PLEASE buy a generator!

[NHawk]

Originally posted by SIM
I read your note. No you didnt disrespect my profession. You basically showed YOUR ignorance then and have done so with your latest post. As before, do my job, then feel free to spout off about what you THINK you know.

 Find your IDs, like I said, maybe, just maybe you'll find someone whos impressed. Not here, theres better things to be impressed with than egos.


 Oh, BTW, your appraisal of what happens when a generator is not hooked up right, well I wouldnt work a line with your knowledge in any way. I like being in the land of the living. People like you get killed on my job.


 Enough for me......

Ok, after reading this yes I got really worked up. So, FYI what I posted was my old ID from Commonwealth Edison Station 22, the Zion Nuclear Power Plant. But even blocked out it provided a little more information than I was comfortable with.

So I will post simple diagrams of what I posted verbally before. I would appreciate your comment on what is wrong. And trust me I will back up what I post if needed.

Now, I'm using a pretty common voltage for the final leg to home service. It MAY or MAY NOT be accurate for all areas but it is fairly common. I AM NOT talking about the main transmission lines here.

We'll keep things low and say each home has a constant 3Kw load. So, under normal circumstances this is what common wiring looks like....

Remember these are simple diagrams. Is this correct or incorrect? If incorrect why?

If during a power outage a generator is hooked up properly is looks like this...

Is this correct or incorrect? If incorrect why?

Now if the owner fails to disconnect the main service while the generator is hooked up, the first thing that happens is the generator attempts to power the other homes on the circuit. We are IGNORING the step down transformer here....

Because the surrounding homes overload the generator it would normally either kick out in overload or go up in smoke attempting to provide the 12Kw demand. Is this correct or incorrect? If incorrect why?

Now, put the transformer back in the mix. The step down transformer is now working as a step UP transformer.


If the generator survived the initial demand and continued to produce power there is a VERY dangerous situation for line workers here.

Under normal circumstances the danger would be for a very short period of time because not only is the generator trying to supply every home on the circuit, it is also feeding the transformer and getting a very high inductive load from that and everything upline from there. The generator would/should fail.

But no matter what amount of time that generator actually provides power, the danger to workers is VERY real. It only takes a millisecond and someone could be hurt or even killed.

Is this correct or incorrect. If incorrect why?

Sim, you're very good with bashing someone verbally and claiming they don't know what they are talking about. So back up your claims with information to the contrary of what I posted. I other words, educate me and others here.

If I can be proven wrong, I'll gladly admit it. But if I'm right, I'd expect the same from you.

[Wes14]

Originally posted by ForrestS
BTW i just looked outside and its getting darker.  

Nightime?

[storch]

what do you think people did for entertainment before television and computers?  here's a hint if they couldn't read (as with most of us here who post on this obscure BBS) they warmed the old lady up and consequently had twelve offspring.  fire the old lady up, you'll be glad you did.

[Sweet2th]

They say everything is BIG in Texas, apparently that doesn't cover thier Electrical system.

[Shifty]

Originally posted by Sweet2th
They say everything is BIG in Texas, apparently that doesn't cover thier Electrical system.

Well there seems to be global whining when it goes down, so it must be BIG.

[storch]

Originally posted by Shifty
Well there seems to be global whining when it goes down, so it must be BIG.

[Shuffler]

Originally posted by Anyone
last time i had a power outage was probably 2002.... so maybe america needs to sort its power lines out?

     
A summer shower in Texas would probably be considered a flood in England. Until you see what hot and cold temps acting against eachother can do to the atmosphere, you might want to refrain from comment on electrical systems. Our State is well known for it's high winds, large hail, and lightning.  

[Anyone]

hence the winky

i went to a comedy club last week and one of the jokes was about the weather here... vs the US.


normaly the UK has little ppfts and is our weather is a bit like a very camp person (imagin the guy actin gay/camp while doing this part of the joke) he then went onto the "london tornado" which was really just a gust (camp person runnin around stage...) and took the piss outa that.


onto America he mentioned building cities on swamps/hurricane alley.... very clever.... or building cities below the water table, trying to creating the worlds biggest Guinness (black people floating in water = Guinness) oh, and that big crack in the earths skin and deciding to put LA there...


hmmm i supose you have to be there to find it funny lol


however a whole day without power is a bit outrageous.

[rodeo]

YEAH Skuzzy buy a generator.  Then increase our monthly subscription to cover the cost of the generator; don't forget the fees to get the zoning approved.  Then you need to add in the depreciation cost of that generator and then finally - cost to run that generator (fuel).  Lets make the monthly subscription 29.95 and see how many of these whiners will pay for it.

I wounder how many whiners are adults having to figure in every cost?  How many of those are small business owners?  You ignorant (def. lacking the intelligent information in order to make a reasonable decision) bafoons - haven't you realized that a cost in business or a tax increase business IS NOT PAID for by the business?  Its PAID FOR by the users of the products or services rendered!!!!

LOL - prior to this, how many times has HT gone down?  Not many!

[Ghastly]

The cost was $600 for the generator and change for four extension chords.

I'm responsible for the Disaster Recovery Site for my company, and Skuzzy beat me to it:

Finding commercial property that will even consider letting you maintain a backup generation system is incredibly difficult, and then addressing all the red-tape involved in getting one set up is both a major undertaking and serious investment of time, effort and money.  Just fuel storage issues alone can be a nightmare that makes everything else you have to deal with moot.  The actual generator can be one of the more insignificant costs depending upon the amount of power needed.

Very much not worth it just to keep a web site online.  

NHwk, my generators will attempt to an maintain power for up to 5 seconds even when severely overloaded, and if intermittently overloaded will do so until the inverters heat up to the point where the thermal protection circuit kicks in. (Based on the manual, I've always been careful to never overload it and haven't tested it myself)

Since it only takes a few ma across the heart (and enough voltage to generate the current) - and when you consider that there's a transformer involved and that under adverse weather conditions a lineman is almost certainly working in something less than an ideal, dry workspace - I don't think you can count on the "instant overload kills the generator" as you diagrammed as a "protection".

In an imperfect world with impedance and resistance involved I think that under some conditions a lethal voltage can be generated for a significant period of time.

Regardless, if anyone is using a generator and not using a properly designed and rated transfer switch, they are risking their own lives and property as well as that of others.  Some pretty nasty things can happen when power is restored if the generator isn't properly isolated from the grid.  

Hopefully, not too many electricians are that stupid - and not too many DIY'ers either.
 

[NHawk]

Originally posted by Ghastly
....NHwk, my generators will attempt to an maintain power for up to 5 seconds even when severely overloaded, and if intermittently overloaded will do so until the inverters heat up to the point where the thermal protection circuit kicks in. (Based on the manual, I've always been careful to never overload it and haven't tested it myself)

Since it only takes a few ma across the heart (and enough voltage to generate the current) - and when you consider that there's a transformer involved and that under adverse weather conditions a lineman is almost certainly working in something less than an ideal, dry workspace - I don't think you can count on the "instant overload kills the generator" as you diagrammed as a "protection".

In an imperfect world with impedance and resistance involved I think that under some conditions a lethal voltage can be generated for a significant period of time.

Regardless, if anyone is using a generator and not using a properly designed and rated transfer switch, they are risking their own lives and property as well as that of others.  Some pretty nasty things can happen when power is restored if the generator isn't properly isolated from the grid.  

Hopefully, not too many electricians are that stupid - and not too many DIY'ers either.
 

Oh I agree 100%, but I've been talking small 5Kw generators. Something more the homeowner would possibly own. And something that small wouldn't withstand a 140% overload PLUS the inductive load of the transformers acting as step up transformers upstream.

And that's why I said just a millisecond of maintained power could injure or kill.

I'm just trying to figure out where some people think my statements are wrong.

I don't claim to be perfect. As a matter of fact the worst mistake I made was when I calculated the transformer size while converting 3ph 240v to 3ph 480v (I don't recall the amperage but it was high). A slightly misplaced number led me to believe we had enough power to do it. When the transformer was turned on it was like you see in the movies....every light dimmed in the building. Computers weren't happy at that moment either. From that point on I never did calculations without a calculator.

And that pretty nasty thing that can happen when a generator isn't pulled offline when power is restored IS NASTY. I've seen it happen. I've seen someone go into the hospital with 3rd degree burns from it. And I've seen old style rotary transfer switches act like a plane prop. It's not pretty.

[storch]

Originally posted by Anyone
hence the winky

i went to a comedy club last week and one of the jokes was about the weather here... vs the US.


normaly the UK has little ppfts and is our weather is a bit like a very camp person (imagin the guy actin gay/camp while doing this part of the joke) he then went onto the "london tornado" which was really just a gust (camp person runnin around stage...) and took the piss outa that.


onto America he mentioned building cities on swamps/hurricane alley.... very clever.... or building cities below the water table, trying to creating the worlds biggest Guinness (black people floating in water = Guinness) oh, and that big crack in the earths skin and deciding to put LA there...


hmmm i supose you have to be there to find it funny lol


however a whole day without power is a bit outrageous.

let me take this opportunity to remind you that each and every one of those cities/regions you ridicule for their location was located in their settings by a european.

[viper215]

Originally posted by Larry
Wasnt there a huge power outage for on the east coast for like a week a few years back. A week w/o AH, I think alot of people will have mental breakdowns.

yep...

[2bighorn]

Originally posted by NHawk
Is this correct or incorrect. If incorrect why?

Properly installed transfer switch does not allow back-feed. In most of the places that's regulated with building/electric code, requires permit and is properly inspected before taken into operation. The code usually specifies that transfer switch has to be of the same size as building service (same amps) and total load of connected circuits cannot exceed the total load generator is capable of, therefore there's no overloads.
That applies for most backup and alternate power sources including solar systems.

In some states you get paid for any excess power back-feed into the grid (usually solar power systems). Utilities are aware of those and are taken off the grid if necessary during maintenance work.  

Few months ago I got installed 16KW standby aircooled natural gas powered generator (200 amps transfer switch) for less than 6K (hardware+installation+permits).

If home owner can do it, so can any company which core business depends on uptime.

[Dichotomy]

we have a saying in Texas.. if you don't like the weather give it 15 minutes it will change.