230 volt hand held power tools

[DrSparks]

Ok, dumb question.:dunce: How many more times is 230 volts dangerous then 120?

Generally, 240 is no more dangerous than 120. Each leg of a 1PH, 3-wire circuit is still just 120V to ground as was explained before. What are the chances you'll take a shock across both legs and through the heart? Pretty slim, I'd warrant.

 

[Besoeker]

it's a known fact that if you are killed by 240V, you are twice as dead as if you were killed by 120V...

Or maybe four times according to post #55.........

 

[Besoeker]

Generally, 240 is no more dangerous than 120. Each leg of a 1PH, 3-wire circuit is still just 120V to ground as was explained before. What are the chances you'll take a shock across both legs and through the heart? Pretty slim, I'd warrant.

But some countries, including most/all of those in Europe, don't have 120-0-120. It is simply 230V line to neutral with the neutral grounded.

 

[kwired]

But some countries, including most/all of those in Europe, don't have 120-0-120. It is simply 230V line to neutral with the neutral grounded.

There also are 480 volt single phase sources in the US with a grounded center tap - 240 volts to ground on those.

One common application is roadway lighting, they also supply irrigation machines in this area with them where they don't have three phase distribution and we often need to apply phase converters with those sources.

 

[mbrooke]

But some countries, including most/all of those in Europe, don't have 120-0-120. It is simply 230V line to neutral with the neutral grounded.

I think countries that went with 3x230 sans neutral for residential and light commercial did it right imo. Although 230/400 still is preferred when it comes to losses.

 

[Besoeker]

I think countries that went with 3x230 sans neutral for residential and light commercial did it right imo.

That's something I haven't come across. What countries are they?

 

[mbrooke]

That's something I haven't come across. What countries are they?

Old networks in Belgium, parts of the middle east upgrading to 230 volts, parts of the Philippines (center grounded 230 volts) and Norway has 3x230 volt IT earthed networks:

http://www.electrical-contractor.ne...topics/209335/Norwegian_power.html#Post209335

 

[iwire]

I think countries that went with 3x230 sans neutral for residential and light commercial did it right imo.

And this opinion is based on what facts and statistics?

 

[Besoeker]

Old networks in Belgium, parts of the middle east upgrading to 230 volts, parts of the Philippines (center grounded 230 volts) and Norway has 3x230 volt IT earthed networks:

http://www.electrical-contractor.ne...topics/209335/Norwegian_power.html#Post209335

Thank you for that.

 

[mbrooke]

And this opinion is based on what facts and statistics?

What happens when a neutral conductor sharing other phases breaks?

 

[mbrooke]

Thank you for that.

Weclome

Also this around page 4 gives different systems used in the Philippines:

http://www.giz.de/expertise/downloads/Fachexpertise/giz2013-en-manual-interconnection-rooftop-pv.pdf

 

[JDB3]

Quote Originally Posted by fmtjfw

If you just intend to sell them to "households" probably anything goes.

Quote Originally Posted by iwire

It is an NEC violation to install 208 or 240 volt receptacles in dwelling units for appliances less than 1400 VA.

I had never heard about this. :huh: Any code references ? :?

 

[mbrooke]

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Quote Originally Posted by fmtjfw View Post

If you just intend to sell them to "households" probably anything goes.
It is an NEC violation to install 208 or 240 volt receptacles in dwelling units for appliances less than 1400 VA.

I had never heard about this. :huh: Any code references ? :?

Here you go:thumbsup::

210.6 Branch-Circuit Voltage Limitations. The nominal
voltage of branch circuits shall not exceed the values permitted
by 210.6(A) through (E).
(A) Occupancy Limitation. In dwelling units and guest
rooms or guest suites of hotels, motels, and similar occupancies,
the voltage shall not exceed 120 volts, nominal, between
conductors that supply the terminals of the following:

(1) Luminaires
(2) Cord-and-plug-connected loads 1440 volt-amperes,
nominal, or less or less than 1⁄4 hp
(B) 120 Volts Between Conductors. Circuits not exceeding
120 volts, nominal, between conductors shall be permitted
to supply the following:
(1) The terminals of lampholders applied within their voltage
ratings
(2) Auxiliary equipment of electric-discharge lamps
Informational Note: See 410.137 for auxiliary equipment
limitations.
(3) Cord-and-plug-connected or permanently connected
utilization equipment

 

[broadgage]

As others have posted, a few countries use 3 phase 220 or 230 volts with 220/230 volts between phases and no neutral.
However such systems are increasingly being considered as obsolete and I very much doubt that many are being installed these days, though of course old equipment may remain in service.

Many such systems DO in fact have a neutral and should be correctly called 3 phase, 4 wire at 127/220 volts, however the neutral is often unused and may not exist beyond the POCO transformer. All loads on such a system are 220/230 volt.
The drawback of such a system is that they use a lot of copper relative to the load served and revenue produced.
Such systems are also vulnerable to theft of electricity.

Other systems are true 3 phase, 3 wire, with no neutral, obtained from a delta transformer.
The voltage between each phase and ground on such a system will vary according to the degree of leakage from each phase to ground. The system tends to unreliable as a ground fault in one house can put out the neighbours lights !

Virtually all new systems throughout Europe will be 3 phase, 4 wire, with 230 volts between any phase and neutral, and 400 volts between phases.
A 3 phase system at 230/400 volts can transmit a lot more power over the same size cable than a 127/220 volt system.
The only merit of 127/220 volts was decades ago when lamps and small appliances were often 125/127/130 volts.

 

[mbrooke]

As others have posted, a few countries use 3 phase 220 or 230 volts with 220/230 volts between phases and no neutral.
However such systems are increasingly being considered as obsolete and I very much doubt that many are being installed these days, though of course old equipment may remain in service.

Many such systems DO in fact have a neutral and should be correctly called 3 phase, 4 wire at 127/220 volts, however the neutral is often unused and may not exist beyond the POCO transformer. All loads on such a system are 220/230 volt.
The drawback of such a system is that they use a lot of copper relative to the load served and revenue produced.
Such systems are also vulnerable to theft of electricity.

If the neutral is not used for load it would technically be classified as a protective earthing conductor and classified as 3 phase 3 wire.

The meter would be an issue if only two legs are being metered (which is common for 3 phase 3wire), however a wye (3 CT) would not, or adding a 3rd CT with all phase through it to detect zero sequence imbalance. High zero sequence current would indicate theft through the un-metered phase.


Such a system does have higher losses and larger conductors, but in theory this system could easily have been implemented in North America since 120/208 3 phase 4 wire Y and 120/240 1 phase 3 wire make up more then half of all services.

Other systems are true 3 phase, 3 wire, with no neutral, obtained from a delta transformer.
The voltage between each phase and ground on such a system will vary according to the degree of leakage from each phase to ground. The system tends to unreliable as a ground fault in one house can put out the neighbours lights !

I would never consider such a system for residential or most POCO supplies for that matter. Faults blowing fuses in other homes is not unheard of in Norwegian DIY forums.

Virtually all new systems throughout Europe will be 3 phase, 4 wire, with 230 volts between any phase and neutral, and 400 volts between phases.
A 3 phase system at 230/400 volts can transmit a lot more power over the same size cable than a 127/220 volt system.
The only merit of 127/220 volts was decades ago when lamps and small appliances were often 125/127/130 volts.

Ive heard that nearly all the remaining 127/220 supplies in Europe are from decades past. If I am correct Mexico is still 127/220.

 

[broadgage]

Theft of electrical service was common in years gone by in homes that had a 2 wire 220 volt service that was derived from a 3 phase 4 wire 127/220 volt system.
The older mechanical KWH meters measured the voltage between the two wires, and the current in ONE WIRE ONLY. Both wires were live to earth/ground.

Dishonest persons soon found that free electricity was available between whichever wire was unmetered and true earth/ground. This would only be at 127 volts nominal, but still useful. It was common practice to connect lamps between the unmetered line and a water pipe, well casing or metal fence. Sales of 120 volt lamps were substantial in areas where all services were 220 volt.

Where such supplies remain use they are fitted with modern electronic KWH meters that measure the current in BOTH lines, and nothing is then gained by connecting as described above.

It is said that GFCIs were developed by the French POCOs, decades ago, not to improve safety but to be connected by the POCO at the service in order to trip the supply when someone connected a lamp between the unmetered line and a water pipe.

 

[mbrooke]

Theft of electrical service was common in years gone by in homes that had a 2 wire 220 volt service that was derived from a 3 phase 4 wire 127/220 volt system.
The older mechanical KWH meters measured the voltage between the two wires, and the current in ONE WIRE ONLY. Both wires were live to earth/ground.

Dishonest persons soon found that free electricity was available between whichever wire was unmetered and true earth/ground. This would only be at 127 volts nominal, but still useful. It was common practice to connect lamps between the unmetered line and a water pipe, well casing or metal fence. Sales of 120 volt lamps were substantial in areas where all services were 220 volt.

Where such supplies remain use they are fitted with modern electronic KWH meters that measure the current in BOTH lines, and nothing is then gained by connecting as described above.

Id imagine :lol: In any system like that I would never have one leg un-metered.

It is said that GFCIs were developed by the French POCOs, decades ago, not to improve safety but to be connected by the POCO at the service in order to trip the supply when someone connected a lamp between the unmetered line and a water pipe.

Ive heard that story also. From what I heard is that France was originally 110/200 volts, then 127/220 but was then upgraded to 220 volts utilization in the 50/60s where equipment was just reconnected line to line.