You're right, Max. That's what I get from just doing a copy from the internet and looking only at the logic and not all the labels.
Thanks for catching that!
Thanks for catching that!
In those systems, 208 volts is the center voltage. That is what you get with three 120 volt phases. And generally they are able to hold much better than +/- 10%Doesn't allow any error in order to satisfy the ±10% guaranteed or recommended supply tolerance for residential service standards. When running the higher voltage appliances etc.
This is the standard here, and AFAIK most of N.A.
In the event of a 10% drop you would end up with 187v!
I am fully aware what phase to N is on a 208 3ph. Not sure what you mean by "Centre Voltage"? It is 208 phase to phase. 120v phase to star neutral.!In those systems, 208 volts is the center voltage. That is what you get with three 120 volt phases. And generally they are able to hold much better than +/- 10%
How is that an advantage in a residential setting. I can think off some disadvantages.The advantage of a relay, when properly set up, is that in the event of a power failure, even wnen power is restored, the load isn't activated until commanded to do so by the push of a button.
By "center" I meant the middle of the range of voltages. Perhaps "target" would have been better, or maybe the "mean" voltage.I am fully aware what phase to N is on a 208 3ph. Not sure what you mean by "Centre Voltage"? It is 208 phase to phase. 120v phase to star neutral.!
±10% ????All depends on the service provider? Brown outs etc.
With 208 there is no way to go except up!
Here in the USA we use 120 v because the shock hazard and insulation requirements are not as demanding. In addition more items use smaller amounts of power and the voltage step down from 120 is cheaper than from 220. also our electrical outlets and plugs can be much smaller. One more thing is that municipal electrical distribution started here, and the higher voltages elsewhere were selected for the benefits of distribution, not use.Why You guys are speaking a nonsense about 208 Volts if the 380/220 is a century long Worldwide standard containing both voltages in it name, 380 between phases and 220 (not 208) from any phase to the null-wire.
And there in no ANY need to explore the motors if motor may be built only two ways, or delta or star. One have 380 V coils other 220 Volt coils.
All all all other type of motors are few continent specialisms creating nothing but headache. And if the author have 380/220, it means he is not living in those exemption continents like N-America and may not meet the "full beauties" of 60 Hz 110V.
I`ve met, it still stays unused in cellar. No way exempt the frequency invertor plus PWM how to work it up. But all I tried soon was exploded as soon the power may change a bit. I bought this 3 kW angle grinder from US Military Base soldiers near the fence exchanging it against the vodka bottle. That was bad idea to do so, very bad indeed.
Really, WHY the whole world may not unite on the common frequency and voltage standard? Just any. As well the plug standards. Most worst are the variety.
And noisy: not a problem in a factory, but you'll notice that hum late at night in a residential situationWhat has not yet been mentioned is that the coil that makes that contactor close the circuit requires a fair amount of power to operate, and so it is going to be getting warm.
My wife has a couple of computerized sewing/embroidery machines and a short power interruption (some would call it a major dip, but enough to cause the lights to blink) can result in major damage to the control system. If there is a major dip, the relay drops, does not come back on until reset. This allows the machine system to do a full shutdown without being confused by the power coming back on while it is still shutting down. They don't shut down the instant incoming power is dropped. The internal power supplies keep them up for a short time.How is that an advantage in a residential setting. I can think off some disadvantages.
As I mentioned, remote control/indication might be one, BTW your comment reminds me of another advantage of using a DC contactor coil/control, with power dips, the DC coil is much less likely to drop out with a brown out, compared to AC version.If there is a major dip, the relay drops, does not come back on until reset.
I guess I must ask... Why do you feel you need a contactor or relay in a residential system?
Many ratings use a safety factor. And I have had a few extension cords rated at 300 volts. That 600 volt insulation rating allows that wire to be used in areas where 580 volts is also present.Then, if that is true, explain why most residential or industrial wire is rated at 600V? Unless a higher voltage is needed.
The 600 volts is the voltage that an electrician would read on an accurate VOM (Multimeter), just like the 120 volts and the 240 volts. Insulation voltage ratings relate to classes of wiring, as much as anything else. Why is this a big deal???I once tried to look up voltage ratings of wires. Got nowhere. Dunno if 600 V is AC, DC, 0-peak or what. Units really aren't specified.
Makes sense. It's just one of those oddities. Scientifically, I'd figure peak voltage.The 600 volts is the voltage that an electrician would read on an accurate VOM (Multimeter), just like the 120 volts and the 240 volts. Insulation voltage ratings relate to classes of wiring, as much as anything else. Why is this a big deal???
This is the first time I saw a reference to RMS.The voltage rating of a cable refers to the maximum voltage to which it may be connected (and have running through it).
If the voltage rating is exceeded, the insulation between cable cores, or between a cable core and earth, may break down and cause a short circuit or a fire.
A typical voltage rating is 0.6/1 kV. This means that a cable with this rating is capable of withstanding a voltage of 0.6 kV (600 volts rms) between the conductor and earth, and 1 kV (1000 V rms) between adjacent conductors.
The voltage rating of a particular cable can usually be found on the cable reel or drum.
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