Need some help, what is percentage US voltages on 115V, 208V WYE, 240V?

Generation and distribution is 3 phase in the US and just about all of the world. We just don't run 3 phases into houses, it ends at the street.

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The trouble with using two neutrals is that if you lose one, you no longer have the protection of a dual system and no indication that it is no longer protected. Actually, this guy doesn't have two neutrals anyway. His 240 volt connection is two hot and a protective ground (PE). That's the proble m. Tying any load to the PE invalidates its use as a protective earth.

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No, like I said, if the loads are only 240v, then you don't need to run the neutral. Most cases though there is a neutral for 120 for lights, 120 receptacles, etc. But if you have a 240v well pump, you would not run the neutral.

That's fine. But +10% of 115 volts is 126.5 volts. So, close enough is engineering speak for, "We don't quite make the spec, but we won't worry with that."

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ilon,

V.

-6% allows both 220v and 240v to be within the standard with no physical ch ange.

ange.

an outlet. The fuse within the plug can be appropriate for the load.

imiting for high-power portable devices such as kitchen appliances.

ize

a 3-phase input that allows up to 43kW input power in some vehicles. In the case of the Tesla there are essentially 3 separate chargers in the car.

input at 43 kW, but that would be pretty amazing if they did. The charger s you are talking about handle 24 amps each, so 17.2 kW total... at least i n the US version. My car has three of these chargers, but since my car was made they dropped back to two units each which still gives 48 amps, plenty of power and more than most connections will support.

would seem odd for them to do that. Bottom line is I can't find any info o n the max charging rate in Teslas from 3 phase power in the EU. The Tesla site doesn't easily provide that info since I'm not in the EU.

several times that.

DC charging from a Tesla supercharger does not use the same electronics in the car that AC charging does. In reality, the charger is in the car when AC charging. The external "charger" is really just a smart outlet that pre vents problems from wrong charging rates and disconnecting while powered. It doesn't actually do anything with the power other than run it through a relay to prevent hot contacts in the connector.

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I have newer seen here single phase induction motors greater than about 1 kW, they are all three phase. No starter capacitor needed, you can change between CW and CCW rotation simply by swapping two phases.

Induction motors starting current is up to six times compared to normal running current. This could be reduced by using wye/delta starter (no neutral connection needed) by first connecting the winding in wye (240 V) and when the motor starts to rotate, the windings are connected into delta (400 V). These days SCR based soft starters are also used.

Of course if large DC loads are used (such as welding machines), the simple six pulse rectifier is handy, In many cases, you do not even need storage capacitors on the DC bus, the ripple is often sufficiently low without it. Usually no neutral connection is used.

Stupid is that they are rated WAY below the capacity of the line and their value reflects the maximal allocated power budget, as per ones contract. E.g. a typical older flat has 20A fuse, because the contract specifies 4.5kW power budget. You can get at most 32A on a single phase and on this very same line -- this is entirely a contractual update. If you need more, you need to upgrade to a three-phase system. Then you get

3x20A.

The building lines are protected separately.

In case of houses the limits are higher, usually 3x63A, but I have never heard of 200A. This rating is typical for buildings.

No, you protect the lines, not throttle the consumption level. This is OK.

But come on, you claimed 90A wiring capability elsewhere in the thread. Do you use busbars for that? 90A is 8W waste power per milliohm -- creepy.

Nothing needs to be explained, because this is whay you are given without asking. You don't need to explain the need for a water pipe as well.

The kitchen equipment can use enormous amount of power. Waer heaters even more.

I don't, but many of my friends do. I am considering buying one.

Best regards, Piotr

mains voltage

phase), and 240V (120V, 180 degrees phase inverted)

A local company had a pipe bending machine for over a decade. It was really wimpy on 208V. I finally got a manual in English (Italian OEM) and found t hat it was actually 240 V A boost transformer brought the line up to 245V, and it had amazing torque. I got involved when they moved to a new building , and it didn't work. the 'Industrial' electrician they hired had wired it for 120V in the breaker box. The outlet was OK, but the moron had connected the red wire to Neutral, because he didn't have the right dual pole breaker with him.

On Thursday, October 31, 2019 at 4:05:29 PM UTC-4, snipped-for-privacy@downunder.com w rote:

4% would have a noticeable hum and never meet FCC standards. HV capacito rs were available for big transmitters. They were large, oil filled with ce ramic insulators. Some weighed several hundred pounds, but were still in da ily service over 50 years later. Phase correction capacitors used in power distribution were similar but usually lower capacitance.

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act, Tesla home car chargers can be wired up with 100 amp service to drive

80 amp charging to some of the older cars. Mine will only accept 72 amps, so no point in more than 90 amps on a single charger but they can be used i n parallel on a single 100 amp circuit. We derate our socketed connections to 80% for continuous loads, not sure exactly why.

ent loads. I don't see the need for 3 phase.

e of ~30A

for using 240 volt circuits. In the US we only require two conductors for the power and a smaller one for protective earth, the neutral is only requ ired if you need 120 volts. I know in the UK the whole protective earth th ing is complicated and allows the use of a system that loses safety if you run an extension cord outside. I don't know what the regulations require i n the rest of the EU.

he Tesla HPWC only requires a pair of heavy gauge wires for the power and a protective earth.

Wye requires a Neutral, Delta doesn't.

A VFD is more likely, these days. Rotary converters are last millenium.

The 120-240 outlets are common in some commercial buildings. They are for the custodial service to power floor buffers of either type. I saw a lot of them in schools, in hallways and large rooms when I serviced industrial electronics.

Leviton and Hubbel both sell a wide variety of residential, commercial and industrial power connectors.

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t US mains voltage

ase phase), and 240V (120V, 180 degrees phase inverted)

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is to say you would always have the option to use the line neutral 120V?

he neutral. Most cases though there is a neutral for 120 for lights, 120 r eceptacles, etc. But if you have a 240v well pump, you would not run the n eutral.

I saw a botched wiring job at a church near here. They ran 240 to the pump house, without a neutral. Someone later added a light by connecting to one line, and the well casing instead of Neutral. You can bet it that was never inspected!

My well pump is 240V without a neutral, but I ran two 120 volt circuits to the wellhead. One for tools or a work light, and the other is for a small s pace heater for the rare occasion it drops well below freezing. I turn off that breaker, except when I need the heater.

yep a vfd is smaller quieter and variable

but some still use rotary converters because they don't believe in modern electronics, it can run multiple machines and some machines need not just three-phase to run motors but also single phase for a controller

three phase is also a big advantage for VFDs because you don't need nearly as big diodes and capacitors in the input

fredag den 1. november 2019 kl. 14.44.24 UTC+1 skrev Michael Terrell:

tors were available for big transmitters. They were large, oil filled with ceramic insulators. Some weighed several hundred pounds, but were still in daily service over 50 years later. Phase correction capacitors used in powe r distribution were similar but usually lower capacitance.

you can get from three phases to six phases with just transformers, I think a 12 pulse 6-phase rectifier is ~1% ripple

A main breaker obviously does both. You can't exceed the limit of the fuse, that certainly "throttles" the total capacity of the service. It also only protects the wires against an overload past the breaker. It doesn't protect the wires between the transformer and breaker. If something comes in contact with them, the breaker does nothing. Which is different than a breaker protecting branch circuits, where the breaker protects the wiring from the breaker to the loads.

No, we use wire. Not unusual to see 100A subpanels, for example, wired to the main panel. And that's just the peak capacity. Actual usage is something totally different. The bill here is typical ~600kwh for a month. That works out to about 7a continuous. The wire losses depend on the current. If we take an average wire run of 50 ft, use 14g which is the smallest branch circuit gauge allowed, you have a whopping .25 ohms resistance. Using a 7a current, that works out to 12 watts lost, 840 watts delivered to the load. That's a loss of just 1.4%. If we doubled the voltage, the loss would be 0.7%, not what I'd call significant. My bill for that monthly power is about $75. So, I'd save 52 cents a month. Doesn't get me too excited....

If we were to start from scratch, I see compelling advantages to going with 240V as the standard for all loads, eg an electric kettle could heat twice as fast. I see some small advantages, eg the 50 cents above, but I sure don't see a compelling advantage to 3 phase for homes.

In other words, you have no explanation.

The only kitchen equipment in a house that I'm aware of that needs a lot of power are cooktops and ovens and I wouldn't call those "enormous". We run those off 240V single phase just fine. Typically a 30A or 40A circuit. Which also works fine for AC equipment, heat pumps, etc.

For electric dryers in homes too.

ome.

I don't know what to tell you pal. The utility has to provide distribution and someone provides generation, all of which need to be budgeted for. If your usage is on the charts as 4.5 kW and you start drawing 9 or 13 kW at the same time as everyone else, I expect that would cause problems. Having a limiter in the line makes perfect sense to me.

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I don't know how the utility deals with extreme peak loads here. In some a reas they just cut power off to sections. Which do you prefer, getting you r apportioned amount of power or getting what you ask for most of the time but none a other times?

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I don't know what you are talking about or where you are going with this. A 90 amp circuit would provide 72 amps to charge my car and would require 3 gauge wire. That's about 24 kW. My wire run would be around 30 feet not counting the 20 foot flexible cable to the car.

I have no idea why you have an issue with this. Such a set up is common wi th Tesla owners who elect to install a HPWC... if they don't install a 100 amp breaker and put two HPWCs on the same line. This is legit because the two units talk and can share the power without going over 80 amps on the ci rcuit.

ower in the home.

ll.

That's easy to explain. Water is required for humans to habitate. A given size pipe coming into a home I can't justify, but I'm sure others can.

I'm thinking the only reason for bringing three phase power into a home it if it saves some cost in the transformer or elsewhere. I've never heard of that.

h 240 volts?

"Enormous" is a subjective term. We manage just fine on 240 volts here in the US. If it is typical that homes need instant on hot water for showers, fine. I've just not heard anyone say that. Certainly there is nothing in the kitchen that can't be supplied by 240 volts.

Lol

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the custodial service to power floor buffers of either type. I saw a lot o f them in schools, in hallways and large rooms when I serviced industrial e lectronics.

d industrial power connectors.

I worked in a shop that was in a room off a parking level in an apartment b uilding. The 120 volt outlets were wired with one phase of the 240 on one socket and the other phase on the other socket in the standard two socket o utlet box. So you could measure 240 volts between the two. I assume this saved on wire costs and also helped to spread the loads between the two pha ses.

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