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Joined: Aug 2001
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If the Electrician is incompetent to lockout the main, is he competent to install the transfer switch?

True, but surely we're talking about a situation in which an untrained, non-electrician will be doing the transfer most of the time?

All of us here at ECN might be capable of safely locking out a main and making a temporary connection for a generator in an emergency situation where power is needed right this moment and there's no other way.


I don't think that means that we should install such as a system as the standard method though, and certainly not where an unskilled householder who doesn;t really understand the dangers is going to be using it.

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I suppose, whenever we consider taking a "shortcut," we should consider what one cynic told me:

"As soon as you make something idiot-proof, they come out with a better idiot."

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I have discovered a "Suicide lead" in a basement garage for two apartments. The shared garage had two socket outlets, one fed from each apartment for laundry purposes.

Mr Upstairs yanked the load the wire out of his meter and back-fed his apartment with the dodgy lead in the two sockets in the garage.

Mr Downstairs found it " a bit strange " when his power bill had doubled a few months earlier, but only voiced concern to the landlord when he noticed that the garage door opener stopped working when the strange lead was pulled out of his socket by the laundry machine in the garage.

The PoCo meter reader had read the meters 5 times ( 5 months ), looking straight at the yanked out 16mm phase cable with tape over the end, and didn't say a thing.

Epilogue : Mr Upstairs vacated said premises the same day. No forwarding adress. Mr Downstairs received cheque from PoCo

Joined: Mar 2005
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I hate to admit it on here, but I have a generator cable like that. Well, not EXACTLY like that, I at least wired mine up to go from my 240V 20Amp generator to a 240V 30Amp dryer jack with #12 wire. Besides, so long as you disconnect the mains first, it's perfectly safe! I mean, I don't exactly have a kirk key on there but it's not like my family or I make a habit of playing with the main breaker. Not that I'd recommend this to a laymen.... And oh man the lady at the checkout at lowes gave me a "I hope you're not planning on doing what I think you are!" when I roll up to the checkout with a generator, a dryer cord, a handy box and 25' of romex. "It's OK, I'm an engineer!"

Re: risk to linemen, I don't think there is much, if any risk at all of someone not closing the main and energizing the lines- a typical 20 or 30amp generator would trip it's own breaker or stall with just the hot water heater or A/C on the homeowner's own panel, forcing them to shut off every breaker in the house (including the main) but the most critical lights & receptacles before bringing the generator online.

At any rate, it's way safer than the double-ended plug I made from an old interior-grade ungrounded extension cord to plug my shed in because I'm too lazy to dig the conduit and finish wiring it up right (ducks). Don't worry about my shed bursting into flames though, alas, the suicide jumper is no more. Damn thing scared the hell outa me anyway, I don't know what I was thinking... See, now I have a NEMA plug wired directly into the panel so I can just plug in my shed to an extension cord like any normal "small" appliance (ducks again). I hope I'm providing a good professional role model for the vocational students browsing this forum!

[This message has been edited by SteveFehr (edited 12-02-2005).]

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don't think there is much, if any risk at all of someone not closing the main and energizing the lines- a typical 20 or 30amp generator would trip it's own breaker or stall with just the hot water heater or A/C on the homeowner's own panel, forcing them to shut off every breaker in the house (including the main) but the most critical lights & receptacles before bringing the generator online.
Maybe, but if the house is on a single transformer, and the primary is feed is open before the next transformer, then the primay will be energized by the generator without loading it down.
Don


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Would not the typical inrush current required to energize a typical utility 15 to 30KVA transformer trip the generator's circuit breaker instantly?

I've read of folks using pole pigs in reverse to build tesla coils, and they HAVE TO use series resistance to energize the LV side of the pole pig, otherwise the breaker trips instantly from the extremely high inrush current.

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... My dad used to make stupid things like that,..until I found them in the garage/basement and killed them all..he would save old,broken receptacles and switches,cracked porcelain keyless fixtures,even old boxes with all the KO's taken out..so whenever I was over doing any work,I'd make a habit of breaking the devices up with my linesmans,so he couldn't use them again...he got sooo mad... [Linked Image] [Linked Image] [Linked Image] [Linked Image]
Russ


.."if it ain't fixed,don't break it...call a Licensed Electrician"
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I hope I'm providing a good professional role model for the vocational students browsing this forum!
And I hope you're kidding!

Of course, those who say that they'd never forget to throw the main are the only ones who would use this method to begin with, and are the ones who injure and/or kill linemen.

At least, look into buying a replacement panel cover with an integrated interlock mechanism that prevents the main and the (usually) top-right breaker from being on simultaneously.


Larry Fine
Fine Electric Co.
fineelectricco.com
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Would not the typical inrush current required to energize a typical utility 15 to 30KVA transformer trip the generator's circuit breaker instantly?
No. Most generators cannot produce enough current to open a breaker in the instantaneous or very short time trip ranges. Also with a large inrush load the voltage output of the generator drops to limit the current.
Don

corrected typos

[This message has been edited by resqcapt19 (edited 12-12-2005).]


Don(resqcapt19)
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Wouldn't that stall the average home generator then, even if it didn't trip the breaker? It would be like a huge brake slamming down on the output shaft!

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