50HZ VS 60HZ

Ha, this is a trick question!

If there is 50 Hz on the duct and you supply 60Hz it will be 55 Hz as well as 50 Hz as well as 60 Hz, not? Not sure what it should be but usually if you replace 50 Hz and supply 60 Hz you will get ....

.... oh wait its coffee time. I'll come back later to see if you refined the question.....

Everything that branches off the bus will then run at 60Hz, unless there are VFDs or other frequency converters involved. Most AC motors will run 1.2 times as fast as on 50Hz.

I've just tried superimposing 60Hz on to a 50Hz waveform.

I've got a headache now!

Hertz dont it?

The bus does not care which power distribution frequency gets applied to it. Depending on the nature of the load(s) attached to this bus the loads may work fine, burst into flames, or any of a number of other unpleasant scenarios.

But it would need to be three phase DC, correct? ;-)

Not really - positive, common, and either a spare or ground. Or if we are working with OP amps we can have positive, ground, negative. Works for this argument.

Actually, the OP never did say it was 3 phase - we are just assuming that, which is the point - too little information once again.

It was an attempt at humour.

Unfortunately, so were my poor responses.

Seen it done. Separate 220V and 440V three wire systems with a common neutral.

They were supposed to be separate systems, somewhere in the mists of time the neutrals got connected together. It didn't cause problems and I couldn't be bothered to look for it.

Only on one side.

Phys,

I have to disagree with you on this one. Although some could humorously argue that a bus duct doesn't care because an inanimate object can't have emotions, the users should care. As the frequency goes up from DC to 400Hz, the current flowing in the individual bus bars is increasingly forced onto the surface, instead of flowing equally throughout the entire cross-section of the conductor. This requires a decrease in the ampacity of the bus bars. This decrease is not uniformly proportional to the change in frequency, but depends in a complex manner on the cross section as well as the frequency. There are a few good articles that discuss this (unfortunately, I don't have their references right now). The 400/60 Hz ampacity ratio varies from 1.0 in very small conductors to less than 0.7 in large ones.

--JMM

This may help http://chemandy.com/calculators/skin-effect-calculator.htm

I agree with you : the busbar is a conductor. So, skin effect and proximity effect will be involved. The resistance will grow and so the losses. The temperature will rise. If it will be over the limits-it depends on insulators type, also-you have to oversize a bit.

For skin and proximity effect see[for information]:

http://www.aluminum.org/sites/default/files/aecd13.pdf

[pages 13-12 up to 13-16]

Note: usually from 50 to 60 Hz the resistance increases with about 3-4%[so the losses do].

You will have to change the core material from Iron to Kryptonite, unless it powers a resistance heater.

I wonder what temperature and pressure would one need to make a crystallized noble gas?

really low and really high at the same time to make Krypton solid, a.k.a. Kyrptonite.

I really have no idea what to dissolve in it for the colors though. Perhaps red Kool-Aid, there seems to be plenty of that to go around these days.

I thought the GOP drank the red Kool-Aid, and the Democrats drank the blue? Did you mistype, did I mishear, or did you intend to slam the Republicans with that?

It was an allusion to red kryptonite. Usually all Kool-Aid being drank by whatever uninformed voter block (whether they vote for Dem or GOP) is red. Jonestown Kool-Aid was also red, as I recall, and Lemming Kool-Aid is also red.

Q: What's the difference between 50Hz DC and 60Hz DC?

10Hz DC!!!

5Hz on each leg.

That could hurt really badly...

Dear Friend,

You are not clear in your expression.

1. Do you have equal voltage.

2. Do you have same phase sequence

3. The following combination is possible.

a. Do you switch off 50 Hz. supply and switch on 60 Hz.

b. Do you switch on 60 Hz. supply while 50 Hz. supply is on.

Nett result - Short Circuit and fuse blow-up. happen.

If you have 50Hz equipment and you are supplying 60Hz power, you may damage the equipment. This cannot me bade as a general call, as each piece of equipment needs to be looked at individually to see the results. A light bulb won't care, a motor will run faster (and possibly overheat) a PLC might release the Magic Blue Smoke and stop working altogether.

If you are connecting a 50Hz power supply and a 60Hz power supply to the same bus at the same time, then you are a dangerous idiot who should be fired immediately before you kill someone.

What did the 50Hz duck say to the 60Hz duck? Quack! If it looks like a duck, sounds like a duck, and smells like a duck, and even waddles like a duck, it must be a duck.

DUCK!

I am not an engineer, but the little bit of theory I learnt tells me if its a pure resistive device then frequency has no effect.

But IS it a pure resistive device? The OP hasn't told us yet.

We've only got part of the question so far, it's like trying to answer "What do you get when you cross - " Cross what with what?

All we know are "a power buss at 50Hz" and "a generator at 60Hz." We don't know what sort of load, we don't know if there is another 50Hz power source on the buss, we know just enough to make wild guesses, and ask leading questions to try and draw out more information, and the OP does not seem to be very forthcoming with the latter.

No, we can make all sorts of WAG on absolutely no information at all. Just look at all of the previous 32 replies.

One thing I can tell you for sure: There will not be 10Hz leaking off to one side so the bus can still run at 50 Hz. What planet are you from, once again please? Here on Earth, the frequency the power is supplied to the bus is equal to the frequency at the output side of the bus. If there are multiple frequencies, there is a problem, and usually it lets the smoke, fire escape from the conductors.