirement to measure fault current at all points in the circuit and ensure this is adequate to trip the short-circuit pickup.

UK & europe have begun to follow suit.

First move, a 1:1 Isolation transformer.

Next step, 2XX to 1XX step-down, center tappable to protective Earth.

Works well, it can be made safer yet. So ... a transformer even splits the 110 VAC to 55-0-55 for safer use of portable power tools:

110V Centre Tap Earth (55V-0V-55V) - Electrical Transformers | GS Transformers
That's not a 'begun'. 110V centre tap supplies have been around in the UK for, I believe, several decades. Their intention is to be at a voltage that doesn't pose a shock hazard, which the US system can't claim to be anyway.

Both 230V isolating transformers and 55/110V transformers have been recognised methods of providing safe electrical supply since at least the 1961 regulations (R102) here in NZ. This is not a new thing.

Putting the modern EU and China in the same boat is ridiculous. Like the rest of the US, you're stuck in the 50s and throwing a tantrum.

And you want to remove the Neutral?

Whilst I'm running FIVE WIRE 3-Phase outlets..... because I re-derived a 'local' Neutral, (Delta-Wye transformer..) for the output side of Phase Perfect XOR RPC (transfer switched, not both at once). Gen set is already split-phase ELSE 3-P WYE NATO has had electrocution deaths as well.

And I'm only a lapsed Presbyterian!

Go figure it isn't ABOUT the cost or convenience of the devices.

It is about the safety of the PEOPLE!
Adding or removing a neutral doesn't affect shock safety unless you're expecting people to get hit phase-to-phase. As long as it's the star/centre-point you've grounded, it doesn't matter if you bring a neutral to the load or not.
 
HKG Gov top gun for enforcement of that was a bud of mine.
I'm so happy for you. And I guess they were so pleased with your work they won't let you come back ?

Anyway, fact is, your statement was poop, China and Hong Kong do not want or care about 110v 60hz hand tools. Everything here is 220v 50hz, unless it's three-phase 380v 50 hz. And if they cared about safety, the first thing they would not do is cut off the ground prong.

I myself have been surprised more people are not electrocuted, but it doesn't seem to be a problem.
 
I suspect it's one of those cases where a 1% failure rate is absolutely unacceptable, but means 99% of the time you see it work fine.
 
I suspect it's one of those cases where a 1% failure rate is absolutely unacceptable, but means 99% of the time you see it work fine.

As said - it isn't the Engineering.

It's all about the risks of litigation. Poor suffering Widow against seen-to-be "deep pockets" of the manufacturers and "bottomless well" utility company treasuries.

Look at PG&E in the Kalifornikyah SSR.

The Kommissars regulate them into poverty, fine them into bankruptcy, then AFTER driving them bankrupt, FURTHER fine them larger millions for not doing what they had neither permission (clear fire hazards..) nor money to do?

Eventually the Kommissars will sell-off the rights to the metal in the poles and wires, strip the lot off the face of the Earth, go after taking over the flashlight BATTERY industry.

Then candles...

That would be funny were it not tragic!

I can recall "back in the day", deep-dive recce's in the "East Bloc".

Not a lot of electric lights after dark once you got out away from the major cities. See also night time satellite shots of the Korean peninsula.

STRIKING the blackness of DPRK at night compared to ROK and China.

Kalifornickyah's future? Seems so.


Note also, BTW ... that our so-called "National Electrical Code"... isn't, really.

It is promulgated by the "NFPA". To reduce risk of fire and electrocution.

The "Engineering" has to kowtow to the Fire Marshall, IOW, not to a PhD theoretical Physicist.

Perfect? Nothing ever is. Safer? Yes.

But Japan does it even better!

I REALLY like the way they do shuttered, twist to lock outlets on even cheap 100 VAC two-prong flat-blade small appliance power bars! Simple, cheap, and downright ELEGANT, actually!

:D
 
Granted this situation is my fault, since I assumed a three wire oven used two hots and a ground, not two hots and a neutral (which is also now illegal, so I get to buy a new cord and receptacle). But at what point can we stop running neutral wires? They aren't very useful these days.

It's long been my opinion (and I think the opinion of many) that machine tools running on 208 or 240 volts and requiring a neutral connection for the controls is lazy. It's cheaper to add in a transformer for the half amp or so you need (or just use 240V based controls on capacitive dropped timers and such) than to run a 6 gauge or larger neutral everywhere. It just doesn't justify the copper or the conduit. Residential appliance makers seem to disagree, but I haven't yet met a single person happy with their modern appliances anyway.

But now that I get to shove an extra 6 gauge wire in conduit already at 36% fill, I started wondering what I have that needs neutral. The answer is a space heater, old oscilloscope, toaster, microwave, and heat gun totaling maybe $300 in value. Everything else I have runs fine on 240 with nothing other than a different cord.

So given the advantages of double the power for the same amount of wire, and running fewer wires, and being able to use true 240 delta for all 3 phase stuff, why not just ditch the neutral in general? I honestly like having double pole breakers because it lets you have only 120VAC to ground instead of 240 directly as well.

So, as I would like to at some point grow my business to being able to get a new tilt up shop built, would it be a bad idea just to get 240 delta (Probably wye for ground)? Is there any reason other than strictly 120V appliances to run a neutral connection to anything?

Also, is it to code to install European sockets for 240, since it's readily available?

I don't know how old your house is but 4 wire stove/oven outlets have been required for many years now. The neutral is a current carrying carrying conductor. It should not be assumed that because the ground and neutral are at near the same potential that they could be used interchangeably. The oven likely has components that flow current on the neutral, putting this current on the grounding system, and frame of the appliance,is not a wise idea. You can bond the ground to the neutral, like the old appliances were set up, but then the liability and warranty are on you and not the appliance manufacturer.

If you have an intact conduit system that should be an easy fix, use the conduit as the ground, an add an insulated neutral along with two hots. If it was a cable supply,you'd be replacing the entire run. If you looked at the oven specifications, you might find that you can run a reduced neutral, it only needs to be sized for the unbalanced current.

For 120V equipment, I think your forgetting some basic needs like lighting, heating, electronic loads and appliances. And possibly a phone and internet connection.

For a new building, you normally will accept whatever your utility supplies as standard, unless your wallet is very thick.

240 delta without the center tap, needs corner grounding, with the center tap, needs midpoint grounding. Neither one of these systems are ideal for equipment that contains VFD's or electronic loads. A wye system is the preferred system, just like they use in Europe. 230/400 50Hz.

US 240 systems are not normally supplied in a wye configuration 133/230, for a wye you would need to use either a 120/208 or a 277/480 system. Most utilities will supply a center tapped 240 delta with a high leg if you want 240. But again, what system you will end up with, will be decide upon by your utility and your wallet. As for European wiring devices, today many use 5 wire devices as compared to our 4 wire.

Oh, one more thing about new construction or wiring additions to an existing structures. It is now required to have a neutral present at every lighting switch box, weather you use it or not. It's required so that when an occupant adds electronic controls to the wall box, that control current is not placed on the grounding system, its the same deal with the stove/oven requirement.
So I don't think that neutral wires are going away anytime soon, either here or in Europe.

SAF Ω
 
"The "needed for UL" is also puzzling. I do not know why that would be, and I was involved with putting many dozens of products through UL/CSA/CE/C-Tick, etc, etc."

It was puzzling to me too - note that the motor is the least of their worries - on that machine the controller is in the box with the rest of the motion head assembly, with a lead from the control to the motor.

And it was intended for labs/offices, (yes, a waterjet, with all its mess) which often don't have 3 phase (in the US)

[Make no mistake, it's the bees knees at what it does, I only bought a new one to get waaay bigger.]

Note that the globalmax I replaced it with uses full-on three-phase power line for the pump, while the controller for the motion device is actually plugged into a separate 120v GFI outlet.

And as SAF notes, for houses at least as of 2014, modern code requires a lot of things to be done whether they'll ever be used or not. Things like an outlet every X inches on kitchen counter, come hell or high water. ???? Turns out it's part of a grand scheme to have all appliances have really really short cords so that children won't pull them over on themselves. I thought about running an air fryer on an extension cord in the middle of the floor during a code visit as a demonstration of futility but ran out of energy for fighting with Kafka. There's a similar rule about outlets in walls, designed to assure that things like vacuum cleaners only need short cords, I observe that cleaning staff really prefer a vaccum with about 3 miles of power cord, as do I, and so these outlets have gone totally unused for the last 6 years.

(Water feed rates - your garden hose can be whatever, but the shower is limited to x gallons per minute - OK, I'll just stand there for an hour... Also, since the fixed costs are so high - and sensibly forced to be a base price in WA - there's sensible reasons for that - the return on convservation is close to zero. But they keep passing these laws, I guess to "show" how "environmentally concious" they are.)

Anyway, while you *could* build a stove that is 240v only, when I looked in 2014, no such animal was for sale in my local stores. Probably in part because in any house meeting new code, by law, there would have to be hot-hot-neutral-ground anyway. If the customer's house is required by law to have it, why spend money trying to avoid it?
 








 
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